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Liu Yabin, Pang Jinghao, Liang Shen, Yu Dongmei, Shi Xingping, Li Guorong, Miao Xiaoxing, Wang Yanxiu, Zhu Haili, Hu Xiasong
2024,44(4):1-11
, DOI: 10.13961/j.cnki.stbctb.2024.04.001
Abstract:
[Objective] The characteristics of runoff and sediment production on the slopes of mine dumps with different recovery periods in alpine regions were analyzed in order to provide scientific basis for the efficient and rational restoration of vegetation, as well as for improving the soil and water conservation efforts, on such mine dumps. [Methods] Seven dumps of the Delni copper mine in Machin County, Guoluo Xizang Autonomous Prefecture, Qinghai Province, with recovery periods ranging from 2 to 15 years, were selected as the research subjects. Runoff, sediment, and hydrodynamic characteristics of dump slopes with different recovery periods were determined through simulated rainfall tests, and their influencing factors were analysed. [Results] The runoff and sediment yield of the dump slopes in the study area were relatively complex and random. Large variations were observed in runoff and sediment yield per unit area with rainfall duration in the different recovery years. No significant relationship was observed between the cumulative runoff per unit area of dump slope and recovery period. The cumulative sediment per unit area and average volume diameter of the eroded sediment decreased with increasing recovery period. A significant power function relationship was observed between the average volume diameter of the eroded sediment and recovery period (p<0.05). The runoff generation period increased linearly with the recovery period (p<0.05). Laminar flow was the main runoff flow pattern at the dump slopes each year, and all patterns demonstrated tranquil flow. The Reynolds number and flow shear stress of runoff showed significant exponential and linear decreases, respectively, with an increase in the recovery period (p<0.05). No significant relationship was observed between the velocity and Froude number during the runoff and recovery periods. With increasing recovery period, the erosion and sediment-carrying capacity of runoff on the dump slope decreased. Significant positive correlations (p<0.05) were observed between the slope gradient and cumulative sediment per unit area, runoff velocity, and Reynolds number of the dump slope. [Conclusion] When applied to artificial vegetation restoration, the anti-erosion ability of dump slopes in alpine regions showed a positive trend with increasing recovery years. When vegetation regreening was incomplete, the impact of the slope gradient on runoff and sediment production characteristics, including the hydrodynamic characteristics, outweighed that of vegetation coverage.
[Objective] The characteristics of runoff and sediment production on the slopes of mine dumps with different recovery periods in alpine regions were analyzed in order to provide scientific basis for the efficient and rational restoration of vegetation, as well as for improving the soil and water conservation efforts, on such mine dumps. [Methods] Seven dumps of the Delni copper mine in Machin County, Guoluo Xizang Autonomous Prefecture, Qinghai Province, with recovery periods ranging from 2 to 15 years, were selected as the research subjects. Runoff, sediment, and hydrodynamic characteristics of dump slopes with different recovery periods were determined through simulated rainfall tests, and their influencing factors were analysed. [Results] The runoff and sediment yield of the dump slopes in the study area were relatively complex and random. Large variations were observed in runoff and sediment yield per unit area with rainfall duration in the different recovery years. No significant relationship was observed between the cumulative runoff per unit area of dump slope and recovery period. The cumulative sediment per unit area and average volume diameter of the eroded sediment decreased with increasing recovery period. A significant power function relationship was observed between the average volume diameter of the eroded sediment and recovery period (p<0.05). The runoff generation period increased linearly with the recovery period (p<0.05). Laminar flow was the main runoff flow pattern at the dump slopes each year, and all patterns demonstrated tranquil flow. The Reynolds number and flow shear stress of runoff showed significant exponential and linear decreases, respectively, with an increase in the recovery period (p<0.05). No significant relationship was observed between the velocity and Froude number during the runoff and recovery periods. With increasing recovery period, the erosion and sediment-carrying capacity of runoff on the dump slope decreased. Significant positive correlations (p<0.05) were observed between the slope gradient and cumulative sediment per unit area, runoff velocity, and Reynolds number of the dump slope. [Conclusion] When applied to artificial vegetation restoration, the anti-erosion ability of dump slopes in alpine regions showed a positive trend with increasing recovery years. When vegetation regreening was incomplete, the impact of the slope gradient on runoff and sediment production characteristics, including the hydrodynamic characteristics, outweighed that of vegetation coverage.
Tan Jiangfeng, Lu Lu, Qu Bingpeng, Zhou Wei, Wang Xinyu, Jiang Ying, Zhang Xinying, Song Shuqiao, Ren Shulei
2024,44(4):12-19
, DOI: 10.13961/j.cnki.stbctb.2024.04.002
Abstract:
[Objective] This study aimed to optimise organic and inorganic mulches suitable for urban bare soil coverage and provide theoretical guidance for urban bare soil management. [Methods] Four types of organic ecological mulches (straw, mushroom residue, sawdust, and pine bark) and four types of inorganic ecological mulches (ceramsite, volcanic stone, perlite, and maifan stone) were used as research objects, and the indoor immersion method was used to compare the water retention effect of the organic and inorganic ecological mulches applied to urban bare soil. Several ecological mulches with good water retention effects were selected. [Results] ① The changing trends of the water-holding capacity and water absorption rate of the organic and inorganic ecological mulches were basically consistent. The water-holding capacity, water absorption rate, and soaking time of the two types of ecological mulches had significant logarithmic and power function relationships, respectively. ② The maximum water-holding capacity and effective storage capacity of the organic ecological mulches were generally higher than those of the inorganic ecological mulches. Among the four types of organic ecological mulches, sawdust and straw had the best (i.e., highest) water-holding capacity and effective storage capacity, followed by mushroom residue and pine bark. Among the four types of inorganic ecological mulches, volcanic rock, perlite, and ceramsite had the best water-holding capacity and effective retaining capacity, and maifan stone had the worst. [Conclusion] In the actual application of urban bare soil coverage, organic ecological mulches (sawdust and straw) and inorganic ecological mulches (volcanic stone, perlite, and ceramsite) with good water retention effects can be selected preferentially when various local natural environmental factors are fully considered.
[Objective] This study aimed to optimise organic and inorganic mulches suitable for urban bare soil coverage and provide theoretical guidance for urban bare soil management. [Methods] Four types of organic ecological mulches (straw, mushroom residue, sawdust, and pine bark) and four types of inorganic ecological mulches (ceramsite, volcanic stone, perlite, and maifan stone) were used as research objects, and the indoor immersion method was used to compare the water retention effect of the organic and inorganic ecological mulches applied to urban bare soil. Several ecological mulches with good water retention effects were selected. [Results] ① The changing trends of the water-holding capacity and water absorption rate of the organic and inorganic ecological mulches were basically consistent. The water-holding capacity, water absorption rate, and soaking time of the two types of ecological mulches had significant logarithmic and power function relationships, respectively. ② The maximum water-holding capacity and effective storage capacity of the organic ecological mulches were generally higher than those of the inorganic ecological mulches. Among the four types of organic ecological mulches, sawdust and straw had the best (i.e., highest) water-holding capacity and effective storage capacity, followed by mushroom residue and pine bark. Among the four types of inorganic ecological mulches, volcanic rock, perlite, and ceramsite had the best water-holding capacity and effective retaining capacity, and maifan stone had the worst. [Conclusion] In the actual application of urban bare soil coverage, organic ecological mulches (sawdust and straw) and inorganic ecological mulches (volcanic stone, perlite, and ceramsite) with good water retention effects can be selected preferentially when various local natural environmental factors are fully considered.
2024,44(4):20-32
, DOI: 10.13961/j.cnki.stbctb.20240715.002
Abstract:
[Objective] We aimed to elucidate the process of runoff and sediment production on the upper and lower slopes of construction access roads under vegetation recovery conditions, reveal the impact of vegetation recovery on soil and water loss at the slope scale after the disturbance caused by the construction of access roads in an ecologically fragile subalpine forest and shrubland area of Southeastern Xizang Autonomous Region, in order to provide a theoretical basis for the prevention and control of soil and water loss and vegetation restoration after the disturbance caused by the construction road project. [Methods] Typical slopes under different vegetation recovery conditions after disturbances on the upper and lower slopes of construction access roads were selected for indoor simulated rainfall experiments. In this study, we investigated the processes of runoff and sediment production under four types of vegetation coverage (0%, 30%, 60%, and 90%), three slopes (15°, 30°, and 45°), and two rainfall intensities (30, 60 mm/h) after engineering disturbance to determine the impact of vegetation recovery in construction access roads on soil and water loss. [Results] ① After the engineering disturbance of the construction access roads, vegetation recovery on the bare upper and lower slopes effectively delayed the initial runoff time, and this effect became more pronounced with increasing vegetation coverage, especially on the upper slopes. ② When the vegetation coverage was within the range of 0 to 60%, the stable runoff rate on both the upper and lower slopes significantly decreased with increasing vegetation coverage, wherein the stable runoff rates under 60% and 90% vegetation coverage were similar. Compared with bare slopes, the benefits of runoff reduction under 60% and 90% vegetation coverage were 59%—75% and 58%—77% respectively, indicating that the critical vegetation coverage value for runoff reduction was 60%. ③ Sediment reduction benefits under 30% and 60% vegetation coverage reached 29%—82% and 86%—96% respectively. Below a vegetation coverage of 60%, the sediment reduction effect significantly increased with increasing coverage; beyond this critical threshold, even with increased coverage, the sediment reduction benefits showed slight change. ④ Under the same vegetation coverage, slope, and rainfall intensity conditions, the total runoff volume from the upper slopes formed by excavation was always higher than that from the lower slopes formed by filling, whereas the total sediment yield from the lower slopes was always higher than that from the upper slopes, indicating significant differences in soil erosion on the slope surface after the disturbance of the construction of access roads between the excavation and filling slopes. [Conclusion] For the prevention and control of soil and water loss in areas disturbed by the construction of access roads in Southeastern Xizang Autonomous Region, a vegetation recovery rate of 60% offers good control benefits and economic feasibility. When designing soil and water conservation measures, more emphasis should be placed on ‘controlling water’ for excavation slopes and ‘blocking sediment’ for filling slopes. Only by fully considering these differences can better soil and water conservation be achieved in disturbed areas on access roads.
[Objective] We aimed to elucidate the process of runoff and sediment production on the upper and lower slopes of construction access roads under vegetation recovery conditions, reveal the impact of vegetation recovery on soil and water loss at the slope scale after the disturbance caused by the construction of access roads in an ecologically fragile subalpine forest and shrubland area of Southeastern Xizang Autonomous Region, in order to provide a theoretical basis for the prevention and control of soil and water loss and vegetation restoration after the disturbance caused by the construction road project. [Methods] Typical slopes under different vegetation recovery conditions after disturbances on the upper and lower slopes of construction access roads were selected for indoor simulated rainfall experiments. In this study, we investigated the processes of runoff and sediment production under four types of vegetation coverage (0%, 30%, 60%, and 90%), three slopes (15°, 30°, and 45°), and two rainfall intensities (30, 60 mm/h) after engineering disturbance to determine the impact of vegetation recovery in construction access roads on soil and water loss. [Results] ① After the engineering disturbance of the construction access roads, vegetation recovery on the bare upper and lower slopes effectively delayed the initial runoff time, and this effect became more pronounced with increasing vegetation coverage, especially on the upper slopes. ② When the vegetation coverage was within the range of 0 to 60%, the stable runoff rate on both the upper and lower slopes significantly decreased with increasing vegetation coverage, wherein the stable runoff rates under 60% and 90% vegetation coverage were similar. Compared with bare slopes, the benefits of runoff reduction under 60% and 90% vegetation coverage were 59%—75% and 58%—77% respectively, indicating that the critical vegetation coverage value for runoff reduction was 60%. ③ Sediment reduction benefits under 30% and 60% vegetation coverage reached 29%—82% and 86%—96% respectively. Below a vegetation coverage of 60%, the sediment reduction effect significantly increased with increasing coverage; beyond this critical threshold, even with increased coverage, the sediment reduction benefits showed slight change. ④ Under the same vegetation coverage, slope, and rainfall intensity conditions, the total runoff volume from the upper slopes formed by excavation was always higher than that from the lower slopes formed by filling, whereas the total sediment yield from the lower slopes was always higher than that from the upper slopes, indicating significant differences in soil erosion on the slope surface after the disturbance of the construction of access roads between the excavation and filling slopes. [Conclusion] For the prevention and control of soil and water loss in areas disturbed by the construction of access roads in Southeastern Xizang Autonomous Region, a vegetation recovery rate of 60% offers good control benefits and economic feasibility. When designing soil and water conservation measures, more emphasis should be placed on ‘controlling water’ for excavation slopes and ‘blocking sediment’ for filling slopes. Only by fully considering these differences can better soil and water conservation be achieved in disturbed areas on access roads.
2024,44(4):33-44
, DOI: 10.13961/j.cnki.stbctb.2024.04.004
Abstract:
[Objective] The effects of water content, root content, and root arrangement on the shear strength of the root-soil composite were analyzed to reveal the reinforcement mechanism of Amorpha fruticosa root system on loess slopes, in order to provide a reference for the ecological protection of loess slopes and engineering practices for improving slope stability. [Methods] A shear test of the root-soil complex of A. fruticosa was conducted using a ZJ strain-controlled direct shear apparatus. This study analysed the effects of various water contents, root contents, and root distributions on the shear strength, with non-root soil serving as the control. Additionally, the FLAC 3D software was used to simulate the influence of the root distribution of A. fruticosa on the stability of the loess slope. [Results] ① The cohesion and internal friction angle of the shear strength index decreased with increase in water content. ② With an increase in root content, the shear strength exhibited different patterns under different water content levels. When the water content was 9.31%, the shear strength initially increased with an increase in root area ratio (RAR) but then decreased with further increase in RAR. At RAR was 0.15%, the shear strength reached its maximum value. However, when the water content was 15.65% and 17.44%, the shear strength in RAR. ③ The “卄” shape root arrangement can significantly improve the shear strength of the root soil complex. When the water content was 17.44%, the average shear strength of the root-soil composite increased by 31.81 kPa compared to the control. ④ Numerical simulation results indicated that both root length and the angle between the main root and vertical direction were positively correlated with stability. [Conclusion] The findings from laboratory tests and numerical simulations demonstrated that A. fruticosa can enhance the stability of loess slopes and that an interlaced planting pattern of A. fruticosa provides a more effective protective effect.
[Objective] The effects of water content, root content, and root arrangement on the shear strength of the root-soil composite were analyzed to reveal the reinforcement mechanism of Amorpha fruticosa root system on loess slopes, in order to provide a reference for the ecological protection of loess slopes and engineering practices for improving slope stability. [Methods] A shear test of the root-soil complex of A. fruticosa was conducted using a ZJ strain-controlled direct shear apparatus. This study analysed the effects of various water contents, root contents, and root distributions on the shear strength, with non-root soil serving as the control. Additionally, the FLAC 3D software was used to simulate the influence of the root distribution of A. fruticosa on the stability of the loess slope. [Results] ① The cohesion and internal friction angle of the shear strength index decreased with increase in water content. ② With an increase in root content, the shear strength exhibited different patterns under different water content levels. When the water content was 9.31%, the shear strength initially increased with an increase in root area ratio (RAR) but then decreased with further increase in RAR. At RAR was 0.15%, the shear strength reached its maximum value. However, when the water content was 15.65% and 17.44%, the shear strength in RAR. ③ The “卄” shape root arrangement can significantly improve the shear strength of the root soil complex. When the water content was 17.44%, the average shear strength of the root-soil composite increased by 31.81 kPa compared to the control. ④ Numerical simulation results indicated that both root length and the angle between the main root and vertical direction were positively correlated with stability. [Conclusion] The findings from laboratory tests and numerical simulations demonstrated that A. fruticosa can enhance the stability of loess slopes and that an interlaced planting pattern of A. fruticosa provides a more effective protective effect.
2024,44(4):45-54
, DOI: 10.13961/j.cnki.stbctb.20240711.001
Abstract:
[Objective] The species composition and diversity characteristics of different types of vegetation communities along with the correlation between plant community characteristics and soil moisture content in the Zhangye desert-oasis transition zone in Gansu Province were analysed, in order to provide a scientific basis for the evaluation of water and soil conservation benefits in the region. [Methods] Different types of desert vegetation were chosen, and the diversity of different types of vegetation community plants and soil moisture content at 0—120 cm were investigated and determined. [Results] ① There were six vegetation types in this area, and the vegetation structure was very simple, and the species composition was dominated by drought-tolerant and super-drought-tolerant small shrubs, semi-shrubs and herbs such as Reaumuria songarica, Sympegma regelii, Salsola passerina, Aristida adscensionis, and Bassia dasyphylla that were suitable for arid desert habitats. The plant community was a shrub and grass community with a relatively small species diversity index. ② The change of soil moisture in the vertical direction presented a “double peak”, and the soil humidity gradually increased from the surface layer to the deeper layers; it increased to the “first peak” at 20—40 cm, decreased to a lower level at 40—60 cm, and gradually increased at 60—120 cm, until to the “second peak” at 120 cm. ③ The vegetation height, density, and cover of each plant community increased with increasing soil moisture content. Vegetation height was significantly positively correlated with soil moisture in the soil layer of 40—120 cm, and the density and vegetation cover of herbaceous plants and shrubs were significantly positively correlated with soil moisture content in the layer where their root systems were mainly distributed. [Conclusion] In the desert oasis transition zone where the moisture content of the surface soil (0—20 cm) and deep soil (40—80 cm) was less than 2%, it is appropriate to plant arid shrubs such as R. songarica, S. regelii, Nitraria tangutorum and other herbaceous plants such as A. adscensionis, Salsola tragus, B. dasyphylla, Eragrostis pilosa and Artemisia scoparia. In the desert zones where the moisture content of the surface soil and the deep soil is more than 2%, it is appropriate to plant arid shrubs such as R. songarica and S. passerina and herbaceous plants such as Artemisia frigida, Artemisia xerophytica, and Carex duriuscula, which are capable of effectively promoting ecological recovery and reconstruction.
[Objective] The species composition and diversity characteristics of different types of vegetation communities along with the correlation between plant community characteristics and soil moisture content in the Zhangye desert-oasis transition zone in Gansu Province were analysed, in order to provide a scientific basis for the evaluation of water and soil conservation benefits in the region. [Methods] Different types of desert vegetation were chosen, and the diversity of different types of vegetation community plants and soil moisture content at 0—120 cm were investigated and determined. [Results] ① There were six vegetation types in this area, and the vegetation structure was very simple, and the species composition was dominated by drought-tolerant and super-drought-tolerant small shrubs, semi-shrubs and herbs such as Reaumuria songarica, Sympegma regelii, Salsola passerina, Aristida adscensionis, and Bassia dasyphylla that were suitable for arid desert habitats. The plant community was a shrub and grass community with a relatively small species diversity index. ② The change of soil moisture in the vertical direction presented a “double peak”, and the soil humidity gradually increased from the surface layer to the deeper layers; it increased to the “first peak” at 20—40 cm, decreased to a lower level at 40—60 cm, and gradually increased at 60—120 cm, until to the “second peak” at 120 cm. ③ The vegetation height, density, and cover of each plant community increased with increasing soil moisture content. Vegetation height was significantly positively correlated with soil moisture in the soil layer of 40—120 cm, and the density and vegetation cover of herbaceous plants and shrubs were significantly positively correlated with soil moisture content in the layer where their root systems were mainly distributed. [Conclusion] In the desert oasis transition zone where the moisture content of the surface soil (0—20 cm) and deep soil (40—80 cm) was less than 2%, it is appropriate to plant arid shrubs such as R. songarica, S. regelii, Nitraria tangutorum and other herbaceous plants such as A. adscensionis, Salsola tragus, B. dasyphylla, Eragrostis pilosa and Artemisia scoparia. In the desert zones where the moisture content of the surface soil and the deep soil is more than 2%, it is appropriate to plant arid shrubs such as R. songarica and S. passerina and herbaceous plants such as Artemisia frigida, Artemisia xerophytica, and Carex duriuscula, which are capable of effectively promoting ecological recovery and reconstruction.
2024,44(4):55-65,76
, DOI: 10.13961/j.cnki.stbctb.2024.04.006
Abstract:
[Objective] The structural characteristics of the near-surface airflow field and wind-sand flow under the disturbance of photovoltaic (PV) arrays in the Tengger Desert were analysed to assess the effect of PV arrays in preventing winds and fixing sands, in order to provide theoretical support for both the management of wind-sand disasters in desert areas and the sustainable development of ecological environments. [Methods] The vertical distribution of wind speed, wind velocity flow field, and wind-sand flow structure of PV arrays (front edge of electric panels, back edge of electric panels, and midline between arrays) and control points were assessed in the field using gradient wind speed observation equipment, and the airflow field and sand transport characteristics at different locations inside and outside a power plant were compared and analysed. [Results] (1) The overall wind speed inside the power station decreased, the average wind speed between arrays and along the back edge of the electric panel increased with height, and the average wind speed along the front edge of the electric panel decreased and then increased with height. (2) ① For the grass square observation section, the wind speed at the wind outlet in front of the electric panel increased significantly, and the wind speed along the wind inlet behind the electric panel and below 100 cm of the centre line between arrays decreased; ② For the wind erosion pit observation section, the wind speed of PV panels below 150 cm decreased, and the wind speed pulsation between arrays varied significantly; ③ For the gravel observation section, the relative rate of change of the wind speed and the pattern of the wind flow field were stable, and the wind speed along the back edge of the electric panel above 150 cm increased. The wind speed increased in the section above 150 cm behind the electric plate. The average wind protection effect occurred in the order of gravel > grass squares. (3) The order for sand transport was as follows: front edge of the electric plate > back edge of the electric plate > midline between the arrays; the reference point of the mobile sand dune (upwind) was saturated with λ (a characteristic value of the wind-sand flow structure) at the front edge of the electric plate, and unsaturated at the back edge of both the electric plate and λ between the arrays. [Conclusion] Compared with the mobile sand dune, the PV array perturbed the wind velocity flow field pattern, the wind velocity pulsation and turbulence degree changed, sand transport decreased significantly, and a sand fixation benefit was evident.
[Objective] The structural characteristics of the near-surface airflow field and wind-sand flow under the disturbance of photovoltaic (PV) arrays in the Tengger Desert were analysed to assess the effect of PV arrays in preventing winds and fixing sands, in order to provide theoretical support for both the management of wind-sand disasters in desert areas and the sustainable development of ecological environments. [Methods] The vertical distribution of wind speed, wind velocity flow field, and wind-sand flow structure of PV arrays (front edge of electric panels, back edge of electric panels, and midline between arrays) and control points were assessed in the field using gradient wind speed observation equipment, and the airflow field and sand transport characteristics at different locations inside and outside a power plant were compared and analysed. [Results] (1) The overall wind speed inside the power station decreased, the average wind speed between arrays and along the back edge of the electric panel increased with height, and the average wind speed along the front edge of the electric panel decreased and then increased with height. (2) ① For the grass square observation section, the wind speed at the wind outlet in front of the electric panel increased significantly, and the wind speed along the wind inlet behind the electric panel and below 100 cm of the centre line between arrays decreased; ② For the wind erosion pit observation section, the wind speed of PV panels below 150 cm decreased, and the wind speed pulsation between arrays varied significantly; ③ For the gravel observation section, the relative rate of change of the wind speed and the pattern of the wind flow field were stable, and the wind speed along the back edge of the electric panel above 150 cm increased. The wind speed increased in the section above 150 cm behind the electric plate. The average wind protection effect occurred in the order of gravel > grass squares. (3) The order for sand transport was as follows: front edge of the electric plate > back edge of the electric plate > midline between the arrays; the reference point of the mobile sand dune (upwind) was saturated with λ (a characteristic value of the wind-sand flow structure) at the front edge of the electric plate, and unsaturated at the back edge of both the electric plate and λ between the arrays. [Conclusion] Compared with the mobile sand dune, the PV array perturbed the wind velocity flow field pattern, the wind velocity pulsation and turbulence degree changed, sand transport decreased significantly, and a sand fixation benefit was evident.
2024,44(4):66-76
, DOI: 10.13961/j.cnki.stbctb.2024.04.007
Abstract:
[Objective] The application prospects of using landslide deposits as a new type of soil improvement material were explored, and the changes in soil nutrients after landslide deposit improvement were analysed in order to provide new approaches for local landslide deposit utilisation and purple soil rehabilitation. [Methods] Purple soil improved by landslide deposits was selected as the research object, and the quality of the improved soil was analysed using weighted grey correlation analysis. [Results] At the same fertility irrigation level, adding collapsed deposits significantly increased the nutrient content of topsoil (0—20 cm) compared to the blank control group (Y0). The average total nitrogen content in this layer of soil increased by 3.26% to 10.60%, the average total phosphorus content increased by 10.61% to 43.33%, the average organic matter content increased by 9.14% to 24.12%, the average alkaline nitrogen content increased by 5.76% to 12.73%, the average effective phosphorus content increased by 24.75% to 46.22%, the average available potassium content increased by 16.21% to 28.96%, and the soil electrical conductivity (EC) increased by 11.32% to 27.41%. The different treatment schemes had no significant effect on soil pH value. Using the AHP grey correlation analysis evaluation model, a preliminary evaluation of the soil quality of each treatment group was conducted. Within the topsoil (0—20 cm), the grey correlation degree of each treatment group was ranked as follows: Y2 〔rock soil composite ratio (RSCR): 20%〕 > Y3 (RSCR: 30%) > Y4 (RSCR: 40%) > Y1 (RSCR: 10%) > Y0 (RSCR: 0%) > Y5 (RSCR: 50%). The grey correlation degree of each treatment group within the deep soil range of 20—40 cm was ranked as follows: Y5 > Y4 > Y3 > Y2 > Y1 > Y0. [Conclusion] An appropriate proportion of composite treatment between landslide deposits and soil can improve the nutrient content of purple soil.
[Objective] The application prospects of using landslide deposits as a new type of soil improvement material were explored, and the changes in soil nutrients after landslide deposit improvement were analysed in order to provide new approaches for local landslide deposit utilisation and purple soil rehabilitation. [Methods] Purple soil improved by landslide deposits was selected as the research object, and the quality of the improved soil was analysed using weighted grey correlation analysis. [Results] At the same fertility irrigation level, adding collapsed deposits significantly increased the nutrient content of topsoil (0—20 cm) compared to the blank control group (Y0). The average total nitrogen content in this layer of soil increased by 3.26% to 10.60%, the average total phosphorus content increased by 10.61% to 43.33%, the average organic matter content increased by 9.14% to 24.12%, the average alkaline nitrogen content increased by 5.76% to 12.73%, the average effective phosphorus content increased by 24.75% to 46.22%, the average available potassium content increased by 16.21% to 28.96%, and the soil electrical conductivity (EC) increased by 11.32% to 27.41%. The different treatment schemes had no significant effect on soil pH value. Using the AHP grey correlation analysis evaluation model, a preliminary evaluation of the soil quality of each treatment group was conducted. Within the topsoil (0—20 cm), the grey correlation degree of each treatment group was ranked as follows: Y2 〔rock soil composite ratio (RSCR): 20%〕 > Y3 (RSCR: 30%) > Y4 (RSCR: 40%) > Y1 (RSCR: 10%) > Y0 (RSCR: 0%) > Y5 (RSCR: 50%). The grey correlation degree of each treatment group within the deep soil range of 20—40 cm was ranked as follows: Y5 > Y4 > Y3 > Y2 > Y1 > Y0. [Conclusion] An appropriate proportion of composite treatment between landslide deposits and soil can improve the nutrient content of purple soil.
2024,44(4):77-85
, DOI: 10.13961/j.cnki.stbctb.20240718.001
Abstract:
[Objective] The biological mechanisms underlying the effect of shrub forest development on soil in the Hobq Desert was analyzed in order to provide theoretical support for the establishment of a reasonable and effective desert shelter forest system. [Methods] Soil from 0—10, 10—20 cm, and 20—30 cm soil layers in a Salix psammophila forest system with different forest ages (6, 12, and 15 years) in the Hobq Desert was collected in early July 2023. The main physical and chemical properties and enzyme activities of the soil were analysed to reveal the mechanism of vegetation restoration on soil in this area. [Results] ① The fine particle content increased gradually with increasing forest age, whereas the soil bulk density and pH value decreased. ② Soil nutrients and enzyme activity levels clearly indicated surface aggregation in the vertical direction. There were significant differences in soil nutrients and enzyme activity levels among the different S. psammophila forest ages (p<0.05). The soil alkali-hydrolysable nitrogen, available phosphorus, available potassium, alkaline phosphatase activity, and catalase activity in the 12-year S. psammophila forest were 316.4%, 420.3%, 134.6%, 164.5%, and 94.8% higher than those of bare sand, respectively. Organic carbon, urease activity, and invertase activity under 15-year S. psammophila were 186.2%, 145.3%, and 2 703.4% higher than those of CK, respectively. ③ Soil enzyme activity was closely related to soil alkali-hydrolysable nitrogen, available phosphorus, available potassium, and organic carbon in different forest age restoration stages. [Conclusion] The establishment of the S. psammophila shelter forest in the Hobq Desert significantly improved soil nutrient levels and enzyme activity.
[Objective] The biological mechanisms underlying the effect of shrub forest development on soil in the Hobq Desert was analyzed in order to provide theoretical support for the establishment of a reasonable and effective desert shelter forest system. [Methods] Soil from 0—10, 10—20 cm, and 20—30 cm soil layers in a Salix psammophila forest system with different forest ages (6, 12, and 15 years) in the Hobq Desert was collected in early July 2023. The main physical and chemical properties and enzyme activities of the soil were analysed to reveal the mechanism of vegetation restoration on soil in this area. [Results] ① The fine particle content increased gradually with increasing forest age, whereas the soil bulk density and pH value decreased. ② Soil nutrients and enzyme activity levels clearly indicated surface aggregation in the vertical direction. There were significant differences in soil nutrients and enzyme activity levels among the different S. psammophila forest ages (p<0.05). The soil alkali-hydrolysable nitrogen, available phosphorus, available potassium, alkaline phosphatase activity, and catalase activity in the 12-year S. psammophila forest were 316.4%, 420.3%, 134.6%, 164.5%, and 94.8% higher than those of bare sand, respectively. Organic carbon, urease activity, and invertase activity under 15-year S. psammophila were 186.2%, 145.3%, and 2 703.4% higher than those of CK, respectively. ③ Soil enzyme activity was closely related to soil alkali-hydrolysable nitrogen, available phosphorus, available potassium, and organic carbon in different forest age restoration stages. [Conclusion] The establishment of the S. psammophila shelter forest in the Hobq Desert significantly improved soil nutrient levels and enzyme activity.
2024,44(4):86-96
, DOI: 10.13961/j.cnki.stbctb.2024.04.009
Abstract:
[Objective] The influence mechanism of soil water erosion on the patch distribution pattern of Stipa krylovii in a Xilamuren grassland was analysed in order to provide a theoretical basis for soil erosion control in this area. [Methods] Three distribution patterns (aggregation, uniform, and random distribution patterns) and two controls patterns (non-grazing and bare slope ) were set up by field investigation and the variance mean ratio method. Indoor simulated rainfall experiments with rainfall intensity of 30, 60, 90 mm/h, and 120 mm/h were conducted to quantify the sediment production and abortion processes on slopes with different distribution patterns. [Results] ① The distribution pattern of heavy grazing and no grazing was aggregation distribution pattern, the distribution pattern of moderate grazing was uniform distribution pattern, and the distribution pattern of light grazing was random distribution pattern. ② At 30 mm/h rainfall intensity, no runoff was produced, whereas at 60 mm/h rainfall intensity the runoff yield was in the order of bare slope ＞ aggregation distribution pattern＞ random distribution pattern＞ uniform distribution pattern＞ no grazing. For the rainfall intensity at 90 mm/h, the runoff yield was in the order of bare slope ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern＞ no grazing. At 120 mm/h rainfall intensity, the runoff yield showed the order of bare slope ＞ aggregation distribution pattern＞ no grazing ＞ uniform distribution pattern＞ random distribution pattern. ③ At 30 mm/h, there was no sediment production. However, at 60 mm/h the sediment production rate was in the order of bare slope ＞ uniform distribution pattern＞ no grazing ＞ random distribution pattern＞ aggregation distribution pattern. The rainfall intensity at 90 mm/h resulted in sediment distribution in the order of bare slope ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern＞ no grazing. Furthermore, at 120 mm/h rainfall intensity, the sediment distribution was in the order of bare slope ＞ no grazing ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern. ④ At 120 mm/h rainfall intensity, the sediment reduction benefit of the random distribution pattern can be reduced by 88.76%, whereas at 90 mm/h rain intensity the flow reduction benefit of the non-grazing pattern can be reduced by 45.78%. [Conclusion] Grazing promoted the patching phenomenon of S. Krylovii, and soil water erosion intensified the formation of bare patches, which led to different distribution patterns of S. krylovii patches.
[Objective] The influence mechanism of soil water erosion on the patch distribution pattern of Stipa krylovii in a Xilamuren grassland was analysed in order to provide a theoretical basis for soil erosion control in this area. [Methods] Three distribution patterns (aggregation, uniform, and random distribution patterns) and two controls patterns (non-grazing and bare slope ) were set up by field investigation and the variance mean ratio method. Indoor simulated rainfall experiments with rainfall intensity of 30, 60, 90 mm/h, and 120 mm/h were conducted to quantify the sediment production and abortion processes on slopes with different distribution patterns. [Results] ① The distribution pattern of heavy grazing and no grazing was aggregation distribution pattern, the distribution pattern of moderate grazing was uniform distribution pattern, and the distribution pattern of light grazing was random distribution pattern. ② At 30 mm/h rainfall intensity, no runoff was produced, whereas at 60 mm/h rainfall intensity the runoff yield was in the order of bare slope ＞ aggregation distribution pattern＞ random distribution pattern＞ uniform distribution pattern＞ no grazing. For the rainfall intensity at 90 mm/h, the runoff yield was in the order of bare slope ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern＞ no grazing. At 120 mm/h rainfall intensity, the runoff yield showed the order of bare slope ＞ aggregation distribution pattern＞ no grazing ＞ uniform distribution pattern＞ random distribution pattern. ③ At 30 mm/h, there was no sediment production. However, at 60 mm/h the sediment production rate was in the order of bare slope ＞ uniform distribution pattern＞ no grazing ＞ random distribution pattern＞ aggregation distribution pattern. The rainfall intensity at 90 mm/h resulted in sediment distribution in the order of bare slope ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern＞ no grazing. Furthermore, at 120 mm/h rainfall intensity, the sediment distribution was in the order of bare slope ＞ no grazing ＞ aggregate distribution pattern＞ uniform distribution pattern＞ random distribution pattern. ④ At 120 mm/h rainfall intensity, the sediment reduction benefit of the random distribution pattern can be reduced by 88.76%, whereas at 90 mm/h rain intensity the flow reduction benefit of the non-grazing pattern can be reduced by 45.78%. [Conclusion] Grazing promoted the patching phenomenon of S. Krylovii, and soil water erosion intensified the formation of bare patches, which led to different distribution patterns of S. krylovii patches.
2024,44(4):97-106,116
, DOI: 10.13961/j.cnki.stbctb.2024.04.010
Abstract:
[Objective] The dynamic characteristics of soil moisture in sandy arid lands were analysed to provide scientific support for desertification control. [Methods] Sandy land (mobile dunes, semi-fixed dunes, fixed dunes and shelter forest) in east of the Yellow River in Ningxia Hui Autonomous Region was selected as the research object. According to data from the positioning observation and automatic observation systems, the soil moisture distribution characteristics of sandy soils (0—150 cm depth) were analysed. [Results] ① Changes in soil moisture content in the different plots showed a consistent pattern with time. Changes in soil moisture content could be divided into three periods: the soil moisture accumulation period from April to May, the soil moisture consumption period from June to August, and the soil moisture stable period from September to November. ② The soil moisture content in the 0—10 cm topsoil layer was significantly different in the three periods, whereas the soil mositure content in the 40—150 cm soil layer did not differ significantly. ③ The topsoil (0—20 cm) was the active layer of soil moisture, 20—40 cm was the subactive layer, and 40—150 cm was the stable layer of soil moisture. ④ The soil moisture content between the different plots was as follows: moving dune > shelter forest (Salix matsudana, Populus bolleana, and Pinus sylvestris forest) > fixed dune (Hedysarum scoparium forest) > fixed dune (Calligonum mongolicum and Caragana korshinskii forest) > semi-fixed dune (C. mongolicum and C. korshinskii forest). ⑤ The soil moisture content in different terrain parts decreased from the slope bottom > slope middle > hill top. [Conclusion] The vertical distribution and stratification characteristics of soil moisture in the sandy arid lands in east of the Yellow River in Ningxia are clear. Changes in soil moisture content are not only affected by rainfall, vegetation type, and vegetation distribution patterns, but also by the microgeomorphology of the sand dunes.
[Objective] The dynamic characteristics of soil moisture in sandy arid lands were analysed to provide scientific support for desertification control. [Methods] Sandy land (mobile dunes, semi-fixed dunes, fixed dunes and shelter forest) in east of the Yellow River in Ningxia Hui Autonomous Region was selected as the research object. According to data from the positioning observation and automatic observation systems, the soil moisture distribution characteristics of sandy soils (0—150 cm depth) were analysed. [Results] ① Changes in soil moisture content in the different plots showed a consistent pattern with time. Changes in soil moisture content could be divided into three periods: the soil moisture accumulation period from April to May, the soil moisture consumption period from June to August, and the soil moisture stable period from September to November. ② The soil moisture content in the 0—10 cm topsoil layer was significantly different in the three periods, whereas the soil mositure content in the 40—150 cm soil layer did not differ significantly. ③ The topsoil (0—20 cm) was the active layer of soil moisture, 20—40 cm was the subactive layer, and 40—150 cm was the stable layer of soil moisture. ④ The soil moisture content between the different plots was as follows: moving dune > shelter forest (Salix matsudana, Populus bolleana, and Pinus sylvestris forest) > fixed dune (Hedysarum scoparium forest) > fixed dune (Calligonum mongolicum and Caragana korshinskii forest) > semi-fixed dune (C. mongolicum and C. korshinskii forest). ⑤ The soil moisture content in different terrain parts decreased from the slope bottom > slope middle > hill top. [Conclusion] The vertical distribution and stratification characteristics of soil moisture in the sandy arid lands in east of the Yellow River in Ningxia are clear. Changes in soil moisture content are not only affected by rainfall, vegetation type, and vegetation distribution patterns, but also by the microgeomorphology of the sand dunes.
2024,44(4):107-116
, DOI: 10.13961/j.cnki.stbctb.2024.04.011
Abstract:
[Objective] The nutrient content and ecological stoichiometric characteristics of plants across various altitudinal gradients in fragile forest ecosystems in arid regions were analysed in order to provide scientific support for their nutrient management. [Methods] This study focused on the dominant plant species at five distinct altitudinal intervals, i.e. 1 730, 1 799, 2 025, 2 487, and 2 544 m in the Helan Mountains National Nature Reserve. The variations and correlations of carbon (C), nitrogen (N), and phosphorus (P) contents and stoichiometric features in leaves, fine roots, and soil along these gradients were analysed. [Results] ① Soil organic carbon (SOC) displayed a unimodal pattern with altitude, peaking at 2 487 m (42.92 g/kg). Soil total nitrogen (TN) levels at the three highest altitude sites (2 025, 2 487, 2 544 m) were significantly greater than those at the two lowest altitudes (1 730, 1 799 m), whereas total phosphorus (TP) remained relatively stable. The C∶P and N∶P initially increased and then decreased with increasing altitude. ② There was no significant change in leaf and fine root C across altitudes, but the P content increased with altitude. Fine root N content progressively declined with altitude, whereas leaf N exhibited a fluctuating trend. At high altitudes, the N∶P ratio in the leaves and fine roots was less than 14; however, at low altitudes, the ratio exceeded 16. ③ Nutrient concentrations in the leaves were significantly higher than those in the fine roots. ④ Correlation analyses revealed that C content in leaf positively correlated with SOC, TN, C∶P and N∶P in soil. In contrast, N content in leaf and fine root significantly decreased as SOC, TN, C∶P and N∶P in soil increased, and the relationship between leaf and fine root P and soil TP was not significant. [Conclusion] Plant growth at high and low altitudes is mainly limited by N and P, respectively. Leaves of dominant plant species at different altitudes exhibit higher nutrient contents than their fine roots, and variations in soil nutrient supply due to altitude influence the N, P and stoichiometric characteristics of plants in the Helan Mountains.
[Objective] The nutrient content and ecological stoichiometric characteristics of plants across various altitudinal gradients in fragile forest ecosystems in arid regions were analysed in order to provide scientific support for their nutrient management. [Methods] This study focused on the dominant plant species at five distinct altitudinal intervals, i.e. 1 730, 1 799, 2 025, 2 487, and 2 544 m in the Helan Mountains National Nature Reserve. The variations and correlations of carbon (C), nitrogen (N), and phosphorus (P) contents and stoichiometric features in leaves, fine roots, and soil along these gradients were analysed. [Results] ① Soil organic carbon (SOC) displayed a unimodal pattern with altitude, peaking at 2 487 m (42.92 g/kg). Soil total nitrogen (TN) levels at the three highest altitude sites (2 025, 2 487, 2 544 m) were significantly greater than those at the two lowest altitudes (1 730, 1 799 m), whereas total phosphorus (TP) remained relatively stable. The C∶P and N∶P initially increased and then decreased with increasing altitude. ② There was no significant change in leaf and fine root C across altitudes, but the P content increased with altitude. Fine root N content progressively declined with altitude, whereas leaf N exhibited a fluctuating trend. At high altitudes, the N∶P ratio in the leaves and fine roots was less than 14; however, at low altitudes, the ratio exceeded 16. ③ Nutrient concentrations in the leaves were significantly higher than those in the fine roots. ④ Correlation analyses revealed that C content in leaf positively correlated with SOC, TN, C∶P and N∶P in soil. In contrast, N content in leaf and fine root significantly decreased as SOC, TN, C∶P and N∶P in soil increased, and the relationship between leaf and fine root P and soil TP was not significant. [Conclusion] Plant growth at high and low altitudes is mainly limited by N and P, respectively. Leaves of dominant plant species at different altitudes exhibit higher nutrient contents than their fine roots, and variations in soil nutrient supply due to altitude influence the N, P and stoichiometric characteristics of plants in the Helan Mountains.
Shi Xiaopeng, Gou Heran, He Shuqin, Liu Baiting, Ran Lanfang, Yang Qilin, Tashilhamo, Chen Yuxin, Luo Ziteng
2024,44(4):117-125
, DOI: 10.13961/j.cnki.stbctb.2024.04.012
Abstract:
[Objective] The anti-erosion and anti-scouring characteristics and factors influencing road and campus green spaces in Wenjiang District, Chengdu City were analysed in order o provide functional guidance for urban green space soil and water conservation and promote ecologically sustainable development. [Methods] The soil anti-erosion and anti-scouring properties of arbour + grass, arbour + bush, bush, bush + grass and grass in road and campus green spaces were characterised through field sampling and laboratory tests. [Results] The >5 mm soil water-stable aggregate content was highest in both roads (79.72%) and campus green spaces (39.23%). Total soil porosity, soil water content, and silt content were greater in campus green spaces than road green spaces (p<0.05). Mean weight diameter (MWD), geometric mean diameter (GMD), soil anti-erosion, water stability aggregate index, and anti-scouring were all higher in the road green space than in the campus green space (p<0.05). Specifically, the anti-erosion and anti-scouring of arbour + bush and bush + grass structures were better than that of the other vegetation structures, and the soil anti-scouring coefficient decreased with increasing landscape slope. Soil anti-erosion and-scouring were positively correlated with >5 mm soil water-stable aggregates, organic matter content, and soil clay particles, and negatively correlated with the percentage of aggregate destruction (PAD), unstable aggregate index (ELT) and <0.25 mm and 0.25～2 mm water-stable aggregates (p<0.01). [Conclusion] Arbour + bush and bush + grass had the best soil anti anti-erosion and-scouring effects on road green areas. Campus green space can reduce the risk of soil erosion by adjusting the vegetation structure, thereby enhancing the stress resistance and ornamental property.
[Objective] The anti-erosion and anti-scouring characteristics and factors influencing road and campus green spaces in Wenjiang District, Chengdu City were analysed in order o provide functional guidance for urban green space soil and water conservation and promote ecologically sustainable development. [Methods] The soil anti-erosion and anti-scouring properties of arbour + grass, arbour + bush, bush, bush + grass and grass in road and campus green spaces were characterised through field sampling and laboratory tests. [Results] The >5 mm soil water-stable aggregate content was highest in both roads (79.72%) and campus green spaces (39.23%). Total soil porosity, soil water content, and silt content were greater in campus green spaces than road green spaces (p<0.05). Mean weight diameter (MWD), geometric mean diameter (GMD), soil anti-erosion, water stability aggregate index, and anti-scouring were all higher in the road green space than in the campus green space (p<0.05). Specifically, the anti-erosion and anti-scouring of arbour + bush and bush + grass structures were better than that of the other vegetation structures, and the soil anti-scouring coefficient decreased with increasing landscape slope. Soil anti-erosion and-scouring were positively correlated with >5 mm soil water-stable aggregates, organic matter content, and soil clay particles, and negatively correlated with the percentage of aggregate destruction (PAD), unstable aggregate index (ELT) and <0.25 mm and 0.25～2 mm water-stable aggregates (p<0.01). [Conclusion] Arbour + bush and bush + grass had the best soil anti anti-erosion and-scouring effects on road green areas. Campus green space can reduce the risk of soil erosion by adjusting the vegetation structure, thereby enhancing the stress resistance and ornamental property.
2024,44(4):126-134
, DOI: 10.13961/j.cnki.stbctb.2024.04.013
Abstract:
[Objective] The effects of short-duration high-intensity rainfall on runoff and sediment yield in a karst slope farmland were analysed to reveal the mechanism of soil erosion, in order provide a scientific basis for reducing it, and ensuring food production in karst slope farmlands. [Methods] Through simulated rainfall experiments, the effects of short-duration high-intensity rainfall on the runoff and sediment yields over a karst slope farmland were studied by taking a karst bare slope and a corn slope as research objects. [Results] ① Surface runoff and sediment yield moduli of both bare and corn slopes increased with the rise of the slope. At similar slopes, the surface runoff and sediment yield moduli of the corn slope were much less than those of the bare slope (p＜0.05). With the increase of rainfall duration, the surface runoff yield moduli of both bare and corn slopes increased first and then remained stable, while the surface sediment yield moduli increased first and then decreased. ② The runoff yield moduli of the respective subsurface runoffs of bare and corn slopes increased with the rise of the slope. At a similar slope, the runoff yield of respective subsurface runoffs in the corn slope was much less than that in the bare slope (p＜0.05), whereas when slope was 20°, the total runoff yield of the corn slope’s subsurface runoffs (15—25 cm) decreased by 62.59% compared with that of the bare slope. ③ When the slope was fixed, underground runoff and sediment yield moduli of the corn slope were much less than those of the bare slope (p＜0.05). With the increase of rainfall duration, the underground runoff yield moduli of both bare and corn slopes showed a trend of continuous increase, where their changes were basically consistent, while the underground sediment yield moduli showed a trend of first increasing and then decreasing and reached a maximum between 20 min and 30 min. ④ By comparing the correlations between the runoff and sediment yields of the bare and the corn slopes under different slopes, it was found that the correlations between the underground sediment yield and the surface runoff yield, underground runoff yield, and surface sediment yield were enhanced in the corn slope compared with the bare slope, whereas the correlations between the surface sediment yield and the surface and underground runoff yields were weakened. [Conclusion] Under high-intensity rainfall, corn slope can increase infiltration, which has the effect of blocking and inhibiting erosion, in which the surface and subsurface runoff moduli increase with the increase of the slope, the underground runoff moduli increase with the increase of the rainfall duration, and the sediment yield moduli increases first and then decreases.
[Objective] The effects of short-duration high-intensity rainfall on runoff and sediment yield in a karst slope farmland were analysed to reveal the mechanism of soil erosion, in order provide a scientific basis for reducing it, and ensuring food production in karst slope farmlands. [Methods] Through simulated rainfall experiments, the effects of short-duration high-intensity rainfall on the runoff and sediment yields over a karst slope farmland were studied by taking a karst bare slope and a corn slope as research objects. [Results] ① Surface runoff and sediment yield moduli of both bare and corn slopes increased with the rise of the slope. At similar slopes, the surface runoff and sediment yield moduli of the corn slope were much less than those of the bare slope (p＜0.05). With the increase of rainfall duration, the surface runoff yield moduli of both bare and corn slopes increased first and then remained stable, while the surface sediment yield moduli increased first and then decreased. ② The runoff yield moduli of the respective subsurface runoffs of bare and corn slopes increased with the rise of the slope. At a similar slope, the runoff yield of respective subsurface runoffs in the corn slope was much less than that in the bare slope (p＜0.05), whereas when slope was 20°, the total runoff yield of the corn slope’s subsurface runoffs (15—25 cm) decreased by 62.59% compared with that of the bare slope. ③ When the slope was fixed, underground runoff and sediment yield moduli of the corn slope were much less than those of the bare slope (p＜0.05). With the increase of rainfall duration, the underground runoff yield moduli of both bare and corn slopes showed a trend of continuous increase, where their changes were basically consistent, while the underground sediment yield moduli showed a trend of first increasing and then decreasing and reached a maximum between 20 min and 30 min. ④ By comparing the correlations between the runoff and sediment yields of the bare and the corn slopes under different slopes, it was found that the correlations between the underground sediment yield and the surface runoff yield, underground runoff yield, and surface sediment yield were enhanced in the corn slope compared with the bare slope, whereas the correlations between the surface sediment yield and the surface and underground runoff yields were weakened. [Conclusion] Under high-intensity rainfall, corn slope can increase infiltration, which has the effect of blocking and inhibiting erosion, in which the surface and subsurface runoff moduli increase with the increase of the slope, the underground runoff moduli increase with the increase of the rainfall duration, and the sediment yield moduli increases first and then decreases.
2024,44(4):135-142
, DOI: 10.13961/j.cnki.stbctb.2024.04.014
Abstract:
[Objective] The infiltration laws of slope soil bodies under short-duration heavy rainfall were investigated to reveal the causes and mechanisms of geological disasters in order to provide a scientific basis for the formation mechanism, early warning, and prediction of geological disasters in the region. [Methods] Regarding the shallow flow-type landslide event induced by heavy rainfall in Wuping area, Longyan City, Fujian Province, on May 26—27, 2022, an in-situ artificial rainfall infiltration test was conducted at the typical landslide site of the geological disaster area. Systematic observations using monitoring devices such as soil moisture meters, tensiometers, pore water pressure sensors, and rain gauges were conducted. At the same time, finite element software was used to simulate the rainwater infiltration process under different rainfall intensities to deepen the understanding of the infiltration law. [Results] The increase in volumetric water content of the soil was greater near the surface of the slope and decreased with increasing burial depth. The infiltration rate of the slope was fastest at the foot and middle of the slope and slowest at the top of the slope. Under the impact of short-term intense rainfall, the pore water pressure increased gradually, peaked, and then stabilised. Notably, the pore water pressure at a distance of 120 cm from the slope surface was higher than that at the other two depths. This may be attributed to the lower permeability of the soil layer at this location, which resulted in a relatively stable water level. The numerical simulation results reflected this pattern effectively. [Conclusion] The infiltration process of the slope soil is extremely complex in the case of short-duration heavy rainfall and plays a crucial role in triggering geological disasters. Its infiltration characteristics are comprehensively influenced by multiple factors such as rainfall intensity, soil layer depth, and permeability.
[Objective] The infiltration laws of slope soil bodies under short-duration heavy rainfall were investigated to reveal the causes and mechanisms of geological disasters in order to provide a scientific basis for the formation mechanism, early warning, and prediction of geological disasters in the region. [Methods] Regarding the shallow flow-type landslide event induced by heavy rainfall in Wuping area, Longyan City, Fujian Province, on May 26—27, 2022, an in-situ artificial rainfall infiltration test was conducted at the typical landslide site of the geological disaster area. Systematic observations using monitoring devices such as soil moisture meters, tensiometers, pore water pressure sensors, and rain gauges were conducted. At the same time, finite element software was used to simulate the rainwater infiltration process under different rainfall intensities to deepen the understanding of the infiltration law. [Results] The increase in volumetric water content of the soil was greater near the surface of the slope and decreased with increasing burial depth. The infiltration rate of the slope was fastest at the foot and middle of the slope and slowest at the top of the slope. Under the impact of short-term intense rainfall, the pore water pressure increased gradually, peaked, and then stabilised. Notably, the pore water pressure at a distance of 120 cm from the slope surface was higher than that at the other two depths. This may be attributed to the lower permeability of the soil layer at this location, which resulted in a relatively stable water level. The numerical simulation results reflected this pattern effectively. [Conclusion] The infiltration process of the slope soil is extremely complex in the case of short-duration heavy rainfall and plays a crucial role in triggering geological disasters. Its infiltration characteristics are comprehensively influenced by multiple factors such as rainfall intensity, soil layer depth, and permeability.
2024,44(4):143-150
, DOI: 10.13961/j.cnki.stbctb.2024.04.015
Abstract:
[Objective] The influence of the soil water content on the rheological properties of the soil slurry was analysed to provide a scientific basis for understanding the flow law of the slurry and the prevention and control of mudflow in the Loess Plateau region. [Methods] Four main types of soil in the Loess Plateau were studied, and the effects of water content on the soil rheological properties were investigated using rheological oscillation shear tests. [Results] ① The storage modulus, loss modulus and shear stress of lou soil, cinnamon soil and dark loessial soil all decreased with the increase of soil water content (40%~80%). The shear stress reduced from 229.85, 193.38 and 96.46 Pa to 2.25, 2.65 and 2.32 Pa respectively. Under conditions of high water content (> 50%), the loess soil showed a strong strain overshoot. ② With increased shear strain, the storage modulus of the four types of soil slurry appeared in two plateau areas, showing a two-step yield phenomenon. With increased soil water content, the slurry changed from a two-step to a one-step yield. The first step of the yield was related to the destruction of the initial network structure, and the second step indicated that the slurry structure was completely destroyed. ③ When the soil moisture content was less than 50%, the fine soil particles increase the degree of flocculation by forming flocs, thus increasing the shear stress at the flow point of the soil slurry. When the moisture content was greater than 50%, the coarse particles in the soil increased the shear stress at the flow point by increasing the friction between the particles. [Conclusion] Soil rheological properties are not only related to soil properties but also significantly influenced by soil water content. Soils with a high fine particle content have a slurry that is more susceptible to flow under high-water-content conditions.
[Objective] The influence of the soil water content on the rheological properties of the soil slurry was analysed to provide a scientific basis for understanding the flow law of the slurry and the prevention and control of mudflow in the Loess Plateau region. [Methods] Four main types of soil in the Loess Plateau were studied, and the effects of water content on the soil rheological properties were investigated using rheological oscillation shear tests. [Results] ① The storage modulus, loss modulus and shear stress of lou soil, cinnamon soil and dark loessial soil all decreased with the increase of soil water content (40%~80%). The shear stress reduced from 229.85, 193.38 and 96.46 Pa to 2.25, 2.65 and 2.32 Pa respectively. Under conditions of high water content (> 50%), the loess soil showed a strong strain overshoot. ② With increased shear strain, the storage modulus of the four types of soil slurry appeared in two plateau areas, showing a two-step yield phenomenon. With increased soil water content, the slurry changed from a two-step to a one-step yield. The first step of the yield was related to the destruction of the initial network structure, and the second step indicated that the slurry structure was completely destroyed. ③ When the soil moisture content was less than 50%, the fine soil particles increase the degree of flocculation by forming flocs, thus increasing the shear stress at the flow point of the soil slurry. When the moisture content was greater than 50%, the coarse particles in the soil increased the shear stress at the flow point by increasing the friction between the particles. [Conclusion] Soil rheological properties are not only related to soil properties but also significantly influenced by soil water content. Soils with a high fine particle content have a slurry that is more susceptible to flow under high-water-content conditions.
2024,44(4):151-156,235
, DOI: 10.13961/j.cnki.stbctb.2024.04.016
Abstract:
[Objective] The interannual time-series patterns of water quantity changes and seasonal differences in wet, normal and dry in the Chaobai River basin upstream of the Miyun Reservoir were studied to provide decision support for efficient water utilisation and ecological water security in the Beijing-Tianjin-Hebei region. [Methods] Based on the collection of water quantity data and the analysis of the monthly wet, normal, and dry periods, the distance flatness percentage was used to explore the characteristics of water quantity changes in the Chaobai River basin and to derive the quantitative relationship between the wet, normal and dry periods of the basin and the amount of runoff water. [Results] From 2010 to 2021, the dry season of the Chaobai River basin was much longer than that of the wet and normal seasons, but the high water volume and its anomaly percentage showed an exponential growth trend every 1—2 years, indicating that the Chaobai River basin had more extreme climate characteristics in recent years. The wet period in the Chaobai River basin mainly occured from July to December, and the normal period of the basin was accompanied by a wet period. However, from 2010 to 2021, the normal periods of the Chaobai River basin only had a normal water period of 6—7 months, respectively, and the dry period covered most of the 12 years, and it was densely distributed in all periods except the wet dry period and the normal period. During all periods, the water volume of the Baihe River basin was higher than that of the Chaohe River basin, which may be attributed to the recharge of runoff by melting snow in spring. [Conclusion] The Chaobai River basin experienced an increase in extreme precipitation events from 2010 to 2021; however, the percentage of dry periods was much higher than that during the normal and wet periods. The relationship between the proportions of the three periods was the most important factor influencing the change in water quantity in this watershed.
[Objective] The interannual time-series patterns of water quantity changes and seasonal differences in wet, normal and dry in the Chaobai River basin upstream of the Miyun Reservoir were studied to provide decision support for efficient water utilisation and ecological water security in the Beijing-Tianjin-Hebei region. [Methods] Based on the collection of water quantity data and the analysis of the monthly wet, normal, and dry periods, the distance flatness percentage was used to explore the characteristics of water quantity changes in the Chaobai River basin and to derive the quantitative relationship between the wet, normal and dry periods of the basin and the amount of runoff water. [Results] From 2010 to 2021, the dry season of the Chaobai River basin was much longer than that of the wet and normal seasons, but the high water volume and its anomaly percentage showed an exponential growth trend every 1—2 years, indicating that the Chaobai River basin had more extreme climate characteristics in recent years. The wet period in the Chaobai River basin mainly occured from July to December, and the normal period of the basin was accompanied by a wet period. However, from 2010 to 2021, the normal periods of the Chaobai River basin only had a normal water period of 6—7 months, respectively, and the dry period covered most of the 12 years, and it was densely distributed in all periods except the wet dry period and the normal period. During all periods, the water volume of the Baihe River basin was higher than that of the Chaohe River basin, which may be attributed to the recharge of runoff by melting snow in spring. [Conclusion] The Chaobai River basin experienced an increase in extreme precipitation events from 2010 to 2021; however, the percentage of dry periods was much higher than that during the normal and wet periods. The relationship between the proportions of the three periods was the most important factor influencing the change in water quantity in this watershed.
2024,44(4):157-167
, DOI: 10.13961/j.cnki.stbctb.20240510.001
Abstract:
[Objective] The effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after disturbance from alpine wetland highway projects were analyzed in order to provide a theoretical reference for the screening of alpine wetland vegetation restoration models, soil erosion control, and improvement of the ecological environment. [Methods] We compared three slope treatments (natural succession, spraying grass planting, and turf cover) against the original undisturbed vegetation (the control). Soil physicochemical indexes and soil enzyme activities were measured, and their interrelationships and influencing factors were analyzed. [Results] ① All three restoration measures resulted in a significant increase (p＜0.05) in soil pH value and total potassium compared with the control. These restoration measures also resulted in a significant decrease (p＜0.05) in soil organic matter, total nitrogen, fine root biomass, and available potassium under the natural succession treatment, with minimum values of 15.16 (±0.15), 0.75 (±0.01), 0.60 (±0.27), and 65.00 (±4.5), respectively. The proportion of clay particles in the soil was significantly lower (p＜0.05) under the spraying grass planting and turf cover treatments. The richness indices of the spraying grass planting and natural succession treatments were significantly lower (p＜0.05) than observed for the control, with a minimum value of 1.29 (±0.02) under the natural succession treatment. Soil pH value, organic matter, total nitrogen, available potassium, fine root biomass, and richness index were higher for the two types of restoration measures (turf cover and spraying grass planting) than for natural selection. The richness indices for the two restoration measures were higher than for natural succession. ② Compared with natural succession, spraying grass planting and turf cover could better recover sucrase, urease, alkaline phosphatase, and catalase activity,, and even catalase activity could be recovered close to that of the control. The activities of the four enzymes were the smallest under natural succession conditions, which were 12.65±10.87,0.24±0.03,0.23±0.05 and 1.73±0.48, respectively. 0.48). ③ The correlations between the activities of the four enzymes and the physical and chemical properties of the soil were significant. Urease activity was the most sensitive to the physical and chemical properties of the soil, and was able to evaluate the soil quality of the slopes of the plateau wetland very well. [Conclusion] Compared with natural succession, spraying grass planting and turf cover can effectively improve soil physical and chemical properties and increase soil enzyme activity. Soil enzyme activity can be used as a sensitive indicator for evaluating the soil quality of slopes in plateau wetlands.
[Objective] The effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after disturbance from alpine wetland highway projects were analyzed in order to provide a theoretical reference for the screening of alpine wetland vegetation restoration models, soil erosion control, and improvement of the ecological environment. [Methods] We compared three slope treatments (natural succession, spraying grass planting, and turf cover) against the original undisturbed vegetation (the control). Soil physicochemical indexes and soil enzyme activities were measured, and their interrelationships and influencing factors were analyzed. [Results] ① All three restoration measures resulted in a significant increase (p＜0.05) in soil pH value and total potassium compared with the control. These restoration measures also resulted in a significant decrease (p＜0.05) in soil organic matter, total nitrogen, fine root biomass, and available potassium under the natural succession treatment, with minimum values of 15.16 (±0.15), 0.75 (±0.01), 0.60 (±0.27), and 65.00 (±4.5), respectively. The proportion of clay particles in the soil was significantly lower (p＜0.05) under the spraying grass planting and turf cover treatments. The richness indices of the spraying grass planting and natural succession treatments were significantly lower (p＜0.05) than observed for the control, with a minimum value of 1.29 (±0.02) under the natural succession treatment. Soil pH value, organic matter, total nitrogen, available potassium, fine root biomass, and richness index were higher for the two types of restoration measures (turf cover and spraying grass planting) than for natural selection. The richness indices for the two restoration measures were higher than for natural succession. ② Compared with natural succession, spraying grass planting and turf cover could better recover sucrase, urease, alkaline phosphatase, and catalase activity,, and even catalase activity could be recovered close to that of the control. The activities of the four enzymes were the smallest under natural succession conditions, which were 12.65±10.87,0.24±0.03,0.23±0.05 and 1.73±0.48, respectively. 0.48). ③ The correlations between the activities of the four enzymes and the physical and chemical properties of the soil were significant. Urease activity was the most sensitive to the physical and chemical properties of the soil, and was able to evaluate the soil quality of the slopes of the plateau wetland very well. [Conclusion] Compared with natural succession, spraying grass planting and turf cover can effectively improve soil physical and chemical properties and increase soil enzyme activity. Soil enzyme activity can be used as a sensitive indicator for evaluating the soil quality of slopes in plateau wetlands.
2024,44(4):168-176
, DOI: 10.13961/j.cnki.stbctb.20240719.001
Abstract:
[Objective] The capacity of a drainage ditch modified as a root channel wetland (ecological ditch) to purify aquaculture tail water was analysed in order to provide a scientific reference for circular aquaculture and pollution reduction in areas of large-scale aquaculture. [Methods] The study site was Koujia Lake Park, in Helan County, Ningxia Hui Autonomous Region, with an aquaculture area exceeding 500 hectares. We constructed experimental root channel wetlands on both sides of an original farmland drainage ditch to improve the purification capacity of the ditch. To evaluate the purification effect of this ecological ditch system on the tail water from large-scale aquaculture, we collected water samples in the ecological ditch in 2022 and 2023. [Results] In 2022, at the onset of its operation, the ecological ditch effectively purified phosphate, nitrite, and ammonia nitrogen in the aquaculture tail water, with the purification rate being 97.15%, 96.00%, and 59.65%, respectively. In 2023, the ecological ditch effectively purified the aquaculture tail water on a daily basis. The maximum purification rate for phosphate, nitrite, and ammonia nitrogen was 87.70%, 72.89%, and 83.15%, respectively. The concentration of ammonia nitrogen at the purification end of the system was less than 0.5 mg/L, reaching the Class Ⅱ standard of the ‘Surface Water Environmental Quality Standard’ (GB3838-2002). After shortening the purification distance by half, the ecological ditch still had a good purification effect on the aquaculture tail water, with no significant increase in the nutrient concentration at the ditch outlet (p＜0.05). [Conclusion] The construction of a root channel wetland around the drainage ditch could effectively purify the tail water generated in the daily aquaculture operations across a large-scale aquaculture area, and achieve water recycling.
[Objective] The capacity of a drainage ditch modified as a root channel wetland (ecological ditch) to purify aquaculture tail water was analysed in order to provide a scientific reference for circular aquaculture and pollution reduction in areas of large-scale aquaculture. [Methods] The study site was Koujia Lake Park, in Helan County, Ningxia Hui Autonomous Region, with an aquaculture area exceeding 500 hectares. We constructed experimental root channel wetlands on both sides of an original farmland drainage ditch to improve the purification capacity of the ditch. To evaluate the purification effect of this ecological ditch system on the tail water from large-scale aquaculture, we collected water samples in the ecological ditch in 2022 and 2023. [Results] In 2022, at the onset of its operation, the ecological ditch effectively purified phosphate, nitrite, and ammonia nitrogen in the aquaculture tail water, with the purification rate being 97.15%, 96.00%, and 59.65%, respectively. In 2023, the ecological ditch effectively purified the aquaculture tail water on a daily basis. The maximum purification rate for phosphate, nitrite, and ammonia nitrogen was 87.70%, 72.89%, and 83.15%, respectively. The concentration of ammonia nitrogen at the purification end of the system was less than 0.5 mg/L, reaching the Class Ⅱ standard of the ‘Surface Water Environmental Quality Standard’ (GB3838-2002). After shortening the purification distance by half, the ecological ditch still had a good purification effect on the aquaculture tail water, with no significant increase in the nutrient concentration at the ditch outlet (p＜0.05). [Conclusion] The construction of a root channel wetland around the drainage ditch could effectively purify the tail water generated in the daily aquaculture operations across a large-scale aquaculture area, and achieve water recycling.
2024,44(4):177-186
, DOI: 10.13961/j.cnki.stbctb.2024.04.019
Abstract:
[Objective] The effects of surface photovoltaic (PV) power station on the structural characteristics of water quality and phytoplankton communities in subsidence ponds in the winter were investigated in order to provide data references for the application of surface PV in coal mining subsidence waters. [Methods] Water bodies and phytoplankton communities of column PV ponds, floating PV ponds, and non-PV ponds (comparison) were sampled and investigated, and the influencing factors were analysed using Pearson correlation and stepwise regression analyses. [Results] A total of 41 species of phytoplankton were identified in the column PV sinkhole pond, 40 species of phytoplankton in the floating PV sinkhole pond, and 47 species of phytoplankton in the pond without PV sinkholes; the diatom-green-algal type dominated the species. Compared with the control sinkhole ponds, the surface PV power plant effectively reduced the light intensity and lowered the levels of electrical conductivity, total dissolved solids, oxidation reduction potential, and ammonia nitrogen in the sinkhole ponds. Similarly, the floating PV power plants reduced the chemical oxygen demand, total nitrogen (TN), and total phosphorus contents in the water body. Additionally, the column PV power plant had lower levels of the above-mentioned indicators than the floating PV power plant. The number of phytoplankton species, density, and biomass in the floating PV and column PV sinking ponds were slightly lower than those in the control sinking ponds. The values for the Shannon-Wiener diversity index, Pielou homogeneity index, and Margalef richness index were ordered as follows: no PV pond > floating PV pond > column PV pond. [Conclusion] Surface PVs can help reduce the salinity of winter water bodies and maintain both the temperature of the water bodies and the content of dissolved oxygen. The above indices used for the column PV power station to improve its effect were better than those for the floating PV power station, and to a certain extent, the floating PV power station could improve eutrophic water bodies. Surface PVs can affect the structure of phytoplankton communities, and the effect of floating PVs on the phytoplankton of sunken water bodies is smaller than that of column PVs. Pearson and stepwise regression analyses revealed that the phytoplankton community diversity of column PV sunken ponds is mainly affected by water temperature (WT) and TN, while that of floating PV subsidence ponds are mainly affected by the WT. In summary, floating PV power station are more favourable for improving the water quality of subsidence ponds and have the least impact on the phytoplankton community structure.
[Objective] The effects of surface photovoltaic (PV) power station on the structural characteristics of water quality and phytoplankton communities in subsidence ponds in the winter were investigated in order to provide data references for the application of surface PV in coal mining subsidence waters. [Methods] Water bodies and phytoplankton communities of column PV ponds, floating PV ponds, and non-PV ponds (comparison) were sampled and investigated, and the influencing factors were analysed using Pearson correlation and stepwise regression analyses. [Results] A total of 41 species of phytoplankton were identified in the column PV sinkhole pond, 40 species of phytoplankton in the floating PV sinkhole pond, and 47 species of phytoplankton in the pond without PV sinkholes; the diatom-green-algal type dominated the species. Compared with the control sinkhole ponds, the surface PV power plant effectively reduced the light intensity and lowered the levels of electrical conductivity, total dissolved solids, oxidation reduction potential, and ammonia nitrogen in the sinkhole ponds. Similarly, the floating PV power plants reduced the chemical oxygen demand, total nitrogen (TN), and total phosphorus contents in the water body. Additionally, the column PV power plant had lower levels of the above-mentioned indicators than the floating PV power plant. The number of phytoplankton species, density, and biomass in the floating PV and column PV sinking ponds were slightly lower than those in the control sinking ponds. The values for the Shannon-Wiener diversity index, Pielou homogeneity index, and Margalef richness index were ordered as follows: no PV pond > floating PV pond > column PV pond. [Conclusion] Surface PVs can help reduce the salinity of winter water bodies and maintain both the temperature of the water bodies and the content of dissolved oxygen. The above indices used for the column PV power station to improve its effect were better than those for the floating PV power station, and to a certain extent, the floating PV power station could improve eutrophic water bodies. Surface PVs can affect the structure of phytoplankton communities, and the effect of floating PVs on the phytoplankton of sunken water bodies is smaller than that of column PVs. Pearson and stepwise regression analyses revealed that the phytoplankton community diversity of column PV sunken ponds is mainly affected by water temperature (WT) and TN, while that of floating PV subsidence ponds are mainly affected by the WT. In summary, floating PV power station are more favourable for improving the water quality of subsidence ponds and have the least impact on the phytoplankton community structure.
2024,44(4):187-195
, DOI: 10.13961/j.cnki.stbctb.2024.04.020
Abstract:
[Objective] The effects of mulching materials on the collection of faint rainfall and dew from soil moisture were analysed to provide a scientific basis to support their efficient utilisation in central arid belt of Ningxia Hui Aouonomous Region. [Methods] Three treatments were evaluated in the field experiment: ordinary polyethylene film mulch (T1), high-density polyethylene film mulch (T2) and polytetrafluoroethylene film mulch (T3); bare ground (T4) was used as the control. The slopes of the catchment surface were optimised, and the changes in soil moisture during faint rainfall and dew events were determined. [Results] ① The total multi-year single precipitation of less than 5 mm accounted for 29.8% of the annual precipitation in the study area, with an average annual dew of 31.68 mm, representing 13.2% of the average multi-year precipitation. ② The order of soil volumetric moisture content at depths of 5 and 15 cm in different ridge mulching modes was consistent, decreasing from polytetrafluoroethylene film mulching > ordinary polyethylene film mulching > high density polyethylene film mulching > bare ground. ③ The depth of influence of ridge mulching on soil moisture increased significantly when collecting faint rainfall, and was up to 15 cm for 2 mm precipitation, whereas it was only up to 5 cm in the bare ground control. ④ The effect of dew on soil moisture was mainly above 5 cm, and when the dew amount was 0.8 mm, the soil moisture of ordinary polyethylene film mulch, high-density polyethylene film mulch, polytetrafluoroethylene film mulch and bare soil increased by 0.6%, 1.6%, 4.0% and 0.2%, respectively. [Conclusion] We found significant differences in the effects of three mulching treatments to pool faint rainfall and dew to increase soil moisture, of which the polytetrafluoroethylene film mulch ridges pooled the best, with soil moisture content in the ridges being greatest.
[Objective] The effects of mulching materials on the collection of faint rainfall and dew from soil moisture were analysed to provide a scientific basis to support their efficient utilisation in central arid belt of Ningxia Hui Aouonomous Region. [Methods] Three treatments were evaluated in the field experiment: ordinary polyethylene film mulch (T1), high-density polyethylene film mulch (T2) and polytetrafluoroethylene film mulch (T3); bare ground (T4) was used as the control. The slopes of the catchment surface were optimised, and the changes in soil moisture during faint rainfall and dew events were determined. [Results] ① The total multi-year single precipitation of less than 5 mm accounted for 29.8% of the annual precipitation in the study area, with an average annual dew of 31.68 mm, representing 13.2% of the average multi-year precipitation. ② The order of soil volumetric moisture content at depths of 5 and 15 cm in different ridge mulching modes was consistent, decreasing from polytetrafluoroethylene film mulching > ordinary polyethylene film mulching > high density polyethylene film mulching > bare ground. ③ The depth of influence of ridge mulching on soil moisture increased significantly when collecting faint rainfall, and was up to 15 cm for 2 mm precipitation, whereas it was only up to 5 cm in the bare ground control. ④ The effect of dew on soil moisture was mainly above 5 cm, and when the dew amount was 0.8 mm, the soil moisture of ordinary polyethylene film mulch, high-density polyethylene film mulch, polytetrafluoroethylene film mulch and bare soil increased by 0.6%, 1.6%, 4.0% and 0.2%, respectively. [Conclusion] We found significant differences in the effects of three mulching treatments to pool faint rainfall and dew to increase soil moisture, of which the polytetrafluoroethylene film mulch ridges pooled the best, with soil moisture content in the ridges being greatest.
2024,44(4):196-204,214
, DOI: 10.13961/j.cnki.stbctb.20240612.001
Abstract:
[Objective] The weathering degree and provenance of the Pisha sandstone from the Lower Jurassic Yan’an formation in Jungar, Inner Mongolia Autonomous Region was analysed in order to provide a basis for further research on the origins and epigenetic evolution of the Pisha sandstone, and the prevention and control of soil erosion. [Methods] We conducted field investigation and geochemical analyses, including major, trace, and rare earth element analyses, and calculated the chemical alteration index (CIA), plagioclase alteration index (PIA), light-to-heavy rare earth element ratio (LREE/HREE), and related trace and rare earth element relationships in the Pisha sandstone. [Results] ① The geochemical classification diagram showed that the Pisha sandstone in Jungar comprised shale, subarkose, and lithic sandstone facies. The Pisha sandstone was mainly composed of SiO2 and Al2O3. The content of most of the major elements was lower than that in the average upper crust (UCC). The CIA value ranged from 64.95 to 86.57, with an average of 77.46. This was consistent with the characteristics of the Pisha sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering. ② The siltstone and mudstone facies had a higher trace element content than the sandstone facies, with Ba being the most abundant element, followed by Zr. The paleotemperature of the deposition of the Pisha sandstone was 10.67—22.78 ℃, with an average value of 17.68 ℃; the PIA value was 70.48—97.13, with an average of 89.76. ③ The rare earth element distribution pattern in the Pisha sandstone was consistent with that in the UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies. The total rare earth (∑REE), light-to-heavy rare earth ratio (LREE/HREE) and (La/Yb)N values of the siltstone and mudstone facies were higher than those of the sandstone facies. This difference was mainly due to the attraction of most of the trace elements released by rock weathering during epigenetic processes by clay minerals, or due to hydraulic sorting. [Conclusion] The Pisha sandstone from the Lower Jurassic Yan’an Formation in Jungar, Inner Mongolia, consists of terrestrial clastic sedimentary rocks with a low compositional maturity and sorting, sourced from an area that had experienced moderate to strong chemical weathering. The Pisha sandstone formed under arid to semi-humid conditions. The rare earth element distribution pattern combined with the discrimination diagram of major and trace elements indicates that the Pisha sandstone from the Yan’an Formation originated from Hercynian-Indosinian granites in the Yinshan-Daqingshan area, in the Northern Ordos Basin.
[Objective] The weathering degree and provenance of the Pisha sandstone from the Lower Jurassic Yan’an formation in Jungar, Inner Mongolia Autonomous Region was analysed in order to provide a basis for further research on the origins and epigenetic evolution of the Pisha sandstone, and the prevention and control of soil erosion. [Methods] We conducted field investigation and geochemical analyses, including major, trace, and rare earth element analyses, and calculated the chemical alteration index (CIA), plagioclase alteration index (PIA), light-to-heavy rare earth element ratio (LREE/HREE), and related trace and rare earth element relationships in the Pisha sandstone. [Results] ① The geochemical classification diagram showed that the Pisha sandstone in Jungar comprised shale, subarkose, and lithic sandstone facies. The Pisha sandstone was mainly composed of SiO2 and Al2O3. The content of most of the major elements was lower than that in the average upper crust (UCC). The CIA value ranged from 64.95 to 86.57, with an average of 77.46. This was consistent with the characteristics of the Pisha sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering. ② The siltstone and mudstone facies had a higher trace element content than the sandstone facies, with Ba being the most abundant element, followed by Zr. The paleotemperature of the deposition of the Pisha sandstone was 10.67—22.78 ℃, with an average value of 17.68 ℃; the PIA value was 70.48—97.13, with an average of 89.76. ③ The rare earth element distribution pattern in the Pisha sandstone was consistent with that in the UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies. The total rare earth (∑REE), light-to-heavy rare earth ratio (LREE/HREE) and (La/Yb)N values of the siltstone and mudstone facies were higher than those of the sandstone facies. This difference was mainly due to the attraction of most of the trace elements released by rock weathering during epigenetic processes by clay minerals, or due to hydraulic sorting. [Conclusion] The Pisha sandstone from the Lower Jurassic Yan’an Formation in Jungar, Inner Mongolia, consists of terrestrial clastic sedimentary rocks with a low compositional maturity and sorting, sourced from an area that had experienced moderate to strong chemical weathering. The Pisha sandstone formed under arid to semi-humid conditions. The rare earth element distribution pattern combined with the discrimination diagram of major and trace elements indicates that the Pisha sandstone from the Yan’an Formation originated from Hercynian-Indosinian granites in the Yinshan-Daqingshan area, in the Northern Ordos Basin.
2024,44(4):205-214
, DOI: 10.13961/j.cnki.stbctb.2024.04.022
Abstract:
[Objective] The effects of different biochar additions on the physical and chemical properties of yellow loam soil, tobacco growth, yield, and output value were analysed in the Chongqing mountainous region to provide technical support for the application of biochar in soil conservation and tobacco production. [Methods] Flue-cured tobacco K326 was used as the experimental material. In 2022—2023, a completely random design was adopted for the tobacco field, and seven treatments of biochar addition were established based on the conventional film ridge cultivation and fertilisation methods. The seven biochar treatments were as follows: zero biochar addition (CK), 750 (T50), 1 500 (T100), 3 000 (T200), 4 500 (T300), 6 000 (T400), and 7 500 kg/hm2 (T500) of biochar. During the study period, soil physical and chemical properties, tobacco agronomic traits, ground and aboveground dry matter, and yield and output values were measured. [Results] ① The application of biochar increased the soil porosity and capillary water capacity. The total porosity and capillary water capacity of soil treated with T400 and T500 were significantly higher than those treated with CK in the second year of the experiment. ② Compared with the CK treatment, biochar addition significantly increased the contents of available nitrogen, available phosphorus, and available potassium in the 0—20 cm soil profile, and T300, T400, and T500 treatments significantly increased the organic matter content and pH value in the 0—20 cm soil profile, which could effectively alleviate soil acidification. ③ Compared with the CK treatment, the T300, T400, and T500 treatments significantly promoted the growth and biomass accumulation of tobacco and significantly increased the yield and output value of tobacco leaves. Considering the input-output ratio, the T400 treatment was optimal for improving the physical and chemical properties of soil, tobacco yield, and output value. [Conclusion] Adding suitable amounts of biochar to tobacco field soil can improve the physical and chemical properties of soil, increase soil cultivability, promote the growth, development, and dry matter accumulation of tobacco plants, and increase the yield and output value of tobacco leaves.
[Objective] The effects of different biochar additions on the physical and chemical properties of yellow loam soil, tobacco growth, yield, and output value were analysed in the Chongqing mountainous region to provide technical support for the application of biochar in soil conservation and tobacco production. [Methods] Flue-cured tobacco K326 was used as the experimental material. In 2022—2023, a completely random design was adopted for the tobacco field, and seven treatments of biochar addition were established based on the conventional film ridge cultivation and fertilisation methods. The seven biochar treatments were as follows: zero biochar addition (CK), 750 (T50), 1 500 (T100), 3 000 (T200), 4 500 (T300), 6 000 (T400), and 7 500 kg/hm2 (T500) of biochar. During the study period, soil physical and chemical properties, tobacco agronomic traits, ground and aboveground dry matter, and yield and output values were measured. [Results] ① The application of biochar increased the soil porosity and capillary water capacity. The total porosity and capillary water capacity of soil treated with T400 and T500 were significantly higher than those treated with CK in the second year of the experiment. ② Compared with the CK treatment, biochar addition significantly increased the contents of available nitrogen, available phosphorus, and available potassium in the 0—20 cm soil profile, and T300, T400, and T500 treatments significantly increased the organic matter content and pH value in the 0—20 cm soil profile, which could effectively alleviate soil acidification. ③ Compared with the CK treatment, the T300, T400, and T500 treatments significantly promoted the growth and biomass accumulation of tobacco and significantly increased the yield and output value of tobacco leaves. Considering the input-output ratio, the T400 treatment was optimal for improving the physical and chemical properties of soil, tobacco yield, and output value. [Conclusion] Adding suitable amounts of biochar to tobacco field soil can improve the physical and chemical properties of soil, increase soil cultivability, promote the growth, development, and dry matter accumulation of tobacco plants, and increase the yield and output value of tobacco leaves.
2024,44(4):215-224
, DOI: 10.13961/j.cnki.stbctb.2024.04.023
Abstract:
[Objective] To provide a reference for the assessment of meteorological disaster risk and prevention of soil erosion, the spatial and temporal distribution characteristics of rainfall erosivity under different levels of rainfall in Jilin Province were analysed. [Methods] Daily rainfall data from 51 meteorological stations in Jilin Province from 1980 to 2022 were divided based on different rainfall magnitudes according to the rainfall grade. The daily rainfall erosivity calculation model proposed by Xie was adopted to calculate the rainfall erosivity, and the M-K mutation test, coefficient of variation, and climate tendency rate were used to analyse the spatial and temporal distributions of different grades of rainfall erosivity. [Results] ① The average annual erosive rainfall and rainfall erosivity in Jilin Province during 1980—2022 were 420.04 mm and 1 967.12 MJ·mm/(hm2·h), and the coefficients of variation were 0.27 and 0.2, respectively, both of which showed moderate variations. ② Different grades of rainfall erosivity showed an upward trend during 1980—2022. The torrential rain erosivity showed the largest increase of 57.7 MJ·mm/(hm2·h·10 a), whereas the moderate rainfall erosivity showed the smallest increase of 5.8 MJ·mm/(hm2·h·10 a). The contribution of heavy rain erosivity to the average annual rainfall erosivity was the largest at 36.68%. ③ The distribution of different grades of rainfall erosivity was uneven throughout the year. Moderate rainfall erosivity occurred throughout the year, whereas heavy rainfall erosivity only occurred from June to September. Moderate rainfall erosivity played a dominant role in the annual rainfall erosivity from October to May of the subsequent year. From June to September, the heavy and torrential rain erosivities gradually replaced the moderate rainfall erosivity and played a dominant role in the annual rainfall erosivity. ④ The spatial distributions of the average annual erosive rainfall, average annual rainfall erosivity, and different grades of rainfall erosivity were higher in the central and southern regions and lower in the East and West. [Conclusion] The regional characteristics of different grades of rainfall erosivity in Jilin Province were obvious, and the time and region with high probabilities of soil erosion caused by rainfall of different magnitudes were clearly distinguished; thus, meteorological disaster risk prevention and soil and water conservation prevention measures should be formulated according to the local conditions.
[Objective] To provide a reference for the assessment of meteorological disaster risk and prevention of soil erosion, the spatial and temporal distribution characteristics of rainfall erosivity under different levels of rainfall in Jilin Province were analysed. [Methods] Daily rainfall data from 51 meteorological stations in Jilin Province from 1980 to 2022 were divided based on different rainfall magnitudes according to the rainfall grade. The daily rainfall erosivity calculation model proposed by Xie was adopted to calculate the rainfall erosivity, and the M-K mutation test, coefficient of variation, and climate tendency rate were used to analyse the spatial and temporal distributions of different grades of rainfall erosivity. [Results] ① The average annual erosive rainfall and rainfall erosivity in Jilin Province during 1980—2022 were 420.04 mm and 1 967.12 MJ·mm/(hm2·h), and the coefficients of variation were 0.27 and 0.2, respectively, both of which showed moderate variations. ② Different grades of rainfall erosivity showed an upward trend during 1980—2022. The torrential rain erosivity showed the largest increase of 57.7 MJ·mm/(hm2·h·10 a), whereas the moderate rainfall erosivity showed the smallest increase of 5.8 MJ·mm/(hm2·h·10 a). The contribution of heavy rain erosivity to the average annual rainfall erosivity was the largest at 36.68%. ③ The distribution of different grades of rainfall erosivity was uneven throughout the year. Moderate rainfall erosivity occurred throughout the year, whereas heavy rainfall erosivity only occurred from June to September. Moderate rainfall erosivity played a dominant role in the annual rainfall erosivity from October to May of the subsequent year. From June to September, the heavy and torrential rain erosivities gradually replaced the moderate rainfall erosivity and played a dominant role in the annual rainfall erosivity. ④ The spatial distributions of the average annual erosive rainfall, average annual rainfall erosivity, and different grades of rainfall erosivity were higher in the central and southern regions and lower in the East and West. [Conclusion] The regional characteristics of different grades of rainfall erosivity in Jilin Province were obvious, and the time and region with high probabilities of soil erosion caused by rainfall of different magnitudes were clearly distinguished; thus, meteorological disaster risk prevention and soil and water conservation prevention measures should be formulated according to the local conditions.
2024,44(4):225-235
, DOI: 10.13961/j.cnki.stbctb.2024.04.024
Abstract:
[Objective] The morphological features of eroded gullies in rolling hill areas of black soil in Northeast China and temporal-scale variations in their morphology. were analysed in order to provide a scientific basis and empirical data to understand the development and evolution of erosional gullies in this area. [Methods] This study selected 61 typical gullies in Guofu Town, Baiquan County, China. Unmanned aerial vehicle technology was used to generate digital elevation models and manually interprets parameters such as gully length and width-to-depth ratio. Historical aerial imagery data were used to analyse the developmental changes and influencing factors of gullies. [Results] ① From 2003 to 2021, gully development in Baiquan County showed an overall intensification trend, with medium-sized gullies accounting for 60.66% of the total gullies. ② A significant variation was observed in gully morphology within the study area, with gully length, average cross-sectional area, and volume mainly distributed between 41.89—1 173 m, 11.23—440.69 m2, and 895.38—107 686.57 m3, respectively. The overall shape parameter distribution was concentrated. ③ Gully length, area, and shape index exhibited a trend of increase followed by a decrease, with an average development rate of 9.64 m/a for length and 246.39 m2/a for area. The erosion gullys showed narrow and irregular shape. ④ Regression analysis revealed significant positive correlations between gully length and width, perimeter, and area (S), and significant relationships between top width and bottom width, perimeter, and S, with determination coefficients of 0.82, 0.23, and 0.58, respectively. However, gully depth showed a low correlation with erosion volume and S. [Conclusion] In typical areas of Baiquan County, the general trend in gully erosion has shown a relative slowdown compared with previous assessments, although gully erosion remains severe. Furthermore, there is an interrelationship among different morphological parameters, with gully length showing a close positive correlation with the area and perimeter of the eroded gullies.
[Objective] The morphological features of eroded gullies in rolling hill areas of black soil in Northeast China and temporal-scale variations in their morphology. were analysed in order to provide a scientific basis and empirical data to understand the development and evolution of erosional gullies in this area. [Methods] This study selected 61 typical gullies in Guofu Town, Baiquan County, China. Unmanned aerial vehicle technology was used to generate digital elevation models and manually interprets parameters such as gully length and width-to-depth ratio. Historical aerial imagery data were used to analyse the developmental changes and influencing factors of gullies. [Results] ① From 2003 to 2021, gully development in Baiquan County showed an overall intensification trend, with medium-sized gullies accounting for 60.66% of the total gullies. ② A significant variation was observed in gully morphology within the study area, with gully length, average cross-sectional area, and volume mainly distributed between 41.89—1 173 m, 11.23—440.69 m2, and 895.38—107 686.57 m3, respectively. The overall shape parameter distribution was concentrated. ③ Gully length, area, and shape index exhibited a trend of increase followed by a decrease, with an average development rate of 9.64 m/a for length and 246.39 m2/a for area. The erosion gullys showed narrow and irregular shape. ④ Regression analysis revealed significant positive correlations between gully length and width, perimeter, and area (S), and significant relationships between top width and bottom width, perimeter, and S, with determination coefficients of 0.82, 0.23, and 0.58, respectively. However, gully depth showed a low correlation with erosion volume and S. [Conclusion] In typical areas of Baiquan County, the general trend in gully erosion has shown a relative slowdown compared with previous assessments, although gully erosion remains severe. Furthermore, there is an interrelationship among different morphological parameters, with gully length showing a close positive correlation with the area and perimeter of the eroded gullies.
2024,44(4):236-246,382
, DOI: 10.13961/j.cnki.stbctb.2024.04.025
Abstract:
[Objective] The spatial and temporal patterns of vegetation cover and its driving forces in the Tingjiang River basin of the southern red soil erosion area， were scientifically evaluated to reveal the strength of the role of each driving factor in the spatial differentiation of vegetation cover and the mechanism of interaction in order to provide a scientific basis for the restoration of ecosystems and comprehensive control of soil erosion. [Methods] Based on the monthly scale MOD13Q1 (250 m) dataset for 20 years from 2000 to 2020, we used one-way linear regression and Pearson’s correlation analysis to explore the relationship between normalised difference vegetation index (NDVI) and time and incorporated natural and anthropogenic factors such as temperature, precipitation, and elevation, as well as the spatial and temporal dynamics of vegetation NDVI in the watershed using the geoprobe model. A geoprobe model was used to analyse the temporal and spatial changes in vegetation NDVI in the watershed. [Results] ① Temporally, the vegetation cover in the Tingjiang River basin showed a fluctuating upward trend from 2000 to 2020, with a growth rate of 7.11% and an average rate of increase of 0.002 2/year, indicating that the ecological environment of the region was stable and continuously improving. ② Spatially, the overall medium-high and high coverage was dominant, showing a spatial distribution pattern that was lower than the surrounding area in the middle of each district and county, with significant geographical differences; the NDVI improved area was 86.33%, which was much larger than the degraded area region. ③ The driving factor detection results were: precipitation ＞ elevation ＞ temperature ＞ GDP＞ population density ＞ land use type ＞ vegetation type ＞ slope ＞ soil type. [Conclusion] Temporal and spatial variations in vegetation cover within the Tingjiang River Basin were affected by both natural and anthropogenic factors. The explanatory power of the precipitation factor was 0.705, which was the main driving factor affecting the changes in vegetation cover in the study area. Elevation, temperature, and GDP were the secondary driving factors, with explanatory powers of 0.58 or more. The interactions (q) between the factors showed higher explanatory power than the single factors, mainly in the form of a complex relationship between the enhancement and nonlinear enhancement effects of the two factors.
[Objective] The spatial and temporal patterns of vegetation cover and its driving forces in the Tingjiang River basin of the southern red soil erosion area， were scientifically evaluated to reveal the strength of the role of each driving factor in the spatial differentiation of vegetation cover and the mechanism of interaction in order to provide a scientific basis for the restoration of ecosystems and comprehensive control of soil erosion. [Methods] Based on the monthly scale MOD13Q1 (250 m) dataset for 20 years from 2000 to 2020, we used one-way linear regression and Pearson’s correlation analysis to explore the relationship between normalised difference vegetation index (NDVI) and time and incorporated natural and anthropogenic factors such as temperature, precipitation, and elevation, as well as the spatial and temporal dynamics of vegetation NDVI in the watershed using the geoprobe model. A geoprobe model was used to analyse the temporal and spatial changes in vegetation NDVI in the watershed. [Results] ① Temporally, the vegetation cover in the Tingjiang River basin showed a fluctuating upward trend from 2000 to 2020, with a growth rate of 7.11% and an average rate of increase of 0.002 2/year, indicating that the ecological environment of the region was stable and continuously improving. ② Spatially, the overall medium-high and high coverage was dominant, showing a spatial distribution pattern that was lower than the surrounding area in the middle of each district and county, with significant geographical differences; the NDVI improved area was 86.33%, which was much larger than the degraded area region. ③ The driving factor detection results were: precipitation ＞ elevation ＞ temperature ＞ GDP＞ population density ＞ land use type ＞ vegetation type ＞ slope ＞ soil type. [Conclusion] Temporal and spatial variations in vegetation cover within the Tingjiang River Basin were affected by both natural and anthropogenic factors. The explanatory power of the precipitation factor was 0.705, which was the main driving factor affecting the changes in vegetation cover in the study area. Elevation, temperature, and GDP were the secondary driving factors, with explanatory powers of 0.58 or more. The interactions (q) between the factors showed higher explanatory power than the single factors, mainly in the form of a complex relationship between the enhancement and nonlinear enhancement effects of the two factors.
2024,44(4):247-256
, DOI: 10.13961/j.cnki.stbctb.2024.04.026
Abstract:
[Objective] The key ecological functional zone (KEFZ) of the Inner Mongolia Autonomous Region serves as a critical ecological barrier for the security of Northern China. The ecosystem type conversion and its impact on soil wind erosion was analysed in order to provide scientific reference for promoting ecological environment security and green development in this region. [Methods] The revised wind erosion equation (RWEQ) model based on land use, meteorology, and basic geographical information data was adopted to determine spatiotemporal changes in ecosystem structure and soil wind erosion in the KEFZ. This method revealed the impacts of ecosystem type changes on soil wind erosion. [Results] ① Substantial conversion between ecosystems in the KEFZ was observed, with a total area of change amounting to 6 019.59 km2 from 2000 to 2022. The main transformations were between grasslands and deserts, and between cultivated land and forest-grassland ecosystems. The ecosystem tended to stabilise after 2015, with a reduction in the intensity of changes across various ecosystem types. ② The average soil wind erosion modulus in the KEFZ was 56.39 t/hm2, with the erosion levels the highest in desert ecosystems, followed by grasslands, farmlands, and forests. Soil wind erosion was predominantly slight and light, mainly occurring in areas such as the Greater and Lesser Khingan Range forest ecological function area and the Horqin Grassland ecological function area. ③ The conversion between different types of ecosystems in the KEFZ resulted in a net reduction in soil wind erosion of 1.08×108 t. Ecological restoration, land reclamation, grassland quality improvement, desertification control, and the expansion of construction land decreased soil wind erosion modulus by 0.11, 0.23, 0.66, 0.84 t/hm2, and 0.68 t/hm2, respectively. [Conclusion] Strengthening the consolidation of the effectiveness of ecological management in the KEFZ and avoiding the occurrence of and new land reclamation will be conducive to the comprehensive prevention and control of desertification and high-quality development in Inner Mongolia Autonomous Region.
[Objective] The key ecological functional zone (KEFZ) of the Inner Mongolia Autonomous Region serves as a critical ecological barrier for the security of Northern China. The ecosystem type conversion and its impact on soil wind erosion was analysed in order to provide scientific reference for promoting ecological environment security and green development in this region. [Methods] The revised wind erosion equation (RWEQ) model based on land use, meteorology, and basic geographical information data was adopted to determine spatiotemporal changes in ecosystem structure and soil wind erosion in the KEFZ. This method revealed the impacts of ecosystem type changes on soil wind erosion. [Results] ① Substantial conversion between ecosystems in the KEFZ was observed, with a total area of change amounting to 6 019.59 km2 from 2000 to 2022. The main transformations were between grasslands and deserts, and between cultivated land and forest-grassland ecosystems. The ecosystem tended to stabilise after 2015, with a reduction in the intensity of changes across various ecosystem types. ② The average soil wind erosion modulus in the KEFZ was 56.39 t/hm2, with the erosion levels the highest in desert ecosystems, followed by grasslands, farmlands, and forests. Soil wind erosion was predominantly slight and light, mainly occurring in areas such as the Greater and Lesser Khingan Range forest ecological function area and the Horqin Grassland ecological function area. ③ The conversion between different types of ecosystems in the KEFZ resulted in a net reduction in soil wind erosion of 1.08×108 t. Ecological restoration, land reclamation, grassland quality improvement, desertification control, and the expansion of construction land decreased soil wind erosion modulus by 0.11, 0.23, 0.66, 0.84 t/hm2, and 0.68 t/hm2, respectively. [Conclusion] Strengthening the consolidation of the effectiveness of ecological management in the KEFZ and avoiding the occurrence of and new land reclamation will be conducive to the comprehensive prevention and control of desertification and high-quality development in Inner Mongolia Autonomous Region.
2024,44(4):257-264,393
, DOI: 10.13961/j.cnki.stbctb.2024.04.027
Abstract:
[Objective] The width, spacing, and system configuration mode of scientifically designed sand-control forest belts along the Hetian-Ruoqiang railway in areas prone to strong winds and sandstorms were analysed, in order to provide theoretical foundations for the configuration and construction of protective forest belts along the railway in sandy regions. [Methods] The configuration of a sand protection forest belt was studied using wind tunnel experiments and Haloxylon ammodendron and Calligonum mongolicum as forest tree models. [Results] When the protective forest belt spanned five rows and the gap between each belt was six times the height, a noticeable decrease in airflow was observed behind the second belt, with substantial attenuation continuing into the region behind the third sand-control forest belt. Notably, this attenuation remained consistent regardless of wind speed, highlighting its effective protective nature. Utilisation of these three forest belts resulted in enhanced protection. The protective area on the leeward side of the forest belt decreased as the wind speed increased. [Conclusion] The forest belt system employed the configuration modes of five protective forests to enhance the protective effect of the system against high wind speeds.
[Objective] The width, spacing, and system configuration mode of scientifically designed sand-control forest belts along the Hetian-Ruoqiang railway in areas prone to strong winds and sandstorms were analysed, in order to provide theoretical foundations for the configuration and construction of protective forest belts along the railway in sandy regions. [Methods] The configuration of a sand protection forest belt was studied using wind tunnel experiments and Haloxylon ammodendron and Calligonum mongolicum as forest tree models. [Results] When the protective forest belt spanned five rows and the gap between each belt was six times the height, a noticeable decrease in airflow was observed behind the second belt, with substantial attenuation continuing into the region behind the third sand-control forest belt. Notably, this attenuation remained consistent regardless of wind speed, highlighting its effective protective nature. Utilisation of these three forest belts resulted in enhanced protection. The protective area on the leeward side of the forest belt decreased as the wind speed increased. [Conclusion] The forest belt system employed the configuration modes of five protective forests to enhance the protective effect of the system against high wind speeds.
2024,44(4):265-276
, DOI: 10.13961/j.cnki.stbctb.2024.04.028
Abstract:
[Objective] In order to provide references for promoting the development of breakthrough research methods and techniques for monitoring of gully erosion, the status quo, progress, and trends of the research technologies and methods for monitoring of gully erosion in the world from 1993 to 2022 were analysed and the development trend of the research technologies and methods were summarised. [Methods] A total of 376 English language research articles from the Web of Science were selected via a bibliometric approach using the CiteSpace software for knowledge map analysis. [Results] ① Research on gully erosion shows an upward trend during 1993—2022, with a rapid development after 2013, especially in 2020 (47 articles). ② China (20.25%) and the United States (10.44%) had the highest publication outputs among the main research countries. In terms of the citation frequency, the United Kingdom (70.85 times) and Belgium (72.89 times) had the highest citation frequencies. Among the top 10 influential research institutions in this field, there were four institutions from China (Chinese Academy of Sciences, Beijing Normal University, Northwest University of Agriculture and Forestry, and China West Normal University). The most influential author is Poesen Jean, with only one Chinese scholar in the top 10 in terms of publications. ③ Co-occurrence of keywords indicated that current research on gully erosion mainly focus on the spatiotemporal distribution and changes, influencing factors, and mechanisms of gully erosion. The diversity of techniques and methods had been gradually increasing, with 2D plane measurements being replaced by 3D volumetric measurements, and the integration of multi-technology had become a new trend in the field of gully erosion. [Conclusion] The development of techniques and methods for the study of gully erosion has a bright future, emphasizing the combined use of a variety of techniques to improve the accuracy of the measurements, which is conducive to the development of the discipline.
[Objective] In order to provide references for promoting the development of breakthrough research methods and techniques for monitoring of gully erosion, the status quo, progress, and trends of the research technologies and methods for monitoring of gully erosion in the world from 1993 to 2022 were analysed and the development trend of the research technologies and methods were summarised. [Methods] A total of 376 English language research articles from the Web of Science were selected via a bibliometric approach using the CiteSpace software for knowledge map analysis. [Results] ① Research on gully erosion shows an upward trend during 1993—2022, with a rapid development after 2013, especially in 2020 (47 articles). ② China (20.25%) and the United States (10.44%) had the highest publication outputs among the main research countries. In terms of the citation frequency, the United Kingdom (70.85 times) and Belgium (72.89 times) had the highest citation frequencies. Among the top 10 influential research institutions in this field, there were four institutions from China (Chinese Academy of Sciences, Beijing Normal University, Northwest University of Agriculture and Forestry, and China West Normal University). The most influential author is Poesen Jean, with only one Chinese scholar in the top 10 in terms of publications. ③ Co-occurrence of keywords indicated that current research on gully erosion mainly focus on the spatiotemporal distribution and changes, influencing factors, and mechanisms of gully erosion. The diversity of techniques and methods had been gradually increasing, with 2D plane measurements being replaced by 3D volumetric measurements, and the integration of multi-technology had become a new trend in the field of gully erosion. [Conclusion] The development of techniques and methods for the study of gully erosion has a bright future, emphasizing the combined use of a variety of techniques to improve the accuracy of the measurements, which is conducive to the development of the discipline.
2024,44(4):277-288
, DOI: 10.13961/j.cnki.stbctb.2024.04.029
Abstract:
[Objective] The level of coordination between green development and rural revitalisation in the Sichuan-Guizhou region and influencing factors were analysed in order to provide a scientific basis for promoting green development and rural revitalisation in the western regions of China, thus facilitating the coordinated development of both aspects. [Methods] This study focused on data from 30 cities and prefectures in the Sichuan-Guizhou region for the period 2011—2020. A comprehensive indicator system for green development and rural revitalisation was developed. Coupling coordination and Tobit models were employed to analyse the coupling coordination relationships between green development and rural revitalisation and influencing factors. Heterogeneity were conducted based on regional characteristics. [Results] ① The green development index in the Sichuan-Guizhou Province fluctuated slightly because of different policy influences; differences between regions were significant. The rural revitalisation index significantly increased after implementation of the rural revitalisation strategy, and differences between regions were relatively small. ② The coupling coordination level between green development and rural revitalisation in the Sichuan-Guizhou region showed an upward trend over time. ③ Considering the impact of economic, policy, and geographical factors on the level of coordination between green development and rural revitalisation in the region, all influencing factors, except for elevation, were significant and positive. ④ Educational development, scientific and technological innovation, traffic conditions, environmental regulations, terrain slope, and elevation had significant heterogeneity in different regions. [Conclusion] The Sichuan-Guizhou region should encourage and support economic development, take note of government influence, engage in industrial structure adjustment and upgrading, continuously improve levels of education and technological innovation, enhance transportation conditions, and address environmental regulations. Tailored approaches should be implemented to enhance coordination between green development and rural revitalisation based on local conditions.
[Objective] The level of coordination between green development and rural revitalisation in the Sichuan-Guizhou region and influencing factors were analysed in order to provide a scientific basis for promoting green development and rural revitalisation in the western regions of China, thus facilitating the coordinated development of both aspects. [Methods] This study focused on data from 30 cities and prefectures in the Sichuan-Guizhou region for the period 2011—2020. A comprehensive indicator system for green development and rural revitalisation was developed. Coupling coordination and Tobit models were employed to analyse the coupling coordination relationships between green development and rural revitalisation and influencing factors. Heterogeneity were conducted based on regional characteristics. [Results] ① The green development index in the Sichuan-Guizhou Province fluctuated slightly because of different policy influences; differences between regions were significant. The rural revitalisation index significantly increased after implementation of the rural revitalisation strategy, and differences between regions were relatively small. ② The coupling coordination level between green development and rural revitalisation in the Sichuan-Guizhou region showed an upward trend over time. ③ Considering the impact of economic, policy, and geographical factors on the level of coordination between green development and rural revitalisation in the region, all influencing factors, except for elevation, were significant and positive. ④ Educational development, scientific and technological innovation, traffic conditions, environmental regulations, terrain slope, and elevation had significant heterogeneity in different regions. [Conclusion] The Sichuan-Guizhou region should encourage and support economic development, take note of government influence, engage in industrial structure adjustment and upgrading, continuously improve levels of education and technological innovation, enhance transportation conditions, and address environmental regulations. Tailored approaches should be implemented to enhance coordination between green development and rural revitalisation based on local conditions.
2024,44(4):289-297
, DOI: 10.13961/j.cnki.stbctb.2024.04.030
Abstract:
[Objective] The spatiotemporal characteristics of agricultural nonpoint source pollution in Shanxi Province during 2011—2022 were analysed and its development trends was predicted in order to provide a scientific reference for the prevention and control of agricultural non-point source pollution in the Shanxi Province. [Methods] The spatiotemporal characteristics of agricultural non-point source pollution in Shanxi Province were analysed using the pollution emission coefficient and equivalent pollution load methods, and an autoregressive integrated moving average (ARIMA) model was established to predict the development trend. [Results] ① In 2022, the agricultural non-point source pollution in Shanxi Province produced 4.74×105 t of COD (chemical oxygen demand), 5 820 t of NH3-N, 2.86×104 t of total nitrogen (TN), and 4 180 t of total phosphorus (TP). The high-emission areas were located in Lvliang and Yuncheng City, and the low-emission areas were located in Taiyuan and Yangquan City. The equivalent pollution load was 3.95×1010 m3. The primary pollutant was TN, and the primary source of pollution was animal husbandry. ② From 2011—2022, the developmental trends of the four types of pollutants were consistent. All showed an increase in fluctuation, and the highest value for each pollutant was observed in 2022. The ranking of pollutants in each region was stable, with Yuncheng and Lvliang City always occupying important positions. TN has been the primary pollutant for 12 years, animal husbandry has been the source of the primary pollutant, and the proportion was still rising. ③ By determining model parameters, the ARIMA (1,1,2) model was established for the forecast. During the forecast period, agricultural non-point source pollution in Shanxi Province decreased slightly, and the development trend showed a steady increase. [Conclusion] It is necessary to strengthen the prevention and control of key agricultural pollution accounts and pollutants, reduce the discharge of agricultural nonpoint source pollution, and mitigate its rising trend.
[Objective] The spatiotemporal characteristics of agricultural nonpoint source pollution in Shanxi Province during 2011—2022 were analysed and its development trends was predicted in order to provide a scientific reference for the prevention and control of agricultural non-point source pollution in the Shanxi Province. [Methods] The spatiotemporal characteristics of agricultural non-point source pollution in Shanxi Province were analysed using the pollution emission coefficient and equivalent pollution load methods, and an autoregressive integrated moving average (ARIMA) model was established to predict the development trend. [Results] ① In 2022, the agricultural non-point source pollution in Shanxi Province produced 4.74×105 t of COD (chemical oxygen demand), 5 820 t of NH3-N, 2.86×104 t of total nitrogen (TN), and 4 180 t of total phosphorus (TP). The high-emission areas were located in Lvliang and Yuncheng City, and the low-emission areas were located in Taiyuan and Yangquan City. The equivalent pollution load was 3.95×1010 m3. The primary pollutant was TN, and the primary source of pollution was animal husbandry. ② From 2011—2022, the developmental trends of the four types of pollutants were consistent. All showed an increase in fluctuation, and the highest value for each pollutant was observed in 2022. The ranking of pollutants in each region was stable, with Yuncheng and Lvliang City always occupying important positions. TN has been the primary pollutant for 12 years, animal husbandry has been the source of the primary pollutant, and the proportion was still rising. ③ By determining model parameters, the ARIMA (1,1,2) model was established for the forecast. During the forecast period, agricultural non-point source pollution in Shanxi Province decreased slightly, and the development trend showed a steady increase. [Conclusion] It is necessary to strengthen the prevention and control of key agricultural pollution accounts and pollutants, reduce the discharge of agricultural nonpoint source pollution, and mitigate its rising trend.
2024,44(4):298-308
, DOI: 10.13961/j.cnki.stbctb.2024.04.031
Abstract:
[Objective] The water and sediment changes in small and medium-sized rivers under the influence of human activities were analysed to provide scientific support for soil and water conservation and waterway water and sediment management in the watersheds. [Methods] The influence of landscape patterns on water and sediment changes in the basins was analysed based on water and sediment data and land use of the Nanliu and Qinjiang River basins from 1965 to 2021 using the landscape index, water-sediment mutation test, and other methods. [Results] ① Runoff and sediment transport in the Nanliu and Qinjiang River basins showed a gradual downward trend. The decreasing trend of sediment transport was more evident than that of runoff, and sudden change points in both runoff and sediment transport occurred in the 00s of the 21st century. ② The proportion of forestland in the Qinjiang River basin increased from 38% in 1990 to 41.6% in 2020, and the transfer area of cultivated land to forestland in the Nanliujiang River gradually increased. The policy of returning farmland to forests was effective, and the water-sediment change also showed a trend of gradual reduction. ③ The water-sediment changes in the two watersheds were negatively correlated with the degree of landscape fragmentation and positively correlated with the degree of patch aggregation. [Conclusion] In general, the land-use change within the Nanliu and Qinjiang River basins remained stable, and the water-sediment change was more obviously affected by land-use change; therefore, the relevant departments should strengthen the protection and management of eco-lands. Excessive interference of landscape patterns by human activities should be avoided, and landscape spatial configurations should be rationally planned to prevent soil erosion.
[Objective] The water and sediment changes in small and medium-sized rivers under the influence of human activities were analysed to provide scientific support for soil and water conservation and waterway water and sediment management in the watersheds. [Methods] The influence of landscape patterns on water and sediment changes in the basins was analysed based on water and sediment data and land use of the Nanliu and Qinjiang River basins from 1965 to 2021 using the landscape index, water-sediment mutation test, and other methods. [Results] ① Runoff and sediment transport in the Nanliu and Qinjiang River basins showed a gradual downward trend. The decreasing trend of sediment transport was more evident than that of runoff, and sudden change points in both runoff and sediment transport occurred in the 00s of the 21st century. ② The proportion of forestland in the Qinjiang River basin increased from 38% in 1990 to 41.6% in 2020, and the transfer area of cultivated land to forestland in the Nanliujiang River gradually increased. The policy of returning farmland to forests was effective, and the water-sediment change also showed a trend of gradual reduction. ③ The water-sediment changes in the two watersheds were negatively correlated with the degree of landscape fragmentation and positively correlated with the degree of patch aggregation. [Conclusion] In general, the land-use change within the Nanliu and Qinjiang River basins remained stable, and the water-sediment change was more obviously affected by land-use change; therefore, the relevant departments should strengthen the protection and management of eco-lands. Excessive interference of landscape patterns by human activities should be avoided, and landscape spatial configurations should be rationally planned to prevent soil erosion.
2024,44(4):309-320
, DOI: 10.13961/j.cnki.stbctb.2024.04.032
Abstract:
[Objective] The spatiotemporal trends of surface water areas, evolution of surface water spatial patterns in typical wetlands, and imaging factors in the cities of the Beijing-Tianjin-Hebei region from 2000 to 2021 were analysed in order to provide scientific references for the protection, rational development, and utilisation of water resources in the region. [Methods] This study utilised the JRC global surface water dataset to identify surface water variations in Beijing-Tianjin-Hebei region from 2000 to 2021. We examined the spatiotemporal trends in surface water and morphological evolution within the Baiyangdian and Qilihai wetlands using morphological spatial pattern analysis (MSPA). Correlation analyses incorporating climatic and anthropogenic factors had identified the drivers of these spatiotemporal changes. [Results] ① During 2000—2021, from a temporal perspective, a notable decline occurred in the area of permanent water bodies across the Beijing-Tianjin-Hebei region, which was contrasted by a consistent increase in seasonal water bodies. In terms of spatial distribution, the reduction in surface water area was primarily concentrated in the metropolitan areas of Beijing, Tianjin, and Langfang City. Conversely, cities along the South-North Water Diversion central route, such as Handan, Xingtai, and Shijiazhuang City, experienced an increasing trend in surface water area, indicating a directional shift towards increased water resource availability. ② The surface water area of the core wetland of Baiyangdian gradually decreased from 2000 to 2005 and began to gradually increase after 2005. The core wetland area of Qilihai gradually decreased from 2000 to 2010 and gradually increased after 2010. ③ The maximum water body area in the southern cities of Beijing-Tianjin-Hebei was positively correlated with precipitation, whereas the eastern coastal cities were negatively correlated. This indicated an imbalance between human activities and natural recharge. A significant positive correlation was observed between water consumption and maximum surface water area in Beijing, Chengde, and Tangshan City, indicating a greater influence of cross-basin water transfer and ecological recharge. In contrast, Qinhuangdao and Tianjin City showed highly significant negative correlations, indicating that the over-exploitation of groundwater had a negative impact on surface water resources. [Conclusion] Changes in surface water area are significantly affected by climate and human activities. In the future, the Beijing-Tianjin-Hebei region should effectively protect surface water resources through inter-basin water transfers, water conservation campaigns, ecological restoration, and reduction of groundwater extraction to cope with the impacts of climate and human activities.
[Objective] The spatiotemporal trends of surface water areas, evolution of surface water spatial patterns in typical wetlands, and imaging factors in the cities of the Beijing-Tianjin-Hebei region from 2000 to 2021 were analysed in order to provide scientific references for the protection, rational development, and utilisation of water resources in the region. [Methods] This study utilised the JRC global surface water dataset to identify surface water variations in Beijing-Tianjin-Hebei region from 2000 to 2021. We examined the spatiotemporal trends in surface water and morphological evolution within the Baiyangdian and Qilihai wetlands using morphological spatial pattern analysis (MSPA). Correlation analyses incorporating climatic and anthropogenic factors had identified the drivers of these spatiotemporal changes. [Results] ① During 2000—2021, from a temporal perspective, a notable decline occurred in the area of permanent water bodies across the Beijing-Tianjin-Hebei region, which was contrasted by a consistent increase in seasonal water bodies. In terms of spatial distribution, the reduction in surface water area was primarily concentrated in the metropolitan areas of Beijing, Tianjin, and Langfang City. Conversely, cities along the South-North Water Diversion central route, such as Handan, Xingtai, and Shijiazhuang City, experienced an increasing trend in surface water area, indicating a directional shift towards increased water resource availability. ② The surface water area of the core wetland of Baiyangdian gradually decreased from 2000 to 2005 and began to gradually increase after 2005. The core wetland area of Qilihai gradually decreased from 2000 to 2010 and gradually increased after 2010. ③ The maximum water body area in the southern cities of Beijing-Tianjin-Hebei was positively correlated with precipitation, whereas the eastern coastal cities were negatively correlated. This indicated an imbalance between human activities and natural recharge. A significant positive correlation was observed between water consumption and maximum surface water area in Beijing, Chengde, and Tangshan City, indicating a greater influence of cross-basin water transfer and ecological recharge. In contrast, Qinhuangdao and Tianjin City showed highly significant negative correlations, indicating that the over-exploitation of groundwater had a negative impact on surface water resources. [Conclusion] Changes in surface water area are significantly affected by climate and human activities. In the future, the Beijing-Tianjin-Hebei region should effectively protect surface water resources through inter-basin water transfers, water conservation campaigns, ecological restoration, and reduction of groundwater extraction to cope with the impacts of climate and human activities.
2024,44(4):321-329
, DOI: 10.13961/j.cnki.stbctb.2024.04.033
Abstract:
[Objective] The characteristics and influencing factors of cultivated land changes in the Yellow River alluvial area of Southwest Shandong Province were analysed order to provide a scientific basis for regional cultivated land protection. [Methods] Using 2 m high-resolution remote sensing images and data from the ‘Heze statistical yearbook’, various methods including remote sensing interpretation, centre of gravity model, cold and hot spot analysis, and geographical detector were used to analyse land change characteristics and influencing factors of cultivated land in the Yellow River alluvial area of Southwest Shandong from 2019 to 2022. [Results] ① During 2019—2022, the arable land in the Yellow River alluvial area of Southwest Shandong Province accounts for more than 60% of the area, and there was annual cultivated land loss in the studied region, with a decreasing trend year by year. The arable land area in Yuncheng County decreased the most, reaching 18.28 km2, and farmland dynamic attitude in Juancheng County changed the most, reaching -2.26%. The centre of gravity of cultivated land migrated to the Southwest and Northeast of Shandong Province. ② The outflow area of cultivated land was higher than that of the inflow area, and the main outflow and inflow directions were both construction and forest land. The area with the most concentrated cultivated land change was mainly distributed in the southern part of Caoxian County. ③ The single factors affecting the change in cultivated land were mainly rural employees (X5); the two-factor interactive combination was mainly the intersection of the number of rural labour resources (X4) and the per capita income of urban residents (X6). [Conclusion] The loss of cultivated land in the Yellow River alluvial area of Southwest Shandong Province from 2019 to 2022 is the result of the comprehensive effect of multiple factors based on economic and social factors.
[Objective] The characteristics and influencing factors of cultivated land changes in the Yellow River alluvial area of Southwest Shandong Province were analysed order to provide a scientific basis for regional cultivated land protection. [Methods] Using 2 m high-resolution remote sensing images and data from the ‘Heze statistical yearbook’, various methods including remote sensing interpretation, centre of gravity model, cold and hot spot analysis, and geographical detector were used to analyse land change characteristics and influencing factors of cultivated land in the Yellow River alluvial area of Southwest Shandong from 2019 to 2022. [Results] ① During 2019—2022, the arable land in the Yellow River alluvial area of Southwest Shandong Province accounts for more than 60% of the area, and there was annual cultivated land loss in the studied region, with a decreasing trend year by year. The arable land area in Yuncheng County decreased the most, reaching 18.28 km2, and farmland dynamic attitude in Juancheng County changed the most, reaching -2.26%. The centre of gravity of cultivated land migrated to the Southwest and Northeast of Shandong Province. ② The outflow area of cultivated land was higher than that of the inflow area, and the main outflow and inflow directions were both construction and forest land. The area with the most concentrated cultivated land change was mainly distributed in the southern part of Caoxian County. ③ The single factors affecting the change in cultivated land were mainly rural employees (X5); the two-factor interactive combination was mainly the intersection of the number of rural labour resources (X4) and the per capita income of urban residents (X6). [Conclusion] The loss of cultivated land in the Yellow River alluvial area of Southwest Shandong Province from 2019 to 2022 is the result of the comprehensive effect of multiple factors based on economic and social factors.
2024,44(4):330-339
, DOI: 10.13961/j.cnki.stbctb.2024.04.034
Abstract:
[Objective] The spatial patterns and driving factors of the frequency of land-use dynamic transfer changes in Guizhou Province were analysed in order provide theoretical references for land survey work and related policies in the region. [Methods] Based on the land-use data of Guizhou Province from 2000 to 2020, the spatial and temporal distribution characteristics of the frequency of land-use change in Guizhou Province were analysed using land-use change frequency statistics, kernel density analysis, and spatial autocorrelation, and the influencing factors were studied using geographic probes. [Results] ① The area of land changed in the land use change frequency in Guizhou Province from 2000 to 2020 was only 2%, but the inputs of capital and manpower were relatively high; as a result, there was a relationship between the two inputs and discordance. ② The land that changed in land-use change frequency in Guizhou Province from 2000 to 2020 had significant spatial heterogeneity in spatial distribution. ③ The kernel density of changed land in Guizhou Province from 2000 to 2020 showed the distribution characteristic of “higher in the west and lower in the east”, with the distribution density of one land change being the largest and the distribution density of three land changes being the smallest. ④ In 2000 to 2020, both changed and unchanged land in Guizhou Province showed significant spatial agglomeration characteristics, with changed hotspots in areas such as, Hezhang, and Dafang and unchanged hotspots in areas such as Xianning and Congjiang area. ⑤ The results of the interaction detection of the driving factors of land-use change frequency in Guizhou Province from 2000 to 2020 showed that the interaction of slope and slope direction had the strongest explanatory power for the spatial variation in land-use change frequency in Guizhou Province. [Conclusion] An obvious spatial heterogeneity exists in the distribution of land-use change frequency in Guizhou Province. A mechanism to regulate the frequency of land-use change in Guizhou Province should be established to realise the effective use of social resources and reduce the financial burden on society.
[Objective] The spatial patterns and driving factors of the frequency of land-use dynamic transfer changes in Guizhou Province were analysed in order provide theoretical references for land survey work and related policies in the region. [Methods] Based on the land-use data of Guizhou Province from 2000 to 2020, the spatial and temporal distribution characteristics of the frequency of land-use change in Guizhou Province were analysed using land-use change frequency statistics, kernel density analysis, and spatial autocorrelation, and the influencing factors were studied using geographic probes. [Results] ① The area of land changed in the land use change frequency in Guizhou Province from 2000 to 2020 was only 2%, but the inputs of capital and manpower were relatively high; as a result, there was a relationship between the two inputs and discordance. ② The land that changed in land-use change frequency in Guizhou Province from 2000 to 2020 had significant spatial heterogeneity in spatial distribution. ③ The kernel density of changed land in Guizhou Province from 2000 to 2020 showed the distribution characteristic of “higher in the west and lower in the east”, with the distribution density of one land change being the largest and the distribution density of three land changes being the smallest. ④ In 2000 to 2020, both changed and unchanged land in Guizhou Province showed significant spatial agglomeration characteristics, with changed hotspots in areas such as, Hezhang, and Dafang and unchanged hotspots in areas such as Xianning and Congjiang area. ⑤ The results of the interaction detection of the driving factors of land-use change frequency in Guizhou Province from 2000 to 2020 showed that the interaction of slope and slope direction had the strongest explanatory power for the spatial variation in land-use change frequency in Guizhou Province. [Conclusion] An obvious spatial heterogeneity exists in the distribution of land-use change frequency in Guizhou Province. A mechanism to regulate the frequency of land-use change in Guizhou Province should be established to realise the effective use of social resources and reduce the financial burden on society.
2024,44(4):340-351,361
, DOI: 10.13961/j.cnki.stbctb.2024.04.035
Abstract:
[Objective] As a unique mountainous ecological hot spot in Inner Mongolia Autonomous Region, the response relationship of land circulation and intensity to ecosystem service function was studied to provide theoretical basis for scientific allocation of land use pattern and ecological sustainable development in Daxinganling. [Methods] Based on five remote sensing images captured from 1990 to 2022, this study comprehensively applied the InVEST-CASA and four-quadrangle models to assess changes in five typical ecological service functions (habitat quality, carbon storage, water conservation, soil conservation, and the net primary productivity of vegetation) at the county scale. The correlation between the temporal and spatial evolution of land use intensity and ecosystem service function was studied. [Results] ① From 1990 to 2022, the land use pattern of the study area was stable, and farmland, grassland, and woodland (natural forest and plantation forest) were the main land types in the Daxinganling Mountains of Inner Mongolia. ② Ecosystem service function showed a trend of slower degradation in the north and lower degradation in the south, the habitat quality and soil conservation decreased annually, the water production and the net primary productivity of vegetation declined in a fluctuating manner, and the growth rate of carbon storage slowed down. ③ Owing to the change in the land use pattern and the increase in land use intensity, there was a negative correlation between the comprehensive value of ecosystem service function and land use intensity, and counties affected by this change were mainly distributed in the southeastern region of the study area. [Conclusion] There was evident spatial and temporal heterogeneity in ecosystem services in the Greater Khingan Mountains of Inner Mongolia, and rational optimization of land use patterns can effectively improve ecosystem services in this area.
[Objective] As a unique mountainous ecological hot spot in Inner Mongolia Autonomous Region, the response relationship of land circulation and intensity to ecosystem service function was studied to provide theoretical basis for scientific allocation of land use pattern and ecological sustainable development in Daxinganling. [Methods] Based on five remote sensing images captured from 1990 to 2022, this study comprehensively applied the InVEST-CASA and four-quadrangle models to assess changes in five typical ecological service functions (habitat quality, carbon storage, water conservation, soil conservation, and the net primary productivity of vegetation) at the county scale. The correlation between the temporal and spatial evolution of land use intensity and ecosystem service function was studied. [Results] ① From 1990 to 2022, the land use pattern of the study area was stable, and farmland, grassland, and woodland (natural forest and plantation forest) were the main land types in the Daxinganling Mountains of Inner Mongolia. ② Ecosystem service function showed a trend of slower degradation in the north and lower degradation in the south, the habitat quality and soil conservation decreased annually, the water production and the net primary productivity of vegetation declined in a fluctuating manner, and the growth rate of carbon storage slowed down. ③ Owing to the change in the land use pattern and the increase in land use intensity, there was a negative correlation between the comprehensive value of ecosystem service function and land use intensity, and counties affected by this change were mainly distributed in the southeastern region of the study area. [Conclusion] There was evident spatial and temporal heterogeneity in ecosystem services in the Greater Khingan Mountains of Inner Mongolia, and rational optimization of land use patterns can effectively improve ecosystem services in this area.
2024,44(4):352-361
, DOI: 10.13961/j.cnki.stbctb.2024.04.036
Abstract:
[Objective] The spatial distribution patterns and influencing processes of soil pH value in typical industrial and mining areas in the Southern Taihang Mountains were analyzed, to provide scientific support for soil environmental quality assessments and pollution prevention strategies in the complex environment of this area, comprising typical industrial and mining activities. [Methods] Studying the Manghe watershed in industrial and mining areas of the Southern Taihang Mountains, 121 topsoil (0—20 cm) and auxiliary samples were collected. “3S” technology, geostatistics, geographical detectors, and other model methods were comprehensively applied to study the spatial distribution characteristics and factors influencing topsoil pH value in the research area. [Results] The soil pH value in the study area ranged from 6.40 to 8.53, with a mean value of 7.82, which was lower than the background value of the Henan section of the Yellow River basin (8.46). Compared with previous studies, the average soil pH value decreased, indicating a trend of soil acidification. Soil pH value showed weak spatial variation and was significantly influenced by factors such as terrain. When the interval distance between sites was less than 1 905 m, the spatial distribution was continuous and exhibited strong spatial autocorrelation. The spatial interpolation effect of soil pH value based on empirical Bayesian Kriging was better, and the spatial distribution of soil pH value showed an increasing gradient from the central and western regions to the northeast and south. Low-value areas were mainly located in the valleys and piedmont plains in the central and western regions. The explanatory power of individual factors on pH value was unclear; however, the superposition of slope direction, land use, and other factors significantly enhanced the explanation of the spatial distribution of soil pH value in the watershed. [Conclusion] The superposition of multiple factors, such as natural conditions and human activities, were the main drivers explaining the spatial distribution of regional soil pH value and should be the focus of regional soil environmental assessments and pollution remediation efforts.
[Objective] The spatial distribution patterns and influencing processes of soil pH value in typical industrial and mining areas in the Southern Taihang Mountains were analyzed, to provide scientific support for soil environmental quality assessments and pollution prevention strategies in the complex environment of this area, comprising typical industrial and mining activities. [Methods] Studying the Manghe watershed in industrial and mining areas of the Southern Taihang Mountains, 121 topsoil (0—20 cm) and auxiliary samples were collected. “3S” technology, geostatistics, geographical detectors, and other model methods were comprehensively applied to study the spatial distribution characteristics and factors influencing topsoil pH value in the research area. [Results] The soil pH value in the study area ranged from 6.40 to 8.53, with a mean value of 7.82, which was lower than the background value of the Henan section of the Yellow River basin (8.46). Compared with previous studies, the average soil pH value decreased, indicating a trend of soil acidification. Soil pH value showed weak spatial variation and was significantly influenced by factors such as terrain. When the interval distance between sites was less than 1 905 m, the spatial distribution was continuous and exhibited strong spatial autocorrelation. The spatial interpolation effect of soil pH value based on empirical Bayesian Kriging was better, and the spatial distribution of soil pH value showed an increasing gradient from the central and western regions to the northeast and south. Low-value areas were mainly located in the valleys and piedmont plains in the central and western regions. The explanatory power of individual factors on pH value was unclear; however, the superposition of slope direction, land use, and other factors significantly enhanced the explanation of the spatial distribution of soil pH value in the watershed. [Conclusion] The superposition of multiple factors, such as natural conditions and human activities, were the main drivers explaining the spatial distribution of regional soil pH value and should be the focus of regional soil environmental assessments and pollution remediation efforts.
2024,44(4):362-370
, DOI: 10.13961/j.cnki.stbctb.20240719.002
Abstract:
[Objective] The factors and mechanisms influencing the evolution of groundwater flow fields were analysed to provide a theoretical basis for the sustainable utilisation of groundwater resources in the study area. [Methods] Using geostatistics, the projection pursuit regression technique, and other research methods, the impacts of precipitation changes and human activities on the evolution of groundwater systems in six basins in Shanxi Province were analysed. [Results] ① Precipitation showed a linear correlation with fluctuations in the groundwater levels. For every 100 mm increase in precipitation, the groundwater levels in the Taiyuan, Yuncheng, Datong, Xinzhou, Linfen, and Changzhi basins decreased by 0.45, 0.46, 0.20, 0.28, 0.22, 0.73 m respectively. ② Groundwater levels showed a linear correlation with the variations in groundwater storage. For every increase of 1.00×108 m3 in groundwater overexploitation volume, the average groundwater levels in the Yuncheng, Taiyuan, Datong, Xinzhou, Linfen, and Changzhi basins decreased by 0.18, 0.36, 0.25, 0.55, 0.40, 2.0 m respectively. ③ The contributions of the different factors affecting groundwater resources vary significantly across different regions. Precipitation was the primary factor affecting the groundwater resources, with a contribution rate exceeding 40% in all areas. In the Yuncheng and Datong basins, land changes caused by cultivation were the second most influencing factor, with a contribution rate of 22.55%. In the Taiyuan, Xinzhou, Linfen, and Changzhi basins, land changes caused by construction were the second most influencing factor, with contribution rates of 19.12%, 17.57%, 16.56%, and 22.43%, respectively. [Conclusion] ① Artificial rainfall can be conducted in a timely manner to increase precipitation and groundwater recharge, thereby slowing the rate of groundwater level decline. ② In areas experiencing groundwater overextraction, groundwater extraction should be appropriately reduced and efforts should be made to increase the groundwater system storage capacity to gradually restore groundwater levels. ③ Effective measures should be taken to restrain the continuous decrease and rapid expansion of cultivated and construction lands, respectively, thereby reducing the impact of land change due to land use types on groundwater resources.
[Objective] The factors and mechanisms influencing the evolution of groundwater flow fields were analysed to provide a theoretical basis for the sustainable utilisation of groundwater resources in the study area. [Methods] Using geostatistics, the projection pursuit regression technique, and other research methods, the impacts of precipitation changes and human activities on the evolution of groundwater systems in six basins in Shanxi Province were analysed. [Results] ① Precipitation showed a linear correlation with fluctuations in the groundwater levels. For every 100 mm increase in precipitation, the groundwater levels in the Taiyuan, Yuncheng, Datong, Xinzhou, Linfen, and Changzhi basins decreased by 0.45, 0.46, 0.20, 0.28, 0.22, 0.73 m respectively. ② Groundwater levels showed a linear correlation with the variations in groundwater storage. For every increase of 1.00×108 m3 in groundwater overexploitation volume, the average groundwater levels in the Yuncheng, Taiyuan, Datong, Xinzhou, Linfen, and Changzhi basins decreased by 0.18, 0.36, 0.25, 0.55, 0.40, 2.0 m respectively. ③ The contributions of the different factors affecting groundwater resources vary significantly across different regions. Precipitation was the primary factor affecting the groundwater resources, with a contribution rate exceeding 40% in all areas. In the Yuncheng and Datong basins, land changes caused by cultivation were the second most influencing factor, with a contribution rate of 22.55%. In the Taiyuan, Xinzhou, Linfen, and Changzhi basins, land changes caused by construction were the second most influencing factor, with contribution rates of 19.12%, 17.57%, 16.56%, and 22.43%, respectively. [Conclusion] ① Artificial rainfall can be conducted in a timely manner to increase precipitation and groundwater recharge, thereby slowing the rate of groundwater level decline. ② In areas experiencing groundwater overextraction, groundwater extraction should be appropriately reduced and efforts should be made to increase the groundwater system storage capacity to gradually restore groundwater levels. ③ Effective measures should be taken to restrain the continuous decrease and rapid expansion of cultivated and construction lands, respectively, thereby reducing the impact of land change due to land use types on groundwater resources.
2024,44(4):371-382
, DOI: 10.13961/j.cnki.stbctb.20240715.001
Abstract:
[Objective] The study of river ecological water demand in the southern mountain area of Jinan City, Shandong Province based on ecohydrological variation characteristics was carried out to provide theoretical basis for regional water resources integrated management and ecological protection, strengthening ecological protection, and promoting sustainable development of the Yellow River basin. [Methods] The runoff data from Gushan station (Beidasha River) and Wohushan station (Yufu River) in the southern mountainous area of Jinan, located in the lower reaches of the Yellow River, were collected for the period 1979 to 2021. The study utilized the cumulative anomaly method, Mann-Kendall (M-K) test method, sliding T-test method, and double accumulation curve method to analyse abrupt changes in runoff. The IHA-RVA method was additionally used to examine variations in river runoff and ecological water demand. By comparing the rivers’ satisfaction with ecological water demand, this paper investigated key factors influencing the regional ecohydrology and variations in ecological water demand while proposing protective measures to ensure adequate supply within the study area. [Results] The runoff mutation points of Beidasha River and Yufu River were observed in 1996, and the overall hydrological alteration degrees were determined to be 72.75% and 69.42%, respectively, indicating significant alterations in both rivers. The annual ecological water demand of Beidasha River and Yufu River was 1.47×106 m3 and 1.81×106 m3, respectively. Overall, the monthly ecological water demand satisfaction of the Beidasha River and Yufu River was 32.35% and 60.42% on average, respectively. [Conclusion] The hydrological variation in the southern mountainous area of Jinan was found to be large before and after the mutation, and the overall satisfaction of the ecological water demand was relatively low. The ecological water demand of rivers may be guaranteed by strengthening the ecological regulation of rivers and improving the efficiency of water resource utilisation.
[Objective] The study of river ecological water demand in the southern mountain area of Jinan City, Shandong Province based on ecohydrological variation characteristics was carried out to provide theoretical basis for regional water resources integrated management and ecological protection, strengthening ecological protection, and promoting sustainable development of the Yellow River basin. [Methods] The runoff data from Gushan station (Beidasha River) and Wohushan station (Yufu River) in the southern mountainous area of Jinan, located in the lower reaches of the Yellow River, were collected for the period 1979 to 2021. The study utilized the cumulative anomaly method, Mann-Kendall (M-K) test method, sliding T-test method, and double accumulation curve method to analyse abrupt changes in runoff. The IHA-RVA method was additionally used to examine variations in river runoff and ecological water demand. By comparing the rivers’ satisfaction with ecological water demand, this paper investigated key factors influencing the regional ecohydrology and variations in ecological water demand while proposing protective measures to ensure adequate supply within the study area. [Results] The runoff mutation points of Beidasha River and Yufu River were observed in 1996, and the overall hydrological alteration degrees were determined to be 72.75% and 69.42%, respectively, indicating significant alterations in both rivers. The annual ecological water demand of Beidasha River and Yufu River was 1.47×106 m3 and 1.81×106 m3, respectively. Overall, the monthly ecological water demand satisfaction of the Beidasha River and Yufu River was 32.35% and 60.42% on average, respectively. [Conclusion] The hydrological variation in the southern mountainous area of Jinan was found to be large before and after the mutation, and the overall satisfaction of the ecological water demand was relatively low. The ecological water demand of rivers may be guaranteed by strengthening the ecological regulation of rivers and improving the efficiency of water resource utilisation.
2024,44(4):383-393
, DOI: 10.13961/j.cnki.stbctb.2024.04.039
Abstract:
[Objective] The topographic characteristics of abandoned farmland in mountainous areas were analysed in order to provide a scientific reference for regional land resource management and sustainable agricultural development. [Methods] Taking Wushan County of Chongqing City as the research area, this study used Landsat TM/ETM+/OLI and Sentinel-2 data on the Google Earth Engine (GEE) cloud platform and adopted decision tree and time series normalised difference vegetation index (NDVI) change detection methods. We extracted and analysed abandoned land information from the study area from 2017 to 2021. [Results] ① From the perspective of time series characteristics, the area of abandoned land in the study area showed an overall upward trend; the increase from 2017 to 2021 was 2 123.50 hm2, with a growth rate of 19.61%, and the curve shape within the interval showed a “W” shaped characteristic. Spatially, abandoned land was regionally dispersed and locally concentrated. It was mainly distributed along the direction of the water system, significantly concentrated on both sides of the river, and surrounded by sloping farmlands. ② The abandoned land in the study area was distributed differently across different elevation and slope zones. The abandoned land was concentrated at elevations below 1 000 m and slopes within a range of 5°~20°. In areas with an elevation below 1 500 m, the area of abandoned land and rate of abandonment showed a pattern of “first increasing and then decreasing,” reaching the highest point in 2019; in areas with an elevation above 1 500 m, the area of abandoned land and the rate of abandonment showed a pattern of “first decreasing and then increasing” over time. The law of “increase” reached its lowest value in 2020. ③ The distribution index of abandoned land under different terrain levels was continuously decreasing, and the distribution index of terrain gradients 1 and 2 was greater than 1, indicating the dominant area of abandoned land. [Conclusion] The combination of a decision tree and NDVI time series change detection methods can accurately identify abandoned land with a recognition accuracy of 83.59%.
[Objective] The topographic characteristics of abandoned farmland in mountainous areas were analysed in order to provide a scientific reference for regional land resource management and sustainable agricultural development. [Methods] Taking Wushan County of Chongqing City as the research area, this study used Landsat TM/ETM+/OLI and Sentinel-2 data on the Google Earth Engine (GEE) cloud platform and adopted decision tree and time series normalised difference vegetation index (NDVI) change detection methods. We extracted and analysed abandoned land information from the study area from 2017 to 2021. [Results] ① From the perspective of time series characteristics, the area of abandoned land in the study area showed an overall upward trend; the increase from 2017 to 2021 was 2 123.50 hm2, with a growth rate of 19.61%, and the curve shape within the interval showed a “W” shaped characteristic. Spatially, abandoned land was regionally dispersed and locally concentrated. It was mainly distributed along the direction of the water system, significantly concentrated on both sides of the river, and surrounded by sloping farmlands. ② The abandoned land in the study area was distributed differently across different elevation and slope zones. The abandoned land was concentrated at elevations below 1 000 m and slopes within a range of 5°~20°. In areas with an elevation below 1 500 m, the area of abandoned land and rate of abandonment showed a pattern of “first increasing and then decreasing,” reaching the highest point in 2019; in areas with an elevation above 1 500 m, the area of abandoned land and the rate of abandonment showed a pattern of “first decreasing and then increasing” over time. The law of “increase” reached its lowest value in 2020. ③ The distribution index of abandoned land under different terrain levels was continuously decreasing, and the distribution index of terrain gradients 1 and 2 was greater than 1, indicating the dominant area of abandoned land. [Conclusion] The combination of a decision tree and NDVI time series change detection methods can accurately identify abandoned land with a recognition accuracy of 83.59%.
2024,44(4):394-404
, DOI: 10.13961/j.cnki.stbctb.2024.04.040
Abstract:
[Objective] The spatio-temporal evolution and spatial differentiation of cultivated land pressure in the agro-pastoral ecotone of Northern China was analysed, in order to provide reference for the future strategic layout of food security development in this ecotone in Northern China. [Methods] The status of cultivated land resources in the northern agro-pastoral ecotone was analysed between 2000 and 2023 using the modified cultivated land pressure index mode. Thereafter, the study area was subdivided, and the spatiotemporal development trend of cultivated land pressure was analysed. The future change in cultivated land pressure was calculated using the prediction model, and corresponding countermeasures and suggestions were proposed. [Results] ① In general, the cultivated land pressure in the northern agro-pastoral ecotone increased, showing a “W” shape change in time series. The spatial pattern showed an “overall” alert and local stable situation, and the pressure centre of gravity migrated towards the southwest with time. ② The heterogeneity of regional cultivated land pressure showed a gradual trend of differentiation. Further, the heterogeneity was influenced by the development of regional functions and industrial structure and showed a gradual but evident trend in the time pattern. The spatial pattern distribution showed that the desertification area along the Great Wall was stable for a long time, the loess hilly gully area was gradually rising, and the Beijing-Tianjin-Hebei water conservation area was gently declining. In the next 7 years, the pressure of cultivated land in the northern agricultural and pastoral ecotone will show an overall increase, posing a certain threat to food security and regional development, which needs to be protected and paid attention to by relevant departments. [Conclusion] The cultivated land pressure in the northern agro-pastoral ecotone zone is on the rise in general, and the regional differences are gradually obvious. In the future, it is necessary to improve the land fertility and environmental political ability of the whole cultivated land, and carry out the compensation mechanism of cross-regional cultivated land protection.
[Objective] The spatio-temporal evolution and spatial differentiation of cultivated land pressure in the agro-pastoral ecotone of Northern China was analysed, in order to provide reference for the future strategic layout of food security development in this ecotone in Northern China. [Methods] The status of cultivated land resources in the northern agro-pastoral ecotone was analysed between 2000 and 2023 using the modified cultivated land pressure index mode. Thereafter, the study area was subdivided, and the spatiotemporal development trend of cultivated land pressure was analysed. The future change in cultivated land pressure was calculated using the prediction model, and corresponding countermeasures and suggestions were proposed. [Results] ① In general, the cultivated land pressure in the northern agro-pastoral ecotone increased, showing a “W” shape change in time series. The spatial pattern showed an “overall” alert and local stable situation, and the pressure centre of gravity migrated towards the southwest with time. ② The heterogeneity of regional cultivated land pressure showed a gradual trend of differentiation. Further, the heterogeneity was influenced by the development of regional functions and industrial structure and showed a gradual but evident trend in the time pattern. The spatial pattern distribution showed that the desertification area along the Great Wall was stable for a long time, the loess hilly gully area was gradually rising, and the Beijing-Tianjin-Hebei water conservation area was gently declining. In the next 7 years, the pressure of cultivated land in the northern agricultural and pastoral ecotone will show an overall increase, posing a certain threat to food security and regional development, which needs to be protected and paid attention to by relevant departments. [Conclusion] The cultivated land pressure in the northern agro-pastoral ecotone zone is on the rise in general, and the regional differences are gradually obvious. In the future, it is necessary to improve the land fertility and environmental political ability of the whole cultivated land, and carry out the compensation mechanism of cross-regional cultivated land protection.
2024,44(4):405-415
, DOI: 10.13961/j.cnki.stbctb.2024.04.041
Abstract:
[Objective] To assess how farmers’ participation in soil conservation programs affects their welfare, to provide theoretical support for the sustainable development of regional soil conservation. [Methods] We selected counties involved in soil and water conservation projects within the Three Gorges Reservoir area and constructed a welfare evaluation index system based on capability theory. We explored how farmers’ participation in such projects affects their welfare using methods including propensity score matching, fuzzy comprehensive evaluation and quantile regression. [Results] ① After participating in soil and water conservation programs, the welfare indices of the farming and living environments were 0.523 and 0.614, respectively. The happiness index of resident farmers was high, and subjective well-being indices, such as income satisfaction, were above 0.5. ② A marked difference in welfare outcomes was identified between farmers that participated in soil and water conservation and those who did not, with the total fuzzy welfare index of participating farmers being greater than that of non-participating farmers. ③ Soil conservation projects comprehensively improved the welfare level of farmers from economic, social and ecological perspectives, with a welfare effect of 2.75%—2.80%. ④ The overall welfare level of farmers’ families increased with an increasing extent of their participation in soil and water conservation projects. The total welfare generated by farmers’ spontaneous soil conservation behaviours was greater than that generated by government-guided soil and water conservation initiatives, although government-guided welfare was more significant in terms of crop yield and farming environments. Cultivated land area was the main factor affecting farmers’ participation in soil conservation welfare. [Conclusion] The promotion and training of soil conservation interventions should be strengthened, and regional characteristics should be considered when implementing soil and water conservation measures, so as to improve farmers’ participation in such projects and ensure that more farmers benefit from these conservation measures.
[Objective] To assess how farmers’ participation in soil conservation programs affects their welfare, to provide theoretical support for the sustainable development of regional soil conservation. [Methods] We selected counties involved in soil and water conservation projects within the Three Gorges Reservoir area and constructed a welfare evaluation index system based on capability theory. We explored how farmers’ participation in such projects affects their welfare using methods including propensity score matching, fuzzy comprehensive evaluation and quantile regression. [Results] ① After participating in soil and water conservation programs, the welfare indices of the farming and living environments were 0.523 and 0.614, respectively. The happiness index of resident farmers was high, and subjective well-being indices, such as income satisfaction, were above 0.5. ② A marked difference in welfare outcomes was identified between farmers that participated in soil and water conservation and those who did not, with the total fuzzy welfare index of participating farmers being greater than that of non-participating farmers. ③ Soil conservation projects comprehensively improved the welfare level of farmers from economic, social and ecological perspectives, with a welfare effect of 2.75%—2.80%. ④ The overall welfare level of farmers’ families increased with an increasing extent of their participation in soil and water conservation projects. The total welfare generated by farmers’ spontaneous soil conservation behaviours was greater than that generated by government-guided soil and water conservation initiatives, although government-guided welfare was more significant in terms of crop yield and farming environments. Cultivated land area was the main factor affecting farmers’ participation in soil conservation welfare. [Conclusion] The promotion and training of soil conservation interventions should be strengthened, and regional characteristics should be considered when implementing soil and water conservation measures, so as to improve farmers’ participation in such projects and ensure that more farmers benefit from these conservation measures.
2024,44(4):416-428
, DOI: 10.13961/j.cnki.stbctb.2024.04.042
Abstract:
[Objective] The sources, migration characteristics, and influencing factors of non-point source pollution in orchards were analysed in order to provide theoretical support for scientifically aid in preventing and controlling non-point source pollution from orchards and improving the quality of soil and water environments. [Methods] Based on the latest research results (both domestically and abroad), the source, migration characteristics, and influencing factors of pollution by nitrogen, phosphorus, heavy metals, and pesticides in orchards were analysed. Existing research deficiencies were analysed and future research directions were proposed. [Results] ① The application intensities of nitrogen fertiliser in orchards 〔565—1 071.2 kg/(hm2·a)〕 and loss coefficients of nitrogen and phosphorus were generally higher than those in farmland. Nitrogen and phosphorus accumulated easily at the bottom of the orchard slope, and their spatial variabilities in soil were higher than those in the farmland and tea gardens. ② When the orchards were not irrigated by sewage and industrial activities were absent, fertilisers, pesticides, and traffic activities were the main sources of heavy metals in the orchard soil, and the migration ranges of heavy metals in the soil profile were approximately 0.005—0.8 m. ③ The dosages of benzimidazole and pyrethroid pesticides in orchards were approximately 40—4 050 and 60—150 g/hm2, respectively. After application, weakly adsorbed pesticides were significantly affected by short-term rainfall, whereas moderately adsorbed pesticides were affected by rainfall and evaporation. The pesticide content in the river showed a seasonal correlation with rainfall. ④ To control non-point source pollution in orchards, the treatment of initial runoff must be prioritised to effectively intercept the sediment. Planting grasses under fruit trees can reduce runoff by 7.1%—98.7%, control sediments by 15.7%—99.8%, intercept nitrogen and phosphorus by 4.6%—98.5 and 15.3%—96.6%, respectively, and reduce heavy metals by 18.8%—90.1%. ⑤ The migration characteristics of non-point source pollution from orchards were consistent with the temporal and spatial distributions of rainfall. In particular, 20% of the surface runoff produced more than 50% of the pollution load. Under extreme rainfall, the runoff coefficients and loss loads of nitrogen and phosphorus in orchards were 2.6 and 11.5 fold higher than those under normal rainfall. Rainfall volume and intensity were the main factors affecting the migration of heavy metals and pesticides. Under rainfall with long duration and moderate intensity, heavy metals and pesticides were more likely to infiltrate and migrate downstream. [Conclusion] The management of orchards in China is still in its infancy. In the future, the migration laws of non-point source pollution, such as nitrogen, phosphorus, heavy metals and pesticides, under the influence of complex factors must be explored, the spatiotemporal scope and degree of non-point source pollution should be accurately identified, and the loss of non-point source pollution should be effectively reduced to ensure the quality of fruits, improve the ecological benefits of orchards, and reduce environmental risks.
[Objective] The sources, migration characteristics, and influencing factors of non-point source pollution in orchards were analysed in order to provide theoretical support for scientifically aid in preventing and controlling non-point source pollution from orchards and improving the quality of soil and water environments. [Methods] Based on the latest research results (both domestically and abroad), the source, migration characteristics, and influencing factors of pollution by nitrogen, phosphorus, heavy metals, and pesticides in orchards were analysed. Existing research deficiencies were analysed and future research directions were proposed. [Results] ① The application intensities of nitrogen fertiliser in orchards 〔565—1 071.2 kg/(hm2·a)〕 and loss coefficients of nitrogen and phosphorus were generally higher than those in farmland. Nitrogen and phosphorus accumulated easily at the bottom of the orchard slope, and their spatial variabilities in soil were higher than those in the farmland and tea gardens. ② When the orchards were not irrigated by sewage and industrial activities were absent, fertilisers, pesticides, and traffic activities were the main sources of heavy metals in the orchard soil, and the migration ranges of heavy metals in the soil profile were approximately 0.005—0.8 m. ③ The dosages of benzimidazole and pyrethroid pesticides in orchards were approximately 40—4 050 and 60—150 g/hm2, respectively. After application, weakly adsorbed pesticides were significantly affected by short-term rainfall, whereas moderately adsorbed pesticides were affected by rainfall and evaporation. The pesticide content in the river showed a seasonal correlation with rainfall. ④ To control non-point source pollution in orchards, the treatment of initial runoff must be prioritised to effectively intercept the sediment. Planting grasses under fruit trees can reduce runoff by 7.1%—98.7%, control sediments by 15.7%—99.8%, intercept nitrogen and phosphorus by 4.6%—98.5 and 15.3%—96.6%, respectively, and reduce heavy metals by 18.8%—90.1%. ⑤ The migration characteristics of non-point source pollution from orchards were consistent with the temporal and spatial distributions of rainfall. In particular, 20% of the surface runoff produced more than 50% of the pollution load. Under extreme rainfall, the runoff coefficients and loss loads of nitrogen and phosphorus in orchards were 2.6 and 11.5 fold higher than those under normal rainfall. Rainfall volume and intensity were the main factors affecting the migration of heavy metals and pesticides. Under rainfall with long duration and moderate intensity, heavy metals and pesticides were more likely to infiltrate and migrate downstream. [Conclusion] The management of orchards in China is still in its infancy. In the future, the migration laws of non-point source pollution, such as nitrogen, phosphorus, heavy metals and pesticides, under the influence of complex factors must be explored, the spatiotemporal scope and degree of non-point source pollution should be accurately identified, and the loss of non-point source pollution should be effectively reduced to ensure the quality of fruits, improve the ecological benefits of orchards, and reduce environmental risks.
2024,44(4):429-440
, DOI: 10.13961/j.cnki.stbctb.2024.04.043
Abstract:
[Objective] The spatial and temporal evolution and driving factors of agricultural land allocation efficiency were analyzed in order to provide theoretical support and scientific reference for the practice of the all-encompassing approach to food, the effective utilization of agricultural resources and the high-quality development of agriculture. [Methods] The article was based on the concept of the all-encompassing approach to food. Using a three-stage data envelopment analysis (DEA) model, Dagum’s Gini coefficient, kernel density estimation and panel Tobit regression, the article measures the allocation efficiency of agricultural land in 30 provinces in China from 2004 to 2022, and analyzed the characteristics of the spatial and temporal evolution and the driving factors. [Results] The overall level of agricultural land allocation efficiency in China was high and stable, and after removing the effects of environmental factors and random errors, the spatial characteristics of allocation efficiency were reversed, and eventually showed a decreasing trend of central-northeastern-eastern-western; and the overall differences between regions showed a fluctuating upward trend, with hypervariable density dominating the overall differences; There was some spatial polarization phenomenon in all regions; urbanization rate, ecological governance, agricultural technology progress had a significant positive effect on the allocation efficiency of agricultural land, rural road facilities and residents’ food and nutritional needs had a significant negative effect, and the effect of financial support for agriculture was not significant. [Conclusion] We should correctly understand and exert the influence of food consumption structure on the allocation of agricultural land, deeply implement the practice of green ecological agriculture, and realize the organic combination of the government and the market, so as to improve the efficiency of agricultural land allocation in all aspects.
[Objective] The spatial and temporal evolution and driving factors of agricultural land allocation efficiency were analyzed in order to provide theoretical support and scientific reference for the practice of the all-encompassing approach to food, the effective utilization of agricultural resources and the high-quality development of agriculture. [Methods] The article was based on the concept of the all-encompassing approach to food. Using a three-stage data envelopment analysis (DEA) model, Dagum’s Gini coefficient, kernel density estimation and panel Tobit regression, the article measures the allocation efficiency of agricultural land in 30 provinces in China from 2004 to 2022, and analyzed the characteristics of the spatial and temporal evolution and the driving factors. [Results] The overall level of agricultural land allocation efficiency in China was high and stable, and after removing the effects of environmental factors and random errors, the spatial characteristics of allocation efficiency were reversed, and eventually showed a decreasing trend of central-northeastern-eastern-western; and the overall differences between regions showed a fluctuating upward trend, with hypervariable density dominating the overall differences; There was some spatial polarization phenomenon in all regions; urbanization rate, ecological governance, agricultural technology progress had a significant positive effect on the allocation efficiency of agricultural land, rural road facilities and residents’ food and nutritional needs had a significant negative effect, and the effect of financial support for agriculture was not significant. [Conclusion] We should correctly understand and exert the influence of food consumption structure on the allocation of agricultural land, deeply implement the practice of green ecological agriculture, and realize the organic combination of the government and the market, so as to improve the efficiency of agricultural land allocation in all aspects.
2024,44(4):441-447
, DOI: 10.13961/j.cnki.stbctb.2024.04.044
Abstract:
[Objective] China’s soil erosion management has shifted from “comprehensive management, key management” to a new stage of “systematic management, overcome difficulties and challenges”. The concept and criterias of systematic management with mountains, waters, forests, farmlands, lakes, grasses and sands， and its relationship with soil and water conservation were analyzed, to provide references for enriching the theoretical system of soil and water conservation in the new period. Therefore, to lead high-quality development of soil and water conservation. [Methods] On the basis of long-term theoretical exploration and practical verification, the development process of the concept of mountains, rivers, forests, farmlands, lakes, grasses and sands systematic management has been organised, and its connotation, objectives, and practical guidelines have been elaborated. [Results] A comprehensive management technology route with small watersheds as a unit, formed by summarising and improving the long-term practice of soil and water loss management, is the simplest practical embodiment of the systematic thought of the life community in mountains, rivers, forests, farmlands, lakes, grasses, and sands. The systematicness of the integrated management of small watersheds is mainly reflected by six aspects: systematic coordination of governance objects, systematic integration of the overall layout, systematic coordination of governance measures, multi-benefit balance of governance effectiveness, multi-sectoral synergy of implementation and management, and multi-agent participation in shared governance. Specific initiatives based on the concept of systematic governance that need to be followed for the high-quality development of soil and water conservation include: using systematic thinking to understand the connotation and requirements for the high-quality development of soil and water conservation; accurately diagnosing the controlling elements of mountains, rivers, forests, farmlands, lakes, grasses and sands systems; constructing a multi-level, all-round, three-dimensional prevention and control system for mountains, rivers, forests, farmlands, lakes, grasses, and sands; and constructing a complete soil and water conservation management and technical guarantee system. [Conclusion] During the new period, the concept of systematic management of mountains, rivers, forests, farmlands, lakes, grasses, and sands should be completely and accurately understood and fully implemented, and new paths, modes, and mechanisms should be evaluated to enhance the level of academic research on soil and water conservation and effectiveness of governance as a whole. Simultaneously, comprehensive and systematic planning and management of farmland, water conservancy, animal husbandry, forestry, production, and construction activities should be conducted in combination with regional specific conditions to promote the high-quality development of soil and water conservation.
[Objective] China’s soil erosion management has shifted from “comprehensive management, key management” to a new stage of “systematic management, overcome difficulties and challenges”. The concept and criterias of systematic management with mountains, waters, forests, farmlands, lakes, grasses and sands， and its relationship with soil and water conservation were analyzed, to provide references for enriching the theoretical system of soil and water conservation in the new period. Therefore, to lead high-quality development of soil and water conservation. [Methods] On the basis of long-term theoretical exploration and practical verification, the development process of the concept of mountains, rivers, forests, farmlands, lakes, grasses and sands systematic management has been organised, and its connotation, objectives, and practical guidelines have been elaborated. [Results] A comprehensive management technology route with small watersheds as a unit, formed by summarising and improving the long-term practice of soil and water loss management, is the simplest practical embodiment of the systematic thought of the life community in mountains, rivers, forests, farmlands, lakes, grasses, and sands. The systematicness of the integrated management of small watersheds is mainly reflected by six aspects: systematic coordination of governance objects, systematic integration of the overall layout, systematic coordination of governance measures, multi-benefit balance of governance effectiveness, multi-sectoral synergy of implementation and management, and multi-agent participation in shared governance. Specific initiatives based on the concept of systematic governance that need to be followed for the high-quality development of soil and water conservation include: using systematic thinking to understand the connotation and requirements for the high-quality development of soil and water conservation; accurately diagnosing the controlling elements of mountains, rivers, forests, farmlands, lakes, grasses and sands systems; constructing a multi-level, all-round, three-dimensional prevention and control system for mountains, rivers, forests, farmlands, lakes, grasses, and sands; and constructing a complete soil and water conservation management and technical guarantee system. [Conclusion] During the new period, the concept of systematic management of mountains, rivers, forests, farmlands, lakes, grasses, and sands should be completely and accurately understood and fully implemented, and new paths, modes, and mechanisms should be evaluated to enhance the level of academic research on soil and water conservation and effectiveness of governance as a whole. Simultaneously, comprehensive and systematic planning and management of farmland, water conservancy, animal husbandry, forestry, production, and construction activities should be conducted in combination with regional specific conditions to promote the high-quality development of soil and water conservation.
Display Method:
Abstract:
［Objective］ In order to solve the problems of poor soil structure and serious soil erosion in the process of soil reclamation in the alpine region of Qinghai-Tibet, ［Methods］ the Delni copper mine in Qinghai was taken as an example. Using the local serpentine residue soil and the original soil, the effect of mixing and applying three kinds of materials—binder, long fiber, and rice husk—on the improvement of the soil of the side slopes was investigated through an orthogonal test of soil cultivation simulation. The proportion of the mixing materials with the best effect was determined. ［Results］ Orthogonal polar results showed that the binder had a stronger effect on soil aggregates, total porosity, field water holding capacity, and soil bulk density, while long fibers and rice husk had a stronger effect on pH and total salt content. Binder incorporation increased soil bulk density but decreased soil pore space compared to the control (CK). Long fibers and rice husk significantly decreased soil pH, increased total porosity and field water holding capacity, and appropriately increased total salt content. The optimal combination for soil aggregates and pH was A2B2C3 (binder 0.074 g·kg-1, long fiber 2.96 g·kg-1, rice husk 11.11 g·kg-1). Soil bulk density, total porosity, and field water holding capacity regulation were optimized with the combination A1B2C2 (binder 0.037 g·kg-1, long fiber 2.96 g·kg-1, rice husk 7.41 g·kg-1), and the optimal combination for total salt content was A3B1C2 (binder 0.111 g·kg-1, long fiber 1.48 g·kg-1, rice husk 7.41 g·kg-1). ［Conclusion］Taken together, the optimal formulation for soil matrix restoration in alpine mining areas was obtained by the median method as A1.5B2C2, i.e., A (binder) 0.0555 g·kg-1, B (long fibers) 2.96 g·kg-1, and C (rice husk) 7.41 g·kg-1. This formulation is conducive to the restoration and stabilization of soil structure in the Qinghai-Tibet alpine mining area and plays an important role in soil and water conservation in this region.
［Objective］ In order to solve the problems of poor soil structure and serious soil erosion in the process of soil reclamation in the alpine region of Qinghai-Tibet, ［Methods］ the Delni copper mine in Qinghai was taken as an example. Using the local serpentine residue soil and the original soil, the effect of mixing and applying three kinds of materials—binder, long fiber, and rice husk—on the improvement of the soil of the side slopes was investigated through an orthogonal test of soil cultivation simulation. The proportion of the mixing materials with the best effect was determined. ［Results］ Orthogonal polar results showed that the binder had a stronger effect on soil aggregates, total porosity, field water holding capacity, and soil bulk density, while long fibers and rice husk had a stronger effect on pH and total salt content. Binder incorporation increased soil bulk density but decreased soil pore space compared to the control (CK). Long fibers and rice husk significantly decreased soil pH, increased total porosity and field water holding capacity, and appropriately increased total salt content. The optimal combination for soil aggregates and pH was A2B2C3 (binder 0.074 g·kg-1, long fiber 2.96 g·kg-1, rice husk 11.11 g·kg-1). Soil bulk density, total porosity, and field water holding capacity regulation were optimized with the combination A1B2C2 (binder 0.037 g·kg-1, long fiber 2.96 g·kg-1, rice husk 7.41 g·kg-1), and the optimal combination for total salt content was A3B1C2 (binder 0.111 g·kg-1, long fiber 1.48 g·kg-1, rice husk 7.41 g·kg-1). ［Conclusion］Taken together, the optimal formulation for soil matrix restoration in alpine mining areas was obtained by the median method as A1.5B2C2, i.e., A (binder) 0.0555 g·kg-1, B (long fibers) 2.96 g·kg-1, and C (rice husk) 7.41 g·kg-1. This formulation is conducive to the restoration and stabilization of soil structure in the Qinghai-Tibet alpine mining area and plays an important role in soil and water conservation in this region.
Abstract:
[Objective]Gansu Province is an important water conservation and ecological security barrier area in western China, whose research on the water conservation service function is strategic for ensuring the regional ecological security and sustainable development.[Methods] Here, the dynamic changes of water conservation in the temporal and spatial scale in Gansu Province from 2001 to 2023 were quantitatively evaluated using the InVEST model, and the influencing factors of the water conservation service function were analyzed using the geographic detector.[Results] (1) The average water conservation in Gansu Province from 2001 to 2023 was 9.24 mm, and the water conservation fluctuated little in the different periods. The change of the water conservation was consistent with the precipitation and water yield, and showed an upward trend and then a downward trend. The overall distribution pattern of water conservation in the province was lower in the northwest and higher in the southeast.(2) From 2001 to 2023, the average water conservation capacity of different land use types in Gansu Province was ranked as cultivated land, grass land, forest land, urban construction land, unused land, and water area.(3)Precipitation was the most important driver for the change of water conservation in Gansu Province, and the interactions between precipitation and evapotranspiration, land use type, and elevation, respectively, had the most significant influence on the spatial difference of the water conservation service function in Gansu Province. The results showed that the change of the water conservation function in Gansu Province was mainly influenced by climate factors and human activities.[Conclusion] This study will provide scientific basis for quantitative evaluation and objective understanding of water conservation function in Gansu Province, and also provide a valuable reference for the regional water resource management decision and water conservation function restoration.
[Objective]Gansu Province is an important water conservation and ecological security barrier area in western China, whose research on the water conservation service function is strategic for ensuring the regional ecological security and sustainable development.[Methods] Here, the dynamic changes of water conservation in the temporal and spatial scale in Gansu Province from 2001 to 2023 were quantitatively evaluated using the InVEST model, and the influencing factors of the water conservation service function were analyzed using the geographic detector.[Results] (1) The average water conservation in Gansu Province from 2001 to 2023 was 9.24 mm, and the water conservation fluctuated little in the different periods. The change of the water conservation was consistent with the precipitation and water yield, and showed an upward trend and then a downward trend. The overall distribution pattern of water conservation in the province was lower in the northwest and higher in the southeast.(2) From 2001 to 2023, the average water conservation capacity of different land use types in Gansu Province was ranked as cultivated land, grass land, forest land, urban construction land, unused land, and water area.(3)Precipitation was the most important driver for the change of water conservation in Gansu Province, and the interactions between precipitation and evapotranspiration, land use type, and elevation, respectively, had the most significant influence on the spatial difference of the water conservation service function in Gansu Province. The results showed that the change of the water conservation function in Gansu Province was mainly influenced by climate factors and human activities.[Conclusion] This study will provide scientific basis for quantitative evaluation and objective understanding of water conservation function in Gansu Province, and also provide a valuable reference for the regional water resource management decision and water conservation function restoration.
Abstract:
Effect of different washing reagents on the removal of soil salt salinity for coastal reclamation zones Abstract: [Objective]The effectiveness of washing reagents on removal of soil salinity for coastal reclamation zones was evaluated to explore suitable soil conditioner. [Methods] The slight saline soils and heavy saline soils of paddy fields from Chongming coastal reclamation zones in Shanghai were chosen as the research object, and the effects of five kinds of washing reagents (potassium nitrate, iron nitrate, calcium nitrate, magnesium nitrate and ammonium bicarbonate) concentration and extraction times on soil salinity (Na+、K+、Ca2+、Mg2+、CO32-、HCO3-、Cl- and SO42-) removal efficiency were compared and analyzed. [Results] The five kinds of washing reagents promoted the removal of Na+ and Cl- in the slight saline soils and the effect of potassium nitrate on Na+ removal efficiency was the most obvious, since the concentration of Na+ in eluate was increased by 9.9%-25.9% compared with the control. However, Cl- was more easily removed by ammonium bicarbonate, and the increase ratio was about 9.62%-21.2% compared with the control. Considering the effects of washing reagents on the elution of soil nutrients (K+, Ca2+, Mg2+, et al.,), 3.0 mmol/L and 15 mmol/L potassium nitrate had the best result considering the removal of soil salt ions and the loss of soil nutrients (K+, Ca2+, Mg2+, et al.). The concentrations of Na+, Cl-, SO42- and Ca2+ in the eluate of the second washing by potassium nitrate were much lower than the first time, while it was not the case for HCO3- and Mg2+. In this experiment, the five washing reagents showed negligible effects on removal efficiency of Na+ and Cl- in the heavy saline soils because the applied concentration was much lower than the salt ion content in the soils, and the increase rate of the two ions was 0.1%-1.0% and 0.01%-4.4%, respectively compared with the control.[Conclusion] The suitable type and dosage of washing reagents could not only promote the removal of soil salt ions in coastal reclamation zones, but also reduce the loss of soil nutrients elements..
Effect of different washing reagents on the removal of soil salt salinity for coastal reclamation zones Abstract: [Objective]The effectiveness of washing reagents on removal of soil salinity for coastal reclamation zones was evaluated to explore suitable soil conditioner. [Methods] The slight saline soils and heavy saline soils of paddy fields from Chongming coastal reclamation zones in Shanghai were chosen as the research object, and the effects of five kinds of washing reagents (potassium nitrate, iron nitrate, calcium nitrate, magnesium nitrate and ammonium bicarbonate) concentration and extraction times on soil salinity (Na+、K+、Ca2+、Mg2+、CO32-、HCO3-、Cl- and SO42-) removal efficiency were compared and analyzed. [Results] The five kinds of washing reagents promoted the removal of Na+ and Cl- in the slight saline soils and the effect of potassium nitrate on Na+ removal efficiency was the most obvious, since the concentration of Na+ in eluate was increased by 9.9%-25.9% compared with the control. However, Cl- was more easily removed by ammonium bicarbonate, and the increase ratio was about 9.62%-21.2% compared with the control. Considering the effects of washing reagents on the elution of soil nutrients (K+, Ca2+, Mg2+, et al.,), 3.0 mmol/L and 15 mmol/L potassium nitrate had the best result considering the removal of soil salt ions and the loss of soil nutrients (K+, Ca2+, Mg2+, et al.). The concentrations of Na+, Cl-, SO42- and Ca2+ in the eluate of the second washing by potassium nitrate were much lower than the first time, while it was not the case for HCO3- and Mg2+. In this experiment, the five washing reagents showed negligible effects on removal efficiency of Na+ and Cl- in the heavy saline soils because the applied concentration was much lower than the salt ion content in the soils, and the increase rate of the two ions was 0.1%-1.0% and 0.01%-4.4%, respectively compared with the control.[Conclusion] The suitable type and dosage of washing reagents could not only promote the removal of soil salt ions in coastal reclamation zones, but also reduce the loss of soil nutrients elements..
Abstract:
[Objective] Vegetation productivity changes due to changes in heat, water, air and other factors, so it is necessary to explore the change law of vegetation productivity and its response to climate factors. [Methods] Based on GEE (Google Earth Engine), the vegetation productivity (NPP) of Tianjin during 2001-2022 was calculated, and the spatial and temporal variation pattern of NPP was analyzed by Slope trend analysis, F-test, barycentric migration model, standard deviation ellipse model and other methods. Multi-factor sensitivity analysis and correlation coefficient evaluation were used to quantitatively evaluate the NPP response characteristics under temperature, precipitation and wind speed changes. [Results] The results showed that: (1) The average annual vegetation productivity in Tianjin showed an increasing trend of fluctuation, and the fluctuation range was 53.46~96.54 g Cm-2a-1; (2) The vegetation productivity of Tianjin is higher in the north and lower in the south, and higher in the west and lower in the east. The center of gravity is concentrated in the central region, and the center of gravity gradually moves to the south during 2001-2022. (3) The response of vegetation productivity to climate factors in Tianjin has a significant lag time, with a lag time of 1 month for temperature and precipitation and 3 months for wind speed. [Conclusion] This study analyzed the spatio-temporal variation pattern of NPP in Tianjin, identified the relationship between vegetation productivity and climate factors, quantified the lag time of response to climate factors, and provided a research example for evaluating the impact of different climate conditions on vegetation productivity.
[Objective] Vegetation productivity changes due to changes in heat, water, air and other factors, so it is necessary to explore the change law of vegetation productivity and its response to climate factors. [Methods] Based on GEE (Google Earth Engine), the vegetation productivity (NPP) of Tianjin during 2001-2022 was calculated, and the spatial and temporal variation pattern of NPP was analyzed by Slope trend analysis, F-test, barycentric migration model, standard deviation ellipse model and other methods. Multi-factor sensitivity analysis and correlation coefficient evaluation were used to quantitatively evaluate the NPP response characteristics under temperature, precipitation and wind speed changes. [Results] The results showed that: (1) The average annual vegetation productivity in Tianjin showed an increasing trend of fluctuation, and the fluctuation range was 53.46~96.54 g Cm-2a-1; (2) The vegetation productivity of Tianjin is higher in the north and lower in the south, and higher in the west and lower in the east. The center of gravity is concentrated in the central region, and the center of gravity gradually moves to the south during 2001-2022. (3) The response of vegetation productivity to climate factors in Tianjin has a significant lag time, with a lag time of 1 month for temperature and precipitation and 3 months for wind speed. [Conclusion] This study analyzed the spatio-temporal variation pattern of NPP in Tianjin, identified the relationship between vegetation productivity and climate factors, quantified the lag time of response to climate factors, and provided a research example for evaluating the impact of different climate conditions on vegetation productivity.
Abstract:
[Objective] Carbon stock and habitat quality are important indicators for evaluating the function of ecosystem services, and the study of their spatial and temporal distribution patterns is of great significance for the precise implementation of ecosystem protection and management. [Methods] Based on the land use transfer matrix, we analyzed the land use change status in Hebei Province from 2000 to 2020, and selected the PLUS-InVEST-Geodector model to estimate the ecosystem carbon stock and habitat quality in Hebei Province from 2000 to 2030. And we analyzed the change pattern of its spatial and temporal changes and driving factors. [Result] (1) The carbon stock in Hebei province decreased by 13.45 TgC from 2000 to 2020, and the areas with decreasing carbon stock were mostly concentrated in the Damshang Plateau area, the North China Plain and the southeastern hilly areas. (2) In 2030, the carbon stock under the natural development scenario decreases by 6.37 TgC compared with that in 2020. The carbon stock under the economic development scenario decreases by 21.73 TgC, and the carbon stock under the sustainable development scenario increases by 3.65 TgC. (3) The habitat quality index showed a gradual downward trend over time from 2000 to 2020. The main land categories of lowest and lower grade habitat quality are construction land and cropland, while the main land categories of higher and highest grade habitat quality are grassland and forest land. (4) The habitat quality index of Hebei Province in 2030 varies under different scenarios, with the sustainable development scenario (0.4639) > natural development scenario (0.4542) > economic development scenario (0.4500). (5) The strongest explanatory factors for the spatial variations in carbon stock and habitat quality were slope and elevation. Carbon stock and habitat quality were affected by both natural geographic factors and socioeconomic factors. [Conclusion] The land use pattern under the sustainable development scenario can help to improve the carbon stock and habitat quality of the ecosystem in Hebei Province, and can provide a reference for the relevant departments to formulate land policies and carbon emission reduction policies.
[Objective] Carbon stock and habitat quality are important indicators for evaluating the function of ecosystem services, and the study of their spatial and temporal distribution patterns is of great significance for the precise implementation of ecosystem protection and management. [Methods] Based on the land use transfer matrix, we analyzed the land use change status in Hebei Province from 2000 to 2020, and selected the PLUS-InVEST-Geodector model to estimate the ecosystem carbon stock and habitat quality in Hebei Province from 2000 to 2030. And we analyzed the change pattern of its spatial and temporal changes and driving factors. [Result] (1) The carbon stock in Hebei province decreased by 13.45 TgC from 2000 to 2020, and the areas with decreasing carbon stock were mostly concentrated in the Damshang Plateau area, the North China Plain and the southeastern hilly areas. (2) In 2030, the carbon stock under the natural development scenario decreases by 6.37 TgC compared with that in 2020. The carbon stock under the economic development scenario decreases by 21.73 TgC, and the carbon stock under the sustainable development scenario increases by 3.65 TgC. (3) The habitat quality index showed a gradual downward trend over time from 2000 to 2020. The main land categories of lowest and lower grade habitat quality are construction land and cropland, while the main land categories of higher and highest grade habitat quality are grassland and forest land. (4) The habitat quality index of Hebei Province in 2030 varies under different scenarios, with the sustainable development scenario (0.4639) > natural development scenario (0.4542) > economic development scenario (0.4500). (5) The strongest explanatory factors for the spatial variations in carbon stock and habitat quality were slope and elevation. Carbon stock and habitat quality were affected by both natural geographic factors and socioeconomic factors. [Conclusion] The land use pattern under the sustainable development scenario can help to improve the carbon stock and habitat quality of the ecosystem in Hebei Province, and can provide a reference for the relevant departments to formulate land policies and carbon emission reduction policies.
Abstract:
［Objective］Analyzing the dynamic changes in soil moisture on slopes in rocky mountain area of North China and its response to rainfall helps to reveal the characteristics and patterns of rainfall response and recharge.［Methods］This study focuses on typical natural barren slopes in rocky mountain area of North China, employing in-situ monitoring to collect real-time data on soil moisture at different slope positions for detailed analysis. The objective is to uncover the dynamic response characteristics of soil moisture to rainfall and its inherent laws, ensuring the use of precise and professional terminology.［Results］(1) The average annual soil moisture content along the slope exhibits the following pattern: bottom slope (20.3±5.5%) > top slope (19.5±5.7%) > middle slope (15.9±7.0%), and in the vertical profile, deeper soil layers have higher moisture content than shallower layers. (2) The response rate of soil moisture to rainfall is significantly faster in the middle slope (1.5h) compared to the top slope (4.1h) and the bottom slope (2.8h), and in the vertical profile, deeper soil layers respond to rainfall more quickly than shallower layers. (3) The average rates of moisture replenishment and depletion due to rainfall are as follows: middle slope (1.4%·h-1, 0.3%·h-1) > top slope (0.9%·h-1, 0.2%·h-1) > bottom slope (0.7%·h-1, 0.1%·h-1), and in the vertical profile, both the replenishment and depletion rates are higher in deeper soil layers compared to shallower layers.［Conclusion］In rocky mountain area of North China, when rainfall exceeds 2.7 mm, it can effectively recharge soil moisture on slopes. Additionally, the response of middle slope and deeper soil layers to rainfall is notably more rapid.
［Objective］Analyzing the dynamic changes in soil moisture on slopes in rocky mountain area of North China and its response to rainfall helps to reveal the characteristics and patterns of rainfall response and recharge.［Methods］This study focuses on typical natural barren slopes in rocky mountain area of North China, employing in-situ monitoring to collect real-time data on soil moisture at different slope positions for detailed analysis. The objective is to uncover the dynamic response characteristics of soil moisture to rainfall and its inherent laws, ensuring the use of precise and professional terminology.［Results］(1) The average annual soil moisture content along the slope exhibits the following pattern: bottom slope (20.3±5.5%) > top slope (19.5±5.7%) > middle slope (15.9±7.0%), and in the vertical profile, deeper soil layers have higher moisture content than shallower layers. (2) The response rate of soil moisture to rainfall is significantly faster in the middle slope (1.5h) compared to the top slope (4.1h) and the bottom slope (2.8h), and in the vertical profile, deeper soil layers respond to rainfall more quickly than shallower layers. (3) The average rates of moisture replenishment and depletion due to rainfall are as follows: middle slope (1.4%·h-1, 0.3%·h-1) > top slope (0.9%·h-1, 0.2%·h-1) > bottom slope (0.7%·h-1, 0.1%·h-1), and in the vertical profile, both the replenishment and depletion rates are higher in deeper soil layers compared to shallower layers.［Conclusion］In rocky mountain area of North China, when rainfall exceeds 2.7 mm, it can effectively recharge soil moisture on slopes. Additionally, the response of middle slope and deeper soil layers to rainfall is notably more rapid.
Abstract:
[Objective] This study aims to investigate the quantitative characteristics of plant communities and their influencing factors under different slope positions in the Loess Plateau. This research is significant for advancing the theoretical understanding of plant community construction mechanisms within the slope-gully system of the region and for providing practical guidance in the design of artificially restored plant communities. [Methods] The study examines the composition, diversity, stability, and distribution patterns of dominant plants across five slope positions—sunny gully slope, sunny hill slope, hilltop, shady hill slope, and shady gully slope—within the forest-steppe zone of the hilly Loess Plateau under natural conditions. By integrating soil erosion intensity data, the study identifies the primary ecological factors influencing plant community construction across different slope positions. [Results] (1) In the forest-steppe zone of the hilly Loess Plateau, the sunny gully slope and sunny hill slope both exhibit a two-layer vertical structure, predominantly composed of perennial herbs and shrubs, with dominant plants showing a dispersed distribution pattern. The hilltop has a single-layer vertical structure, mainly comprising annual and perennial herbs, where plants demonstrate a highly clustered distribution. The shady gully slope community has a three-layer vertical structure, with plants also showing a clustered distribution pattern. (2) The shady gully slope has the highest species diversity, richness, and stability, whereas the sunny hill slope exhibits the lowest richness and diversity, with significant reductions of 18.4% and 26.5%, respectively, compared to the shady gully slope. The hilltop plant community shows the least stability, with a stability index of only 29. (3) The common key factors influencing community characteristics across different slope positions are soil erosion intensity and soil moisture. However, soil bulk density on the sunny gully slope, organic matter on the sunny and shady hill slopes, and light intensity on the hilltop and shady gully slope are the distinguishing ecological factors affecting plant community structure, stability, and diversity. [Conclusion] Vegetation restoration strategies should be tailored to the specific slope positions in the forest-steppe zone of the hilly Loess Plateau. For instance, the "fertile island" effect formed by perennial shrubs on the sunny gully slope can improve surface conditions, while micro-topographic modifications on the sunny hill slope can reduce soil erosion. On the hilltop, the introduction of drought-tolerant plants can enhance plant community structure. On the shady hill and gully slopes, do not excessively require the construction of complex plant community structure, so as not to cause the degradation of the herbaceous layer under the artificial forest due to insufficient light.
[Objective] This study aims to investigate the quantitative characteristics of plant communities and their influencing factors under different slope positions in the Loess Plateau. This research is significant for advancing the theoretical understanding of plant community construction mechanisms within the slope-gully system of the region and for providing practical guidance in the design of artificially restored plant communities. [Methods] The study examines the composition, diversity, stability, and distribution patterns of dominant plants across five slope positions—sunny gully slope, sunny hill slope, hilltop, shady hill slope, and shady gully slope—within the forest-steppe zone of the hilly Loess Plateau under natural conditions. By integrating soil erosion intensity data, the study identifies the primary ecological factors influencing plant community construction across different slope positions. [Results] (1) In the forest-steppe zone of the hilly Loess Plateau, the sunny gully slope and sunny hill slope both exhibit a two-layer vertical structure, predominantly composed of perennial herbs and shrubs, with dominant plants showing a dispersed distribution pattern. The hilltop has a single-layer vertical structure, mainly comprising annual and perennial herbs, where plants demonstrate a highly clustered distribution. The shady gully slope community has a three-layer vertical structure, with plants also showing a clustered distribution pattern. (2) The shady gully slope has the highest species diversity, richness, and stability, whereas the sunny hill slope exhibits the lowest richness and diversity, with significant reductions of 18.4% and 26.5%, respectively, compared to the shady gully slope. The hilltop plant community shows the least stability, with a stability index of only 29. (3) The common key factors influencing community characteristics across different slope positions are soil erosion intensity and soil moisture. However, soil bulk density on the sunny gully slope, organic matter on the sunny and shady hill slopes, and light intensity on the hilltop and shady gully slope are the distinguishing ecological factors affecting plant community structure, stability, and diversity. [Conclusion] Vegetation restoration strategies should be tailored to the specific slope positions in the forest-steppe zone of the hilly Loess Plateau. For instance, the "fertile island" effect formed by perennial shrubs on the sunny gully slope can improve surface conditions, while micro-topographic modifications on the sunny hill slope can reduce soil erosion. On the hilltop, the introduction of drought-tolerant plants can enhance plant community structure. On the shady hill and gully slopes, do not excessively require the construction of complex plant community structure, so as not to cause the degradation of the herbaceous layer under the artificial forest due to insufficient light.
Abstract:
[Objective] Accurately obtaining slope gradient data of the rolling hilly region in the Chinese Mollisol area is crucial for the quantitative evaluation of soil erosion. [Methods] This study aimed to address the issue of slope gradient reduction when extracting farmland slope gradient in the rolling hilly region in the Chinese Mollisol area using the currently available 30 m resolution Digital Elevation Model (DEM). To achieve this, a 5 cm resolution DEM was generated based on drone survey images and resampled to obtain 1 m, 5 m, and 12.5 m DEM-resolutions. Combined with the free downloaded 30 m resolution DEM, five groups of different DEM-resolutions were obtained. A comparative study was conducted to analyze the difference between the slope gradient information extracted by different DEM-resolutions and 5 cm resolution DEM to determine the best resolution of DEM for extracting slope gradient in the study area. Based on the histogram matching algorithm, a slope gradient conversion model between 30 m and the best resolution DEM was fitted for each slope gradient segment. [Results] (1) The slope gradient information extracted by the five groups of DEM resolutions showed that the frequency distribution of slopes gradient extracted by 1 m and 5 m DEMs have strong similarity with those extracted by 5 cm resolution DEM. Considering that the resolution of 5 m DEM corresponds to that of a 1:10000 scale topographic map, 5 m was determined as the best DEM resolution for building the slope gradient conversion model. (2) Based on the histogram matching method, a univariate linear model and a univariate quadratic non-linear model of slope gradient conversion between 30 m and 5 m resolution DEMs were constructed for each slope gradient segment. It was appropriate to select the linear slope gradient conversion model when the ground slope gradient was less than 7°, while it was appropriate to select the non-linear slope gradient conversion model when the ground slope gradient was greater than 7°. (3) After optimization by linear and non-linear slope gradient conversion models, the frequency distribution of slope gradients was basically similar to that of 5 m resolution, and the covariance and correlation coefficient were greatly improved. This indicated that the slope gradient information extracted by 30 m resolution DEM could truly reflect the ground undulation features after model conversion, and the optimization effect of the non-linear slope gradient conversion model was better. [Conclusion] The constructed low-high resolution slope gradient conversion model provides method support for obtaining the real slope gradient of the ground in the study area.
[Objective] Accurately obtaining slope gradient data of the rolling hilly region in the Chinese Mollisol area is crucial for the quantitative evaluation of soil erosion. [Methods] This study aimed to address the issue of slope gradient reduction when extracting farmland slope gradient in the rolling hilly region in the Chinese Mollisol area using the currently available 30 m resolution Digital Elevation Model (DEM). To achieve this, a 5 cm resolution DEM was generated based on drone survey images and resampled to obtain 1 m, 5 m, and 12.5 m DEM-resolutions. Combined with the free downloaded 30 m resolution DEM, five groups of different DEM-resolutions were obtained. A comparative study was conducted to analyze the difference between the slope gradient information extracted by different DEM-resolutions and 5 cm resolution DEM to determine the best resolution of DEM for extracting slope gradient in the study area. Based on the histogram matching algorithm, a slope gradient conversion model between 30 m and the best resolution DEM was fitted for each slope gradient segment. [Results] (1) The slope gradient information extracted by the five groups of DEM resolutions showed that the frequency distribution of slopes gradient extracted by 1 m and 5 m DEMs have strong similarity with those extracted by 5 cm resolution DEM. Considering that the resolution of 5 m DEM corresponds to that of a 1:10000 scale topographic map, 5 m was determined as the best DEM resolution for building the slope gradient conversion model. (2) Based on the histogram matching method, a univariate linear model and a univariate quadratic non-linear model of slope gradient conversion between 30 m and 5 m resolution DEMs were constructed for each slope gradient segment. It was appropriate to select the linear slope gradient conversion model when the ground slope gradient was less than 7°, while it was appropriate to select the non-linear slope gradient conversion model when the ground slope gradient was greater than 7°. (3) After optimization by linear and non-linear slope gradient conversion models, the frequency distribution of slope gradients was basically similar to that of 5 m resolution, and the covariance and correlation coefficient were greatly improved. This indicated that the slope gradient information extracted by 30 m resolution DEM could truly reflect the ground undulation features after model conversion, and the optimization effect of the non-linear slope gradient conversion model was better. [Conclusion] The constructed low-high resolution slope gradient conversion model provides method support for obtaining the real slope gradient of the ground in the study area.
Abstract:
[Objective] The characteristics of carbon emissions from cultivated land use and their decoupling relationship with grain yield were investigated to provide a scientific basis for coordinating the reduction of carbon emissions from cultivated land use and grain security in the North China Plain. [Methods] Based on data from 45 cities in Shandong, Hebei, and Henan provinces in the North China Plain from 2001 to 2021, the spatial and temporal evolution and influencing factors of carbon emissions from cultivated land use, and the decoupling relationship between these emissions and grain yield were analyzed using the carbon emission coefficient method, the spatial autocorrelation analysis, the spatial Durbin model, and the Tapio decoupling model. [Results] ① From 2001 to 2021, the total carbon emissions from cultivated land use in the three provinces of the North China Plain exhibited an inverted U-shaped pattern, with fertilizer as the main carbon source, accounting for 51.67% of the total emissions. The total carbon emissions from cultivated land use in Shandong Province and Henan Province were higher than those in Hebei Province, and the carbon emission structure differed among the three provinces. ② Spatially, the carbon emissions from cultivated land use in the three provinces of the North China Plain generally shifted from a high-carbon stage to a low-carbon stage, with notable differences in carbon emission levels among different cities. ③ The carbon emissions from cultivated land use generally showed positive spatial agglomeration characteristics and the degree of agglomeration tended to strengthen, with spatial coherence expanding in high-high type clustering areas, while low-low type clustering areas were more dispersed. ④ The agricultural economic level, rural electricity consumption, and fertilizer application intensity had positive effects on carbon emissions from cultivated land use, while the urbanization level had negative effects. The urbanization level and rural electricity consumption had positive spatial spillover effects, while the agricultural economic level had negative spatial spillover effects. ⑤ The decoupling state between carbon emissions from cultivated land use and grain yield shifted from mainly weak decoupling and expansive negative decoupling to mainly strong decoupling and recessive decoupling. [Conclusion] It was recommended that organic fertilizers and precise fertilization techniques be used, that emission reduction measures be formulated according to the different carbon emission structures of each province, that the adaptability of grain varieties be enhanced, and that inter-regional coordination and interaction be strengthened.
[Objective] The characteristics of carbon emissions from cultivated land use and their decoupling relationship with grain yield were investigated to provide a scientific basis for coordinating the reduction of carbon emissions from cultivated land use and grain security in the North China Plain. [Methods] Based on data from 45 cities in Shandong, Hebei, and Henan provinces in the North China Plain from 2001 to 2021, the spatial and temporal evolution and influencing factors of carbon emissions from cultivated land use, and the decoupling relationship between these emissions and grain yield were analyzed using the carbon emission coefficient method, the spatial autocorrelation analysis, the spatial Durbin model, and the Tapio decoupling model. [Results] ① From 2001 to 2021, the total carbon emissions from cultivated land use in the three provinces of the North China Plain exhibited an inverted U-shaped pattern, with fertilizer as the main carbon source, accounting for 51.67% of the total emissions. The total carbon emissions from cultivated land use in Shandong Province and Henan Province were higher than those in Hebei Province, and the carbon emission structure differed among the three provinces. ② Spatially, the carbon emissions from cultivated land use in the three provinces of the North China Plain generally shifted from a high-carbon stage to a low-carbon stage, with notable differences in carbon emission levels among different cities. ③ The carbon emissions from cultivated land use generally showed positive spatial agglomeration characteristics and the degree of agglomeration tended to strengthen, with spatial coherence expanding in high-high type clustering areas, while low-low type clustering areas were more dispersed. ④ The agricultural economic level, rural electricity consumption, and fertilizer application intensity had positive effects on carbon emissions from cultivated land use, while the urbanization level had negative effects. The urbanization level and rural electricity consumption had positive spatial spillover effects, while the agricultural economic level had negative spatial spillover effects. ⑤ The decoupling state between carbon emissions from cultivated land use and grain yield shifted from mainly weak decoupling and expansive negative decoupling to mainly strong decoupling and recessive decoupling. [Conclusion] It was recommended that organic fertilizers and precise fertilization techniques be used, that emission reduction measures be formulated according to the different carbon emission structures of each province, that the adaptability of grain varieties be enhanced, and that inter-regional coordination and interaction be strengthened.
Abstract:
[Objective] Identifying the spatial correlation network characteristics of net carbon sinks in the Yangtze River Economic Belt under the background of carbon peaking and carbon neutrality plays an important role in promoting the synergy of carbon emission reduction in the Yangtze River Economic Belt and realizing regional coordinated development. [Method] The modified gravity model was used to construct the spatial correlation network of net carbon sinks in the Yangtze River Economic Belt at the municipal scale, and the characteristics of the spatial correlation network were identified by using the social network analysis method, and the driving factors of the spatial correlation network of net carbon sinks were identified by the QAP model. [Results] (1) The net carbon sink in the Yangtze River Economic Belt has significant spatial correlation characteristics, and generally presents an intertwined network pattern of "dense in the east and sparse in the west", and forms a network pattern with "Chongqing" and "Shanghai" as the dual cores(2) The correlation of the net carbon sink spatial network in the Yangtze River Economic Belt is mainly affected by the differences in economic development level, industrial structure upgrading, energy consumption intensity and different land use structures, while the impact of urbanization level and grain yield difference is not significant. [Conclusion] To achieve the coordinated development of the Yangtze River Economic Belt and regional coordinated emission reduction, it is necessary to fully consider the spatial correlation of net carbon sinks of each city, as well as the status and role of each city in the spatial correlation network, so as to fully realize the complementary advantages of each city and maximize the benefits of emission reduction. At the same time, cities need to actively promote the upgrading of industrial structure,increase the research and development and innovation of emission reduction technologies, improve energy efficiency, and optimize land use structure to achieve carbon reduction and increase sinks.
[Objective] Identifying the spatial correlation network characteristics of net carbon sinks in the Yangtze River Economic Belt under the background of carbon peaking and carbon neutrality plays an important role in promoting the synergy of carbon emission reduction in the Yangtze River Economic Belt and realizing regional coordinated development. [Method] The modified gravity model was used to construct the spatial correlation network of net carbon sinks in the Yangtze River Economic Belt at the municipal scale, and the characteristics of the spatial correlation network were identified by using the social network analysis method, and the driving factors of the spatial correlation network of net carbon sinks were identified by the QAP model. [Results] (1) The net carbon sink in the Yangtze River Economic Belt has significant spatial correlation characteristics, and generally presents an intertwined network pattern of "dense in the east and sparse in the west", and forms a network pattern with "Chongqing" and "Shanghai" as the dual cores(2) The correlation of the net carbon sink spatial network in the Yangtze River Economic Belt is mainly affected by the differences in economic development level, industrial structure upgrading, energy consumption intensity and different land use structures, while the impact of urbanization level and grain yield difference is not significant. [Conclusion] To achieve the coordinated development of the Yangtze River Economic Belt and regional coordinated emission reduction, it is necessary to fully consider the spatial correlation of net carbon sinks of each city, as well as the status and role of each city in the spatial correlation network, so as to fully realize the complementary advantages of each city and maximize the benefits of emission reduction. At the same time, cities need to actively promote the upgrading of industrial structure,increase the research and development and innovation of emission reduction technologies, improve energy efficiency, and optimize land use structure to achieve carbon reduction and increase sinks.
Abstract:
[Objective] Assessments of soil and water loss and the benefit evaluation of measures caused by rainstorm were carried out, the soil erosion caused by rainstorm were analyzed, and the benefit of terrace measures were evaluated, in order to provide effective supplement for the dynamic monitoring of soil and water loss.[Methods] Based on the daily rainfall data and the results of the national dynamic monitoring of soil and water loss project, the Qingcheng County and Qiugou small watershed of the rainstorm center in Gansu Province were taken as the research areas. Based on the rainfall erosivity of the rainstorm, the improved CSLE model was used to calculate the soil erosion modulus. The relationship between the rainfall erosivity of the rainstorm and the annual rainfall erosivity under the condition of multi-annual average rainfall was analyzed. The spatial distribution of soil erosion intensity grades of different land use types under the condition of rainstorm was analyzed, and the influence of terraces on regional soil erosion was discussed.[Results] The rainfall erosivity generated by this rainstorm in Qingcheng County reached 1.85 times of the annual rainfall erosivity under the condition of multi-year average rainfall, and the rainfall erosivity of the rainstorm center reached 4.88 times of the annual rainfall erosivity under the condition of multi-year average rainfall. The area of soil erosion above the strong level caused by rainstorm is 3.46 times that of the soil erosion above the strong level in 2021, and the rainstorm center is 6.93 times. The strong soil erosion caused by the heavy rainstorm was mainly distributed in dry land, grassland and shrub land. The current terrace area in Qingcheng County is 325km2.Compared with the situation without terrace measures, the amount of soil erosion in the county has decreased by 72.87 %.[Conclusion] Strengthening soil and water conservation work such as returning farmland to forest and grassland, comprehensive improvement of slope farmland, and construction of dry terraces is an effective means to prevent and control soil and water loss disasters under heavy rainstorm conditions.
[Objective] Assessments of soil and water loss and the benefit evaluation of measures caused by rainstorm were carried out, the soil erosion caused by rainstorm were analyzed, and the benefit of terrace measures were evaluated, in order to provide effective supplement for the dynamic monitoring of soil and water loss.[Methods] Based on the daily rainfall data and the results of the national dynamic monitoring of soil and water loss project, the Qingcheng County and Qiugou small watershed of the rainstorm center in Gansu Province were taken as the research areas. Based on the rainfall erosivity of the rainstorm, the improved CSLE model was used to calculate the soil erosion modulus. The relationship between the rainfall erosivity of the rainstorm and the annual rainfall erosivity under the condition of multi-annual average rainfall was analyzed. The spatial distribution of soil erosion intensity grades of different land use types under the condition of rainstorm was analyzed, and the influence of terraces on regional soil erosion was discussed.[Results] The rainfall erosivity generated by this rainstorm in Qingcheng County reached 1.85 times of the annual rainfall erosivity under the condition of multi-year average rainfall, and the rainfall erosivity of the rainstorm center reached 4.88 times of the annual rainfall erosivity under the condition of multi-year average rainfall. The area of soil erosion above the strong level caused by rainstorm is 3.46 times that of the soil erosion above the strong level in 2021, and the rainstorm center is 6.93 times. The strong soil erosion caused by the heavy rainstorm was mainly distributed in dry land, grassland and shrub land. The current terrace area in Qingcheng County is 325km2.Compared with the situation without terrace measures, the amount of soil erosion in the county has decreased by 72.87 %.[Conclusion] Strengthening soil and water conservation work such as returning farmland to forest and grassland, comprehensive improvement of slope farmland, and construction of dry terraces is an effective means to prevent and control soil and water loss disasters under heavy rainstorm conditions.
Abstract:
Report on Field Survey of Soil Erosion in Three-River-Source National Park Abstract: [Purpose] The Three-Rivers-Source region is located in the hinterland of the Qinghai-Tibetan Plateau, soil erosion types are complex and varied. Through the field investigation, we aim to comprehensively understand the characteristics of soil erosion in the region and to provide reference for soil erosion prevention and control in the region. [Methods] The investigation team travelled to Guoluo, Yushu, Hainan and Huangnan prefectures in three separate groups from 25 July to 20 August 2023. We have surveyed and analysed woodland, grassland, farmland, bare land, roads, river banks and mountain gullies in the above areas. [Results] The survey shows that the grassland has the most complex type of soil erosion, which is subjected to the joint action of multiple camp force erosion such as wind erosion, water erosion, freezing and thawing erosion and gravity erosion, resulting in its serious soil erosion. In addition, grassland damage by highland rodents may be another important factor in the occurrence of grassland erosion; The forestland has erosion gullies in the standing forest, but the overall risk of erosion is low due to the engineered slope protection; The foot of the slope on which the shrub land is situated is more exposed to hydraulic and gravitational erosion and is at greater risk of erosion; Farmland is spread over a small area, however, mild water erosion occurs in the field. For bare ground, fine gully erosion is more intense and soil erosion is serious. It is worth noting that on both sides of the road, the slopes are more severely eroded, and the excavation of the project has led to the destruction of the turf, sliding under gravity, and the emergence of larger exposed surfaces, which provide conditions for the occurrence of water erosion, leading to a larger network of erosion gullies that have already been formed in some areas. [Conclusion] Soil erosion in the Three-Rivers-Source region of Qinghai Province is complex and varied, with the intensification of human activities, risk of further exacerbation of soil erosion in localised areas. It is an urgent need to carry out soil and water conservation work in the new era, there is a need to strengthen the basic research on soil erosion in the region, strengthen the deployment of the network of soil and water conservation monitoring stations, intelligent management, etc. Keywords: Three-River-Source National Park; soil erosion; soil and water conservation; land use
Report on Field Survey of Soil Erosion in Three-River-Source National Park Abstract: [Purpose] The Three-Rivers-Source region is located in the hinterland of the Qinghai-Tibetan Plateau, soil erosion types are complex and varied. Through the field investigation, we aim to comprehensively understand the characteristics of soil erosion in the region and to provide reference for soil erosion prevention and control in the region. [Methods] The investigation team travelled to Guoluo, Yushu, Hainan and Huangnan prefectures in three separate groups from 25 July to 20 August 2023. We have surveyed and analysed woodland, grassland, farmland, bare land, roads, river banks and mountain gullies in the above areas. [Results] The survey shows that the grassland has the most complex type of soil erosion, which is subjected to the joint action of multiple camp force erosion such as wind erosion, water erosion, freezing and thawing erosion and gravity erosion, resulting in its serious soil erosion. In addition, grassland damage by highland rodents may be another important factor in the occurrence of grassland erosion; The forestland has erosion gullies in the standing forest, but the overall risk of erosion is low due to the engineered slope protection; The foot of the slope on which the shrub land is situated is more exposed to hydraulic and gravitational erosion and is at greater risk of erosion; Farmland is spread over a small area, however, mild water erosion occurs in the field. For bare ground, fine gully erosion is more intense and soil erosion is serious. It is worth noting that on both sides of the road, the slopes are more severely eroded, and the excavation of the project has led to the destruction of the turf, sliding under gravity, and the emergence of larger exposed surfaces, which provide conditions for the occurrence of water erosion, leading to a larger network of erosion gullies that have already been formed in some areas. [Conclusion] Soil erosion in the Three-Rivers-Source region of Qinghai Province is complex and varied, with the intensification of human activities, risk of further exacerbation of soil erosion in localised areas. It is an urgent need to carry out soil and water conservation work in the new era, there is a need to strengthen the basic research on soil erosion in the region, strengthen the deployment of the network of soil and water conservation monitoring stations, intelligent management, etc. Keywords: Three-River-Source National Park; soil erosion; soil and water conservation; land use
Abstract:
[Objective]The middle reaches of the Yangtze River serve as a crucial support for ecological preservation and economic development within the Yangtze River basin. Despite its abundant water resources, issues concerning water resource consumption remain significant. [Methods]This study focuses on the provinces of Hubei, Hunan, and Jiangxi in the middle reaches of the Yangtze River, analyzing data from 2011 to 2021. Employing the water resource ecological footprint model, the research conducts a temporal and spatial analysis of ecological footprints and related indicators in these regions. Furthermore, utilizing the Pressure-State-Response (PSR) framework and ecological footprint indicators, an evaluation index system for sustainable water resource utilization in the middle reaches of the Yangtze River is constructed. The study calculates pressure indices, state indices, response indices and comprehensive indices for the three provinces. [Results](1)Per capita water resources ecological footprints and carrying capacity in the three provinces show an overall increasing trend, with the carrying capacity exceeding the ecological footprint, leading to an ecological surplus. This indicates a generally favorable water resources ecological status in the provinces. Jiangxi province exhibits the highest per capita water resources ecological surplus ranging between 3.186 and 7.966, while Hubei province records the lowest ranging from 0.304 to 2.603. (2)Production water holds the largest share in the water accounts of the ecological footprints in all three provinces, followed by domestic water. Although environmental water accounts for the smallest share, it exhibits the most significant increase. Notably, Hubei province shows a substantial increase in per capita environmental water footprint, rising from 0.1% in 2011 to 17% in 2021. (3)The water resources ecological footprint per 10,000 GDP demonstrates a notable declining trend, indicating an enhancement in water resources utilization efficiency. Jiangxi province displays the highest water resources ecological footprint per 10,000 GDP, while Hubei province exhibits the lowest. Nonetheless, the gap between them is gradually narrowing each year.(4)The pressure index, state index, and response index in the three provinces generally depict decreasing, increasing, and increasing trends, respectively. The decline in the pressure index is more pronounced, while the rise in the other indices is limited. The comprehensive index for all three provinces fluctuates with an upward tendency. Although stable overall, the provinces exhibit minor discrepancies in their indices. However, none have surpassed the historical best levels. [Conclusion]The overall sustainability level of water resources utilization in the three provinces remains stable, with significant room for improvement. Continued efforts are necessary to enhance the production and domestic water, promote the ecological water, and advance measures for sustainable water resources utilization. These steps aim to elevate the level of sustainable water resource utilization. The findings of this study can serve as a reference for decision-making regarding water resources sustainability in the middle reaches of the Yangtze River and other provinces, cities, urban clusters, or basin areas.
[Objective]The middle reaches of the Yangtze River serve as a crucial support for ecological preservation and economic development within the Yangtze River basin. Despite its abundant water resources, issues concerning water resource consumption remain significant. [Methods]This study focuses on the provinces of Hubei, Hunan, and Jiangxi in the middle reaches of the Yangtze River, analyzing data from 2011 to 2021. Employing the water resource ecological footprint model, the research conducts a temporal and spatial analysis of ecological footprints and related indicators in these regions. Furthermore, utilizing the Pressure-State-Response (PSR) framework and ecological footprint indicators, an evaluation index system for sustainable water resource utilization in the middle reaches of the Yangtze River is constructed. The study calculates pressure indices, state indices, response indices and comprehensive indices for the three provinces. [Results](1)Per capita water resources ecological footprints and carrying capacity in the three provinces show an overall increasing trend, with the carrying capacity exceeding the ecological footprint, leading to an ecological surplus. This indicates a generally favorable water resources ecological status in the provinces. Jiangxi province exhibits the highest per capita water resources ecological surplus ranging between 3.186 and 7.966, while Hubei province records the lowest ranging from 0.304 to 2.603. (2)Production water holds the largest share in the water accounts of the ecological footprints in all three provinces, followed by domestic water. Although environmental water accounts for the smallest share, it exhibits the most significant increase. Notably, Hubei province shows a substantial increase in per capita environmental water footprint, rising from 0.1% in 2011 to 17% in 2021. (3)The water resources ecological footprint per 10,000 GDP demonstrates a notable declining trend, indicating an enhancement in water resources utilization efficiency. Jiangxi province displays the highest water resources ecological footprint per 10,000 GDP, while Hubei province exhibits the lowest. Nonetheless, the gap between them is gradually narrowing each year.(4)The pressure index, state index, and response index in the three provinces generally depict decreasing, increasing, and increasing trends, respectively. The decline in the pressure index is more pronounced, while the rise in the other indices is limited. The comprehensive index for all three provinces fluctuates with an upward tendency. Although stable overall, the provinces exhibit minor discrepancies in their indices. However, none have surpassed the historical best levels. [Conclusion]The overall sustainability level of water resources utilization in the three provinces remains stable, with significant room for improvement. Continued efforts are necessary to enhance the production and domestic water, promote the ecological water, and advance measures for sustainable water resources utilization. These steps aim to elevate the level of sustainable water resource utilization. The findings of this study can serve as a reference for decision-making regarding water resources sustainability in the middle reaches of the Yangtze River and other provinces, cities, urban clusters, or basin areas.
Abstract:
[Objective] Ecological performance is an important indicator to reflect the stable development of ecological and economic systems, which can show the coordination between ecological protection and high-quality development, and the scientific evaluation of ecological performance is of great significance to the sustainable development of the Yellow River Basin in Shanxi. [Method] Taking the Yellow River Basin in Shanxi as the study area, we constructed a theoretical framework based on the "Pressure-State-Response" model, and applied the methods of InVEST, SFA and coupling coordination degree to evaluate the spatial and temporal interactions of ecological performance from 2010 to 2020, and carried out bottom-up ecological performance optimization partitioning based on the current situation of ecological performance level and spatial distribution characteristics. The optimization zoning of ecological performance was carried out bottom-up based on the current situation of ecological performance level and spatial distribution characteristics. [Result] ①From 2010 to 2020, the ecosystem services index of the Yellow River Basin in Shanxi increased by 2.27%, and the spatial distribution was "north-south vertical, high and low", forming a double-core pattern mainly in the Lvliang Mountains and Taiyue Mountains-Zhongtiao Mountains. ②From 2010 to 2020, the ecological efficiency of the Yellow River Basin in Shanxi increased by 43.48%, and the spatial distribution was "low in the centre and high in the periphery".③From 2010 to 2020, the ecological performance of the Yellow River Basin in Shanxi increased by 35.29%, with a spatial distribution of "low in the centre and high in the periphery". ④Based on the characteristics of spatial differentiation of ecological performance, the study area was divided into ecological performance remodelling area, ecological performance improvement area, ecological performance buffer area, ecological performance enhancement area and ecological performance conservation area, and the targeted ecological performance improvement paths were proposed. [Conclusion] The study breaks through the traditional understanding and evaluation of ecological performance, and proposes a coupled evaluation system of “ecosystem services +ecological efficiency”, which provides a new way of thinking for the study of ecological performance.
[Objective] Ecological performance is an important indicator to reflect the stable development of ecological and economic systems, which can show the coordination between ecological protection and high-quality development, and the scientific evaluation of ecological performance is of great significance to the sustainable development of the Yellow River Basin in Shanxi. [Method] Taking the Yellow River Basin in Shanxi as the study area, we constructed a theoretical framework based on the "Pressure-State-Response" model, and applied the methods of InVEST, SFA and coupling coordination degree to evaluate the spatial and temporal interactions of ecological performance from 2010 to 2020, and carried out bottom-up ecological performance optimization partitioning based on the current situation of ecological performance level and spatial distribution characteristics. The optimization zoning of ecological performance was carried out bottom-up based on the current situation of ecological performance level and spatial distribution characteristics. [Result] ①From 2010 to 2020, the ecosystem services index of the Yellow River Basin in Shanxi increased by 2.27%, and the spatial distribution was "north-south vertical, high and low", forming a double-core pattern mainly in the Lvliang Mountains and Taiyue Mountains-Zhongtiao Mountains. ②From 2010 to 2020, the ecological efficiency of the Yellow River Basin in Shanxi increased by 43.48%, and the spatial distribution was "low in the centre and high in the periphery".③From 2010 to 2020, the ecological performance of the Yellow River Basin in Shanxi increased by 35.29%, with a spatial distribution of "low in the centre and high in the periphery". ④Based on the characteristics of spatial differentiation of ecological performance, the study area was divided into ecological performance remodelling area, ecological performance improvement area, ecological performance buffer area, ecological performance enhancement area and ecological performance conservation area, and the targeted ecological performance improvement paths were proposed. [Conclusion] The study breaks through the traditional understanding and evaluation of ecological performance, and proposes a coupled evaluation system of “ecosystem services +ecological efficiency”, which provides a new way of thinking for the study of ecological performance.
Abstract:
[Objective] To investigate the effect of erosion and sedimentation on the form, concentration and enrichment characteristics of heavy metals in soil, so as to further understand the mechanism of the influence of erosion and sedimentation on the form, concentration and enrichment of heavy metals in soil, and provide scientific reference for the prevention and control of soil heavy metal pollution in river basins. [Methods] Based on the relevant articles about the influence of erosion-deposition on heavy metals in soil, the key factors affecting heavy metals in soil during erosion-deposition were systematically studied. [Results] (1) Erosion causes differences in the spatial distribution of heavy metal content in soil through runoff erosion, rainfall promotes the transformation of the form of heavy metal from granular to soluble, and the form of heavy metal may be transformed under sedimentation. Soil aggregates and clay contents in sedimentary environment affect the distribution and enrichment of heavy metals. (2) Organic matter has dual effects on heavy metals, which can adsorb free heavy metal ions, reduce the exchange state content of heavy metals in soil, and can also be complexed with heavy metals to increase the organic binding state content of heavy metals. (3) Soil hydrogenionconcentration (pH) and cationexchangecapacity (CEC) have significant effects on the transformation of heavy metal forms. Under acidic conditions, the complexation and precipitation between heavy metal ions are promoted, while under alkaline conditions, the positive charge on the surface of soil particles increases and repelling the positive charge carried by soil heavy metal ions, thus affecting the adsorption between the surface of soil particles and heavy metal ions. (4) Generally, the higher the soil moisture, the greater the solubility of heavy metals, but excessive water will lead to insufficient oxygen and reduce the redox potential, thus affecting the reduction release of heavy metals. Changes in the redox potential (Eh) directly affect the stability of iron and manganese oxides and sulfides in the soil, and then affect the concentration change of heavy metals. [Conclusion] The form, concentration and enrichment characteristics of heavy metals in soil during erosion-deposition process are affected by various environmental factors, showing significant differences from the erosion area to the deposition area. Future studies should further explore the mechanism and mechanism of soil heavy metal form transformation under different environmental conditions, and clarify the specific influence of soil aggregate and texture on the enrichment characteristics of heavy metals. A more accurate model of heavy metal migration in soil was established.
[Objective] To investigate the effect of erosion and sedimentation on the form, concentration and enrichment characteristics of heavy metals in soil, so as to further understand the mechanism of the influence of erosion and sedimentation on the form, concentration and enrichment of heavy metals in soil, and provide scientific reference for the prevention and control of soil heavy metal pollution in river basins. [Methods] Based on the relevant articles about the influence of erosion-deposition on heavy metals in soil, the key factors affecting heavy metals in soil during erosion-deposition were systematically studied. [Results] (1) Erosion causes differences in the spatial distribution of heavy metal content in soil through runoff erosion, rainfall promotes the transformation of the form of heavy metal from granular to soluble, and the form of heavy metal may be transformed under sedimentation. Soil aggregates and clay contents in sedimentary environment affect the distribution and enrichment of heavy metals. (2) Organic matter has dual effects on heavy metals, which can adsorb free heavy metal ions, reduce the exchange state content of heavy metals in soil, and can also be complexed with heavy metals to increase the organic binding state content of heavy metals. (3) Soil hydrogenionconcentration (pH) and cationexchangecapacity (CEC) have significant effects on the transformation of heavy metal forms. Under acidic conditions, the complexation and precipitation between heavy metal ions are promoted, while under alkaline conditions, the positive charge on the surface of soil particles increases and repelling the positive charge carried by soil heavy metal ions, thus affecting the adsorption between the surface of soil particles and heavy metal ions. (4) Generally, the higher the soil moisture, the greater the solubility of heavy metals, but excessive water will lead to insufficient oxygen and reduce the redox potential, thus affecting the reduction release of heavy metals. Changes in the redox potential (Eh) directly affect the stability of iron and manganese oxides and sulfides in the soil, and then affect the concentration change of heavy metals. [Conclusion] The form, concentration and enrichment characteristics of heavy metals in soil during erosion-deposition process are affected by various environmental factors, showing significant differences from the erosion area to the deposition area. Future studies should further explore the mechanism and mechanism of soil heavy metal form transformation under different environmental conditions, and clarify the specific influence of soil aggregate and texture on the enrichment characteristics of heavy metals. A more accurate model of heavy metal migration in soil was established.
Abstract:
[Objective] In order to clarify the diversity of herbaceous plants in the herbaceous felt layer in Ngoring Lake area, and the measures to prevent and control the damage of landslides, this study was conducted to investigate the diversity of herbaceous plants in Ngoring Lake area. On this basis, further carry out the experimental study on the single-root tensile strength characteristics of the root system of the dominant herbaceous plants, so as to provide theoretical basis for the quantitative evaluation of the indexes of single-root tensile strength characteristics of the herbaceous felt layer and the study of the destruction mechanism of the herbaceous felt layer slides in the Ngoring Lake area. [Methods] Based on the results of the sample survey in the study area, single-root tensile tests were carried out on the dominant herbaceous plants in the area; the differences in single-root tensile strength, single-root tensile strength, single-root ultimate elongation and single-root modulus of elasticity of the different herbaceous plants and their relationship with the root diameter were analysed comparatively in different root-diameter levels. [Results] The dominant herbaceous plants in the study area were Carex moorcroftii Falc. ex Boott, Astragalus polycladus Bur. et Franch., Artemisia frigida Willd., Poa annua L., Leontopodium pusillum (Beauverd) Hand.-Mazz. and Lagotis brachystachya Maxim. Under the condition of root diameter range of 0.10~0.60 mm, the single root tensile force and single root tensile strength of the above six herbaceous plants showed the trend of power function growth and power function decrease with the increase of root diameter, respectively, respectively, and there was no significant functional relationship between the single root ultimate elongation and single root elastic modulus and root diameter. Considering the mechanical property indexes of single root tensile resistance, species importance value and root type of different plant types, Poa annua L. had the best soil fixation capacity in Ngoring Lake area. [Conclusion] The root systems of the six dominant herbaceous plants in the study area have better soil-fixing potential, among which the Poa annua L. has the strongest soil-fixing ability, and the results of this study can provide a certain basis for the soil and water conservation project in the Ngoring Lake area.
[Objective] In order to clarify the diversity of herbaceous plants in the herbaceous felt layer in Ngoring Lake area, and the measures to prevent and control the damage of landslides, this study was conducted to investigate the diversity of herbaceous plants in Ngoring Lake area. On this basis, further carry out the experimental study on the single-root tensile strength characteristics of the root system of the dominant herbaceous plants, so as to provide theoretical basis for the quantitative evaluation of the indexes of single-root tensile strength characteristics of the herbaceous felt layer and the study of the destruction mechanism of the herbaceous felt layer slides in the Ngoring Lake area. [Methods] Based on the results of the sample survey in the study area, single-root tensile tests were carried out on the dominant herbaceous plants in the area; the differences in single-root tensile strength, single-root tensile strength, single-root ultimate elongation and single-root modulus of elasticity of the different herbaceous plants and their relationship with the root diameter were analysed comparatively in different root-diameter levels. [Results] The dominant herbaceous plants in the study area were Carex moorcroftii Falc. ex Boott, Astragalus polycladus Bur. et Franch., Artemisia frigida Willd., Poa annua L., Leontopodium pusillum (Beauverd) Hand.-Mazz. and Lagotis brachystachya Maxim. Under the condition of root diameter range of 0.10~0.60 mm, the single root tensile force and single root tensile strength of the above six herbaceous plants showed the trend of power function growth and power function decrease with the increase of root diameter, respectively, respectively, and there was no significant functional relationship between the single root ultimate elongation and single root elastic modulus and root diameter. Considering the mechanical property indexes of single root tensile resistance, species importance value and root type of different plant types, Poa annua L. had the best soil fixation capacity in Ngoring Lake area. [Conclusion] The root systems of the six dominant herbaceous plants in the study area have better soil-fixing potential, among which the Poa annua L. has the strongest soil-fixing ability, and the results of this study can provide a certain basis for the soil and water conservation project in the Ngoring Lake area.
Abstract:
[Objective] The conversion of farmland to non-agricultural uses poses a threat to food security. However, there is currently few research on the characteristics and causes of farmland conversion in hilly areas. This study takes northeastern Guangdong Province (NGP) as an example to explore the patterns and mechanisms of farmland conversion in hilly regions, providing theoretical guidance for preventing farmland conversion. [Methods] Using land use images from NGP in 1990, 2000, 2010, and 2020, the information on farmland conversion was extracted. Spatial autocorrelation analysis and the optimal parameter geographic detector method were employed to investigate the spatial-temporal distribution and influencing factors of farmland conversion. [Results] (1) From 1990 to 2020, cropland non-agriculturalization in NGP exhibited a trend of "steady development followed by a sharp decline," with a cumulative non-agriculturalized area of 228,537.63 hectares and a non-agriculturalization rate of 25.31%. Forest land and construction land were the primary types of non-agriculturalization. (2) Vertically, cropland above 1000 meters in elevation and with a slope of 25-35° is more prone to non-agriculturalization; horizontally, cropland within 50 meters of construction land and 1000-1500 meters from rivers is more likely to undergo non-agriculturalization. (3) Cropland non-agriculturalization in NGP exhibits significant positive clustering, with Molan’s I gradually decreasing from 0.371 to 0.255. The changes in "high-high" clustering and "low-low" clustering dominated the evolution of the spatial autocorrelation pattern of cropland non-agriculturalization rates. (4) Agricultural population and cropland fragmentation consistently had strong explanatory power for the spatial distribution of cropland non-agriculturalization, while the explanatory power of socio-economic factors for non-agriculturalization has weakened over the past decade. The interaction of multiple factors, especially agricultural and socio-economic factors, can further enhance the explanatory power for cropland non-agriculturalization. [Conclusion] Over the past 30 years, the area and spatial clustering of farmland conversion in NGP have declined. However, the impact of agricultural population and farmland fragmentation on farmland conversion has intensified. It is suggested to reasonably control the speed of urban expansion, consolidate fragmented farmland, introduce small-scale agricultural machinery to improve farming conditions, and encourage farmers to cultivate by promoting rural e-commerce, in order to address the issue of farmland non-agriculturalization.
[Objective] The conversion of farmland to non-agricultural uses poses a threat to food security. However, there is currently few research on the characteristics and causes of farmland conversion in hilly areas. This study takes northeastern Guangdong Province (NGP) as an example to explore the patterns and mechanisms of farmland conversion in hilly regions, providing theoretical guidance for preventing farmland conversion. [Methods] Using land use images from NGP in 1990, 2000, 2010, and 2020, the information on farmland conversion was extracted. Spatial autocorrelation analysis and the optimal parameter geographic detector method were employed to investigate the spatial-temporal distribution and influencing factors of farmland conversion. [Results] (1) From 1990 to 2020, cropland non-agriculturalization in NGP exhibited a trend of "steady development followed by a sharp decline," with a cumulative non-agriculturalized area of 228,537.63 hectares and a non-agriculturalization rate of 25.31%. Forest land and construction land were the primary types of non-agriculturalization. (2) Vertically, cropland above 1000 meters in elevation and with a slope of 25-35° is more prone to non-agriculturalization; horizontally, cropland within 50 meters of construction land and 1000-1500 meters from rivers is more likely to undergo non-agriculturalization. (3) Cropland non-agriculturalization in NGP exhibits significant positive clustering, with Molan’s I gradually decreasing from 0.371 to 0.255. The changes in "high-high" clustering and "low-low" clustering dominated the evolution of the spatial autocorrelation pattern of cropland non-agriculturalization rates. (4) Agricultural population and cropland fragmentation consistently had strong explanatory power for the spatial distribution of cropland non-agriculturalization, while the explanatory power of socio-economic factors for non-agriculturalization has weakened over the past decade. The interaction of multiple factors, especially agricultural and socio-economic factors, can further enhance the explanatory power for cropland non-agriculturalization. [Conclusion] Over the past 30 years, the area and spatial clustering of farmland conversion in NGP have declined. However, the impact of agricultural population and farmland fragmentation on farmland conversion has intensified. It is suggested to reasonably control the speed of urban expansion, consolidate fragmented farmland, introduce small-scale agricultural machinery to improve farming conditions, and encourage farmers to cultivate by promoting rural e-commerce, in order to address the issue of farmland non-agriculturalization.
Abstract:
[Objective] China's important natural forest distribution area is located in Heilongjiang, Jilin, Liaoning in the northeast of the three provinces, including the north of the Greater Khingan Mountains, Lesser Khingan Mountains and Changbai Mountain. Under the influence of decades of forest management measures such as forest tending, forest fire protection and drought disturbance in China, the Net Primary Productivity (NPP) of forests in this region has changed accordingly, which has an impact on the forest carbon cycle. In this paper, the effects of forest management and drought disturbance on forest NPP in this region from 2000 to 2022 were numerically compared, and scientific support was provided for natural forests in Northeast China to cope with climate change and realize sustainable forest management. [Methods] Based on NPP remote sensing data MOD17A3 and GLASS_NPP and land use data during 2000 to 2022, combined with forest vegetation transfer matrix, this paper obtained the net increment of forest NPP in the three northeastern provinces under forest management strategy. Meanwhile, Standardized Precipitation Evapotranspiration Index (SPEI), NPP anomaly index and Pearson correlation analysis were used to standardize precipitation Evapotranspiration index. Quantitative analysis of the effects of severe drought on forest NPP in three provinces of Northeast China. In the analysis, according to the main topography and forest type distribution of the study area, the forests of the three provinces in Northeast China are divided into three regions, namely forest area one mainly located in the Greater Khingan Mountains, forest area two mainly located in the Lesser Khingan Mountains and forest area three mainly located in the Changbai Mountain, which are simply referred to as forest area I, II, III. [Results] (1) The average annual growth rate of forest NPP in the three northeastern provinces from 2000 to 2022 was 1.54%, and the spatial distribution of NPP varied significantly. The NPP average of forest area III was the highest, and the NPP growth trend of forest areas I and II were more significant. Over the past 23 years, drought in the three northeastern provinces has been mitigated, and the area of severe drought zone has gradually shrunk from a large area in the west in 2000 to 2002 and moved north to the northwest of Heilongjiang Province in 2008. (2) As forest management continues, the increase of forest area and the conversion of low NPP vegetation to high NPP vegetation over the past 23 years in the forested areas of the three northeastern provinces were the important reasons for the growth of forest NPP in the site by 15.20 TgC, with the highest percentage of increase in the area of deciduous broadleaved forests, which amounted to 43.29%. (3) Forest NPP and SPEI in the three northeastern provinces showed a significant positive correlation (R=0.60, P<0.01); and also showed highly significant positive correlation (P<0.01) in forest areas I (R=0.57) and II (R=0.79), where forest NPP decreased with drought. Heavy drought decreased forest NPP in the three northeastern provinces by 11.09 TgC during 23 years. [Conclusion] Drought disturbance under climate change and forest management simultaneously affected forest NPP negatively and positively in the three northeastern provinces, but the latter was greater than the former, and forest NPP increased. Among them, the sensitivity to drought was much higher in the Greater and Lesser Khingan Mountains forests than in the Changbai Mountain forests.
[Objective] China's important natural forest distribution area is located in Heilongjiang, Jilin, Liaoning in the northeast of the three provinces, including the north of the Greater Khingan Mountains, Lesser Khingan Mountains and Changbai Mountain. Under the influence of decades of forest management measures such as forest tending, forest fire protection and drought disturbance in China, the Net Primary Productivity (NPP) of forests in this region has changed accordingly, which has an impact on the forest carbon cycle. In this paper, the effects of forest management and drought disturbance on forest NPP in this region from 2000 to 2022 were numerically compared, and scientific support was provided for natural forests in Northeast China to cope with climate change and realize sustainable forest management. [Methods] Based on NPP remote sensing data MOD17A3 and GLASS_NPP and land use data during 2000 to 2022, combined with forest vegetation transfer matrix, this paper obtained the net increment of forest NPP in the three northeastern provinces under forest management strategy. Meanwhile, Standardized Precipitation Evapotranspiration Index (SPEI), NPP anomaly index and Pearson correlation analysis were used to standardize precipitation Evapotranspiration index. Quantitative analysis of the effects of severe drought on forest NPP in three provinces of Northeast China. In the analysis, according to the main topography and forest type distribution of the study area, the forests of the three provinces in Northeast China are divided into three regions, namely forest area one mainly located in the Greater Khingan Mountains, forest area two mainly located in the Lesser Khingan Mountains and forest area three mainly located in the Changbai Mountain, which are simply referred to as forest area I, II, III. [Results] (1) The average annual growth rate of forest NPP in the three northeastern provinces from 2000 to 2022 was 1.54%, and the spatial distribution of NPP varied significantly. The NPP average of forest area III was the highest, and the NPP growth trend of forest areas I and II were more significant. Over the past 23 years, drought in the three northeastern provinces has been mitigated, and the area of severe drought zone has gradually shrunk from a large area in the west in 2000 to 2002 and moved north to the northwest of Heilongjiang Province in 2008. (2) As forest management continues, the increase of forest area and the conversion of low NPP vegetation to high NPP vegetation over the past 23 years in the forested areas of the three northeastern provinces were the important reasons for the growth of forest NPP in the site by 15.20 TgC, with the highest percentage of increase in the area of deciduous broadleaved forests, which amounted to 43.29%. (3) Forest NPP and SPEI in the three northeastern provinces showed a significant positive correlation (R=0.60, P<0.01); and also showed highly significant positive correlation (P<0.01) in forest areas I (R=0.57) and II (R=0.79), where forest NPP decreased with drought. Heavy drought decreased forest NPP in the three northeastern provinces by 11.09 TgC during 23 years. [Conclusion] Drought disturbance under climate change and forest management simultaneously affected forest NPP negatively and positively in the three northeastern provinces, but the latter was greater than the former, and forest NPP increased. Among them, the sensitivity to drought was much higher in the Greater and Lesser Khingan Mountains forests than in the Changbai Mountain forests.
Abstract:
[Objective]To explore the effects of different soil and water conservation measures on soil nutrients and plant diversity in open pit coal mine dumps, and to provide feasible technical measures for ecological restoration of mine dumps and other abandoned lands.[Methods]Eight soil and water conservation measures combining soil and water conservation engineering measures and plant measures were deployed on the exposed slopes of the grassland open pit coal mine discharge site, with no measures (CK) as the control, using sample methods to investigate the characteristics of the plant community and to determine the main physicochemical properties of the soil, to compare and analyze the differences in the changes in the characteristics of the plant community and soil properties of the different soil and water conservation measures, and to analyze the redundancy method to analyze the relationship between the characteristics of the plant community and the characteristics of the soil. The redundancy method was used to analyze the correlation between plant community characteristics and soil properties.[Result]The soil and water conservation measures taken on the slope of the discharge site had different degrees of influence on the main physicochemical properties of the soil, in which the soil quick-acting nutrient content changed significantly (P<0.05), and the soil quick-acting phosphorus content of the two measures, spreading mixed grass + ecological bag spacing 1m (Ⅱ) and spreading mixed grass + ecological bag spacing 2m (Ⅲ), reached 3.38 mg/kg and 3.13 mg/kg, which increased 53.6% and 42.3% compared with that of the control (CK) (2.20mg/kg) respectively. 2.20 mg/kg) increased by 53.6% and 42.3%, respectively. The soil quick-effect potassium content of the three measures of spreading mixed grass + ecological bag spacing 2 m (Ⅲ), spreading mixed grass + geocell (Ⅶ), spreading mixed grass + grass curtain (Ⅷ) was 108.25 mg/kg, 126.25 mg/kg, 124.00 mg/kg, and the soil quick-effect potassium content of the control plot was only 53.25 mg/kg. The effects of soil and water conservation measures on plant community characteristics were mainly manifested in the Simpson's dominance index, which was significantly higher than that of the control (CK), except for the insignificant differences (P>0.05) between the spreading of sedge + salix psammophila sand barriers (Ⅵ) and the spreading of sedge + geocell (Ⅶ) (P<0.05). The results of redundancy analysis showed that Margalef richness, Simpson dominance index and Shannon-Wiener diversity index were all significantly positively correlated with soil quick-acting phosphorus; Louie evenness index was significantly positively correlated with soil total nitrogen, quick-acting potassium and slow-acting potassium.[Conclusion]The implementation of soil and water conservation measures in open-pit coal mine dumps can improve the soil nutrient content and plant diversity, which has a positive effect on ecological restoration; the soil and water conservation measures of spreading mixed grass + ecological bag with an interval of 2m (Ⅲ) and spreading mixed grass + salix psammophila sand barriers (Ⅵ) have a better ecological restoration effect, which can be popularized and applied as the main measures for ecological restoration of dumps in the mining area.
[Objective]To explore the effects of different soil and water conservation measures on soil nutrients and plant diversity in open pit coal mine dumps, and to provide feasible technical measures for ecological restoration of mine dumps and other abandoned lands.[Methods]Eight soil and water conservation measures combining soil and water conservation engineering measures and plant measures were deployed on the exposed slopes of the grassland open pit coal mine discharge site, with no measures (CK) as the control, using sample methods to investigate the characteristics of the plant community and to determine the main physicochemical properties of the soil, to compare and analyze the differences in the changes in the characteristics of the plant community and soil properties of the different soil and water conservation measures, and to analyze the redundancy method to analyze the relationship between the characteristics of the plant community and the characteristics of the soil. The redundancy method was used to analyze the correlation between plant community characteristics and soil properties.[Result]The soil and water conservation measures taken on the slope of the discharge site had different degrees of influence on the main physicochemical properties of the soil, in which the soil quick-acting nutrient content changed significantly (P<0.05), and the soil quick-acting phosphorus content of the two measures, spreading mixed grass + ecological bag spacing 1m (Ⅱ) and spreading mixed grass + ecological bag spacing 2m (Ⅲ), reached 3.38 mg/kg and 3.13 mg/kg, which increased 53.6% and 42.3% compared with that of the control (CK) (2.20mg/kg) respectively. 2.20 mg/kg) increased by 53.6% and 42.3%, respectively. The soil quick-effect potassium content of the three measures of spreading mixed grass + ecological bag spacing 2 m (Ⅲ), spreading mixed grass + geocell (Ⅶ), spreading mixed grass + grass curtain (Ⅷ) was 108.25 mg/kg, 126.25 mg/kg, 124.00 mg/kg, and the soil quick-effect potassium content of the control plot was only 53.25 mg/kg. The effects of soil and water conservation measures on plant community characteristics were mainly manifested in the Simpson's dominance index, which was significantly higher than that of the control (CK), except for the insignificant differences (P>0.05) between the spreading of sedge + salix psammophila sand barriers (Ⅵ) and the spreading of sedge + geocell (Ⅶ) (P<0.05). The results of redundancy analysis showed that Margalef richness, Simpson dominance index and Shannon-Wiener diversity index were all significantly positively correlated with soil quick-acting phosphorus; Louie evenness index was significantly positively correlated with soil total nitrogen, quick-acting potassium and slow-acting potassium.[Conclusion]The implementation of soil and water conservation measures in open-pit coal mine dumps can improve the soil nutrient content and plant diversity, which has a positive effect on ecological restoration; the soil and water conservation measures of spreading mixed grass + ecological bag with an interval of 2m (Ⅲ) and spreading mixed grass + salix psammophila sand barriers (Ⅵ) have a better ecological restoration effect, which can be popularized and applied as the main measures for ecological restoration of dumps in the mining area.
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[Objective] Quantitative analysis and understanding the role of terrace carbon sink and its characteristics are significant for further giving play to the role of terrace carbon sink, consolidating and enhancing the carbon sink capacity of the ecosystem, and aiding in the development of methods for assessing the carbon sequestration capacity of terraces. [Methods] In Wuqi County of the loess hilly and gully region, we selected terraces with operational ages between 1-7 years (T5), 8-12 years (T10), 13-17 years (T15), 18-22 years (T20) and 23-27 years (T25) for our research objects. For baseline comparison, we chose slope cropland without soil and water conservation measures, studying the capabilities of terraces in terms of carbon preservation, emission reduction and carbon sequestration across different years. [Results] ① After the transformation of slope cropland into terraces, we observed an increase in carbon preservation, emission reduction, and carbon sequestration. The annual carbon preservation, emission reduction, and carbon sequestration (0-100 cm) are 0.26, 0.05 and 1.36 t/hm2 respectively. ② Each soil layer of the terraces contributes certain benefits, the carbon sequestration benefits of the surface (0-40 cm) and deep (40-100 cm) soil layers account for 61.50% and 38.50% of the entire soil layer, respectively. ③ With the increase in the operation year of the terrace, the benefits of the terrace surface soil increased significantly, while the benefits of deep soil were slightly improved but remained stable on the whole. The rate of carbon sequestration in surface soil increased from 16.30% of T5 to 51.34% of T25, and that in deep soil increased from 14.00% in T5 to 23.66% of T25. [Conclusion] The terrace in the loess hilly and gully region exhibits significant carbon sink functions, including carbon preservation, emission reduction, and carbon sequestration. Within 27 years of the operation of the terraces, the proportion of the carbon sequestration capacity is the largest, and the increase of the surface soil is more significant. With the increase of terrace operation year, the proportion of carbon preservation in the carbon sink capacity of terrace will gradually increase.
[Objective] Quantitative analysis and understanding the role of terrace carbon sink and its characteristics are significant for further giving play to the role of terrace carbon sink, consolidating and enhancing the carbon sink capacity of the ecosystem, and aiding in the development of methods for assessing the carbon sequestration capacity of terraces. [Methods] In Wuqi County of the loess hilly and gully region, we selected terraces with operational ages between 1-7 years (T5), 8-12 years (T10), 13-17 years (T15), 18-22 years (T20) and 23-27 years (T25) for our research objects. For baseline comparison, we chose slope cropland without soil and water conservation measures, studying the capabilities of terraces in terms of carbon preservation, emission reduction and carbon sequestration across different years. [Results] ① After the transformation of slope cropland into terraces, we observed an increase in carbon preservation, emission reduction, and carbon sequestration. The annual carbon preservation, emission reduction, and carbon sequestration (0-100 cm) are 0.26, 0.05 and 1.36 t/hm2 respectively. ② Each soil layer of the terraces contributes certain benefits, the carbon sequestration benefits of the surface (0-40 cm) and deep (40-100 cm) soil layers account for 61.50% and 38.50% of the entire soil layer, respectively. ③ With the increase in the operation year of the terrace, the benefits of the terrace surface soil increased significantly, while the benefits of deep soil were slightly improved but remained stable on the whole. The rate of carbon sequestration in surface soil increased from 16.30% of T5 to 51.34% of T25, and that in deep soil increased from 14.00% in T5 to 23.66% of T25. [Conclusion] The terrace in the loess hilly and gully region exhibits significant carbon sink functions, including carbon preservation, emission reduction, and carbon sequestration. Within 27 years of the operation of the terraces, the proportion of the carbon sequestration capacity is the largest, and the increase of the surface soil is more significant. With the increase of terrace operation year, the proportion of carbon preservation in the carbon sink capacity of terrace will gradually increase.
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Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
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[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
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[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
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[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
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[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
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[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
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[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
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[Objective] Analyzing the spatial-temporal evolution and influencing factors of carbon emissions in Qingdao City is of great significance for ecological protection and high-quality development.[Methods] Based on the land use data, nighttime light data, and social and economic data of Qingdao city from 2000 to 2020, carbon emissions from land use were calculated. By constructing a fitting model between carbon emissions and nighttime light values, the spatial distribution difference and trend of carbon emissions of different land use types in Qingdao city were revealed. The decoupling status between carbon emissions and economic development in Qingdao city was analyzed through the Tapio decoupling model. The contribution degree of various influencing factors of land use carbon emissions was analyzed by using Kaya decomposition and LMDI models. [Results] ①The net carbon emissions from land use in Qingdao city generally showed an increasing trend from 2000 to 2020. From 13,096,400 tons in 2000 to 36.4820 million tons in 2020, an increase of nearly 1.79 times;②The overall carbon emissions in Qingdao city presented a spatial distribution pattern of "high in the middle and low around", and industrial energy consumption was the main source of carbon emissions from construction land, with high carbon emission areas mainly concentrated in the Jiaozhou Bay area;③The relationship between economic development and carbon emissions in Qingdao city has undergone a transition from "expansion link to weak decoupling to strong decoupling";④The factors that promote the growth of carbon emissions in Qingdao are population size and economic effect, and the factors that inhibit the growth of carbon emissions in Qingdao are energy structure and energy intensity. [Conclusion] In the future, it is necessary to further adjust the industrial structure, accelerate the development of a low-carbon economy, and reduce carbon emissions from the source through measures such as technological innovation and energy structure adjustment.
[Objective] Analyzing the spatial-temporal evolution and influencing factors of carbon emissions in Qingdao City is of great significance for ecological protection and high-quality development.[Methods] Based on the land use data, nighttime light data, and social and economic data of Qingdao city from 2000 to 2020, carbon emissions from land use were calculated. By constructing a fitting model between carbon emissions and nighttime light values, the spatial distribution difference and trend of carbon emissions of different land use types in Qingdao city were revealed. The decoupling status between carbon emissions and economic development in Qingdao city was analyzed through the Tapio decoupling model. The contribution degree of various influencing factors of land use carbon emissions was analyzed by using Kaya decomposition and LMDI models. [Results] ①The net carbon emissions from land use in Qingdao city generally showed an increasing trend from 2000 to 2020. From 13,096,400 tons in 2000 to 36.4820 million tons in 2020, an increase of nearly 1.79 times;②The overall carbon emissions in Qingdao city presented a spatial distribution pattern of "high in the middle and low around", and industrial energy consumption was the main source of carbon emissions from construction land, with high carbon emission areas mainly concentrated in the Jiaozhou Bay area;③The relationship between economic development and carbon emissions in Qingdao city has undergone a transition from "expansion link to weak decoupling to strong decoupling";④The factors that promote the growth of carbon emissions in Qingdao are population size and economic effect, and the factors that inhibit the growth of carbon emissions in Qingdao are energy structure and energy intensity. [Conclusion] In the future, it is necessary to further adjust the industrial structure, accelerate the development of a low-carbon economy, and reduce carbon emissions from the source through measures such as technological innovation and energy structure adjustment.
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[Objective]Within the framework of the dual carbon target vision, addressing the scale effects of forest land changes and quantifying the carbon sequestration benefits at multiple watershed levels not only introduce a fresh perspective into forest land research but also aid in cording and optimizing the forest land pattern. That holds great significance in enhancing future regional carbon sequestration potential.[Methods]Focusing on Chongqing as the study area, we analyzed the spatiotemporal dynamic changes in forest land and carbon storage from 2000 to 2030 at the multi-watershed scale, utilizing PLUS model, landscape pattern indices, biomass expansion factor method and grey correlation degree. Furthermore, we explored the correlation between forest land pattern changes and carbon storage under natural development scenarios.[Results](1)Between 2000 and 2020,the forest area increased by 3404.55 km2,primarily due to the conversion of cultivated land. The forest landscape pattern in the first-grade watershed showed a tendency towards clustering and regularity, with a relatively reduced degree of fragmentation. There were distinct differences in the historical laws and future trends of forest landscape pattern changes in the secondary watershed’s “district and group”.(2)In the initial two decades, the carbon storage of forest land exhibited an increasing-decreasing trend, resulting in an overall increase. The Dongting Lake system in the first level basin witnessed the highest increase in carbon storage, and the high-value area of carbon storage increment in the seconde level basin shifted from north to south.(3)The total carbon storage is predicted to increase by 2030 which is strongly correlated with the irregular index. The scale effect leads to the spatial heterogeneity of landscape pattern change and the correlation degree between landscape pattern index and carbon storage in the primary and secondary basins.[Conclusion]The research outcome contribute to understanding the patterns of forest land changes from a cross-watershed scale perspective. This, in turn, provides a scientific foundation for the Ministry of Natural Resource or relevant forestry departments to formulate effective utilization and protection policies for forest land resources at different scales, It also supports the sustainable development of Chongqing, enhances carbon sink efficiency, and facilitates the achievement of carbon neutrality goals.
[Objective]Within the framework of the dual carbon target vision, addressing the scale effects of forest land changes and quantifying the carbon sequestration benefits at multiple watershed levels not only introduce a fresh perspective into forest land research but also aid in cording and optimizing the forest land pattern. That holds great significance in enhancing future regional carbon sequestration potential.[Methods]Focusing on Chongqing as the study area, we analyzed the spatiotemporal dynamic changes in forest land and carbon storage from 2000 to 2030 at the multi-watershed scale, utilizing PLUS model, landscape pattern indices, biomass expansion factor method and grey correlation degree. Furthermore, we explored the correlation between forest land pattern changes and carbon storage under natural development scenarios.[Results](1)Between 2000 and 2020,the forest area increased by 3404.55 km2,primarily due to the conversion of cultivated land. The forest landscape pattern in the first-grade watershed showed a tendency towards clustering and regularity, with a relatively reduced degree of fragmentation. There were distinct differences in the historical laws and future trends of forest landscape pattern changes in the secondary watershed’s “district and group”.(2)In the initial two decades, the carbon storage of forest land exhibited an increasing-decreasing trend, resulting in an overall increase. The Dongting Lake system in the first level basin witnessed the highest increase in carbon storage, and the high-value area of carbon storage increment in the seconde level basin shifted from north to south.(3)The total carbon storage is predicted to increase by 2030 which is strongly correlated with the irregular index. The scale effect leads to the spatial heterogeneity of landscape pattern change and the correlation degree between landscape pattern index and carbon storage in the primary and secondary basins.[Conclusion]The research outcome contribute to understanding the patterns of forest land changes from a cross-watershed scale perspective. This, in turn, provides a scientific foundation for the Ministry of Natural Resource or relevant forestry departments to formulate effective utilization and protection policies for forest land resources at different scales, It also supports the sustainable development of Chongqing, enhances carbon sink efficiency, and facilitates the achievement of carbon neutrality goals.
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[Objective] To In order to better monitor and evaluate the ecological quality of hilly areas, it is necessary to construct a accurate remote sensing ecological index of middle and high vegetation areas, and explore the influencing factors of its ecological quality, so as to provide scientific support for the balance between development and ecology in Taojiang County. [Method] To address the saturation issue of the Normalized Difference Vegetation Index (NDVI) in densely vegetated areas, this study introduces the kernel Normalized Difference Vegetation Index (kNDVI) and integrates it with humidity, dryness, and heat factors to formulate a Modified Remote Sensing Ecology Index (MRSEI). Utilizing this index, the ecological environment quality and its temporal variation in Taojiang County from 2000 to 2021 were quantified. Additionally, a parameter optimized geographic detector model was employed to analyze the driving forces of six influencing factors, including vegetation coverage, precipitation, temperature, land use, altitude, and population density. [Result] (1) Compared with the RSEI model, the MRSEI model can effectively address the issue of NDVI saturation in areas with high vegetation cover, enabling a more precise monitoring of the ecological environment in Taojiang County; (2) The average RSEI values for the five periods from 2000 to 2021 in the study area were 0.77, 0.84, 0.83, 0.75 and 0.79, respectively, indicating a satisfactory performance in ecological environment quality with a trend of improvement-deterioration-improvement; (3) From the analysis of the factors influencing ecological environment quality, land use emerges as a key factor determinant in the study area. In the factor interactive detection analysis, the interaction between land use and elevation were strongest. [Conclusion] In summary, variation of the ecological environment quality in Taojiang County is primarily influenced by a combination of natural and anthropogenic factors. The research results can provide technical reference for carrying out effective ecological environment protection and restoration measures in Taojiang County.
[Objective] To In order to better monitor and evaluate the ecological quality of hilly areas, it is necessary to construct a accurate remote sensing ecological index of middle and high vegetation areas, and explore the influencing factors of its ecological quality, so as to provide scientific support for the balance between development and ecology in Taojiang County. [Method] To address the saturation issue of the Normalized Difference Vegetation Index (NDVI) in densely vegetated areas, this study introduces the kernel Normalized Difference Vegetation Index (kNDVI) and integrates it with humidity, dryness, and heat factors to formulate a Modified Remote Sensing Ecology Index (MRSEI). Utilizing this index, the ecological environment quality and its temporal variation in Taojiang County from 2000 to 2021 were quantified. Additionally, a parameter optimized geographic detector model was employed to analyze the driving forces of six influencing factors, including vegetation coverage, precipitation, temperature, land use, altitude, and population density. [Result] (1) Compared with the RSEI model, the MRSEI model can effectively address the issue of NDVI saturation in areas with high vegetation cover, enabling a more precise monitoring of the ecological environment in Taojiang County; (2) The average RSEI values for the five periods from 2000 to 2021 in the study area were 0.77, 0.84, 0.83, 0.75 and 0.79, respectively, indicating a satisfactory performance in ecological environment quality with a trend of improvement-deterioration-improvement; (3) From the analysis of the factors influencing ecological environment quality, land use emerges as a key factor determinant in the study area. In the factor interactive detection analysis, the interaction between land use and elevation were strongest. [Conclusion] In summary, variation of the ecological environment quality in Taojiang County is primarily influenced by a combination of natural and anthropogenic factors. The research results can provide technical reference for carrying out effective ecological environment protection and restoration measures in Taojiang County.
Abstract:
[Objective] In order to understand the effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after highway project disturbance in alpine wetland, we aim to provide theoretical reference basis for the screening of vegetation restoration model in alpine wetland, the management of soil erosion and the improvement of ecological environment. [Method] The three treatment slopes of natural succession, spraying grass planting and turf mulching and the original undisturbed control vegetation were taken as the research objects, and the soil physicochemical indexes and soil enzyme activities were measured to analyze their interrelationships and influencing factors. [Result] 1) All three restoration measures resulted in a significant increase (P<0.05) in soil pH and total potassium, and a significant decrease (P<0.05) in soil organic matter, total nitrogen, total phosphorus, and fine root biomass compared to the control; effective phosphorus increased and quick-acting potassium decreased compared to the control; the proportion of clayey silt particles in soil particles of the natural succession was not significantly different from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) in the spraying of grasses and turf mulch treatment; the turf mulch richness index did not differ significantly from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) under spraying of grasses and natural succession. The proportion of sticky powder particles in soil particles in the natural succession was not significantly different from that of the control, and the proportion of sticky powder particles in soil particles in the spraying and sodding treatments was significantly lower (P<0.05); the richness indices of sodding were not significantly different from that of the control, and those of spraying and sodding were significantly lower than that of the control (P<0.05), and the soil pH, organic matter, total nitrogen, quick-acting potassium, fine root biomass, and their richness indices in the sodding and sodding treatments were higher than those in the natural succession (P<0.05).2) Sprayed grass and turf replanting restored the four soil enzymes better than natural succession, and even catalase activity was restored to near control levels. 3)The correlation between the four enzyme activities and soil physicochemical properties was significant, and the urease activity was the most sensitive to soil physicochemical properties, which was able to evaluate the soil fertility of plateau wetland slope well. [Conclusion] Compared with natural succession, spraying grass and turf can effectively improve soil physicochemical properties and soil enzyme activity, and soil enzyme can be used as a sensitive indicator for evaluating soil fertility on slopes in plateau wetlands.
[Objective] In order to understand the effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after highway project disturbance in alpine wetland, we aim to provide theoretical reference basis for the screening of vegetation restoration model in alpine wetland, the management of soil erosion and the improvement of ecological environment. [Method] The three treatment slopes of natural succession, spraying grass planting and turf mulching and the original undisturbed control vegetation were taken as the research objects, and the soil physicochemical indexes and soil enzyme activities were measured to analyze their interrelationships and influencing factors. [Result] 1) All three restoration measures resulted in a significant increase (P<0.05) in soil pH and total potassium, and a significant decrease (P<0.05) in soil organic matter, total nitrogen, total phosphorus, and fine root biomass compared to the control; effective phosphorus increased and quick-acting potassium decreased compared to the control; the proportion of clayey silt particles in soil particles of the natural succession was not significantly different from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) in the spraying of grasses and turf mulch treatment; the turf mulch richness index did not differ significantly from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) under spraying of grasses and natural succession. The proportion of sticky powder particles in soil particles in the natural succession was not significantly different from that of the control, and the proportion of sticky powder particles in soil particles in the spraying and sodding treatments was significantly lower (P<0.05); the richness indices of sodding were not significantly different from that of the control, and those of spraying and sodding were significantly lower than that of the control (P<0.05), and the soil pH, organic matter, total nitrogen, quick-acting potassium, fine root biomass, and their richness indices in the sodding and sodding treatments were higher than those in the natural succession (P<0.05).2) Sprayed grass and turf replanting restored the four soil enzymes better than natural succession, and even catalase activity was restored to near control levels. 3)The correlation between the four enzyme activities and soil physicochemical properties was significant, and the urease activity was the most sensitive to soil physicochemical properties, which was able to evaluate the soil fertility of plateau wetland slope well. [Conclusion] Compared with natural succession, spraying grass and turf can effectively improve soil physicochemical properties and soil enzyme activity, and soil enzyme can be used as a sensitive indicator for evaluating soil fertility on slopes in plateau wetlands.
Abstract:
[Objective] This study explores the effects of long-term Caragana korshinskii (C. korshinskii) plantation on the stability of soil aggregates and erodibility on the loess hilly slopes, providing theoretical support for artificial vegetation construction and ecological restoration in the Loess Plateau region. [Methods] Grassy slope was used as a comparison, C. korshinskii plots with different plantation durations (15, 25, 35 years) along contour lines on slopes were selected as research subjects. The study analyzed the characteristics of changes in soil aggregate stability and erodibility due to long-term C. korshinskii plantation, as well as the main influencing factors. [Results] (1) The soil aggregate stability indicators, mean weight diameter (MWD), geometric mean diameter (GMD), and the content of aggregates >0.25 mm (WR0.25), generally showed a trend of 15-year C. korshinskii plantation > barren grassy land > 25-year C. korshinskii plantation > 35-year C. korshinskii plantation. In terms of slope position, the order was bottom slope > top slope > mid-slope > upper slope. Conversely, the soil erodibility K factor exhibited an opposite trend. (2) With the increase in the plantation duration of C. korshinskii compared to barren grassy land, soil aggregate stability indicators initially increased and then decreased, while the stability in the intervals of barren grassy strips continuously declined. The difference between the two became more pronounced after the plantation duration exceeded 15 years, especially at the bottom slope. (3) Soil organic carbon and slope position were the main factors influencing the soil aggregation stability and erodibility on the slope, explaining 38% and 4.1% of the variation, respectively, followed by planting duration and altitude. [Conclusion] Strip plantation of C. korshinskii on the loess hilly slopes affects the distribution of soil organic carbon, thereby influencing soil aggregate stability and erodibility. Plantation for less than 15 years contributes to the improvement of soil aggregate stability and the reduction of erodibility, but a reverse trend gradually emerges with more extended plantation, particularly at the bottom slope locations.
[Objective] This study explores the effects of long-term Caragana korshinskii (C. korshinskii) plantation on the stability of soil aggregates and erodibility on the loess hilly slopes, providing theoretical support for artificial vegetation construction and ecological restoration in the Loess Plateau region. [Methods] Grassy slope was used as a comparison, C. korshinskii plots with different plantation durations (15, 25, 35 years) along contour lines on slopes were selected as research subjects. The study analyzed the characteristics of changes in soil aggregate stability and erodibility due to long-term C. korshinskii plantation, as well as the main influencing factors. [Results] (1) The soil aggregate stability indicators, mean weight diameter (MWD), geometric mean diameter (GMD), and the content of aggregates >0.25 mm (WR0.25), generally showed a trend of 15-year C. korshinskii plantation > barren grassy land > 25-year C. korshinskii plantation > 35-year C. korshinskii plantation. In terms of slope position, the order was bottom slope > top slope > mid-slope > upper slope. Conversely, the soil erodibility K factor exhibited an opposite trend. (2) With the increase in the plantation duration of C. korshinskii compared to barren grassy land, soil aggregate stability indicators initially increased and then decreased, while the stability in the intervals of barren grassy strips continuously declined. The difference between the two became more pronounced after the plantation duration exceeded 15 years, especially at the bottom slope. (3) Soil organic carbon and slope position were the main factors influencing the soil aggregation stability and erodibility on the slope, explaining 38% and 4.1% of the variation, respectively, followed by planting duration and altitude. [Conclusion] Strip plantation of C. korshinskii on the loess hilly slopes affects the distribution of soil organic carbon, thereby influencing soil aggregate stability and erodibility. Plantation for less than 15 years contributes to the improvement of soil aggregate stability and the reduction of erodibility, but a reverse trend gradually emerges with more extended plantation, particularly at the bottom slope locations.
Abstract:
［Objective］To explore the effects of snow removal during freezing-thawing period on soil organic carbon components and carbon pool stability in Bayanbulak alpine wetland. ［Methods］A field experiment was conducted in September 2022, with two treatments: snow removal and natural snowfall. The samples were collected during the initial freezing period (November), freezing period (March), and thawing period (July) of the freezing-thawing period, and the soil water content (SWC), electrical conductivity (EC), pH value, soil organic carbon (SOC), very unstable organic carbon (F1), unstable organic carbon (F2), stable organic carbon (F3), and inert organic carbon (F4) were determined. ［Results］There were significant differences in the organic carbon content of F1 and F2 components after snow removal in the initial freezing period (P<0.05), compared with the natural snowfall, the organic carbon content of the two components decreased by 8.72% and 12.26%, respectively. There were significant differences in the organic carbon content of F3 components between different treatments in the freezing period (P<0.05), and the organic carbon content of F3 components decreased by 25.57% after snow removal. There were significant differences in the organic carbon content of F1, F2 and F3 in the thawing period (P<0.05), among which F1 and F3 decreased by 22.10% and 25.57%, respectively, and F2 increased by 34.92%, while there were no significant differences in other components. After snow removal, compared with the natural snowfall treatment, the carbon pool activity increased by 5.99%, 9.71% and 20.39% in the three periods, respectively.［Conclusion］The freeze-thaw cycle and snow removal had no significant effect on the organic carbon content and carbon pool stability, but the effect of snow removal on soil was greater than the freeze-thaw change. Snow removal led to the decrease of soil organic carbon content and the increase of soil organic carbon pool stability, which affected the original stable relationship between soil organic carbon components. With the freeze-thaw process, the soil organic carbon content showed a trend of first decrease and then increase, while the soil carbon pool stability showed a trend of first increase and then decrease.
［Objective］To explore the effects of snow removal during freezing-thawing period on soil organic carbon components and carbon pool stability in Bayanbulak alpine wetland. ［Methods］A field experiment was conducted in September 2022, with two treatments: snow removal and natural snowfall. The samples were collected during the initial freezing period (November), freezing period (March), and thawing period (July) of the freezing-thawing period, and the soil water content (SWC), electrical conductivity (EC), pH value, soil organic carbon (SOC), very unstable organic carbon (F1), unstable organic carbon (F2), stable organic carbon (F3), and inert organic carbon (F4) were determined. ［Results］There were significant differences in the organic carbon content of F1 and F2 components after snow removal in the initial freezing period (P<0.05), compared with the natural snowfall, the organic carbon content of the two components decreased by 8.72% and 12.26%, respectively. There were significant differences in the organic carbon content of F3 components between different treatments in the freezing period (P<0.05), and the organic carbon content of F3 components decreased by 25.57% after snow removal. There were significant differences in the organic carbon content of F1, F2 and F3 in the thawing period (P<0.05), among which F1 and F3 decreased by 22.10% and 25.57%, respectively, and F2 increased by 34.92%, while there were no significant differences in other components. After snow removal, compared with the natural snowfall treatment, the carbon pool activity increased by 5.99%, 9.71% and 20.39% in the three periods, respectively.［Conclusion］The freeze-thaw cycle and snow removal had no significant effect on the organic carbon content and carbon pool stability, but the effect of snow removal on soil was greater than the freeze-thaw change. Snow removal led to the decrease of soil organic carbon content and the increase of soil organic carbon pool stability, which affected the original stable relationship between soil organic carbon components. With the freeze-thaw process, the soil organic carbon content showed a trend of first decrease and then increase, while the soil carbon pool stability showed a trend of first increase and then decrease.
Abstract:
[Objective] A large number of red clay slopes exist in Guizhou Province, and soil erosion and shallow landslides are prominent problems. The use of herbaceous plants to protect red clay slopes is of great significance for shallow landslide management and soil and water conservation in Guizhou Province, but there are fewer related studies. [Methods] With red clay slope as the research object, Cynodon dactylon and Vetiver grass were selected as slope protection plants. The slope protection effect of the two herbaceous plants was investigated through planting test, root tensile test, straight shear test, and indoor simulated scouring test. [Results] ① Within 150 days of planting, both herbaceous plants grew steadily and the tensile strength of the root system continued to increase. From 30 to 150 days of growth, the maximum tensile strength of Cynodon dactylon increased from 0.84N to 8.59N, and that of Vetiver grass increased from 4.78N to 89.89N. ② Comparing the rootless soil at 120 days of growth, the cohesion of Cynodon dactylon root-soil complex increased by 91.1% and the angle of internal friction by 12.45%; the cohesion of Vetiver grass root-soil complex increased by 107.47% and the angle of internal friction by 12.74%. ③ Comparing the bare slope at 150 days of growth, the runoff rate of Cynodon dactylon slope decreased by 45.02% to 54.15%, the sediment yield rate decreased by 58.3% to 93.85%, and the 60-min cumulative sediment yield decreased by 81.02%; the runoff rate of Vetiver grass slope decreased by 35.46% to 46.48%, the sediment yield decreased rate by 46.8% to 89.44%, and the 60-min cumulative sediment yield decreased by 74.61%. [Conclusion] Both herbaceous plants have excellent soil consolidation and slope protection effects on red clay slopes, with Vetiver grass having a more pronounced effect on the increase in soil shear strength, and Cynodon dactylon having a more significant effect on soil and water conservation.
[Objective] A large number of red clay slopes exist in Guizhou Province, and soil erosion and shallow landslides are prominent problems. The use of herbaceous plants to protect red clay slopes is of great significance for shallow landslide management and soil and water conservation in Guizhou Province, but there are fewer related studies. [Methods] With red clay slope as the research object, Cynodon dactylon and Vetiver grass were selected as slope protection plants. The slope protection effect of the two herbaceous plants was investigated through planting test, root tensile test, straight shear test, and indoor simulated scouring test. [Results] ① Within 150 days of planting, both herbaceous plants grew steadily and the tensile strength of the root system continued to increase. From 30 to 150 days of growth, the maximum tensile strength of Cynodon dactylon increased from 0.84N to 8.59N, and that of Vetiver grass increased from 4.78N to 89.89N. ② Comparing the rootless soil at 120 days of growth, the cohesion of Cynodon dactylon root-soil complex increased by 91.1% and the angle of internal friction by 12.45%; the cohesion of Vetiver grass root-soil complex increased by 107.47% and the angle of internal friction by 12.74%. ③ Comparing the bare slope at 150 days of growth, the runoff rate of Cynodon dactylon slope decreased by 45.02% to 54.15%, the sediment yield rate decreased by 58.3% to 93.85%, and the 60-min cumulative sediment yield decreased by 81.02%; the runoff rate of Vetiver grass slope decreased by 35.46% to 46.48%, the sediment yield decreased rate by 46.8% to 89.44%, and the 60-min cumulative sediment yield decreased by 74.61%. [Conclusion] Both herbaceous plants have excellent soil consolidation and slope protection effects on red clay slopes, with Vetiver grass having a more pronounced effect on the increase in soil shear strength, and Cynodon dactylon having a more significant effect on soil and water conservation.
Abstract:
［Objective］This study aims to investigate the soil runoff characteristics on the southern slopes of the Taihang Mountains and explore the influencing factors. The goal is to provide scientific basis for soil erosion control and ecological environment protection in the southern foothills of the Taihang Mountains. ［Methods］The study focuses on the fish scale pits and natural barren slopes on the southern foothills of the Taihang Mountains. The runoff characteristics on the slopes under different vegetation types including herbs, shrubs, and trees were measured, and the influencing factors were analyzed. The geographic detector statistical method was used to quantify the individual and interactive effects of various factors on slope runoff. ［Results］The results indicate the following: (1) There was no significant difference in the average runoff depth between herb, shrub, and tree communities on the fish scale pits. However, the average runoff depth of the shrub and herb communities on the natural barren slopes was significantly greater than that of the tree community. Compared to the natural barren slopes, the average runoff depth decreased by 56.61%, 72.80%, and 39.58% in the herb, shrub, and tree communities on the fish scale pits, respectively. The average runoff depth showed a decreasing trend with increasing gravel content. The control effect of gravel coverage on slope runoff had a threshold, and the minimum slope runoff depth was observed when the gravel coverage ranged from 6% to 9%. (2) The single-factor influence of gravel coverage (0.31) was the highest on slope runoff in the southern foothills of the Taihang Mountains, followed by vegetation coverage (0.29). (3) The interaction of slope runoff influencing factors mostly exhibited nonlinear enhancement and dual-factor enhancement effects. The interaction between rainfall and non-rainfall factors showed nonlinear enhancement effects. ［Conclusion］The presence of a large amount of gravel contributes to the complexity of slope runoff processes in the southern foothills of the Taihang Mountains. Increasing vegetation coverage is an important measure to reduce slope runoff in this region.
［Objective］This study aims to investigate the soil runoff characteristics on the southern slopes of the Taihang Mountains and explore the influencing factors. The goal is to provide scientific basis for soil erosion control and ecological environment protection in the southern foothills of the Taihang Mountains. ［Methods］The study focuses on the fish scale pits and natural barren slopes on the southern foothills of the Taihang Mountains. The runoff characteristics on the slopes under different vegetation types including herbs, shrubs, and trees were measured, and the influencing factors were analyzed. The geographic detector statistical method was used to quantify the individual and interactive effects of various factors on slope runoff. ［Results］The results indicate the following: (1) There was no significant difference in the average runoff depth between herb, shrub, and tree communities on the fish scale pits. However, the average runoff depth of the shrub and herb communities on the natural barren slopes was significantly greater than that of the tree community. Compared to the natural barren slopes, the average runoff depth decreased by 56.61%, 72.80%, and 39.58% in the herb, shrub, and tree communities on the fish scale pits, respectively. The average runoff depth showed a decreasing trend with increasing gravel content. The control effect of gravel coverage on slope runoff had a threshold, and the minimum slope runoff depth was observed when the gravel coverage ranged from 6% to 9%. (2) The single-factor influence of gravel coverage (0.31) was the highest on slope runoff in the southern foothills of the Taihang Mountains, followed by vegetation coverage (0.29). (3) The interaction of slope runoff influencing factors mostly exhibited nonlinear enhancement and dual-factor enhancement effects. The interaction between rainfall and non-rainfall factors showed nonlinear enhancement effects. ［Conclusion］The presence of a large amount of gravel contributes to the complexity of slope runoff processes in the southern foothills of the Taihang Mountains. Increasing vegetation coverage is an important measure to reduce slope runoff in this region.
Abstract:
Abstract：[Objective] To support building a low-carbon agricultural model, promoting agricultural carbon reduction and high-quality regional agriculture development. [Methods] The estimation model of carbon emission from cultivated land and ArcGIS calculation were used to analyze the temporal and spatial characteristics of carbon emission from cultivated land in the urban belt along the Yellow River in Ningxia, and the unexpected output super-efficiency model (SBM) was used to evaluate the ecological efficiency of cultivated land. [Results] (1) The total carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia showed an overall downward trend from 2011 to 2020, and chemical fertilizer and agricultural diesel were the primary sources of carbon emission from cultivated land. (2) The carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia shows a spatial distribution pattern of high in the north-south and low in the middle. Pingluo County and Zhongning County are the largest cultivated land carbon emission cities. (3) The trend of carbon emission intensity of cultivated land in the urban belt along the Yellow River in Ningxia is similar to that of cultivated land. (4) The ecological efficiency of cultivated land use in the urban belt along the Yellow River in Ningxia fluctuates as a whole, and the ecological efficiency of cultivated land in the Litong area is low, so it is necessary to adjust the input factors in the agricultural production process. [Conclusion] To study the temporal and spatial evolution characteristics of carbon emission and ecological efficiency of cultivated land in the urban belt along the Yellow River in Ningxia and explore their key influencing factors. The relevant conclusions can provide a reference for the construction of low-carbon agriculture and accurate policy implementation in Ningxia.
Abstract：[Objective] To support building a low-carbon agricultural model, promoting agricultural carbon reduction and high-quality regional agriculture development. [Methods] The estimation model of carbon emission from cultivated land and ArcGIS calculation were used to analyze the temporal and spatial characteristics of carbon emission from cultivated land in the urban belt along the Yellow River in Ningxia, and the unexpected output super-efficiency model (SBM) was used to evaluate the ecological efficiency of cultivated land. [Results] (1) The total carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia showed an overall downward trend from 2011 to 2020, and chemical fertilizer and agricultural diesel were the primary sources of carbon emission from cultivated land. (2) The carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia shows a spatial distribution pattern of high in the north-south and low in the middle. Pingluo County and Zhongning County are the largest cultivated land carbon emission cities. (3) The trend of carbon emission intensity of cultivated land in the urban belt along the Yellow River in Ningxia is similar to that of cultivated land. (4) The ecological efficiency of cultivated land use in the urban belt along the Yellow River in Ningxia fluctuates as a whole, and the ecological efficiency of cultivated land in the Litong area is low, so it is necessary to adjust the input factors in the agricultural production process. [Conclusion] To study the temporal and spatial evolution characteristics of carbon emission and ecological efficiency of cultivated land in the urban belt along the Yellow River in Ningxia and explore their key influencing factors. The relevant conclusions can provide a reference for the construction of low-carbon agriculture and accurate policy implementation in Ningxia.
Abstract:
[Objective]This study aims to analyze the carbon emission characteristics and driving factors of agriculture and animal husbandry in Qinghai Province, and to provide theoretical and empirical evidence for Qinghai government on how to promote scientifically and orderly the green and low-carbon development of agriculture and animal husbandry.[Methods] Carbon emissions from agriculture and animal husbandry in Qinghai Province during 2000 to 2021 are calculated from consumption of agricultural materials, livestock and poultry breeding, and crop growth. The methods of LMDI and Tapio decoupling models are used to examine the driving factors and decoupling state of carbon emissions from agriculture and animal husbandry, and the future development tendency from 2022 to 2035 is predicted.[Results]①Carbon emissions from agriculture and animal husbandry in Qinghai Province shows a fluctuating upward trend during 2000 to 2021, with an average annual growth rate of 1.61%. Intestinal fermentation and manure management during livestock and poultry breeding are the main sources of carbon emissions, accounting for 94.94% per year.②The effect of the level of agricultural economic development and agricultural structure can increase the carbon emissions, with the annual contribution rates of 39.40% and 16.53%; The effect of agricultural production technology and agricultural labor force can inhibit the carbon emissions , with the annual contribution rates of -37.45% and -6.63%.③On the whole, the decoupling state between carbon emissions and economic growth of agricultural and animal husbandry in Qinghai Province is in weak decoupling. Agricultural production technology and agricultural labor force scale have weak decoupling efforts, while agricultural structure has no decoupling efforts.④From 2022 to 2035, the carbon emissions from agriculture and animal husbandry shows an increasing trend, with an average annual growth rate of 1.23%, and 0.38% lower than that from 2000 to 2021.[Conclusion]: This study contributes to call the attention of Qinghai government and relevant authorities to achieve low-carbon development in agriculture and animal husbandry. Some useful suggestions are put forward as follows: enhance the carbon sequestration capacity of farmland soil, reduce the intensity of intestinal methane emissions from livestock and poultry products, strengthen the leadership of carbon reduction and fixation technology in agriculture and animal husbandry, cultivate high-quality talents in agriculture and animal husbandry.
[Objective]This study aims to analyze the carbon emission characteristics and driving factors of agriculture and animal husbandry in Qinghai Province, and to provide theoretical and empirical evidence for Qinghai government on how to promote scientifically and orderly the green and low-carbon development of agriculture and animal husbandry.[Methods] Carbon emissions from agriculture and animal husbandry in Qinghai Province during 2000 to 2021 are calculated from consumption of agricultural materials, livestock and poultry breeding, and crop growth. The methods of LMDI and Tapio decoupling models are used to examine the driving factors and decoupling state of carbon emissions from agriculture and animal husbandry, and the future development tendency from 2022 to 2035 is predicted.[Results]①Carbon emissions from agriculture and animal husbandry in Qinghai Province shows a fluctuating upward trend during 2000 to 2021, with an average annual growth rate of 1.61%. Intestinal fermentation and manure management during livestock and poultry breeding are the main sources of carbon emissions, accounting for 94.94% per year.②The effect of the level of agricultural economic development and agricultural structure can increase the carbon emissions, with the annual contribution rates of 39.40% and 16.53%; The effect of agricultural production technology and agricultural labor force can inhibit the carbon emissions , with the annual contribution rates of -37.45% and -6.63%.③On the whole, the decoupling state between carbon emissions and economic growth of agricultural and animal husbandry in Qinghai Province is in weak decoupling. Agricultural production technology and agricultural labor force scale have weak decoupling efforts, while agricultural structure has no decoupling efforts.④From 2022 to 2035, the carbon emissions from agriculture and animal husbandry shows an increasing trend, with an average annual growth rate of 1.23%, and 0.38% lower than that from 2000 to 2021.[Conclusion]: This study contributes to call the attention of Qinghai government and relevant authorities to achieve low-carbon development in agriculture and animal husbandry. Some useful suggestions are put forward as follows: enhance the carbon sequestration capacity of farmland soil, reduce the intensity of intestinal methane emissions from livestock and poultry products, strengthen the leadership of carbon reduction and fixation technology in agriculture and animal husbandry, cultivate high-quality talents in agriculture and animal husbandry.
WANG Jingzheng, ZHAO Chuanchuan, WANG Yuqin, XIE Linghua, WANG Yuqin, WANG Jiayi, ZHANG Sha, JIA Dongjin
Abstract:
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott''s second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott''s second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
Abstract:
[Purpose] The proposal of the dual carbon target has put forward higher requirements for the development of agriculture in China. This study takes the Beijing Tianjin Hebei region as the research object, divides the region into six major agricultural regions based on agricultural carbon emissions, and proposes corresponding emission reduction optimization paths, aiming to provide policy recommendations for the development of low-carbon agriculture in the Beijing Tianjin Hebei region Method: This study calculated agricultural carbon emissions based on the IPCC guidelines, and used trend analysis to study the linear changes in agricultural carbon emissions in the Beijing Tianjin Hebei region. ArcGIS breakpoint analysis and kernel density method were used to analyze the spatial evolution trends of the six major agricultural regions in the Beijing Tianjin Hebei region The study found that, in terms of time, the overall carbon emissions and carbon intensity of agriculture in the Beijing Tianjin Hebei region have shown a downward trend, especially the carbon emission intensity, which has been rapidly decreasing since 2005. Compared with the whole country, although the proportion of total agricultural carbon emissions is small, the carbon emission intensity is higher than the national level, with the highest carbon emission levels in the Bashang Agricultural Zone and the Jinan Agricultural Zone. From a spatial perspective, the northern part of the Bashang Agricultural Area, far from Beijing and Tianjin, as well as some counties in the Central Plains and Southern Hebei Agricultural Areas, have higher carbon emission intensity. However, the suburban agricultural area of Beijing and Tianjin, as well as the southern part of the adjacent Bashang Agricultural Area, maintain a light and low emission state. In addition, according to the results of nuclear density analysis, the overall carbon emission intensity of the six major agricultural regions is decreasing, with a greater degree of internal differentiation in carbon emission intensity between the Beijing Tianjin suburban agricultural region and the Hebei Central Plain agricultural region Conclusion: Based on the research results, an optimization path for carbon reduction in the Beijing Tianjin Hebei region is proposed from four aspects: agricultural positioning, resource sharing, carbon reduction and sink enhancement, and cross industry cooperation.
[Purpose] The proposal of the dual carbon target has put forward higher requirements for the development of agriculture in China. This study takes the Beijing Tianjin Hebei region as the research object, divides the region into six major agricultural regions based on agricultural carbon emissions, and proposes corresponding emission reduction optimization paths, aiming to provide policy recommendations for the development of low-carbon agriculture in the Beijing Tianjin Hebei region Method: This study calculated agricultural carbon emissions based on the IPCC guidelines, and used trend analysis to study the linear changes in agricultural carbon emissions in the Beijing Tianjin Hebei region. ArcGIS breakpoint analysis and kernel density method were used to analyze the spatial evolution trends of the six major agricultural regions in the Beijing Tianjin Hebei region The study found that, in terms of time, the overall carbon emissions and carbon intensity of agriculture in the Beijing Tianjin Hebei region have shown a downward trend, especially the carbon emission intensity, which has been rapidly decreasing since 2005. Compared with the whole country, although the proportion of total agricultural carbon emissions is small, the carbon emission intensity is higher than the national level, with the highest carbon emission levels in the Bashang Agricultural Zone and the Jinan Agricultural Zone. From a spatial perspective, the northern part of the Bashang Agricultural Area, far from Beijing and Tianjin, as well as some counties in the Central Plains and Southern Hebei Agricultural Areas, have higher carbon emission intensity. However, the suburban agricultural area of Beijing and Tianjin, as well as the southern part of the adjacent Bashang Agricultural Area, maintain a light and low emission state. In addition, according to the results of nuclear density analysis, the overall carbon emission intensity of the six major agricultural regions is decreasing, with a greater degree of internal differentiation in carbon emission intensity between the Beijing Tianjin suburban agricultural region and the Hebei Central Plain agricultural region Conclusion: Based on the research results, an optimization path for carbon reduction in the Beijing Tianjin Hebei region is proposed from four aspects: agricultural positioning, resource sharing, carbon reduction and sink enhancement, and cross industry cooperation.
Abstract:
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
Abstract:
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:
[Objective]The morphological characteristics and influencing factors of gully head in the mollisols farmland area were studied to provide basic data and theoretical support for gully head were investigated in the controlling gully erosion in the mollisols farmland area. [Methods]Taking the gully head in Hainan town small field, and the active state of gully watershed of Hailun as the research object, the morphological characteristics, soil
[Objective]The morphological characteristics and influencing factors of gully head in the mollisols farmland area were studied to provide basic data and theoretical support for gully head were investigated in the controlling gully erosion in the mollisols farmland area. [Methods]Taking the gully head in Hainan town small field, and the active state of gully watershed of Hailun as the research object, the morphological characteristics, soil
Abstract:
Abstract: The eastern foothills of Helan Mountain is a wonderful wine grape producing area in China. Exploring the carbon sequestration potential of the cultivated vineyards in the desert steppe area is crucial for achieving China's dual carbon goals in the region. To quantify soil carbon storage characteristics in grape plantations, this study focused on a typical vineyard of Xinhuibin, conducting a sampling investigation and analyzing soil organic carbon at the vineyard scale, examining its content, density, and composition. The results indicated that （1）in the 0-100 cm soil layer of the vineyard, the average soil organic carbon content was 4.65 g/kg, and the density was 64.5 t/hm2. Despite the low soil organic matter content and nutrient scarcity, it still constituted the main component of the vineyard's carbon pool. （2）Vertically, the soil organic carbon content decreased with depth, showing a significant difference between the 0-40 cm surface layer and the 40-100 cm deeper layer. The enrichment coefficient of organic carbon in the surface soil exceeded 1, indicating its enhanced ability to retain organic carbon. （3）Within the vineyard, soil organic carbon content exhibited spatial heterogeneity. This spatial heterogeneity, especially in the surface soil, was influenced by varied reclamation activities, including different grape varieties and fertilization practices across plots. The spatial heterogeneity of organic carbon in deep soil was determined by the formation of the original soil.（4）The ratio of active, neutral, and inert soil organic carbon components was approximately 1:2:5. This indicates a relatively high proportion of inert components, signifying a low active carbon pool with strong stability. While the inert organic carbon content governs the level of total organic carbon, variations in neutral organic carbon content also influence both total organic carbon and total carbon levels. These research findings provide valuable insights into the mechanisms of carbon sink formation and the potential for carbon sequestration in vineyards in arid regions.
Abstract: The eastern foothills of Helan Mountain is a wonderful wine grape producing area in China. Exploring the carbon sequestration potential of the cultivated vineyards in the desert steppe area is crucial for achieving China's dual carbon goals in the region. To quantify soil carbon storage characteristics in grape plantations, this study focused on a typical vineyard of Xinhuibin, conducting a sampling investigation and analyzing soil organic carbon at the vineyard scale, examining its content, density, and composition. The results indicated that （1）in the 0-100 cm soil layer of the vineyard, the average soil organic carbon content was 4.65 g/kg, and the density was 64.5 t/hm2. Despite the low soil organic matter content and nutrient scarcity, it still constituted the main component of the vineyard's carbon pool. （2）Vertically, the soil organic carbon content decreased with depth, showing a significant difference between the 0-40 cm surface layer and the 40-100 cm deeper layer. The enrichment coefficient of organic carbon in the surface soil exceeded 1, indicating its enhanced ability to retain organic carbon. （3）Within the vineyard, soil organic carbon content exhibited spatial heterogeneity. This spatial heterogeneity, especially in the surface soil, was influenced by varied reclamation activities, including different grape varieties and fertilization practices across plots. The spatial heterogeneity of organic carbon in deep soil was determined by the formation of the original soil.（4）The ratio of active, neutral, and inert soil organic carbon components was approximately 1:2:5. This indicates a relatively high proportion of inert components, signifying a low active carbon pool with strong stability. While the inert organic carbon content governs the level of total organic carbon, variations in neutral organic carbon content also influence both total organic carbon and total carbon levels. These research findings provide valuable insights into the mechanisms of carbon sink formation and the potential for carbon sequestration in vineyards in arid regions.
Abstract:
[Objective] In the construction of high-standard farmland, it is essential to consider carbon emissions and absorption in the agricultural production process while ensuring food security, in order to achieve China"s goal of carbon neutrality and contribute to the development of a strong agricultural sector.[Methods] This study measures the profit and loss of farmland in 60 cities within the Yellow River Basin from the perspective of food security, establishes a standard for farmland ecological compensation based on opportunity cost method, calculates carbon emissions from agricultural resources used in production and crop growth across these cities, estimates total carbon absorption through photosynthesis during crop growth, and determines the net carbon sink of farmland in this region by considering both sources and sinks. The average carbon trading price in 2021 serves as the compensation standard for calculating regional farmland ecological compensation from a "dual-carbon" perspective. Finally, by calculating farmland ecological compensation amounts separately under perspectives of food security and "double-carbon", we obtain comprehensive figures for dual-perspective ecological compensation within the Yellow River basin.[Results] Results indicate that most cities along Qinghai and Henan provinces where Yellow River flows accept certain levels of compensation.[Conclusion] Provincial capitals such as Xi"an, Zhengzhou, and Taiyuan need to pay higher amounts due to their significant urbanization level, industrialization progress, and robust economic development. These findings highlight a more pronounced conflict between local farmland security on one hand and food/ecological security on another.
Keywords:Yellow River Basin; Farmland ecological compensation; Food security;Carbon source；Carbon sink
[Objective] In the construction of high-standard farmland, it is essential to consider carbon emissions and absorption in the agricultural production process while ensuring food security, in order to achieve China"s goal of carbon neutrality and contribute to the development of a strong agricultural sector.[Methods] This study measures the profit and loss of farmland in 60 cities within the Yellow River Basin from the perspective of food security, establishes a standard for farmland ecological compensation based on opportunity cost method, calculates carbon emissions from agricultural resources used in production and crop growth across these cities, estimates total carbon absorption through photosynthesis during crop growth, and determines the net carbon sink of farmland in this region by considering both sources and sinks. The average carbon trading price in 2021 serves as the compensation standard for calculating regional farmland ecological compensation from a "dual-carbon" perspective. Finally, by calculating farmland ecological compensation amounts separately under perspectives of food security and "double-carbon", we obtain comprehensive figures for dual-perspective ecological compensation within the Yellow River basin.[Results] Results indicate that most cities along Qinghai and Henan provinces where Yellow River flows accept certain levels of compensation.[Conclusion] Provincial capitals such as Xi"an, Zhengzhou, and Taiyuan need to pay higher amounts due to their significant urbanization level, industrialization progress, and robust economic development. These findings highlight a more pronounced conflict between local farmland security on one hand and food/ecological security on another.
Keywords:Yellow River Basin; Farmland ecological compensation; Food security;Carbon source；Carbon sink
Abstract:
[Objective] In order to investigate the rainstorms and floods process and the soil erosion caused by rainstorms in small watershed, it is urgent to carry out the investigation of rainstorms and floods process and soil and water conservation, so as to provide scientific support for the next soil and water conservation decision. [Methods] The flood marks were measured and investigated in Huangmi East Ditch and Liangjiazhuang West Ditch by field investigation method, and the flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm flood to small watershed. [Results]① The rainfall lasted for a long time and was strong. The cumulative rainfall in Liangjiazhuang West Ditch Valley and Huangmi East Ditch Valley reached 1008.5mm and 613.6mm, respectively. According to the flood mark survey, the peak discharge modulus of Huangmi East Ditch and Liangjiazhuang West Ditch watershed are 10.80m3/s·km2 and 36.07m3/s·km2 respectively. Slope and soil and water conservation measures are the main factors affecting flood peak discharge. Larger slope will increase flood peak discharge, and perfect soil and water conservation measures can play an effective role in peak reduction. (3) The investigated small watershed is located in the upper reaches of 泜 river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watershed is larger than that of the downstream hydrology station. (4) The erosion situation of Liangjiazhuang West Ditch is more serious than that of Huangmi East Ditch, mainly because the area proportion of orchards, terraces and check dam in Huangmi East Ditch is larger than that of Huangmi West Ditch, the average slope of Huangmi East Ditch is smaller than that of Liangjiazhuang West Ditch, and the peak duration of rainfall at Liangjiazhuang rain measuring station is longer. [Conclusion] It is necessary and effective to implement soil and water conservation measures, and to further improve the construction of terrace and terrace valley. Good soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon.
[Objective] In order to investigate the rainstorms and floods process and the soil erosion caused by rainstorms in small watershed, it is urgent to carry out the investigation of rainstorms and floods process and soil and water conservation, so as to provide scientific support for the next soil and water conservation decision. [Methods] The flood marks were measured and investigated in Huangmi East Ditch and Liangjiazhuang West Ditch by field investigation method, and the flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm flood to small watershed. [Results]① The rainfall lasted for a long time and was strong. The cumulative rainfall in Liangjiazhuang West Ditch Valley and Huangmi East Ditch Valley reached 1008.5mm and 613.6mm, respectively. According to the flood mark survey, the peak discharge modulus of Huangmi East Ditch and Liangjiazhuang West Ditch watershed are 10.80m3/s·km2 and 36.07m3/s·km2 respectively. Slope and soil and water conservation measures are the main factors affecting flood peak discharge. Larger slope will increase flood peak discharge, and perfect soil and water conservation measures can play an effective role in peak reduction. (3) The investigated small watershed is located in the upper reaches of 泜 river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watershed is larger than that of the downstream hydrology station. (4) The erosion situation of Liangjiazhuang West Ditch is more serious than that of Huangmi East Ditch, mainly because the area proportion of orchards, terraces and check dam in Huangmi East Ditch is larger than that of Huangmi West Ditch, the average slope of Huangmi East Ditch is smaller than that of Liangjiazhuang West Ditch, and the peak duration of rainfall at Liangjiazhuang rain measuring station is longer. [Conclusion] It is necessary and effective to implement soil and water conservation measures, and to further improve the construction of terrace and terrace valley. Good soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon.
Abstract:
[Objective] Weathering degree and provenance of Pisha Sandstone were studied aiming to provide a basic theoretical basis for further research on Pisha Sandstone and prevention and control of soil erosion.[Methods] Taking the Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia as the research object, through field investigation and experimental research including major element, trace element and rare earth element geochemical characteristics, the Chemical Alteration Index (CIA), Plagioclase Alteration Index (PIA), ratios of light to heavy rare earth element (LREE/HREE) and related trace and rare earth element relationships of Pisha Sandstone were analyzed.[Results] ① Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar is mainly composed of SiO2 and Al2O3, with most of the major elements having lower content than the average upper crust (UCC); The geochemical classification diagram shows that Pisha Sandstone consists of shale, feldspar sandstone and lithic sandstone; The CIA value of Pisha Sandstone ranges from 64.95 to 86.57, with an average value of 77.46. This is consistent with the characteristics of the Pisha Sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering.② The trace element contents in siltstone and mudstone are higher than that in sandstone, with the highest content of Ba followed by Zr; The paleotemperature for the formation of Pisha Sandstone is 10.67 ℃~22.78 ℃, with an average value of 17.68 ℃ and the PIA value of Pisha Sandstone is 70.48~97.13, with an average of 89.76.③ The rare earth element distribution pattern of Pisha Sandstone is consistent with UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies; The total rare earth (∑REE), ratio of light rare earth to heavy rare earth (LREE/HREE) and (La/Yb)N values of siltstone and mudstone are all higher than those of sandstone. The differentiation is mainly due to the attraction of most of trace elements released by rock weathering during epigenetic processes by clay minerals or due to hydraulic sorting.[Conclusion] The Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia is a set of terrestrial clastic sedimentary rock with low compositional maturity and sorting degree, and the source area had experienced moderate to strong chemical weathering; The formation of Pisha Sandstone was under arid to semi-humid conditions; The Pisha Sandstone rare earth element distribution pattern, combined with the discrimination diagram of major and trace elements, indicates that the studied Pisha Sandstone from Yan'an Formation originated from the Hercynian-Indosinian granites in Yinshan-Daqingshan area to the northern Ordos Basin.
[Objective] Weathering degree and provenance of Pisha Sandstone were studied aiming to provide a basic theoretical basis for further research on Pisha Sandstone and prevention and control of soil erosion.[Methods] Taking the Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia as the research object, through field investigation and experimental research including major element, trace element and rare earth element geochemical characteristics, the Chemical Alteration Index (CIA), Plagioclase Alteration Index (PIA), ratios of light to heavy rare earth element (LREE/HREE) and related trace and rare earth element relationships of Pisha Sandstone were analyzed.[Results] ① Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar is mainly composed of SiO2 and Al2O3, with most of the major elements having lower content than the average upper crust (UCC); The geochemical classification diagram shows that Pisha Sandstone consists of shale, feldspar sandstone and lithic sandstone; The CIA value of Pisha Sandstone ranges from 64.95 to 86.57, with an average value of 77.46. This is consistent with the characteristics of the Pisha Sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering.② The trace element contents in siltstone and mudstone are higher than that in sandstone, with the highest content of Ba followed by Zr; The paleotemperature for the formation of Pisha Sandstone is 10.67 ℃~22.78 ℃, with an average value of 17.68 ℃ and the PIA value of Pisha Sandstone is 70.48~97.13, with an average of 89.76.③ The rare earth element distribution pattern of Pisha Sandstone is consistent with UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies; The total rare earth (∑REE), ratio of light rare earth to heavy rare earth (LREE/HREE) and (La/Yb)N values of siltstone and mudstone are all higher than those of sandstone. The differentiation is mainly due to the attraction of most of trace elements released by rock weathering during epigenetic processes by clay minerals or due to hydraulic sorting.[Conclusion] The Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia is a set of terrestrial clastic sedimentary rock with low compositional maturity and sorting degree, and the source area had experienced moderate to strong chemical weathering; The formation of Pisha Sandstone was under arid to semi-humid conditions; The Pisha Sandstone rare earth element distribution pattern, combined with the discrimination diagram of major and trace elements, indicates that the studied Pisha Sandstone from Yan'an Formation originated from the Hercynian-Indosinian granites in Yinshan-Daqingshan area to the northern Ordos Basin.
Abstract:
[Objective] The coal mining process also causes a series of ecological and environmental problems such as the reduction of biodiversity, the destruction of soil structure and the loss of nutrients. The severe disturbance to the soil structure in the mining area results in the exposure of organic carbon protected by soil aggregates, which is de-composed and mineralized by soil microorganisms, resulting in the loss of soil organic carbon. Vegetation recon-struction in disturbed open pit dump is considered to be an effective measure to improve soil structure and increase biodiversity. In recent years, microbial restoration technology (arbuscular mycorrhizal fungi) has been widely used in ecological restoration of mining areas, and has achieved obvious ecological improvement effect. In addition, exogenous substances such as weathered coal and green fertilizer are also considered to have a positive role in soil improvement. However, the effect of arbuscular mycorrhizal fungi combined with weathering coal and green fertilizer on vegetation growth and soil improvement is still unclear. [Methods] Therefore, based on the sea buckthorns demonstration base in the open pit of Hedaigou, Inner Mongolia, this study analyzed the effects of the combined action of fertilizer modes such as arbuscular mycorrhizal fungi (AMF) and other factors (weathered coal and green fertilizer) on the stability of soil aggregates and organic carbon recovery in the early vegetation resto-ration area of the open pit dump by investigating vegetation populations and collecting soil aggregate samples. [Result] The results showed that under the six treatment modes, the experimental group inoculated with AMF, applied green fertilizer and added weathered coal (sand and green wind) had the best effect on the improvement of understory vegetation diversity, and the diversity index was significantly improved compared with the control treatment. The experimental group inoculated with AMF and applied with green fertilizer (sand green) had the most significant effect on the development and stability of aggregates. The crushing rate of the experimental group was significantly lower than that of the control group, while the mean diameter of aggregate weight and geometric mean diameter were significantly higher than that of the control group. The analysis of the effect of organic carbon and total nitrogen in aggregates showed that the organic carbon and total nitrogen in aggregates treated with sand green were significantly higher than those in the experimental group inoculated only with AMF (sand grafting). [Con-clusion]:Overall, these results evaluated the effects of weathering coal, green fertilizer and AMF inoculation on improving vegetation diversity, aggregate stability and aggregate organic carbon recovery in field trials, and had important reference significance for optimizing artificial ecological restoration strategies in open-pit mines and accelerating soil carbon pool recovery.
[Objective] The coal mining process also causes a series of ecological and environmental problems such as the reduction of biodiversity, the destruction of soil structure and the loss of nutrients. The severe disturbance to the soil structure in the mining area results in the exposure of organic carbon protected by soil aggregates, which is de-composed and mineralized by soil microorganisms, resulting in the loss of soil organic carbon. Vegetation recon-struction in disturbed open pit dump is considered to be an effective measure to improve soil structure and increase biodiversity. In recent years, microbial restoration technology (arbuscular mycorrhizal fungi) has been widely used in ecological restoration of mining areas, and has achieved obvious ecological improvement effect. In addition, exogenous substances such as weathered coal and green fertilizer are also considered to have a positive role in soil improvement. However, the effect of arbuscular mycorrhizal fungi combined with weathering coal and green fertilizer on vegetation growth and soil improvement is still unclear. [Methods] Therefore, based on the sea buckthorns demonstration base in the open pit of Hedaigou, Inner Mongolia, this study analyzed the effects of the combined action of fertilizer modes such as arbuscular mycorrhizal fungi (AMF) and other factors (weathered coal and green fertilizer) on the stability of soil aggregates and organic carbon recovery in the early vegetation resto-ration area of the open pit dump by investigating vegetation populations and collecting soil aggregate samples. [Result] The results showed that under the six treatment modes, the experimental group inoculated with AMF, applied green fertilizer and added weathered coal (sand and green wind) had the best effect on the improvement of understory vegetation diversity, and the diversity index was significantly improved compared with the control treatment. The experimental group inoculated with AMF and applied with green fertilizer (sand green) had the most significant effect on the development and stability of aggregates. The crushing rate of the experimental group was significantly lower than that of the control group, while the mean diameter of aggregate weight and geometric mean diameter were significantly higher than that of the control group. The analysis of the effect of organic carbon and total nitrogen in aggregates showed that the organic carbon and total nitrogen in aggregates treated with sand green were significantly higher than those in the experimental group inoculated only with AMF (sand grafting). [Con-clusion]:Overall, these results evaluated the effects of weathering coal, green fertilizer and AMF inoculation on improving vegetation diversity, aggregate stability and aggregate organic carbon recovery in field trials, and had important reference significance for optimizing artificial ecological restoration strategies in open-pit mines and accelerating soil carbon pool recovery.
Abstract:
[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.
[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.
Abstract:
[Objective] changes in land use and carbon storage in the Maowei Sea were analyzed to provide a scientific basis for increasing its carbon sink and improving ecological value. [Methods] In this study, the remote sensing image data of the Maowei Sea in 2009, 2015 and 2021 were used for interpretation and acquisition by using supervised classification method. Based on the ArcGIS and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the study analyzed the spatiotemporal change of the land use and carbon storage in the Maowei Sea. [Results] The results show that: ①The land types in the Maowei Sea mainly showed the distribution characteristics of "large settlement, small miscellaneous areas", the area of cultivated land, shallow sea waters and fishery breeding areas decreased, and the area of mangrove wetlands, building land, forest grassland and silty tidal flats increased in 2009-2021. ②The carbon storage showed a trend of decline and then increase, the net carbon sequestration and its net present value in the Maowei Sea was increased by -110500 tons, 37700 tons, -72900 tons and -137 million, 47 million, -90 million respectively in 2009-2015, 2015-2021 and 2009-2021. ③The transformation mainly from high carbon sequestration land use types such as fishery breeding areas and forest and grasslands to low carbon sequestration type such as building land in the Maowei Sea in 2009-2021, the largest carbon storage loss caused by the conversion to building land, reaching 285100 tons, and the additional carbon storage increased by the fishery breeding area reached 180,800 tons. [Conclusion] accelerating the transformation and upgrading of farming methods, enhancing the proliferation of mangrove forests in terrestrial and aquatic forested areas and accelerating the construction of forest city in the Maowei Sea to promote its carbon sequestration and sustainable development.
[Objective] changes in land use and carbon storage in the Maowei Sea were analyzed to provide a scientific basis for increasing its carbon sink and improving ecological value. [Methods] In this study, the remote sensing image data of the Maowei Sea in 2009, 2015 and 2021 were used for interpretation and acquisition by using supervised classification method. Based on the ArcGIS and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the study analyzed the spatiotemporal change of the land use and carbon storage in the Maowei Sea. [Results] The results show that: ①The land types in the Maowei Sea mainly showed the distribution characteristics of "large settlement, small miscellaneous areas", the area of cultivated land, shallow sea waters and fishery breeding areas decreased, and the area of mangrove wetlands, building land, forest grassland and silty tidal flats increased in 2009-2021. ②The carbon storage showed a trend of decline and then increase, the net carbon sequestration and its net present value in the Maowei Sea was increased by -110500 tons, 37700 tons, -72900 tons and -137 million, 47 million, -90 million respectively in 2009-2015, 2015-2021 and 2009-2021. ③The transformation mainly from high carbon sequestration land use types such as fishery breeding areas and forest and grasslands to low carbon sequestration type such as building land in the Maowei Sea in 2009-2021, the largest carbon storage loss caused by the conversion to building land, reaching 285100 tons, and the additional carbon storage increased by the fishery breeding area reached 180,800 tons. [Conclusion] accelerating the transformation and upgrading of farming methods, enhancing the proliferation of mangrove forests in terrestrial and aquatic forested areas and accelerating the construction of forest city in the Maowei Sea to promote its carbon sequestration and sustainable development.
Abstract:
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
Abstract:
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract:
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
Abstract:
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
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[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
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[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
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[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
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[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
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[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
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[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
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[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
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[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
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[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
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[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
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[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
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[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
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[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
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Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
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[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
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Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
Abstract:
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
Abstract:
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
Abstract:
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
Abstract:
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
Abstract:
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
Abstract:
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
Abstract:
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
Abstract:
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
Abstract:
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
Abstract:
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
YANG Cuihong, LI Yong, WANG Xu, CHEN Tingting, GUO Hao, YANG Yijiang, WU Zongmeng, ZHOU Xiaoqi, HUANG Zhigang
Abstract:
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
Abstract:
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
Abstract:
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
Display Method:
2023,43(4):238-247, DOI: 10.13961/j.cnki.stbctb.20230508.007
Abstract:
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
2023,43(4):154-161,210, DOI: 10.13961/j.cnki.stbctb.2023.04.019
Abstract:
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
2012(5):8-12, DOI: 10.13961/j.cnki.stbctb.2012.05.011
Abstract:
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
2023,43(4):220-228,326, DOI: 10.13961/j.cnki.stbctb.2023.04.027
Abstract:
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
2022,42(2):264-274, DOI: 10.13961/j.cnki.stbctb.2022.02.036
Abstract:
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
2006(3):1-5, DOI: 10.13961/j.cnki.stbctb.2006.03.002
Abstract:
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
2009(1):62-65, DOI: 10.13961/j.cnki.stbctb.2009.01.027
Abstract:
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
2022,42(2):210-218, DOI: 10.13961/j.cnki.stbctb.20220124.001
Abstract:
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
2002(4):50-53, DOI: 10.13961/j.cnki.stbctb.2002.04.013
Abstract:
对青藏铁路格尔木—拉萨段的生态环境本底状况作了全面地分析,指出建于世界上最高、最大的高原面上的青藏铁路沿线的生态环境具有无以比拟的特殊性、敏感性、脆弱性和生态景观的差异性,如果施工期间未能采取行之有效的环保措施,那么巨大的土石开挖量、堆积量和工程迹地量定会对青藏高原的生态环境造成严重的负面影响。提出了一系列的环保措施,以期对铁路建设单位有所帮助,将对青藏高原生态环境造成的负面影响减少到最小,使生态环境恢复到最好
对青藏铁路格尔木—拉萨段的生态环境本底状况作了全面地分析,指出建于世界上最高、最大的高原面上的青藏铁路沿线的生态环境具有无以比拟的特殊性、敏感性、脆弱性和生态景观的差异性,如果施工期间未能采取行之有效的环保措施,那么巨大的土石开挖量、堆积量和工程迹地量定会对青藏高原的生态环境造成严重的负面影响。提出了一系列的环保措施,以期对铁路建设单位有所帮助,将对青藏高原生态环境造成的负面影响减少到最小,使生态环境恢复到最好
2019,39(5):194-203, DOI: 10.13961/j.cnki.stbctb.2019.05.027
Abstract:
[Objective] This study aims to explore the regional water stress state and their causes and provides a theoretical basis for the development and allocation of rational water resources.[Methods] A three-dimensional water footprint model was built to analyze the sustainability of water resources by using the sustainability index of water resource. The logarithmic mean divisia index (LMDI) factor decomposition model was also applied to quantitatively analyze the structural, technological, economic, and population effects on water resources in Anhui Province from 2007 to 2016.[Results] ① From 2007 to 2016, the water footprint of Anhui Province, in which the internal water footprints accounted for 97.88% to 98.73%, at first increased and then decreased. The consumption of water by agriculture among the internal water footprints was the highest and showed the same variation as the overall water footprint. In 2016, the per capita agricultural water use in Anhui Province decreased from north to south, meanwhile, the Yangtze River basin accounted for the highest proportion in the other types of water footprint. ② During 2007-2016, the footprint depth of the Anhui Province fluctuated within 2~4 and eventually declined from north to south. The results indicated that the overall sustainable use of water resources in Anhui Province increased from 2007 to 2016. ③ The driving factors of the water footprint in Anhui Province showed that the technical effect was a reverse driving, and the economic effect contributed the most to the positive driving.[Conclusion] The three-dimensional water footprint model used in this study can be a helpful tool to better reflect the actual situation of the water footprint in Anhui Province. Although of the use of water resources generally increased, optimizing the structure of the water resources utilization and accelerating improvements in the efficiency of water resource usage is necessary to alleviate the pressure on water resources resulting from economic development and population growth.
[Objective] This study aims to explore the regional water stress state and their causes and provides a theoretical basis for the development and allocation of rational water resources.[Methods] A three-dimensional water footprint model was built to analyze the sustainability of water resources by using the sustainability index of water resource. The logarithmic mean divisia index (LMDI) factor decomposition model was also applied to quantitatively analyze the structural, technological, economic, and population effects on water resources in Anhui Province from 2007 to 2016.[Results] ① From 2007 to 2016, the water footprint of Anhui Province, in which the internal water footprints accounted for 97.88% to 98.73%, at first increased and then decreased. The consumption of water by agriculture among the internal water footprints was the highest and showed the same variation as the overall water footprint. In 2016, the per capita agricultural water use in Anhui Province decreased from north to south, meanwhile, the Yangtze River basin accounted for the highest proportion in the other types of water footprint. ② During 2007-2016, the footprint depth of the Anhui Province fluctuated within 2~4 and eventually declined from north to south. The results indicated that the overall sustainable use of water resources in Anhui Province increased from 2007 to 2016. ③ The driving factors of the water footprint in Anhui Province showed that the technical effect was a reverse driving, and the economic effect contributed the most to the positive driving.[Conclusion] The three-dimensional water footprint model used in this study can be a helpful tool to better reflect the actual situation of the water footprint in Anhui Province. Although of the use of water resources generally increased, optimizing the structure of the water resources utilization and accelerating improvements in the efficiency of water resource usage is necessary to alleviate the pressure on water resources resulting from economic development and population growth.
2002(3):58-58, DOI: 10.13961/j.cnki.stbctb.2002.03.017
Abstract:
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
2023,43(2):43-49,59, DOI: 10.13961/j.cnki.stbctb.20230423.001
Abstract:
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
2001(1):30-34, DOI: 10.13961/j.cnki.stbctb.2001.01.008
Abstract:
水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.
水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.
2014(5):153-157, DOI: 10.13961/j.cnki.stbctb.20140928.002
Abstract:
北京市水资源短缺的问题已成为制约社会经济发展和影响社会稳定的重要因素之一,因此,如何协调北京市城市绿化与水资源的合理有效利用问题亟需得到解决。基于北京市城市绿化现状及水资源利用现状,采用尺度扩展法,计算了2012年北京市城市绿化的生态需水量,并结合北京市有效降雨利用量和实地调查数据,求得2012年北京市城市绿化的理论供水量和实际供水量。在此基础上,利用灰色马尔科夫链模型与熵值法对北京市城市绿化供水的3种来源(地表水、地下水、再生水)做出评估,得出2014年实际供水量预测值区间。2012年北京市理论供水量为5.07×108 m3,实际供水量为6.86×108 m3。2014年预测实际供水量区间为7.29×108~7.93×108 m3。评估结果表明,北京市仍存在城市绿化用水供需风险问题,并据此提出相关节水措施和建议,为保障北京城市供水安全与水资源可持续利用相关研究提供参考和借鉴。
北京市水资源短缺的问题已成为制约社会经济发展和影响社会稳定的重要因素之一,因此,如何协调北京市城市绿化与水资源的合理有效利用问题亟需得到解决。基于北京市城市绿化现状及水资源利用现状,采用尺度扩展法,计算了2012年北京市城市绿化的生态需水量,并结合北京市有效降雨利用量和实地调查数据,求得2012年北京市城市绿化的理论供水量和实际供水量。在此基础上,利用灰色马尔科夫链模型与熵值法对北京市城市绿化供水的3种来源(地表水、地下水、再生水)做出评估,得出2014年实际供水量预测值区间。2012年北京市理论供水量为5.07×108 m3,实际供水量为6.86×108 m3。2014年预测实际供水量区间为7.29×108~7.93×108 m3。评估结果表明,北京市仍存在城市绿化用水供需风险问题,并据此提出相关节水措施和建议,为保障北京城市供水安全与水资源可持续利用相关研究提供参考和借鉴。
2001(3):59-62, DOI: 10.13961/j.cnki.stbctb.2001.03.020
Abstract:
分析了田间同深度土壤含水量的半方差和不同深度土壤含水量的交互半方差特征，探讨了土壤含水量的Kriging和Cokriging估值方法。研究表明，同深度土壤含水量与不同深度的土壤含水量之间均具有显着的空间相关性，用Kriging方法进行土壤含水量的估值精度较传统方法高。加入浅层土壤含水量用Cokriging方法来估测深层土壤含水量，可进一步提高估值精度。
分析了田间同深度土壤含水量的半方差和不同深度土壤含水量的交互半方差特征，探讨了土壤含水量的Kriging和Cokriging估值方法。研究表明，同深度土壤含水量与不同深度的土壤含水量之间均具有显着的空间相关性，用Kriging方法进行土壤含水量的估值精度较传统方法高。加入浅层土壤含水量用Cokriging方法来估测深层土壤含水量，可进一步提高估值精度。
2020,40(2):85-91,99, DOI: 10.13961/j.cnki.stbctb.2020.02.012
Abstract:
[Objective] The evolution and driving forces of the sea reclamation in the Bohai Rim from 1985 to 2017 were analyzed, in order to provide support for the comprehensive management of the sea reclamation and promote the sustainable development of the region.[Methods] Using the remote sensing data, ENVI and ArcGIS were used to process and extract the sea reclamation coastline and land use types in each period, and the characteristics of reclamation evolution were analyzed by fractal dimension, coastal reclamation index, development intensity index and transfer matrix. The driving mechanism of reclamation activity was discussed by grey correlation degree method.[Results] ①From 1985 to 2017, the total area of reclamation around Bohai Sea increased by 4.25×105 hm2, with an average annual development intensity index of 2.6%. The reclamation coastline increased by 1 734 km, with an increase rate of 62%. In terms of time, the average annual development intesity index and coastal reclamation index changed in a similar way, showing a trend of decreasing, increasing and decreasing. In terms of space, the development intensity in the south was much higher than that in the north and the west was much higher than that in the East. ② There are two reclamation peaks in the study period, the first one was mainly for aquaculture, occupying a large number of vegetation land and unused land, and the second one was mainly for construction, taking up lots of natural sea areas. ③ The main driving forces of sea reclamation activities were social and economic development, among which aquatic product production, regional population and fishery industry development were the main driving forces. In addition, national policies and natural factors were of great significance to the sea reclamation activities.[Conclusion] The effective ways to restore the coastal ecological environment are to reasonably plan the aquaculture water area and increase the production capacity of unit area. Balancing the intensity of regional development and regulating the growth of regional population are of great significance to the realization of regional sustainable development.
[Objective] The evolution and driving forces of the sea reclamation in the Bohai Rim from 1985 to 2017 were analyzed, in order to provide support for the comprehensive management of the sea reclamation and promote the sustainable development of the region.[Methods] Using the remote sensing data, ENVI and ArcGIS were used to process and extract the sea reclamation coastline and land use types in each period, and the characteristics of reclamation evolution were analyzed by fractal dimension, coastal reclamation index, development intensity index and transfer matrix. The driving mechanism of reclamation activity was discussed by grey correlation degree method.[Results] ①From 1985 to 2017, the total area of reclamation around Bohai Sea increased by 4.25×105 hm2, with an average annual development intensity index of 2.6%. The reclamation coastline increased by 1 734 km, with an increase rate of 62%. In terms of time, the average annual development intesity index and coastal reclamation index changed in a similar way, showing a trend of decreasing, increasing and decreasing. In terms of space, the development intensity in the south was much higher than that in the north and the west was much higher than that in the East. ② There are two reclamation peaks in the study period, the first one was mainly for aquaculture, occupying a large number of vegetation land and unused land, and the second one was mainly for construction, taking up lots of natural sea areas. ③ The main driving forces of sea reclamation activities were social and economic development, among which aquatic product production, regional population and fishery industry development were the main driving forces. In addition, national policies and natural factors were of great significance to the sea reclamation activities.[Conclusion] The effective ways to restore the coastal ecological environment are to reasonably plan the aquaculture water area and increase the production capacity of unit area. Balancing the intensity of regional development and regulating the growth of regional population are of great significance to the realization of regional sustainable development.
2017,37(5):128-134, DOI: 10.13961/j.cnki.stbctb.2017.05.022
Abstract:
[Objective] This paper illustrated the influencing factors of water resource security and its evolution trend aimed to put forward some suggestions about the water resource security in Karst area.[Methods] Based on the data of Guizhou Province in the past ten years, this paper established a BP network model and applied the mean impact value(MIV) algorithm method to analyze the influencing factors of the water resource security in Karst area.[Results] The groundwater supply ratio, the industrial water use proportion, water use efficiency, per capital grain yield and water yield modulus were the obstacles to the development of water resources system. The influencing degree of water yield modulus was decreasing year by year, while the other four factors showed increasing trends. Comprehensive utilization rate of industrial solid waste, the attainment rate of the industrial waste water, the ratio of moderate rocky desertification area, water requirement per-unit GDP and exploitation degree of groundwater were the driving factors. In chronological order, the influence of water requirement of per-unit GDP and exploitation degree of groundwater were stable, while the ratio of moderate rocky desertification area was more and more pronounced. The impact of the attainment rate of the industrial waste water decreased year by year, while comprehensive utilization rate of industrial solid waste fluctuated greatly.[Conclusion] The MIV-BP model is feasible in studying influencing factors of water resource security in karst area.
[Objective] This paper illustrated the influencing factors of water resource security and its evolution trend aimed to put forward some suggestions about the water resource security in Karst area.[Methods] Based on the data of Guizhou Province in the past ten years, this paper established a BP network model and applied the mean impact value(MIV) algorithm method to analyze the influencing factors of the water resource security in Karst area.[Results] The groundwater supply ratio, the industrial water use proportion, water use efficiency, per capital grain yield and water yield modulus were the obstacles to the development of water resources system. The influencing degree of water yield modulus was decreasing year by year, while the other four factors showed increasing trends. Comprehensive utilization rate of industrial solid waste, the attainment rate of the industrial waste water, the ratio of moderate rocky desertification area, water requirement per-unit GDP and exploitation degree of groundwater were the driving factors. In chronological order, the influence of water requirement of per-unit GDP and exploitation degree of groundwater were stable, while the ratio of moderate rocky desertification area was more and more pronounced. The impact of the attainment rate of the industrial waste water decreased year by year, while comprehensive utilization rate of industrial solid waste fluctuated greatly.[Conclusion] The MIV-BP model is feasible in studying influencing factors of water resource security in karst area.
2008(4):121-125, DOI: 10.13961/j.cnki.stbctb.2008.04.023
Abstract:
公路建设过程中产生的水土流失非常严重。在标定人工降雨器降雨参数的基础上,研究了华北地区公路土质边坡水土流失规律。结果表明,土体硬度、前期土壤含水量、降雨强度相同条件下,土壤侵蚀量随坡度的增大而增加,在25°附近达最大值,之后随坡度的增加侵蚀量略有下降并渐趋稳定;土壤侵蚀量随土体硬度的加大而减小,且降雨强度越大这种影响愈显著;前期土体含水量愈大,土壤侵蚀量呈增大趋势。本研究可为科学评价工程土质边坡的水土流失提供依据。
公路建设过程中产生的水土流失非常严重。在标定人工降雨器降雨参数的基础上,研究了华北地区公路土质边坡水土流失规律。结果表明,土体硬度、前期土壤含水量、降雨强度相同条件下,土壤侵蚀量随坡度的增大而增加,在25°附近达最大值,之后随坡度的增加侵蚀量略有下降并渐趋稳定;土壤侵蚀量随土体硬度的加大而减小,且降雨强度越大这种影响愈显著;前期土体含水量愈大,土壤侵蚀量呈增大趋势。本研究可为科学评价工程土质边坡的水土流失提供依据。
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Journal Information
- Founded in 1981, bimonthly
- CN：
61-1094/X
- ISSN：
1000-288X
- Administrted by：
Chinese Academy of Sciences
- Sponsored by：
Institute of Soil and Water Conservation, CAS & MWR;
Monitoring Center of Soil and Water Conservation, Ministry of Water Resources - Published by：
Science Press
- Editor-in-Chief：
FENG Hao
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