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- Welcome to visit the official website of Bulletin of Soil and Water Conservation
- Welcome to visit the official website of Bulletin of Soil and Water Conservation
- Welcome to visit the official website of Bulletin of Soil and Water Conservation
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2025,45(1):1-9
, DOI: 10.13961/j.cnki.stbctb.2025.01.001
Abstract:
[Objective] The pollutants distribution during grassland digestion and utilization of rural domestic sewage was explored in order to provide a scientific reference for risk prevention and control in the resource utilization of rural domestic sewage. [Methods] This study investigated the effects of hydraulic load on soil solution and soil pollutant distribution during the grassland digestion and utilization of rural domestic sewage. It also analyzed the variations in soil solution and soil pollutants at different depths and explored the correlation among hydraulic load, soil solution, adn soil pollutants using the Pearson correlation coefficient. [Results] ① As the hydraulic load increased gradually from 0.005 m3/(m2·d) to 0.05 m3/(m2·d), an accumulation of NH+4-N and NO-3-N was observed in the grassland. The poor denitrification performance of NO-3-N was identified as the limiting step restricting the denitrification rate of the grassland. ② The hydraulic load showed a strong positive correlation with the NH+4-N content in the soil, with a correlation coefficient of 0.94. [Conclusion] During the grassland digestion and utilization of rural domestic sewage, it is necessary to distribute the hydraulic load rationally and control the environmental risks.
[Objective] The pollutants distribution during grassland digestion and utilization of rural domestic sewage was explored in order to provide a scientific reference for risk prevention and control in the resource utilization of rural domestic sewage. [Methods] This study investigated the effects of hydraulic load on soil solution and soil pollutant distribution during the grassland digestion and utilization of rural domestic sewage. It also analyzed the variations in soil solution and soil pollutants at different depths and explored the correlation among hydraulic load, soil solution, adn soil pollutants using the Pearson correlation coefficient. [Results] ① As the hydraulic load increased gradually from 0.005 m3/(m2·d) to 0.05 m3/(m2·d), an accumulation of NH+4-N and NO-3-N was observed in the grassland. The poor denitrification performance of NO-3-N was identified as the limiting step restricting the denitrification rate of the grassland. ② The hydraulic load showed a strong positive correlation with the NH+4-N content in the soil, with a correlation coefficient of 0.94. [Conclusion] During the grassland digestion and utilization of rural domestic sewage, it is necessary to distribute the hydraulic load rationally and control the environmental risks.
2025,45(1):10-19
, DOI: 10.13961/j.cnki.stbctb.2025.01.002
Abstract:
[Objective] The relationship between the fractal characteristics of soil particle size distribution and properties in different forest types in the typical karst regions of Guangxi Zhuang Autonomous Region (GZAR) was investigated in order to provide scientific guidance for sustainable forestry development in rocky desertification areas. [Methods] The particle size distribution and properties of soil in Eucalyptus spp., Pinus massoniana, and natural secondary forests were determined. Single and multiple fractal dimensions of soil from different forest types were calculated using fractal models, and the their correlations with soil properties were explored. [Results] Compared to natural secondary forests, the bulk densities of Eucalyptus spp. and P. massoniana plantations were 23% and 15% lesser, respectively. However, the total porosities of Eucalyptus spp. and P. massoniana plantations were greater by 27% and 17%, respectively, than that of natural secondary forests. The clay contents in Eucalyptus spp. and P. massoniana plantations were lower(58% and 42%, respectively) whereas the sand contents were higher (24% and 14%, respectively), than that of natural secondary forests. Additionally, the single fractal dimensions (Ds) were 6% and 4% lesser in Eucalyptus spp. and P. massoniana plantations, respectively, than that of secondary natural forests. Furthermore, the available phosphorus, readily available potassium, and total calcium contents for Eucalyptus spp. were 68%, 49%, and 6% lower, and, those for P. massoniana were 42%, 40%, and 25% lower, respectively, than those of secondary natural forests. D0-D2, ΔD and Δα were the multifractal parameters that reflect the heterogeneity of soil particle size distribution across different dimensions; for Eucalyptus spp. (0.13, 1.29, 1.52) and P. massoniana (0.13, 0.99, 1.18) plantations these values were higher than those for natural forests (0.08, 0.83, 1.02). Furthermore, there was a significant correlation between multifractal parameters and soil nutrient content in the different plantations. [Conclusion] Improper cultivation and management of plantations in karst regions may promote the loss of fine soil particles and depletion of key nutrients. This, in turn, can result in a concentration of the soil particle size distribution in low-probability dense areas, increasing the heterogeneity of the soil particle size distribution and further accelerating the process of rocky desertification. The single fractal dimension Ds can reflect the degree of soil fertility degradation in karst forest areas, and the multifractal parameters can reveal the heterogeneous distribution characteristics of soil particle size at the microlevel in detail. Therefore, single and multiple fractal dimensions have the potential to become precise indicators for evaluating the soil quality of plantations in karst regions.
[Objective] The relationship between the fractal characteristics of soil particle size distribution and properties in different forest types in the typical karst regions of Guangxi Zhuang Autonomous Region (GZAR) was investigated in order to provide scientific guidance for sustainable forestry development in rocky desertification areas. [Methods] The particle size distribution and properties of soil in Eucalyptus spp., Pinus massoniana, and natural secondary forests were determined. Single and multiple fractal dimensions of soil from different forest types were calculated using fractal models, and the their correlations with soil properties were explored. [Results] Compared to natural secondary forests, the bulk densities of Eucalyptus spp. and P. massoniana plantations were 23% and 15% lesser, respectively. However, the total porosities of Eucalyptus spp. and P. massoniana plantations were greater by 27% and 17%, respectively, than that of natural secondary forests. The clay contents in Eucalyptus spp. and P. massoniana plantations were lower(58% and 42%, respectively) whereas the sand contents were higher (24% and 14%, respectively), than that of natural secondary forests. Additionally, the single fractal dimensions (Ds) were 6% and 4% lesser in Eucalyptus spp. and P. massoniana plantations, respectively, than that of secondary natural forests. Furthermore, the available phosphorus, readily available potassium, and total calcium contents for Eucalyptus spp. were 68%, 49%, and 6% lower, and, those for P. massoniana were 42%, 40%, and 25% lower, respectively, than those of secondary natural forests. D0-D2, ΔD and Δα were the multifractal parameters that reflect the heterogeneity of soil particle size distribution across different dimensions; for Eucalyptus spp. (0.13, 1.29, 1.52) and P. massoniana (0.13, 0.99, 1.18) plantations these values were higher than those for natural forests (0.08, 0.83, 1.02). Furthermore, there was a significant correlation between multifractal parameters and soil nutrient content in the different plantations. [Conclusion] Improper cultivation and management of plantations in karst regions may promote the loss of fine soil particles and depletion of key nutrients. This, in turn, can result in a concentration of the soil particle size distribution in low-probability dense areas, increasing the heterogeneity of the soil particle size distribution and further accelerating the process of rocky desertification. The single fractal dimension Ds can reflect the degree of soil fertility degradation in karst forest areas, and the multifractal parameters can reveal the heterogeneous distribution characteristics of soil particle size at the microlevel in detail. Therefore, single and multiple fractal dimensions have the potential to become precise indicators for evaluating the soil quality of plantations in karst regions.
2025,45(1):20-29
, DOI: 10.13961/j.cnki.stbctb.2025.01.003
Abstract:
[Objective] The effect of combining organic fertilizer with a water retaining agent on the hydraulic properties of brown soil in the tillage layer was analyzed in order to provide a technical approach and theoretical basis that can be used to improve brown soil tillage by finding the optimal organic fertilizer application amount and the optimal water retaining agent ratio. [Methods] A brown soil topsoil from Shanxi Province and a split-plot experimental design were used for the experiment. The main plot treatments were the amount of organic fertilizer applied: F1 (0 t/hm2), F2 (45 t/hm2), F3 (60 t/hm2), and F4 (75 t/hm2), and the subplot treatments were four water-retaining agent applications: B1 (0 kg/hm2), B2 (300 kg/hm2), B3 (600 kg/hm2), and B4 (900 kg/hm2). The effects of the amount of organic fertilizer and water-retaining agent on the soil water characteristics curve, specific water capacity, and available water content were analyzed. [Results] ① Soil water-holding capacity, water-supply capacity, and the effective water content increased in the organic fertilizer combined with water-retaining agent treatments compared to the water-retaining agent alone treatments. ② The effects of organic fertilizer combined with a water-retaining agent on soil hydraulic properties varied depending on the amounts of organic fertilizer applied. The water-holding capacity and water-supplying capacity of the test soil at low suction section followed the order F3 > F2 > F4 > F1, and the same was true for the effective water content. ③ Under the F3 treatment, the water holding capacity and water supply capacity of the soil first increased and then decreased as the water retaining agent application rate increased. There was a parabolic relationship between the effective soil water content and water-retaining agent application ratio (R2=0.949 3). [Conclusion] The improvement effect was greatest under the treatments with a medium amount of organic fertilizer (60 t/hm2) combined with a water-retaining agent and the optimum proportion of water-retaining agent under this amount of organic fertilizer was 0.91%.
[Objective] The effect of combining organic fertilizer with a water retaining agent on the hydraulic properties of brown soil in the tillage layer was analyzed in order to provide a technical approach and theoretical basis that can be used to improve brown soil tillage by finding the optimal organic fertilizer application amount and the optimal water retaining agent ratio. [Methods] A brown soil topsoil from Shanxi Province and a split-plot experimental design were used for the experiment. The main plot treatments were the amount of organic fertilizer applied: F1 (0 t/hm2), F2 (45 t/hm2), F3 (60 t/hm2), and F4 (75 t/hm2), and the subplot treatments were four water-retaining agent applications: B1 (0 kg/hm2), B2 (300 kg/hm2), B3 (600 kg/hm2), and B4 (900 kg/hm2). The effects of the amount of organic fertilizer and water-retaining agent on the soil water characteristics curve, specific water capacity, and available water content were analyzed. [Results] ① Soil water-holding capacity, water-supply capacity, and the effective water content increased in the organic fertilizer combined with water-retaining agent treatments compared to the water-retaining agent alone treatments. ② The effects of organic fertilizer combined with a water-retaining agent on soil hydraulic properties varied depending on the amounts of organic fertilizer applied. The water-holding capacity and water-supplying capacity of the test soil at low suction section followed the order F3 > F2 > F4 > F1, and the same was true for the effective water content. ③ Under the F3 treatment, the water holding capacity and water supply capacity of the soil first increased and then decreased as the water retaining agent application rate increased. There was a parabolic relationship between the effective soil water content and water-retaining agent application ratio (R2=0.949 3). [Conclusion] The improvement effect was greatest under the treatments with a medium amount of organic fertilizer (60 t/hm2) combined with a water-retaining agent and the optimum proportion of water-retaining agent under this amount of organic fertilizer was 0.91%.
Chen Fengting, Tan Qingfang, Huang Yuhan, Zhao Mingquan, Chang Zhiyong, Wu Di, Huang Zixuan, Wei Juan
2025,45(1):30-39
, DOI: 10.13961/j.cnki.stbctb.2025.01.004
Abstract:
[Objective] The hydrodynamic properties of red soil slopes under varying surface roughness, slope, and flow rate were analyzed in order to provide scientific basis for a better understanding and prediction of sheet erosion on red soil slopes. [Methods] A study was conducted to simulate red soil slopes with varying surface roughness by using different particle sizes (0.25—1, 1—3, 3—5, 5—7, and 7—10 mm). The experiments involved four flow rates (2, 4, 8, and 16 L/min) and four slopes (5°, 10°, 15°, and 20°). Photogrammetry based on the structure from the motion technique and the electrolyte tracing method were used to determine the surface roughness and flow velocity on the slope. The collected data were used to calculate the surface roughness and hydrodynamic parameters under each condition. [Results] The mean flow velocity varied from 0.022 to 0.531 m/s under the experimental design conditions. The Reynolds numbers ranged from 63 to 1 155, Froude numbers ranged from 0.1 to 4.1, and the resistance coefficients were within the range of 0.13 to 68.86. The surface roughness was positively correlated with the resistance coefficient (p<0.01) and negatively correlated with the Reynolds number (p<0.05), Froude number, and flow velocity (p<0.01). The slope was positively correlated with the unit-width discharge of overland flow and the Froude number (p<0.01). The width discharge was positively correlated with the Reynolds number, Froude number, and average flow velocity (p<0.01) and negatively correlated with the resistance coefficient (p<0.01). [Conclusion] Increased surface roughness augments the resistance to overland flow and reduces the influence of flow inertia, serving as a crucial factor in determining the mean flow velocity, Froude number, and resistance coefficient. The unit-width discharge primarily influences the Reynolds number by altering the water depth and flow inertia of the overland flow. Compared with the surface roughness and unit-width discharge, the slope had the least impact on the mean flow velocity, Reynolds number, Froude number, and resistance coefficient. The relationship of the mean flow velocity and Froude number with the surface roughness, unit-width discharge, and slope can be described well by the power function. Similarly, the Reynolds number and resistance coefficient exhibited a strong power function relationship with the unit width discharge and surface roughness.
[Objective] The hydrodynamic properties of red soil slopes under varying surface roughness, slope, and flow rate were analyzed in order to provide scientific basis for a better understanding and prediction of sheet erosion on red soil slopes. [Methods] A study was conducted to simulate red soil slopes with varying surface roughness by using different particle sizes (0.25—1, 1—3, 3—5, 5—7, and 7—10 mm). The experiments involved four flow rates (2, 4, 8, and 16 L/min) and four slopes (5°, 10°, 15°, and 20°). Photogrammetry based on the structure from the motion technique and the electrolyte tracing method were used to determine the surface roughness and flow velocity on the slope. The collected data were used to calculate the surface roughness and hydrodynamic parameters under each condition. [Results] The mean flow velocity varied from 0.022 to 0.531 m/s under the experimental design conditions. The Reynolds numbers ranged from 63 to 1 155, Froude numbers ranged from 0.1 to 4.1, and the resistance coefficients were within the range of 0.13 to 68.86. The surface roughness was positively correlated with the resistance coefficient (p<0.01) and negatively correlated with the Reynolds number (p<0.05), Froude number, and flow velocity (p<0.01). The slope was positively correlated with the unit-width discharge of overland flow and the Froude number (p<0.01). The width discharge was positively correlated with the Reynolds number, Froude number, and average flow velocity (p<0.01) and negatively correlated with the resistance coefficient (p<0.01). [Conclusion] Increased surface roughness augments the resistance to overland flow and reduces the influence of flow inertia, serving as a crucial factor in determining the mean flow velocity, Froude number, and resistance coefficient. The unit-width discharge primarily influences the Reynolds number by altering the water depth and flow inertia of the overland flow. Compared with the surface roughness and unit-width discharge, the slope had the least impact on the mean flow velocity, Reynolds number, Froude number, and resistance coefficient. The relationship of the mean flow velocity and Froude number with the surface roughness, unit-width discharge, and slope can be described well by the power function. Similarly, the Reynolds number and resistance coefficient exhibited a strong power function relationship with the unit width discharge and surface roughness.
2025,45(1):40-48,136
, DOI: 10.13961/j.cnki.stbctb.2025.01.005
Abstract:
[Objective] The regulatory effectiveness of S-shaped vegetation dams with varying flow path width ratios on debris flows were analyzed to explore the role of bioengineering measures in energy dissipation and disaster mitigation, in order to provide a theoretical foundation for constructing an eco-geotechnical synergistic disaster mitigation model. [Methods] Flume experiments were conducted on vegetation dams with S-shaped flow paths and width ratios of 0% (S0), 30% (S30), 45% (S45), 60% (S60), and 75% (S75). These tests focused on the flow velocity regulation, flow volume regulation, sediment control, and energy dissipation. [Results] ① The vegetation dam with a 0% flow path width ratio (S0) exhibited impressive debris flow interception capabilities, reducing 31.03%—44.19% of the flow velocity, 45.88%—56.02% of the flow volume, 34.37%—52.72% of energy dissipation levels, meanwhile, it also achieved an increase in sediment interception rate of 3.31%—75.69%. ② The vegetation dam with a 75% flow path width ratio (S75) showed strong sediment discharge capabilities, reducing 7.69%—29.03% of flow velocity, and 2.94%—35.54% of flow volume, and 11.56%—34.09% of energy dissipation levels, meanwhile, it also achieved and increase in sediment interception rafe of 4.13%—45.69%. ③ The vegetation dam with a 45% flow path width ratio (S45) demonstrated a balanced performance in interception and discharge compared to S30 and S60. It reduced 11.11%—40.00%, 16.47%—51.20%, 1.63%—54.75% of flow velocity, flow volume, and energy dissipation, respectively. The interception rate of the plant dam reached 18.04%—45.16%. [Conclusion] An S-shaped vegetation dam with a 0% flow path width ratio (S0) is ideal for debris-flow channels focused on interception. In contrast, a width ratio of 75%(S75) was better suited for channels that prioritize sediment discharge. The 45% width ratio (S45) effectively balances the interception and discharge.
[Objective] The regulatory effectiveness of S-shaped vegetation dams with varying flow path width ratios on debris flows were analyzed to explore the role of bioengineering measures in energy dissipation and disaster mitigation, in order to provide a theoretical foundation for constructing an eco-geotechnical synergistic disaster mitigation model. [Methods] Flume experiments were conducted on vegetation dams with S-shaped flow paths and width ratios of 0% (S0), 30% (S30), 45% (S45), 60% (S60), and 75% (S75). These tests focused on the flow velocity regulation, flow volume regulation, sediment control, and energy dissipation. [Results] ① The vegetation dam with a 0% flow path width ratio (S0) exhibited impressive debris flow interception capabilities, reducing 31.03%—44.19% of the flow velocity, 45.88%—56.02% of the flow volume, 34.37%—52.72% of energy dissipation levels, meanwhile, it also achieved an increase in sediment interception rate of 3.31%—75.69%. ② The vegetation dam with a 75% flow path width ratio (S75) showed strong sediment discharge capabilities, reducing 7.69%—29.03% of flow velocity, and 2.94%—35.54% of flow volume, and 11.56%—34.09% of energy dissipation levels, meanwhile, it also achieved and increase in sediment interception rafe of 4.13%—45.69%. ③ The vegetation dam with a 45% flow path width ratio (S45) demonstrated a balanced performance in interception and discharge compared to S30 and S60. It reduced 11.11%—40.00%, 16.47%—51.20%, 1.63%—54.75% of flow velocity, flow volume, and energy dissipation, respectively. The interception rate of the plant dam reached 18.04%—45.16%. [Conclusion] An S-shaped vegetation dam with a 0% flow path width ratio (S0) is ideal for debris-flow channels focused on interception. In contrast, a width ratio of 75%(S75) was better suited for channels that prioritize sediment discharge. The 45% width ratio (S45) effectively balances the interception and discharge.
Zhang Binyan, He Guangxiong, Wang Yandan, Yang Haozhou, Yu Jianlin, Leng Peng, Fang Haidong, Shi Liangtao, Ran Lin
2025,45(1):49-57
, DOI: 10.13961/j.cnki.stbctb.2025.01.006
Abstract:
[Objective] The runoff distribution and soil-water conservation benefits of slope croplands with different planting patterns in dry-hot valleys were analyzed in order to provide a scientific basis for the construction of soil and water conservation orchards in the Jinsha River dry-hot valley. [Methods] An in-situ runoff plot monitoring was used, and two typical planting patterns of fruit trees in dry-hot valley slope cropland were selected for the study: monoculture (grapes, dates, and stylosanthes) and fruit-grass intercropping (grapes+stylosanthes, dates+stylosanthes); the bare land was used as a control. The differences in surface runoff, subsurface flow, and soil erosion between different crops and planting patterns were compared to explore the runoff allocation mechanism and evaluate the soil and water conservation benefits on different planting patterns. [Results] Surface runoff was dominant in dry-hot valleys under different cropping patterns, and bare land runoff(53.2%—94.07%), rainfall amount, rainfall intensity, and vegetation coverage were the key factors affecting soil erosion in the dry-hot valley slope cropland. Different planting patterns regulated the distribution of runoff in the deep soil layers to significantly reduce surface runoff (50.79%—89.70%) and sediment runoff (54.66%—77.13%). The 50 cm and 100 cm interflows of the fruit-grass intercropping pattern were higher than those of the other patterns. The runoff reduction (78.53%, 72.54%) and sediment reduction (71.76%, 63.21%) benefits of the fruit-grass intercropping pattern (dates+stylosanthes, grapes+stylosanthes) were significantly higher than those of the monoculture pattern. [Conclusion] The fruit-grass composite intercropping system redistributes rainfall runoff by directing surface runoff into deep soil, thus providing better benefits for soil and water conservation.
[Objective] The runoff distribution and soil-water conservation benefits of slope croplands with different planting patterns in dry-hot valleys were analyzed in order to provide a scientific basis for the construction of soil and water conservation orchards in the Jinsha River dry-hot valley. [Methods] An in-situ runoff plot monitoring was used, and two typical planting patterns of fruit trees in dry-hot valley slope cropland were selected for the study: monoculture (grapes, dates, and stylosanthes) and fruit-grass intercropping (grapes+stylosanthes, dates+stylosanthes); the bare land was used as a control. The differences in surface runoff, subsurface flow, and soil erosion between different crops and planting patterns were compared to explore the runoff allocation mechanism and evaluate the soil and water conservation benefits on different planting patterns. [Results] Surface runoff was dominant in dry-hot valleys under different cropping patterns, and bare land runoff(53.2%—94.07%), rainfall amount, rainfall intensity, and vegetation coverage were the key factors affecting soil erosion in the dry-hot valley slope cropland. Different planting patterns regulated the distribution of runoff in the deep soil layers to significantly reduce surface runoff (50.79%—89.70%) and sediment runoff (54.66%—77.13%). The 50 cm and 100 cm interflows of the fruit-grass intercropping pattern were higher than those of the other patterns. The runoff reduction (78.53%, 72.54%) and sediment reduction (71.76%, 63.21%) benefits of the fruit-grass intercropping pattern (dates+stylosanthes, grapes+stylosanthes) were significantly higher than those of the monoculture pattern. [Conclusion] The fruit-grass composite intercropping system redistributes rainfall runoff by directing surface runoff into deep soil, thus providing better benefits for soil and water conservation.
2025,45(1):58-64,104
, DOI: 10.13961/j.cnki.stbctb.2025.01.007
Abstract:
[Objective] The characteristics and processes of soil nutrient loss in the platform slope system of a discharge site in China’s mining area were analyzed in order to provide a theoretical basis for preventing and controlling nutrient loss at discharge sites. [Methods] Using the discharge site of the Haizhou open-pit coal mine in Fuxin City, Liaoning Province, as the research object, an indoor model of the platform-slope system of the discharge site was established through the principle of a similar simulation, and an artificial rainfall simulation test was used to study the process and characteristics of nutrient loss from the platform-slope system of the discharge site under different rainfall intensities (60, 90, and 120 mm/h). [Results] ① With escalating rainfall intensity, the soil nutrient concentrations for nitrogen, phosphorus, and potassium in the dump waste platform-slope system exhibited a pattern of initial decline, subsequent rise, and then a gradual decrease, 60 mm/h ＞ 90 mm/h ＞ 120 mm/h for each intensity. ② The runoff nutrient loss from the platform slope soil increased with increasing rainfall intensity, notably for total nitrogen (TN), total phosphorus (TP), and total potassium (TK). However, the loss of nitrate (NO-3-N), ammonium (NH+4-N), available phosphorus (AP), and available potassium (AK) in runoff did not change significantly with increasing rainfall intensity. ③ The nutrient concentration in the soil sediment from the dump waste platform slope consistently exceeded that found in surface runoff, with sediment nutrient loss escalating as the rainfall intensity increased. ④ The enrichment ratio of total nitrogen and total potassium in soil sediment rose with greater rainfall intensity, expressed as TN ＞ TP＞ TK. [Conclusion] The concentration of soil nutrients lost in the dump waste platform-slope system was predominantly influenced by rainfall intensity and soil characteristics.
[Objective] The characteristics and processes of soil nutrient loss in the platform slope system of a discharge site in China’s mining area were analyzed in order to provide a theoretical basis for preventing and controlling nutrient loss at discharge sites. [Methods] Using the discharge site of the Haizhou open-pit coal mine in Fuxin City, Liaoning Province, as the research object, an indoor model of the platform-slope system of the discharge site was established through the principle of a similar simulation, and an artificial rainfall simulation test was used to study the process and characteristics of nutrient loss from the platform-slope system of the discharge site under different rainfall intensities (60, 90, and 120 mm/h). [Results] ① With escalating rainfall intensity, the soil nutrient concentrations for nitrogen, phosphorus, and potassium in the dump waste platform-slope system exhibited a pattern of initial decline, subsequent rise, and then a gradual decrease, 60 mm/h ＞ 90 mm/h ＞ 120 mm/h for each intensity. ② The runoff nutrient loss from the platform slope soil increased with increasing rainfall intensity, notably for total nitrogen (TN), total phosphorus (TP), and total potassium (TK). However, the loss of nitrate (NO-3-N), ammonium (NH+4-N), available phosphorus (AP), and available potassium (AK) in runoff did not change significantly with increasing rainfall intensity. ③ The nutrient concentration in the soil sediment from the dump waste platform slope consistently exceeded that found in surface runoff, with sediment nutrient loss escalating as the rainfall intensity increased. ④ The enrichment ratio of total nitrogen and total potassium in soil sediment rose with greater rainfall intensity, expressed as TN ＞ TP＞ TK. [Conclusion] The concentration of soil nutrients lost in the dump waste platform-slope system was predominantly influenced by rainfall intensity and soil characteristics.
2025,45(1):65-73
, DOI: 10.13961/j.cnki.stbctb.2025.01.008
Abstract:
[Objective] The use of modified hydrophilic polyurethane resin binder (W-OH) solution at different concentrations to reduce leakage from gravel slag slopes was investigated to provide theoretical support for reducing leakages from coarse gravel slag and to improve vegetation restoration in rocky desertification areas. [Methods] A highway slag slope in the rocky desertification area of the Guangxi Zhuang Autonomous Region was investigated. Artificial erosion experiments were conducted on a sloping gravel surface and the treatments were different concentrations of added W-OH solution with different erosion flow rates. [Results] The slope that was not treated with the W-OH solution produced large amounts of leakage water and runoff on the slope only appeared when the scouring discharge was greater than 30 L/min. When the scouring discharge was 30 L/min, the runoff rate accounted for 18.3% of the incoming flow rate and 81.7% of the water was lost due to slope leakage. However, the average runoff and average infiltration rates for the slope after treatment with the W-OH solution increased as the inflow rate and W-OH solution concentration rose. The stable runoff rate for the slope treated with W-OH solution concentrations of 3%—6% increased by 200%—385.5% compared to that of the untreated slopes and the higher the concentration of the W-OH solution, the better the treatment effect on the slope. The infiltration runoff ratio decreased as the inflow rate and the W-OH solution concentration increased. [Conclusion] Treatment with the W-OH solution effectively reduced leakage from coarse-grained slag slopes and improved the water retention capacity of the slope. These improvements contributed to slope vegetation restoration.
[Objective] The use of modified hydrophilic polyurethane resin binder (W-OH) solution at different concentrations to reduce leakage from gravel slag slopes was investigated to provide theoretical support for reducing leakages from coarse gravel slag and to improve vegetation restoration in rocky desertification areas. [Methods] A highway slag slope in the rocky desertification area of the Guangxi Zhuang Autonomous Region was investigated. Artificial erosion experiments were conducted on a sloping gravel surface and the treatments were different concentrations of added W-OH solution with different erosion flow rates. [Results] The slope that was not treated with the W-OH solution produced large amounts of leakage water and runoff on the slope only appeared when the scouring discharge was greater than 30 L/min. When the scouring discharge was 30 L/min, the runoff rate accounted for 18.3% of the incoming flow rate and 81.7% of the water was lost due to slope leakage. However, the average runoff and average infiltration rates for the slope after treatment with the W-OH solution increased as the inflow rate and W-OH solution concentration rose. The stable runoff rate for the slope treated with W-OH solution concentrations of 3%—6% increased by 200%—385.5% compared to that of the untreated slopes and the higher the concentration of the W-OH solution, the better the treatment effect on the slope. The infiltration runoff ratio decreased as the inflow rate and the W-OH solution concentration increased. [Conclusion] Treatment with the W-OH solution effectively reduced leakage from coarse-grained slag slopes and improved the water retention capacity of the slope. These improvements contributed to slope vegetation restoration.
2025,45(1):74-81
, DOI: 10.13961/j.cnki.stbctb.2025.01.009
Abstract:
[Objective] The variation patterns of C, N, and P contents in soil and their ecological stoichiometric characteristics during the process of vegetation restoration in arid zones was analysed in order to provide a scientific basis for accurately assessing the impacts of sand-fixing vegetation on soil nutrients in arid environments. [Methods] A Hedysarum scoparium community in the 1992 aerial seeding afforestation area at the northeastern edge of the Tengger Desert was taken as the research object. The native vegetation Artemisia oleifera as well as a quicksand land without vegetation restoration measures were used as the control (CK). The soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) levels across a soil profile in the H. scoparium community and their eco-chemometric characteristics were analyzed. [Results] ① The SOC, TN, and TP contents of the soil from the H. scoparium community, which was established more than 30 years ago, were 0.71, 0.03, and 0.27 g/kg, respectively. These were all significantly higher than those of the unseeded quicksand land by 73.2%, 50%, and 145.5%, respectively. The SOC was restored to 58.6% of that of the native vegetation A. oleifera. The distributions of SOC, TN, and TP content in the H. scoparium soil decreased with soil depth and were significantly higher in the 0—10 cm soil layer than in the other soil layers (p<0.05). ② The soil C∶P and N∶P ratios of the H. scoparium community were 0.57, and 0.13, which were 30.5% and 48% lower than those of the bare sand, respectively. The C∶N ratio was 22.41, which was 73.2% higher than that of the bare sand. The soil C∶P and N∶P ratios decreased with increasing soil depth, whereas the C∶N ratio showed an increasing followed by a decreasing trend. The average N∶P ratio in the H. scoparium community at a soil depth of 0—200 cm was 0.13, which was much smaller than 14 in the control groups. [Conclusion] The accumulation of soil nutrients in the study area became evident as sand-fixing vegetation was restored. The growth of the H. scoparium community was mainly limited by N. Thus, it is recommended to apply increased amounts of N fertilizer in the later stages of the H. scoparium community establishment. In addition, the H. scoparium community was observed to have a low soil organic matter mineralization rate, a lower rate of SOC decomposition than SOC accumulation, and a favorable soil environment for C accumulation.
[Objective] The variation patterns of C, N, and P contents in soil and their ecological stoichiometric characteristics during the process of vegetation restoration in arid zones was analysed in order to provide a scientific basis for accurately assessing the impacts of sand-fixing vegetation on soil nutrients in arid environments. [Methods] A Hedysarum scoparium community in the 1992 aerial seeding afforestation area at the northeastern edge of the Tengger Desert was taken as the research object. The native vegetation Artemisia oleifera as well as a quicksand land without vegetation restoration measures were used as the control (CK). The soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) levels across a soil profile in the H. scoparium community and their eco-chemometric characteristics were analyzed. [Results] ① The SOC, TN, and TP contents of the soil from the H. scoparium community, which was established more than 30 years ago, were 0.71, 0.03, and 0.27 g/kg, respectively. These were all significantly higher than those of the unseeded quicksand land by 73.2%, 50%, and 145.5%, respectively. The SOC was restored to 58.6% of that of the native vegetation A. oleifera. The distributions of SOC, TN, and TP content in the H. scoparium soil decreased with soil depth and were significantly higher in the 0—10 cm soil layer than in the other soil layers (p<0.05). ② The soil C∶P and N∶P ratios of the H. scoparium community were 0.57, and 0.13, which were 30.5% and 48% lower than those of the bare sand, respectively. The C∶N ratio was 22.41, which was 73.2% higher than that of the bare sand. The soil C∶P and N∶P ratios decreased with increasing soil depth, whereas the C∶N ratio showed an increasing followed by a decreasing trend. The average N∶P ratio in the H. scoparium community at a soil depth of 0—200 cm was 0.13, which was much smaller than 14 in the control groups. [Conclusion] The accumulation of soil nutrients in the study area became evident as sand-fixing vegetation was restored. The growth of the H. scoparium community was mainly limited by N. Thus, it is recommended to apply increased amounts of N fertilizer in the later stages of the H. scoparium community establishment. In addition, the H. scoparium community was observed to have a low soil organic matter mineralization rate, a lower rate of SOC decomposition than SOC accumulation, and a favorable soil environment for C accumulation.
2025,45(1):82-93
, DOI: 10.13961/j.cnki.stbctb.2025.01.010
Abstract:
[Objective] The temporal and spatial variation of understory vegetation coverage and its driving factors in Hubei Province were studied to provide scientific basis for ecological environment protection and vegetation management in this area. [Methods] Hubei Province was selected as the study area, and understory green leaf vegetation cover and understory litter cover were extracted from 28 sample plots for every half month in 2022 through field survey and DeepLabV3+ semantic segmentation method. Based on this, various machine learning models were used to analyze the impact of four driving factors, namely spatial location, natural environment, social and economic environment, and climate conditions, on changes in understory green leaf vegetation cover. [Results] Monthly variations in understory litter cover did not show obvious seasonal characteristics, and there was considerable spatial and temporal heterogeneity in the understory litter cover among the sample plots. In contrast, understory green leaf vegetation cover showed obvious seasonal change characteristics, and there were significant differences in understory green leaf vegetation cover among different vegetation types; the understory green leaf vegetation cover of economic forests and conifers was generally higher than that of broadleaf deciduous forests and evergreen broadleaf forests, and the differences in understory green leaf vegetation cover between broadleaf deciduous and evergreen broadleaf forests were relatively small. The random forest regression model showed the best prediction performance, with a root mean square error (RMSE) of 11.072 3 and a coefficient of determination (R2) of 0.732. [Conclusion] The random forest regression model showed that temperature, NDVI, and precipitation in the previous month were the key driving factors for spatiotemporal changes in the understory green leaf vegetation cover.
[Objective] The temporal and spatial variation of understory vegetation coverage and its driving factors in Hubei Province were studied to provide scientific basis for ecological environment protection and vegetation management in this area. [Methods] Hubei Province was selected as the study area, and understory green leaf vegetation cover and understory litter cover were extracted from 28 sample plots for every half month in 2022 through field survey and DeepLabV3+ semantic segmentation method. Based on this, various machine learning models were used to analyze the impact of four driving factors, namely spatial location, natural environment, social and economic environment, and climate conditions, on changes in understory green leaf vegetation cover. [Results] Monthly variations in understory litter cover did not show obvious seasonal characteristics, and there was considerable spatial and temporal heterogeneity in the understory litter cover among the sample plots. In contrast, understory green leaf vegetation cover showed obvious seasonal change characteristics, and there were significant differences in understory green leaf vegetation cover among different vegetation types; the understory green leaf vegetation cover of economic forests and conifers was generally higher than that of broadleaf deciduous forests and evergreen broadleaf forests, and the differences in understory green leaf vegetation cover between broadleaf deciduous and evergreen broadleaf forests were relatively small. The random forest regression model showed the best prediction performance, with a root mean square error (RMSE) of 11.072 3 and a coefficient of determination (R2) of 0.732. [Conclusion] The random forest regression model showed that temperature, NDVI, and precipitation in the previous month were the key driving factors for spatiotemporal changes in the understory green leaf vegetation cover.
2025,45(1):94-104
, DOI: 10.13961/j.cnki.stbctb.2025.01.011
Abstract:
[Objective] The plant composition of typical catchment area of the Loess Plateau was analyzed to evaluate its ecological restoration status and provide scientific guidance for further implementation of vegetation restoration measures to improve the effectiveness of soil and water conservation. [Methods] Based on the Heshui (HS) and Jingbian (JB) landslide-dammed reservoir catchments located in the plateau-gully region of the southern central area and the hill-gully region of the northern central area of the Loess Plateau, respectively, comprehensive surveys were conducted to document the existing vegetation types, identify the pollen composition in the topsoil, and analyze the physical properties of the topsoil, including water content, grain size, and loss on ignition at 550 ℃. [Results] In total, 230 genera from 84 families were identified in the HS catchment, and 223 genera from 78 families were identified in the JB catchment. Nevertheless, there was a higher abundance of woody plants, moisture-loving grasses, and herbs around the HS catchment (51.74%), whereas xerophytic shrubs and herbs dominated around the JB catchment (56.50%). These patterns reflected a combination of climatic conditions, soil properties, land use conditions, and agricultural and economic development. In addition, the current high vegetation coverage area under the 'Grain for Green’ project accounted for 82.61% and 37.80% of the area around the HS and JB catchments, respectively. However, certain adverse phenomena, including invasive non-native plant species, a low proportion of indigenous flora, and a noticeable presence of artificial plants, have been observed. [Conclusion] To ensure sustainable vegetation regeneration, ecological restoration of small catchments in the Loess Plateau should fully consider the local climate and plant characteristics.
[Objective] The plant composition of typical catchment area of the Loess Plateau was analyzed to evaluate its ecological restoration status and provide scientific guidance for further implementation of vegetation restoration measures to improve the effectiveness of soil and water conservation. [Methods] Based on the Heshui (HS) and Jingbian (JB) landslide-dammed reservoir catchments located in the plateau-gully region of the southern central area and the hill-gully region of the northern central area of the Loess Plateau, respectively, comprehensive surveys were conducted to document the existing vegetation types, identify the pollen composition in the topsoil, and analyze the physical properties of the topsoil, including water content, grain size, and loss on ignition at 550 ℃. [Results] In total, 230 genera from 84 families were identified in the HS catchment, and 223 genera from 78 families were identified in the JB catchment. Nevertheless, there was a higher abundance of woody plants, moisture-loving grasses, and herbs around the HS catchment (51.74%), whereas xerophytic shrubs and herbs dominated around the JB catchment (56.50%). These patterns reflected a combination of climatic conditions, soil properties, land use conditions, and agricultural and economic development. In addition, the current high vegetation coverage area under the 'Grain for Green’ project accounted for 82.61% and 37.80% of the area around the HS and JB catchments, respectively. However, certain adverse phenomena, including invasive non-native plant species, a low proportion of indigenous flora, and a noticeable presence of artificial plants, have been observed. [Conclusion] To ensure sustainable vegetation regeneration, ecological restoration of small catchments in the Loess Plateau should fully consider the local climate and plant characteristics.
2025,45(1):105-113,404
, DOI: 10.13961/j.cnki.stbctb.2025.01.012
Abstract:
[Objective] The spatiotemporal evolution characteristics and attributes of land desertification in the middle and upper reaches of Yarlung Zangbo River were analyzed and identified to provide scientific support for ecological restoration and protection and promote a virtuous cycle of the ecosystem in this region. [Methods] An improved desertification difference index method based on the three-dimensional space of vegetation, surface reflectance, and soil moisture (NDVI-Albedo-Wet) were employed to analyze the spatiotemporal evolution of land desertification in the research area during 1990—2020. On this basis, attribute analysis of land desertification was conducted from the perspectives of temporal changes and spatial differentiation using principal component analysis and geographical detector methods, respectively. [Results] The total area of land desertification decreased from 3.48×104 km2 in 1990 to 1.67×104 km2 in 2020; however, the degree of land desertification increased in certain areas, particularly in the western part of the study area, such as Saga and Jilong, and the southeastern parts, such as Kangma and Qiongjie County. The spatial distribution of land desertification exhibited a strip-like pattern along the main river channel from west to east, being concentrated on gentle slopes, moderate slopes, grasslands, and unused land. During 1990—2020, the reversal of land desertification in the study area was primarily influenced by human activities, with the principal contributing factors accounting for 59.1% of the total reversal. The spatial differentiation of land desertification shifted from dependence on natural geographical factors, such as elevation and wind speed, in 1990, to the synergistic influence of multiple factors, including natural and socioeconomic factors, in 2020, with the impact of various driving factors on the spatial distribution of land desertification exhibiting dual-factor enhancement and non-linear increase. [Conclusion] The degree of land desertification in the middle and upper reaches of the Yarlung Zangbo River basin was alleviated between 1988 and 2020; however, local exacerbations persisted. Hence, further strengthening the ecological restoration of the source area and enhancing sand source management and vegetation cultivation within a 10 km radius of both the left and right banks of the river is necessary.
[Objective] The spatiotemporal evolution characteristics and attributes of land desertification in the middle and upper reaches of Yarlung Zangbo River were analyzed and identified to provide scientific support for ecological restoration and protection and promote a virtuous cycle of the ecosystem in this region. [Methods] An improved desertification difference index method based on the three-dimensional space of vegetation, surface reflectance, and soil moisture (NDVI-Albedo-Wet) were employed to analyze the spatiotemporal evolution of land desertification in the research area during 1990—2020. On this basis, attribute analysis of land desertification was conducted from the perspectives of temporal changes and spatial differentiation using principal component analysis and geographical detector methods, respectively. [Results] The total area of land desertification decreased from 3.48×104 km2 in 1990 to 1.67×104 km2 in 2020; however, the degree of land desertification increased in certain areas, particularly in the western part of the study area, such as Saga and Jilong, and the southeastern parts, such as Kangma and Qiongjie County. The spatial distribution of land desertification exhibited a strip-like pattern along the main river channel from west to east, being concentrated on gentle slopes, moderate slopes, grasslands, and unused land. During 1990—2020, the reversal of land desertification in the study area was primarily influenced by human activities, with the principal contributing factors accounting for 59.1% of the total reversal. The spatial differentiation of land desertification shifted from dependence on natural geographical factors, such as elevation and wind speed, in 1990, to the synergistic influence of multiple factors, including natural and socioeconomic factors, in 2020, with the impact of various driving factors on the spatial distribution of land desertification exhibiting dual-factor enhancement and non-linear increase. [Conclusion] The degree of land desertification in the middle and upper reaches of the Yarlung Zangbo River basin was alleviated between 1988 and 2020; however, local exacerbations persisted. Hence, further strengthening the ecological restoration of the source area and enhancing sand source management and vegetation cultivation within a 10 km radius of both the left and right banks of the river is necessary.
2025,45(1):114-126
, DOI: 10.13961/j.cnki.stbctb.2025.01.013
Abstract:
[Objective] The soil and water conservation benefits and the economic benefits of crop increments in terrace reclamation projects at the small watershed scale in the hilly areas of Southern China were evaluated and optimized, and the trade-off relationship between the conservation benefits and the economic benefits was analyzed in order to provide scientific guidance for the formulation of a spatial optimization layout for the Danjiangkou City, Hubei Province. [Methods] Remote sensing and spatial analysis techniques were used to identify the spatial distribution of terraces in Danjiangkou City and delineate the small watersheds. The Chinese Soil Loss Equation (CSLE) model was combined with field investigations to evaluate the trade-off between soil and water conservation benefits and crop value added when slope cropland was converted to terrace cropland. A linear optimization method was used to determine the optimal spatial layout of the project under multiple scenarios. [Results] The terraces and slope croplands in Danjiangkou City were mainly distributed in the central and northern watersheds and they exhibited higher total benefits in terms of soil and water conservation and value-added economic benefits. The spatial optimization analysis of each small watershed indicated that under the soil and water conservation priority scenario, the changing slope cropland to terrace land project areas were primarily concentrated in the southwestern watershed, whereas under the crop value-added economic benefits priority scenario, the project areas were more heavily concentrated in the central watershed. The linear optimization results under the different scenarios showed a significant trade-off between the soil and water conservation priority and the crop value-added economic benefits priority. Under the different scenarios, the maximum soil and water conservation benefit was an approximately 3.21×106 t reduction in erosion with crop value-added economic benefits of approximately 1.78×108 yuan. The maximum crop value-added economic benefit result was approximately 1.87×108 yuan with soil and water conservation benefits reduced to approximately 3.01×106 t. The Pareto optimal solutions reflected the tradeoff between the two. [Conclusion] The spatial optimization methods used in this study quantified and optimized the trade-off relationship between water conservation benefits and the crop value-added economic benefits in projects where sloping land was converted to terrace land. The results provide a series of non-dominated solutions that can be used to aid government decision-making processes.
[Objective] The soil and water conservation benefits and the economic benefits of crop increments in terrace reclamation projects at the small watershed scale in the hilly areas of Southern China were evaluated and optimized, and the trade-off relationship between the conservation benefits and the economic benefits was analyzed in order to provide scientific guidance for the formulation of a spatial optimization layout for the Danjiangkou City, Hubei Province. [Methods] Remote sensing and spatial analysis techniques were used to identify the spatial distribution of terraces in Danjiangkou City and delineate the small watersheds. The Chinese Soil Loss Equation (CSLE) model was combined with field investigations to evaluate the trade-off between soil and water conservation benefits and crop value added when slope cropland was converted to terrace cropland. A linear optimization method was used to determine the optimal spatial layout of the project under multiple scenarios. [Results] The terraces and slope croplands in Danjiangkou City were mainly distributed in the central and northern watersheds and they exhibited higher total benefits in terms of soil and water conservation and value-added economic benefits. The spatial optimization analysis of each small watershed indicated that under the soil and water conservation priority scenario, the changing slope cropland to terrace land project areas were primarily concentrated in the southwestern watershed, whereas under the crop value-added economic benefits priority scenario, the project areas were more heavily concentrated in the central watershed. The linear optimization results under the different scenarios showed a significant trade-off between the soil and water conservation priority and the crop value-added economic benefits priority. Under the different scenarios, the maximum soil and water conservation benefit was an approximately 3.21×106 t reduction in erosion with crop value-added economic benefits of approximately 1.78×108 yuan. The maximum crop value-added economic benefit result was approximately 1.87×108 yuan with soil and water conservation benefits reduced to approximately 3.01×106 t. The Pareto optimal solutions reflected the tradeoff between the two. [Conclusion] The spatial optimization methods used in this study quantified and optimized the trade-off relationship between water conservation benefits and the crop value-added economic benefits in projects where sloping land was converted to terrace land. The results provide a series of non-dominated solutions that can be used to aid government decision-making processes.
He Na, Zhu Xisong, Wu Fu, Liu Chang, Wu Qiuju, Huang Ximing, Jiang Li, Xiao Jigui, Wen Haitao, He Tianjie, Chang Ming
2025,45(1):127-136
, DOI: 10.13961/j.cnki.stbctb.2025.01.014
Abstract:
[Objective] A comprehensive risk assessment system for collapses and landslides in the karst regions of the Guangxi Zhuang Autonomous Region was established, in order to offerscientific support for early warning, disaster prevention, and mitigation in the area. [Methods] Beiliu City was selected as the study area, and a database of collapses and landslides was constructed. Slope units were used as the basis for the evaluation, with multisource data systematically collected and analyzed. Key evaluation indicators, including groundwater type and runoff intensity index, were identified, and a fully connected neural network model was employed to assess the susceptibility to collapses and landslides. Given the region’s vulnerability to rainfall and karst erosion, the soil erosion modulus was incorporated into the hazard assessment. Finally, a risk evaluation model for collapses and landslides in Beiliu City was developed by integrating vulnerability assessments of the exposed elements. [Results] The findings revealed that high- and very high-risk zones covered 252.22 km2, accounting for 10.27% of Beiliu City’s total area. These zones are primarily located in Longsheng Town, Xinfeng Town, Pingzheng Town, and Liujing Town, which are characterized by eroded and denuded hills and tectonic erosion of low mountains. Factors such as loose geotechnical body, high soil erosion modulus, dense population, and concentrated buildings significantly heightened the collapse and landslide risks, resulting in a high-risk classification. [Conclusion] Validation through ROC curves and field investigations showed an accuracy of 0.966 4 for susceptibility evaluation and 89.3% for risk assessment in Beiliu City. These results demonstrate the high precision and practical applicability of the constructed model, which aligns closely with real-world scenarios.
[Objective] A comprehensive risk assessment system for collapses and landslides in the karst regions of the Guangxi Zhuang Autonomous Region was established, in order to offerscientific support for early warning, disaster prevention, and mitigation in the area. [Methods] Beiliu City was selected as the study area, and a database of collapses and landslides was constructed. Slope units were used as the basis for the evaluation, with multisource data systematically collected and analyzed. Key evaluation indicators, including groundwater type and runoff intensity index, were identified, and a fully connected neural network model was employed to assess the susceptibility to collapses and landslides. Given the region’s vulnerability to rainfall and karst erosion, the soil erosion modulus was incorporated into the hazard assessment. Finally, a risk evaluation model for collapses and landslides in Beiliu City was developed by integrating vulnerability assessments of the exposed elements. [Results] The findings revealed that high- and very high-risk zones covered 252.22 km2, accounting for 10.27% of Beiliu City’s total area. These zones are primarily located in Longsheng Town, Xinfeng Town, Pingzheng Town, and Liujing Town, which are characterized by eroded and denuded hills and tectonic erosion of low mountains. Factors such as loose geotechnical body, high soil erosion modulus, dense population, and concentrated buildings significantly heightened the collapse and landslide risks, resulting in a high-risk classification. [Conclusion] Validation through ROC curves and field investigations showed an accuracy of 0.966 4 for susceptibility evaluation and 89.3% for risk assessment in Beiliu City. These results demonstrate the high precision and practical applicability of the constructed model, which aligns closely with real-world scenarios.
2025,45(1):137-146
, DOI: 10.13961/j.cnki.stbctb.2025.01.015
Abstract:
[Objective] The key ecological corridors, ecological nodes, and obstacle points in the Hainan Zang Autonomous Prefecture, Qinghai Province was identified, and the ecological security pattern of the Hainan Prefecture was described in order to provide a reference for its ecological environmental protection and sustainable development. [Methods] The ecological security pattern of the Hainan Prefecture was described using the InVEST model and circuit theory method based on the source-resistance surface-corridor framework. The Hainan Zang Autonomous Prefecture (Hainan Prefecture) in the Qinghai Province, an important water conservation area at the headwaters of the Yellow River, was the research object. [Results] ① Ecosystem services in the Hainan Prefecture were generally good and mainly included very important and highly important services. ② The ecological source area in this study was approximately 5 463 km2, accounting for 12.0% of the total study area. Scattered patches were mainly distributed in the south and east of the Hainan Prefecture and at the southern bank of the Qinghai Lake. A total of 55 ecological corridors were identified, with a total length of 1 963 km, including 22 key corridors, with a dense distribution pattern in the south and east and sparse distribution in the west. A total of 37 ecological pinch points and 32 ecological obstacle points were identified, which were mainly distributed in the central parts of Gonghe and Guide County. ③ The ecological source, corridor, pinch point, and obstacle point areas were combined to form an ecological security pattern. [Conclusion] Future endeavors should focus on the protection and restoration of habitats in the western part of the study area, strengthening the service capacity of the ecological source area at the southern, eastern, and southern banks of the Qinghai Lake to improve the overall connectivity of the ecosystem in the Hainan Prefecture.
[Objective] The key ecological corridors, ecological nodes, and obstacle points in the Hainan Zang Autonomous Prefecture, Qinghai Province was identified, and the ecological security pattern of the Hainan Prefecture was described in order to provide a reference for its ecological environmental protection and sustainable development. [Methods] The ecological security pattern of the Hainan Prefecture was described using the InVEST model and circuit theory method based on the source-resistance surface-corridor framework. The Hainan Zang Autonomous Prefecture (Hainan Prefecture) in the Qinghai Province, an important water conservation area at the headwaters of the Yellow River, was the research object. [Results] ① Ecosystem services in the Hainan Prefecture were generally good and mainly included very important and highly important services. ② The ecological source area in this study was approximately 5 463 km2, accounting for 12.0% of the total study area. Scattered patches were mainly distributed in the south and east of the Hainan Prefecture and at the southern bank of the Qinghai Lake. A total of 55 ecological corridors were identified, with a total length of 1 963 km, including 22 key corridors, with a dense distribution pattern in the south and east and sparse distribution in the west. A total of 37 ecological pinch points and 32 ecological obstacle points were identified, which were mainly distributed in the central parts of Gonghe and Guide County. ③ The ecological source, corridor, pinch point, and obstacle point areas were combined to form an ecological security pattern. [Conclusion] Future endeavors should focus on the protection and restoration of habitats in the western part of the study area, strengthening the service capacity of the ecological source area at the southern, eastern, and southern banks of the Qinghai Lake to improve the overall connectivity of the ecosystem in the Hainan Prefecture.
Ma Zhiliang, Zhuang Jianqi, Wu Jing, Cao Yanbo, Chen Shengyin, Chang Lei, Zhan Jiewei, Ma Penghui, Kong Jiaxu
2025,45(1):147-157,177
, DOI: 10.13961/j.cnki.stbctb.2025.01.016
Abstract:
[Objective] The characteristics and causal mechanisms of low-frequency debris flows in the Qinling Mountains was analyzed in order to provide a scientific reference for their prevention and mitigation. [Methods] The “8·11” Jiwozi flash flood and debris flow of 2023 served as the research subject. Using field investigations and numerical simulations, actual precipitation frequencies were used to reverse engineer the formation process of the flash flood and debris flow, and a risk assessment was carried out. [Results] ① Intense rainfall accumulated quickly, forming torrents that erode loose materials in upstream channels. This process, known as the “fire hose” effect, triggered mountain floods and debris flows. Assisted by steep terrain, these flows eroded channels across the watershed, and a significant amount of sediment spreads downstream, forming alluvial fans and blocking river channels. ② Simulations under actual rainfall frequencies showed that the sediment deposition depths across the watershed ranges from 0.04 to 5.63 meters, with a maximum flow velocity of 7.43 m/s. The area of the alluvial fan was 1.91×104 m2, and the one-time discharge volume was 78 271 m3. ③ Based on flow velocity, sediment depth, and hazard range, three danger zones were identified (high, medium, and low). The area on the western side of the alluvial fan, with higher elevation, was classified as a low-risk zone, accounting for approximately 10% of the fan area. The central area and the area from the edge of the fan to the road were classified as medium-risk zones, comprising 62% of the total area. The southeastern and southwestern areas of the alluvial fan were high-risk zones, accounting for 28% of the area. [Conclusion] The “8·11” Jiwozi flash flood and debris flow in 2023 was a typical low-frequency flash flood and debris flow disaster triggered by extreme short-duration heavy rainfall. The FLO-2D model effectively simulates the movement and deposition processes of the debris flow and determines the hazardous areas.
[Objective] The characteristics and causal mechanisms of low-frequency debris flows in the Qinling Mountains was analyzed in order to provide a scientific reference for their prevention and mitigation. [Methods] The “8·11” Jiwozi flash flood and debris flow of 2023 served as the research subject. Using field investigations and numerical simulations, actual precipitation frequencies were used to reverse engineer the formation process of the flash flood and debris flow, and a risk assessment was carried out. [Results] ① Intense rainfall accumulated quickly, forming torrents that erode loose materials in upstream channels. This process, known as the “fire hose” effect, triggered mountain floods and debris flows. Assisted by steep terrain, these flows eroded channels across the watershed, and a significant amount of sediment spreads downstream, forming alluvial fans and blocking river channels. ② Simulations under actual rainfall frequencies showed that the sediment deposition depths across the watershed ranges from 0.04 to 5.63 meters, with a maximum flow velocity of 7.43 m/s. The area of the alluvial fan was 1.91×104 m2, and the one-time discharge volume was 78 271 m3. ③ Based on flow velocity, sediment depth, and hazard range, three danger zones were identified (high, medium, and low). The area on the western side of the alluvial fan, with higher elevation, was classified as a low-risk zone, accounting for approximately 10% of the fan area. The central area and the area from the edge of the fan to the road were classified as medium-risk zones, comprising 62% of the total area. The southeastern and southwestern areas of the alluvial fan were high-risk zones, accounting for 28% of the area. [Conclusion] The “8·11” Jiwozi flash flood and debris flow in 2023 was a typical low-frequency flash flood and debris flow disaster triggered by extreme short-duration heavy rainfall. The FLO-2D model effectively simulates the movement and deposition processes of the debris flow and determines the hazardous areas.
Risk evaluation of Benggang in Shangyou County, Jiangxi Province based on matrix discriminant method
2025,45(1):158-167
, DOI: 10.13961/j.cnki.stbctb.2025.01.017
Abstract:
[Objective] The distribution characteristics of Benggang in Shangyou County, Jiangxi Province was analyzed, and its risk was evaluated, so as to provide data support and scientific basis for priority decision-making of Benggang governance. [Methods] Shangyou County, Jiangxi Province was taken as the research area. Based on the comprehensive investigation of Benggang and its hazard characteristics, according to the principle of three elements of Benggang risk, the scale and development status of Benggang were selected as the main risk potential indicators of the main body of Benggang. Hazard receptors such as houses, roads, and farmland were selected and combined with the hazard distance as the hazard degree index. The risk evaluation index system of Benggang based on the matrix discriminant method was constructed to explore the accuracy of this method in evaluating the Benggang risk. [Results] ① There were 227 Benggang in Shangyou County, of which 25 had been controlled and 202 had not been controlled. The type of development status was mostly active, scale was mostly large, morphological type was mainly dipper, hazard object was mainly farmland, and hazard distance was mainly less than 10 m. ② In Shangyou County, the proportions of the five risk levels of no, small, medium, large, and great to the number of Benggang was 47.5%,14.9%,15.8%,14.9% and 6.9%, respectively, and the accuracy of on-site verification reached 80%. ③ The Benggang of large and extremely dangerous levels in Shangyou County was mainly distributed in Yingqian Town and Shuiyan Township, and a small part was located in Meishui Township and Huangbu Town, which needs priority treatment. [Conclusion] The matrix discriminant method proposed in this study is accurate and the indicators are easy to obtain. The method is easy to operate and is applicable to the evaluation of the risk of Benggang.
[Objective] The distribution characteristics of Benggang in Shangyou County, Jiangxi Province was analyzed, and its risk was evaluated, so as to provide data support and scientific basis for priority decision-making of Benggang governance. [Methods] Shangyou County, Jiangxi Province was taken as the research area. Based on the comprehensive investigation of Benggang and its hazard characteristics, according to the principle of three elements of Benggang risk, the scale and development status of Benggang were selected as the main risk potential indicators of the main body of Benggang. Hazard receptors such as houses, roads, and farmland were selected and combined with the hazard distance as the hazard degree index. The risk evaluation index system of Benggang based on the matrix discriminant method was constructed to explore the accuracy of this method in evaluating the Benggang risk. [Results] ① There were 227 Benggang in Shangyou County, of which 25 had been controlled and 202 had not been controlled. The type of development status was mostly active, scale was mostly large, morphological type was mainly dipper, hazard object was mainly farmland, and hazard distance was mainly less than 10 m. ② In Shangyou County, the proportions of the five risk levels of no, small, medium, large, and great to the number of Benggang was 47.5%,14.9%,15.8%,14.9% and 6.9%, respectively, and the accuracy of on-site verification reached 80%. ③ The Benggang of large and extremely dangerous levels in Shangyou County was mainly distributed in Yingqian Town and Shuiyan Township, and a small part was located in Meishui Township and Huangbu Town, which needs priority treatment. [Conclusion] The matrix discriminant method proposed in this study is accurate and the indicators are easy to obtain. The method is easy to operate and is applicable to the evaluation of the risk of Benggang.
Wang Shangxiao, Zhang Xiaodong, Zhang Ming, Niu Xiaonan, Zhou Mo, Tang Zhimin, Zhang Jie, Zong Leli, Xu Shuai
2025,45(1):168-177
, DOI: 10.13961/j.cnki.stbctb.2025.01.018
Abstract:
[Objective] The effective soil thickness of a region was rapidly and accurately obtained, and its spatial distribution and influencing factors was analyzed, in order to provide theoretical guidance for vegetation growth, soil conservation, and food security. [Methods] Taking the Xinanjiang River basin as the research area, combining field survey data, topography, lithology, climate, and other soil-forming factors, the empirical Bayesian Kriging regression prediction (EBKRP) and random forest (RF) algorithms were applied to obtain the effective soil thickness inversion results. The relationship between this data and environmental variables was also analyzed. [Results] ① The average effective soil thickness in the region ranged from 0.2 to 0.3 m. Soil thickness was higher in basin and plain areas with concentrated urban development and intensive human activity. Meanwhile, it was lower in hilly and mountainous regions. ② Based on three accuracy evaluation indicators of MAE (mean absolute error), R2 (coefficient of determination), and RMSE (root mean square error), the prediction results of the RF algorithm were significantly better than those of the EBKRP algorithm. It could more effectively show the spatial heterogeneity distribution of soil thickness, improving the effect of soil thickness digital mapping. ③ The effective soil thickness estimation was strongly influenced by topography and climate variables, which accounted for 46.77% and 18.78% of the variable importance, respectively. [Conclusion] The RF algorithm could effectively invert regional effective soil thickness, overcoming the spatial heterogeneity of soil thickness, and is more accurate and has a higher resolution compared to models with limited sampling.
[Objective] The effective soil thickness of a region was rapidly and accurately obtained, and its spatial distribution and influencing factors was analyzed, in order to provide theoretical guidance for vegetation growth, soil conservation, and food security. [Methods] Taking the Xinanjiang River basin as the research area, combining field survey data, topography, lithology, climate, and other soil-forming factors, the empirical Bayesian Kriging regression prediction (EBKRP) and random forest (RF) algorithms were applied to obtain the effective soil thickness inversion results. The relationship between this data and environmental variables was also analyzed. [Results] ① The average effective soil thickness in the region ranged from 0.2 to 0.3 m. Soil thickness was higher in basin and plain areas with concentrated urban development and intensive human activity. Meanwhile, it was lower in hilly and mountainous regions. ② Based on three accuracy evaluation indicators of MAE (mean absolute error), R2 (coefficient of determination), and RMSE (root mean square error), the prediction results of the RF algorithm were significantly better than those of the EBKRP algorithm. It could more effectively show the spatial heterogeneity distribution of soil thickness, improving the effect of soil thickness digital mapping. ③ The effective soil thickness estimation was strongly influenced by topography and climate variables, which accounted for 46.77% and 18.78% of the variable importance, respectively. [Conclusion] The RF algorithm could effectively invert regional effective soil thickness, overcoming the spatial heterogeneity of soil thickness, and is more accurate and has a higher resolution compared to models with limited sampling.
2025,45(1):178-189,198
, DOI: 10.13961/j.cnki.stbctb.2025.01.019
Abstract:
[Objective] The evolution process of land use conflict and its formation and change mechanisms were explored to promote the alleviation of regional land-use conflict and optimize the allocation of regional land resources. [Methods] Based on a spatiotemporal dynamic process, a model for identifying land-use conflicts developed from a landscape pattern perspective was applied to diagnose land-use conflict situations across five periods (2000, 2005, 2010, 2015, and 2020) in Wuhu City, Anhui Province. By integrating the Bayesian hierarchical spatiotemporal model and the optimal parameter-based geographical detector, a framework was established to understand the formation mechanisms of the spatiotemporal dynamics of land-use conflicts, identifying the spatiotemporal dynamics and driving forces of land use conflicts in Wuhu City. The PLUS model was applied to conduct multi-scenario simulations and conflict mitigation analyses for land use in Wuhu City in 2030. [Results] ① Over the study period, the level of land-use conflicts in Wuhu City fluctuated upward, with the spatial pattern predominantly displaying a higher conflict density in the south and lower in the north, continuously expanding along the Changjiang River axis. Hotspots of local variation were concentrated in the urban-rural fringe areas, where agricultural and ecological spaces intersected. ② Land-use conflict patterns in Wuhu City were primarily formed by factors such as elevation, slope, proximity to roads, and distance from water systems, while GDP and population distribution had less influence on land-use conflict formation. ③ The pattern of land-use conflicts was expected to persist under different scenarios; notably, scenarios focused on farmland conservation and ecological protection could effectively mitigate the emergence of land-use conflicts, and the balance between agriculture, ecology and economic development should be maintained in the management process. [Conclusion] Land-use conflict in Wuhu City is constantly strengthening with the impact of deepening social development. In the future, it is still necessary to strengthen the control of land use according to local conditions, improve the level of land use conservation and intensive, and achieve high-quality development.
[Objective] The evolution process of land use conflict and its formation and change mechanisms were explored to promote the alleviation of regional land-use conflict and optimize the allocation of regional land resources. [Methods] Based on a spatiotemporal dynamic process, a model for identifying land-use conflicts developed from a landscape pattern perspective was applied to diagnose land-use conflict situations across five periods (2000, 2005, 2010, 2015, and 2020) in Wuhu City, Anhui Province. By integrating the Bayesian hierarchical spatiotemporal model and the optimal parameter-based geographical detector, a framework was established to understand the formation mechanisms of the spatiotemporal dynamics of land-use conflicts, identifying the spatiotemporal dynamics and driving forces of land use conflicts in Wuhu City. The PLUS model was applied to conduct multi-scenario simulations and conflict mitigation analyses for land use in Wuhu City in 2030. [Results] ① Over the study period, the level of land-use conflicts in Wuhu City fluctuated upward, with the spatial pattern predominantly displaying a higher conflict density in the south and lower in the north, continuously expanding along the Changjiang River axis. Hotspots of local variation were concentrated in the urban-rural fringe areas, where agricultural and ecological spaces intersected. ② Land-use conflict patterns in Wuhu City were primarily formed by factors such as elevation, slope, proximity to roads, and distance from water systems, while GDP and population distribution had less influence on land-use conflict formation. ③ The pattern of land-use conflicts was expected to persist under different scenarios; notably, scenarios focused on farmland conservation and ecological protection could effectively mitigate the emergence of land-use conflicts, and the balance between agriculture, ecology and economic development should be maintained in the management process. [Conclusion] Land-use conflict in Wuhu City is constantly strengthening with the impact of deepening social development. In the future, it is still necessary to strengthen the control of land use according to local conditions, improve the level of land use conservation and intensive, and achieve high-quality development.
2025,45(1):190-198
, DOI: 10.13961/j.cnki.stbctb.2025.01.020
Abstract:
[Objective] The soil water evaporation characteristics of soil cracks after different backfilling techniques was analyzed in order to provide scientific basis for the effective control of soil cracks in the dump hence promote ecological environment restoration and land reclamation. [Methods] The soil was collected from the surface of the west dump of Haizhou open-pit mine and the soil cracks were simulated by backfilling treatment and analyzed by the simulated evaporation test in the laboratory. [Results] The daily evaporation of cracks showed an obvious three-stage evaporation rule, and different backfilling treatments had little effect on the daily evaporation of cracks. With the increase of crack width, the cumulative evaporation of cracks increased and backfill treatment effectively reduced the cumulative evaporation of cracks. The cumulative evaporation of cracks with a backfilling ratio of 1∶1 (treatment 1) was the minimum value under the same group of cracks backfilling. The appearance of cracks would lead to the reduction of soil moisture content, but backfill treatment could improve the moisture content of cracks, and the water content of backfilling ratio of 1∶1 (treatment 1) was the highest value of the three groups of cracks, with an average value of 29.74%. The increase of crack width also had an impact on the evaporative water-loss ratio and the backfill treatment could reduce the evaporative water-loss ratio. The backfill ratio of 1∶1 (treatment 1) had the best performance in reducing the evaporative water-loss ratio. [Conclusion] The existence of cracks has an effect on the daily evaporation, cumulative evaporation, water content, and evaporation water loss ratio of cracks, and the 1∶1 backfill ratio (treatment 1) has the best performance in the study of water evaporation of soil cracks in the dump.
[Objective] The soil water evaporation characteristics of soil cracks after different backfilling techniques was analyzed in order to provide scientific basis for the effective control of soil cracks in the dump hence promote ecological environment restoration and land reclamation. [Methods] The soil was collected from the surface of the west dump of Haizhou open-pit mine and the soil cracks were simulated by backfilling treatment and analyzed by the simulated evaporation test in the laboratory. [Results] The daily evaporation of cracks showed an obvious three-stage evaporation rule, and different backfilling treatments had little effect on the daily evaporation of cracks. With the increase of crack width, the cumulative evaporation of cracks increased and backfill treatment effectively reduced the cumulative evaporation of cracks. The cumulative evaporation of cracks with a backfilling ratio of 1∶1 (treatment 1) was the minimum value under the same group of cracks backfilling. The appearance of cracks would lead to the reduction of soil moisture content, but backfill treatment could improve the moisture content of cracks, and the water content of backfilling ratio of 1∶1 (treatment 1) was the highest value of the three groups of cracks, with an average value of 29.74%. The increase of crack width also had an impact on the evaporative water-loss ratio and the backfill treatment could reduce the evaporative water-loss ratio. The backfill ratio of 1∶1 (treatment 1) had the best performance in reducing the evaporative water-loss ratio. [Conclusion] The existence of cracks has an effect on the daily evaporation, cumulative evaporation, water content, and evaporation water loss ratio of cracks, and the 1∶1 backfill ratio (treatment 1) has the best performance in the study of water evaporation of soil cracks in the dump.
2025,45(1):199-207,253
, DOI: 10.13961/j.cnki.stbctb.2025.01.021
Abstract:
[Objective] Vegetation restoration and screening with suitable trees and grasses in power transmission projects were performed to provide scientific guidance to improve vegetation restoration success in power transmission and transformation projects, reduce soil erosion caused by the project, and reduce ecological restoration costs. This is particularly important to guarantee the green, high-quality and sustainable development of power grids. [Methods] Using on-site investigation, field observation, and indoor analysis, 26 planting observation points were set up to observe the growth of grass and tree taxa two and five years after planting. The observation indices mainly included grass taxa and their height, hay production, tree taxa and their height, branch number, and crown width. The entropy value method was used to sort and screen the suitability of the growth of the grass and tree taxa in the various vegetation sub-zones along the transmission and substation routes. [Results] According to the observations, six grass taxa (Agropyron ristatum, Achnathurum splendens, Melilotus suavcolen, Medicago sativa, Elymus sibiricus and Elymus dahuricus) and six tree taxa (Tamarix hohenackeri, Caragana korshinskii, Hippophae rhamnoides, Haloxylon aphyllum, Sabina vulgaris, and Populus euphratica) were screened for the suitability evaluation. The results showed that in the broadleaf-deciduous mixed zone of the Qinling Mountains, A. splendens, M. sativa, and C. korshinskii ranked No. 1. In the desert Gobi zone of the West Hebei Corridor, M. suavcolen (No. 2) and H. aphyllum (No. 1) ranked the highest. In the oasis plain zone of the Hexi Corridor, A. ristatum (No. 2) and H. rhamnoides subsp. sinensis (No. 1) ranked the highest. In the desert grassland zone of the Hexi Corridor, E. sibiricus (No. 2), T. hohenackeri (No. 1) and P. euphratica (No. 1) ranked the highest. In the desert steppe zone of the Loess Plateau, E. dahuricus, T. hohenacke, C. korshinskii, H. aphyllum, and S. vulgaris were the most highly ranked species, and they were all ranked No. 2. In the dry steppe zone of the Loess Plateau, A. splendens (No. 2) and S. vulgaris ranked No. 1. [Conclusion] Selecting suitable tree and grass taxa for vegetation restoration in each vegetation zone along the transmission line should be adapted to local conditions, taking into account the suitability for growth and ecological function. It is recommended to prioritize selecting native species. For example, in the dry grassland area of the Loess Plateau, it is preferable to prioritize planting water with A. splendens, H. rhamnoides and S. vulgaris.
[Objective] Vegetation restoration and screening with suitable trees and grasses in power transmission projects were performed to provide scientific guidance to improve vegetation restoration success in power transmission and transformation projects, reduce soil erosion caused by the project, and reduce ecological restoration costs. This is particularly important to guarantee the green, high-quality and sustainable development of power grids. [Methods] Using on-site investigation, field observation, and indoor analysis, 26 planting observation points were set up to observe the growth of grass and tree taxa two and five years after planting. The observation indices mainly included grass taxa and their height, hay production, tree taxa and their height, branch number, and crown width. The entropy value method was used to sort and screen the suitability of the growth of the grass and tree taxa in the various vegetation sub-zones along the transmission and substation routes. [Results] According to the observations, six grass taxa (Agropyron ristatum, Achnathurum splendens, Melilotus suavcolen, Medicago sativa, Elymus sibiricus and Elymus dahuricus) and six tree taxa (Tamarix hohenackeri, Caragana korshinskii, Hippophae rhamnoides, Haloxylon aphyllum, Sabina vulgaris, and Populus euphratica) were screened for the suitability evaluation. The results showed that in the broadleaf-deciduous mixed zone of the Qinling Mountains, A. splendens, M. sativa, and C. korshinskii ranked No. 1. In the desert Gobi zone of the West Hebei Corridor, M. suavcolen (No. 2) and H. aphyllum (No. 1) ranked the highest. In the oasis plain zone of the Hexi Corridor, A. ristatum (No. 2) and H. rhamnoides subsp. sinensis (No. 1) ranked the highest. In the desert grassland zone of the Hexi Corridor, E. sibiricus (No. 2), T. hohenackeri (No. 1) and P. euphratica (No. 1) ranked the highest. In the desert steppe zone of the Loess Plateau, E. dahuricus, T. hohenacke, C. korshinskii, H. aphyllum, and S. vulgaris were the most highly ranked species, and they were all ranked No. 2. In the dry steppe zone of the Loess Plateau, A. splendens (No. 2) and S. vulgaris ranked No. 1. [Conclusion] Selecting suitable tree and grass taxa for vegetation restoration in each vegetation zone along the transmission line should be adapted to local conditions, taking into account the suitability for growth and ecological function. It is recommended to prioritize selecting native species. For example, in the dry grassland area of the Loess Plateau, it is preferable to prioritize planting water with A. splendens, H. rhamnoides and S. vulgaris.
2025,45(1):208-214
, DOI: 10.13961/j.cnki.stbctb.2025.01.022
Abstract:
[Objective] The effect of afforestation on soil organic carbon density (SOCD) was studied to provide a scientific basis for improving the carbon sink of terrestrial ecosystems in the forest-steppe ecotone of Northern Hebei Province. [Methods] Scotch pines (Pinus Sylvestris var. mongolica) and larch (Larix principis-rupprechtii) plantations were selected as the research subjects in the Yudaokou area located in a forest-steppe ecotone. Unforested lands (including unforested land Ⅰ with high biomass, unforested land Ⅱ with medium biomass, and unforested land Ⅲ with low biomass) served as controls. The soil organic carbon (SOC ) content and soil organic carbon density (SOCD) of different terrestrial ecosystems were studied. [Results] ① The SOC content of unforested lands in Yudaokou area ranging from 2.54 to 60.57 g/kg were positively correlated with the vegetation biomass. ② At the same age (16—20 years), the SOC content in the L. principis-rupprechtii and P. Sylvestris var. mongolica plantations was significantly higher than that in unforested land Ⅱ and unforested land Ⅲ and lower than that in unforested land Ⅰ (p<0.05), and the SOC content in the L. principis-rupprechtii plantations was higher than that in the P. Sylvestris var. mongolica plantations, with a significant difference observed in the 0—10 cm soil layer (p<0.05). ③ The order of SOCD (0—60 cm) from high to low was unforested land Ⅰ (127.56 t/hm2)＞L. principis-rupprechtii plantation(105.26 t/hm2)＞P. Sylvestris var. mongolica plantation (75.52 t/hm2)＞ unforested land Ⅱ (56.06 t/hm2)＞ unforested land Ⅲ (31.78 t/hm2), and there were significant differences between the vegetation types (p＜0.05) except that between P. Sylvestris var. mongolica plantations and unforested land Ⅱ (p>0.05). ④ The SOCD of 0—60 cm in the L. principis-rupprechtii plantations increased with the increase of the ages in all soil layer, and they were 105.26 t/hm2 (16~20 a), 112.29 t/hm2(21~25 a) and 159.73 t/hm2 (26~30 a), respectively; the SOCD of the P. Sylvestris var. mongolica plantations decreased first and then increased with the increase of the ages, and the SOCD of 0—60 cm soil depth was 79.38 t/hm2(6～10 a), 54.24 t/hm2(11～15 a), 75.52 t/hm2(16～20 a) and 82.24 t/hm2(＞20 a), respectively. [Conclusion] The effect of afforestation on SOC content and storage depends on the initial conditions of forested land and the tree species; in Yudaokou area, afforestation using L. principis-rupprechtii and P. Sylvestris var. mongolica pine in places with lower SOC content can increase SOCD, and L. principis-rupprechtii can increase SOCD more than P. Sylvestris var. mongolica.
[Objective] The effect of afforestation on soil organic carbon density (SOCD) was studied to provide a scientific basis for improving the carbon sink of terrestrial ecosystems in the forest-steppe ecotone of Northern Hebei Province. [Methods] Scotch pines (Pinus Sylvestris var. mongolica) and larch (Larix principis-rupprechtii) plantations were selected as the research subjects in the Yudaokou area located in a forest-steppe ecotone. Unforested lands (including unforested land Ⅰ with high biomass, unforested land Ⅱ with medium biomass, and unforested land Ⅲ with low biomass) served as controls. The soil organic carbon (SOC ) content and soil organic carbon density (SOCD) of different terrestrial ecosystems were studied. [Results] ① The SOC content of unforested lands in Yudaokou area ranging from 2.54 to 60.57 g/kg were positively correlated with the vegetation biomass. ② At the same age (16—20 years), the SOC content in the L. principis-rupprechtii and P. Sylvestris var. mongolica plantations was significantly higher than that in unforested land Ⅱ and unforested land Ⅲ and lower than that in unforested land Ⅰ (p<0.05), and the SOC content in the L. principis-rupprechtii plantations was higher than that in the P. Sylvestris var. mongolica plantations, with a significant difference observed in the 0—10 cm soil layer (p<0.05). ③ The order of SOCD (0—60 cm) from high to low was unforested land Ⅰ (127.56 t/hm2)＞L. principis-rupprechtii plantation(105.26 t/hm2)＞P. Sylvestris var. mongolica plantation (75.52 t/hm2)＞ unforested land Ⅱ (56.06 t/hm2)＞ unforested land Ⅲ (31.78 t/hm2), and there were significant differences between the vegetation types (p＜0.05) except that between P. Sylvestris var. mongolica plantations and unforested land Ⅱ (p>0.05). ④ The SOCD of 0—60 cm in the L. principis-rupprechtii plantations increased with the increase of the ages in all soil layer, and they were 105.26 t/hm2 (16~20 a), 112.29 t/hm2(21~25 a) and 159.73 t/hm2 (26~30 a), respectively; the SOCD of the P. Sylvestris var. mongolica plantations decreased first and then increased with the increase of the ages, and the SOCD of 0—60 cm soil depth was 79.38 t/hm2(6～10 a), 54.24 t/hm2(11～15 a), 75.52 t/hm2(16～20 a) and 82.24 t/hm2(＞20 a), respectively. [Conclusion] The effect of afforestation on SOC content and storage depends on the initial conditions of forested land and the tree species; in Yudaokou area, afforestation using L. principis-rupprechtii and P. Sylvestris var. mongolica pine in places with lower SOC content can increase SOCD, and L. principis-rupprechtii can increase SOCD more than P. Sylvestris var. mongolica.
2025,45(1):215-224,263
, DOI: 10.13961/j.cnki.stbctb.2025.01.023
Abstract:
[Objective] The effects of microplastic type and size on the infiltration process of carbonatite laterite soils was investigated in order to provide new data revealing the hydrological processes of microplastic-contaminated agricultural soils. [Methods] The effects of polyethylene (PE), polypropylene (PP), and polystyrene (PS) microplastics with different particle sizes (550, 150, and 50 μm) on the infiltration rate, cumulative infiltration, and the depth of the wetting front of the lateritic soil were investigated by an indoor simulation of infiltration into a flattened soil column using a fixed-head vertical infiltration method. The effects of the cumulative infiltration, Philip, Horton, and Kostiakov models on the infiltration rate of the lateritic soil, cumulative infiltration, and the depth of the wetting front were also evaluated. The five hydraulic parameters (θr, θs, α, n, Ks) were inverted under different microplastic treatments using the Hydrus-1D model. [Results] ① The infiltration rate and cumulative infiltration of PS microplastics increased with decreasing particle size, while the cumulative infiltration and infiltration rate of PE and PP microplastics increased and then decreased with increasing particle size, and the differences in cumulative infiltration between different particle sizes were significant (p＜0.05); PS microplastics facilitated and then inhibited water transport, while both PP and PE played the role of facilitating water transport. ② All models were applicable to the infiltration simulation of microplastic-containing laterite soils, with Horton’s model and the cumulative infiltration model performing the best (R2, CE > 0.98). ③ The effect of microplastic treatment on soil hydraulic parameters (θr, θs, α, n, Ks) was insignificant, but the PS microplastic saturated hydraulic conductivity showed an increase with decreasing particle size. [Conclusion] The effects of PS, PP, and PE microplastics on soil infiltration processes were significantly different, and the Horton, cumulative infiltration, and Hydrus-1D models showed high applicability.
[Objective] The effects of microplastic type and size on the infiltration process of carbonatite laterite soils was investigated in order to provide new data revealing the hydrological processes of microplastic-contaminated agricultural soils. [Methods] The effects of polyethylene (PE), polypropylene (PP), and polystyrene (PS) microplastics with different particle sizes (550, 150, and 50 μm) on the infiltration rate, cumulative infiltration, and the depth of the wetting front of the lateritic soil were investigated by an indoor simulation of infiltration into a flattened soil column using a fixed-head vertical infiltration method. The effects of the cumulative infiltration, Philip, Horton, and Kostiakov models on the infiltration rate of the lateritic soil, cumulative infiltration, and the depth of the wetting front were also evaluated. The five hydraulic parameters (θr, θs, α, n, Ks) were inverted under different microplastic treatments using the Hydrus-1D model. [Results] ① The infiltration rate and cumulative infiltration of PS microplastics increased with decreasing particle size, while the cumulative infiltration and infiltration rate of PE and PP microplastics increased and then decreased with increasing particle size, and the differences in cumulative infiltration between different particle sizes were significant (p＜0.05); PS microplastics facilitated and then inhibited water transport, while both PP and PE played the role of facilitating water transport. ② All models were applicable to the infiltration simulation of microplastic-containing laterite soils, with Horton’s model and the cumulative infiltration model performing the best (R2, CE > 0.98). ③ The effect of microplastic treatment on soil hydraulic parameters (θr, θs, α, n, Ks) was insignificant, but the PS microplastic saturated hydraulic conductivity showed an increase with decreasing particle size. [Conclusion] The effects of PS, PP, and PE microplastics on soil infiltration processes were significantly different, and the Horton, cumulative infiltration, and Hydrus-1D models showed high applicability.
2025,45(1):225-234
, DOI: 10.13961/j.cnki.stbctb.2025.01.024
Abstract:
[Objective] The influence of overlying carbonate red soil on the infiltration characteristics of phosphogypsum was analyzed in order to provide an scientific basis for the rational disposal and utilization of phosphogypsum storage yards in southwest karst areas. [Methods] The influences of three phosphogypsum bulk densities (1.2, 1.3, 1.4 g/cm3) and three overburden thicknesses (0, 6, 12 cm) on the water infiltration process of phosphogypsum were studied through an indoor flat soil column infiltration test, and the infiltration process was numerically simulated using the improved layered Green-Ampt model. [Results] ① The difference in water infiltration time to the bottom between the 6 cm and 12 cm soil cover treatments was not significant (p>0.05). However, significant differences in infiltration time were observed between the 0 and 6 cm treatments, as well as between the 0 and 12 cm treatments (p<0.05). The initial infiltration rate, average infiltration rate, and stable infiltration rate of the 0 cm soil cover were significantly higher than those of the 6 and 12 cm soil cover (p<0.05), and the stable infiltration rate decreased significantly with the increase in soil cover thickness. There was no significant difference in cumulative infiltration between the 6 and 12 cm cover soil thicknesses (p>0.05), but there was a significant difference among the other cover soil thicknesses (p<0.05). ② For the same cover thickness, the influence of phosphogypsum bulk density on the initial infiltration rate, average infiltration rate, and stable infiltration rate was not significant (p>0.05). ③ The coefficient of determination (R2) between the measured and simulated values of the wetting peak depth varied was 0.951—0.995, the root mean square error (RMSE) ranged was 12.174—40.856, and the average absolute percentage error (MAPE) ranged was 0.070—0.227. When the soil was covered at 6 and 12 cm, the variation range of the determination coefficient (R2) between the measured and simulated values was 0.963—0.999, the root mean square error (RMSE) was 1.471—11.201, and the average absolute percentage error (MAPE) was 0.046—0.169. [Conclusion] There were significant differences in soil water infiltration characteristics between phosphogypsum-covered soil and uncovered soil, and the improved layered Green-Ampt model could be used to simulate the infiltration process of phosphogypsum under the condition of overlying soil.
[Objective] The influence of overlying carbonate red soil on the infiltration characteristics of phosphogypsum was analyzed in order to provide an scientific basis for the rational disposal and utilization of phosphogypsum storage yards in southwest karst areas. [Methods] The influences of three phosphogypsum bulk densities (1.2, 1.3, 1.4 g/cm3) and three overburden thicknesses (0, 6, 12 cm) on the water infiltration process of phosphogypsum were studied through an indoor flat soil column infiltration test, and the infiltration process was numerically simulated using the improved layered Green-Ampt model. [Results] ① The difference in water infiltration time to the bottom between the 6 cm and 12 cm soil cover treatments was not significant (p>0.05). However, significant differences in infiltration time were observed between the 0 and 6 cm treatments, as well as between the 0 and 12 cm treatments (p<0.05). The initial infiltration rate, average infiltration rate, and stable infiltration rate of the 0 cm soil cover were significantly higher than those of the 6 and 12 cm soil cover (p<0.05), and the stable infiltration rate decreased significantly with the increase in soil cover thickness. There was no significant difference in cumulative infiltration between the 6 and 12 cm cover soil thicknesses (p>0.05), but there was a significant difference among the other cover soil thicknesses (p<0.05). ② For the same cover thickness, the influence of phosphogypsum bulk density on the initial infiltration rate, average infiltration rate, and stable infiltration rate was not significant (p>0.05). ③ The coefficient of determination (R2) between the measured and simulated values of the wetting peak depth varied was 0.951—0.995, the root mean square error (RMSE) ranged was 12.174—40.856, and the average absolute percentage error (MAPE) ranged was 0.070—0.227. When the soil was covered at 6 and 12 cm, the variation range of the determination coefficient (R2) between the measured and simulated values was 0.963—0.999, the root mean square error (RMSE) was 1.471—11.201, and the average absolute percentage error (MAPE) was 0.046—0.169. [Conclusion] There were significant differences in soil water infiltration characteristics between phosphogypsum-covered soil and uncovered soil, and the improved layered Green-Ampt model could be used to simulate the infiltration process of phosphogypsum under the condition of overlying soil.
Lu Zhangxin, Yan Feiyang, Wu Choufei, Shi Jiayi, Li Peng, Zhao Mingxing, Zhang Xiancui, Zeng Huihui, Zhang Feng
2025,45(1):235-243,275
, DOI: 10.13961/j.cnki.stbctb.2025.01.025
Abstract:
[Objective] Changes in soil properties and microbial community structure in 0—20 cm soil under different land use modes in wetlands were analyzed, and the characteristics of soil carbon sequestration microbial communities and functional gene changes under different land use modes were explored to provide scientific references for the protection and sustainable utilization of wetland ecosystem resources. [Methods] The Xianshan Lake National Wetland Park in Changxing, Zhejiang Province was taken as the research object. High-throughput sequencing technology was used to sequence the genes. [Results] ① The carbon sequestration capacity of the Xianshan Lake wetland was as follows: sedge swamp>natural coastal forest>bamboo forest>nursery>artificially intervened riverbank forest (Chinese fir forest)>artificial pine forest>broad-leaved forest>artificially intervened coastal vegetation>artificially intervened riverbank forest (willow swamp)>reed swamp>reed and willow coastal vegetation. The organic carbon storage of sedge swamp was the highest (38.68±0.56 t/hm2), accounting for 171% of forest organic carbon storage, and its soil microbial carbon utilization efficiency (0.66±0.005) was 150% of bamboo forest microbial carbon utilization efficiency. ② The carbon sequestration pathways of microorganisms in the Xianshan Lake wetland were mainly facilitated through the Calvin cycle, reducing the tricarboxylic acid cycle and reducing acetyl CoA pathway, with Proteobacteria, Bacteroidetes, Acidobacteria, and Chloroflexia as the main carbon sequestration microbial communities. The relative abundance of Proteobacteria and Bacteroidetes in the sedge swamp soil were 56.40% and 17.40%, respectively. The relative abundance of Proteobacteria in the natural coastal forest soil was 59.60%, and that of Acidobacteria in the bamboo forest soil was 36.00%. There was a positive correlation between organic carbon storage and soil carbon-fixing bacterial abundance in the Xianshan Lake wetland. [Conclusion] The dominant microbial communities for carbon sequestration in the Xianshan Lake wetland ecosystem varied greatly, and changes in soil carbon sequestration microbial communities and functional genes under different land use patterns affected the carbon sequestration capacity of wetland microorganisms. Among them, soil organic carbon storage, total nitrogen content, and microbial carbon utilization efficiency were the highest in the sedge swamp, and its carbon sequestration functional genes were higher than those of other land-use methods. Therefore, sedge marshes have a high carbon storage capacity.
[Objective] Changes in soil properties and microbial community structure in 0—20 cm soil under different land use modes in wetlands were analyzed, and the characteristics of soil carbon sequestration microbial communities and functional gene changes under different land use modes were explored to provide scientific references for the protection and sustainable utilization of wetland ecosystem resources. [Methods] The Xianshan Lake National Wetland Park in Changxing, Zhejiang Province was taken as the research object. High-throughput sequencing technology was used to sequence the genes. [Results] ① The carbon sequestration capacity of the Xianshan Lake wetland was as follows: sedge swamp>natural coastal forest>bamboo forest>nursery>artificially intervened riverbank forest (Chinese fir forest)>artificial pine forest>broad-leaved forest>artificially intervened coastal vegetation>artificially intervened riverbank forest (willow swamp)>reed swamp>reed and willow coastal vegetation. The organic carbon storage of sedge swamp was the highest (38.68±0.56 t/hm2), accounting for 171% of forest organic carbon storage, and its soil microbial carbon utilization efficiency (0.66±0.005) was 150% of bamboo forest microbial carbon utilization efficiency. ② The carbon sequestration pathways of microorganisms in the Xianshan Lake wetland were mainly facilitated through the Calvin cycle, reducing the tricarboxylic acid cycle and reducing acetyl CoA pathway, with Proteobacteria, Bacteroidetes, Acidobacteria, and Chloroflexia as the main carbon sequestration microbial communities. The relative abundance of Proteobacteria and Bacteroidetes in the sedge swamp soil were 56.40% and 17.40%, respectively. The relative abundance of Proteobacteria in the natural coastal forest soil was 59.60%, and that of Acidobacteria in the bamboo forest soil was 36.00%. There was a positive correlation between organic carbon storage and soil carbon-fixing bacterial abundance in the Xianshan Lake wetland. [Conclusion] The dominant microbial communities for carbon sequestration in the Xianshan Lake wetland ecosystem varied greatly, and changes in soil carbon sequestration microbial communities and functional genes under different land use patterns affected the carbon sequestration capacity of wetland microorganisms. Among them, soil organic carbon storage, total nitrogen content, and microbial carbon utilization efficiency were the highest in the sedge swamp, and its carbon sequestration functional genes were higher than those of other land-use methods. Therefore, sedge marshes have a high carbon storage capacity.
2025,45(1):244-253
, DOI: 10.13961/j.cnki.stbctb.2025.01.026
Abstract:
[Objective] Spatial and temporal succession patterns and predictions of ecosystem carbon storage in the Miyun Reservoir basin from 1985 to 2035 were conducted to provide a scientific basis for the integrated protection and restoration of mountains, rivers, forests, fields, lakes, grasslands, and sands and the optimization of ecological compensation standards under the goal of “double carbon” in the basin. [Methods] The InVEST-PLUS model was used to analyze the spatial and temporal evolution patterns of carbon storage in the basin during 1985—2020, and the changing trend of carbon storage under three scenarios (natural development, cultivated land protection, and ecological protection) in 2035 was predicted. [Results] ① During 1985—2020, the ecosystem carbon storage of Miyun Reservoir basin showed a continuous growth trend, and the carbon storage increased by 4.03×107 t in 35 years. The largest contributors to carbon storage were forest land, grassland, and cultivated land, which accounted for approximately 98% of the total carbon storage. ② In 2035, the carbon storage of the basin will tend to increase under the three simulation scenarios. In the protection scenario, owing to the increase in forestland area, carbon storage remains at a high level. ③ Carbon storage in the basin showed a spatial pattern of 'higher in the south-central part and lower in the west and northeast’. The south-central part corresponds to the mountainous landform of the basin, which was the core area of water conservation, and the forest coverage rate was higher, while the west and northeast were mainly distributed in grassland, cultivated land, and urban construction land, with relatively lower carbon storage. [Conclusion] Carbon storage is consistent with the spatial pattern of land use. The consolidation and improvement of ecosystem carbon storage can be promoted by increasing forests and grasslands through ecological construction, controlling the transfer of forest land, and reasonably controlling the expansion of construction land.
[Objective] Spatial and temporal succession patterns and predictions of ecosystem carbon storage in the Miyun Reservoir basin from 1985 to 2035 were conducted to provide a scientific basis for the integrated protection and restoration of mountains, rivers, forests, fields, lakes, grasslands, and sands and the optimization of ecological compensation standards under the goal of “double carbon” in the basin. [Methods] The InVEST-PLUS model was used to analyze the spatial and temporal evolution patterns of carbon storage in the basin during 1985—2020, and the changing trend of carbon storage under three scenarios (natural development, cultivated land protection, and ecological protection) in 2035 was predicted. [Results] ① During 1985—2020, the ecosystem carbon storage of Miyun Reservoir basin showed a continuous growth trend, and the carbon storage increased by 4.03×107 t in 35 years. The largest contributors to carbon storage were forest land, grassland, and cultivated land, which accounted for approximately 98% of the total carbon storage. ② In 2035, the carbon storage of the basin will tend to increase under the three simulation scenarios. In the protection scenario, owing to the increase in forestland area, carbon storage remains at a high level. ③ Carbon storage in the basin showed a spatial pattern of 'higher in the south-central part and lower in the west and northeast’. The south-central part corresponds to the mountainous landform of the basin, which was the core area of water conservation, and the forest coverage rate was higher, while the west and northeast were mainly distributed in grassland, cultivated land, and urban construction land, with relatively lower carbon storage. [Conclusion] Carbon storage is consistent with the spatial pattern of land use. The consolidation and improvement of ecosystem carbon storage can be promoted by increasing forests and grasslands through ecological construction, controlling the transfer of forest land, and reasonably controlling the expansion of construction land.
2025,45(1):254-263
, DOI: 10.13961/j.cnki.stbctb.2025.01.027
Abstract:
[Objective] The response and vulnerability of carbon storage to land-use change in the Dawen River basin were analyzed in order to provide a reference for promoting the green and sustainable development of the basin and the land-use optimization management and control. [Methods] Based on land use data, the InVEST model was used to study the impact of land-use change on carbon storage evolution in the Dawen River basin from 2000 to 2020, and the potential impact index (PI) was used to assess the vulnerability of ecosystem carbon storage. [Results] ① During 2000—2020, the land-use structure of the study area changed significantly, with a sharp decline in cultivated land (316.44 km2) and a sharp increase in construction land (523.98 km2). The conversion of cultivated land into construction land was the primary type of land transfer. ② During 2000—2020, the carbon storage decreased by 1.09×107 t, and the transfer of cultivated land to construction land was the leading factor in the decrease. The spatial distribution characteristics of basin carbon storage were “overall higher in the north and lower in the south, and significantly higher or significantly lower in local areas.” ③ During 2000—2020, the land use degree index increased by 8.12. The PI for the first and last 10 years was -1.33 and -1.42, respectively, indicating that the vulnerability of carbon storage services increased. [Conclusion] The reduction in cultivated land, grassland and forest land, and the expansion of construction land in the Dawen River basin have significant effects on carbon storage and its vulnerability. In future, carbon storage should be considered as an important reference factor in land-use planning to achieve an optimal balance of carbon storage functions.
[Objective] The response and vulnerability of carbon storage to land-use change in the Dawen River basin were analyzed in order to provide a reference for promoting the green and sustainable development of the basin and the land-use optimization management and control. [Methods] Based on land use data, the InVEST model was used to study the impact of land-use change on carbon storage evolution in the Dawen River basin from 2000 to 2020, and the potential impact index (PI) was used to assess the vulnerability of ecosystem carbon storage. [Results] ① During 2000—2020, the land-use structure of the study area changed significantly, with a sharp decline in cultivated land (316.44 km2) and a sharp increase in construction land (523.98 km2). The conversion of cultivated land into construction land was the primary type of land transfer. ② During 2000—2020, the carbon storage decreased by 1.09×107 t, and the transfer of cultivated land to construction land was the leading factor in the decrease. The spatial distribution characteristics of basin carbon storage were “overall higher in the north and lower in the south, and significantly higher or significantly lower in local areas.” ③ During 2000—2020, the land use degree index increased by 8.12. The PI for the first and last 10 years was -1.33 and -1.42, respectively, indicating that the vulnerability of carbon storage services increased. [Conclusion] The reduction in cultivated land, grassland and forest land, and the expansion of construction land in the Dawen River basin have significant effects on carbon storage and its vulnerability. In future, carbon storage should be considered as an important reference factor in land-use planning to achieve an optimal balance of carbon storage functions.
2025,45(1):264-275
, DOI: 10.13961/j.cnki.stbctb.2025.01.028
Abstract:
[Objective] The characteristics of cultivated land use transformation and the differences in spatial and temporal distribution of carbon emissions were analyzed to explore the mechanisms of influencing factors in the process of cultivated land use transformation carbon emissions, in order to provide scientific basis for the low-carbonization of cultivated land use. [Methods] Using land use data and the carbon emission coefficients, the temporal evolution characteristics of cultivated land use transformation and its carbon emissions from 2000 to 2020 in Hunan Province were shown at the county and 5 km grid scales. The spatial distribution characteristics of carbon emissions were identified and analyzed using the spatial autocorrelation method. The depth of the influence of factors and the degree of interaction between them were assessed using the optimal parameter Geodetector model. [Results] ① Throughout the study period, the area of cultivated land in Hunan Province decreased continuously. With frequent conversions between cultivated land and forest land, water areas, and construction land, carbon emissions showed a fluctuating and increasing dynamic change trend. ② A spatial autocorrelation analysis showed significant high-high and low-low concentration phenomena at both scales, indicating strong concentration distribution characteristics in both spatial and temporal dimensions. ③ The interactions among factors were stronger than those of single factors, with socioeconomic factors and locational conditions having significant explanatory power at both scales. [Conclusion] The effect of cultivated land use transformation on carbon emissions in Hunan Province is significant, with clear differences in carbon emission characteristics and drivers at different spatial scales. Future measures for carbon emission reduction measures and cultivated land use planning should be formulated both scientifically and rationally.
[Objective] The characteristics of cultivated land use transformation and the differences in spatial and temporal distribution of carbon emissions were analyzed to explore the mechanisms of influencing factors in the process of cultivated land use transformation carbon emissions, in order to provide scientific basis for the low-carbonization of cultivated land use. [Methods] Using land use data and the carbon emission coefficients, the temporal evolution characteristics of cultivated land use transformation and its carbon emissions from 2000 to 2020 in Hunan Province were shown at the county and 5 km grid scales. The spatial distribution characteristics of carbon emissions were identified and analyzed using the spatial autocorrelation method. The depth of the influence of factors and the degree of interaction between them were assessed using the optimal parameter Geodetector model. [Results] ① Throughout the study period, the area of cultivated land in Hunan Province decreased continuously. With frequent conversions between cultivated land and forest land, water areas, and construction land, carbon emissions showed a fluctuating and increasing dynamic change trend. ② A spatial autocorrelation analysis showed significant high-high and low-low concentration phenomena at both scales, indicating strong concentration distribution characteristics in both spatial and temporal dimensions. ③ The interactions among factors were stronger than those of single factors, with socioeconomic factors and locational conditions having significant explanatory power at both scales. [Conclusion] The effect of cultivated land use transformation on carbon emissions in Hunan Province is significant, with clear differences in carbon emission characteristics and drivers at different spatial scales. Future measures for carbon emission reduction measures and cultivated land use planning should be formulated both scientifically and rationally.
2025,45(1):276-285
, DOI: 10.13961/j.cnki.stbctb.2025.01.029
Abstract:
[Objective] The spatial land use resources of Changsha-Zhuzhou-Xiangtan urban agglomeration were optimized from the perspective of carbon balance, in order to provide theoretical support for the sustainable development of the region’s society and economy. [Methods] The carbon sinks and carbon emissions of the Chang-Zhu-Tan urban agglomeration were calculated from a land use perspective. Using the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, carbon balance zoning was conducted, and land use optimization strategies were proposed for each type of city and county. Economic benefits, carbon sink benefits, compactness, and conversion costs were set as optimization functions for a multi-objective algorithm, achieving a more scientific optimization of land use spatial structure using the CoMOLA model. [Results] ① From 2000 to 2020, the total carbon emissions of the Chang-Zhu-Tan urban agglomeration increased annually, while the carbon sink levels in various districts and counties remained relatively stable, with an overall slight decline. ② Based on the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, the Chang-Zhu-Tan urban agglomeration was classified into carbon sink development zones, economic development zones, comprehensive optimization zones, and green development zones. ③ The optimized land use increased economic benefits by 28.5%, carbon sink volume by 4.2%, and compactness by 3.6%. [Conclusion] The optimized land resources effectively meet the needs for economic and ecological sustainable development in the Chang-Zhu-Tan urban agglomeration, with a more rational spatial arrangement of land. This provides a decision-making basis for future land resource allocation.
[Objective] The spatial land use resources of Changsha-Zhuzhou-Xiangtan urban agglomeration were optimized from the perspective of carbon balance, in order to provide theoretical support for the sustainable development of the region’s society and economy. [Methods] The carbon sinks and carbon emissions of the Chang-Zhu-Tan urban agglomeration were calculated from a land use perspective. Using the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, carbon balance zoning was conducted, and land use optimization strategies were proposed for each type of city and county. Economic benefits, carbon sink benefits, compactness, and conversion costs were set as optimization functions for a multi-objective algorithm, achieving a more scientific optimization of land use spatial structure using the CoMOLA model. [Results] ① From 2000 to 2020, the total carbon emissions of the Chang-Zhu-Tan urban agglomeration increased annually, while the carbon sink levels in various districts and counties remained relatively stable, with an overall slight decline. ② Based on the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, the Chang-Zhu-Tan urban agglomeration was classified into carbon sink development zones, economic development zones, comprehensive optimization zones, and green development zones. ③ The optimized land use increased economic benefits by 28.5%, carbon sink volume by 4.2%, and compactness by 3.6%. [Conclusion] The optimized land resources effectively meet the needs for economic and ecological sustainable development in the Chang-Zhu-Tan urban agglomeration, with a more rational spatial arrangement of land. This provides a decision-making basis for future land resource allocation.
2025,45(1):286-295,316
, DOI: 10.13961/j.cnki.stbctb.2025.01.030
Abstract:
[Objective] The spatial-temporal changes and their causes of soil and water conservation services in the Sanjiangyuan region were explored in order to provide scientific evidence and data support for environmental protection measures and sustainable development in the area. [Methods] The soil and water conservation service capacity of the Sanjiangyuan region from 2000 to 2020 was quantitatively assessed using the net primary productivity (NPP) method and a driver factor analysis was performed using the optimal parameter geographical detector. [Results] ① From 2000 to 2020, land use in the Sanjiangyuan region underwent significant changes. The cultivated land, grassland, water bodies, and construction land continuously expanded, whereas the forest land and unused land areas decreased. The region is mainly dominated by grassland, followed by water bodies and forest land. Over the 20 year period, vegetation coverage showed a generally stable increasing trend with an overall spatial distribution pattern of “higher in the east and lower in the west.” ② From 2000 to 2020, the soil and water conservation service capacity index followed an N-shaped trend, but overall, the index had an increasing trend over the time period with a growth rate of 26.13%, indicating a significant improvement in the soil and water conservation service capacity. The distribution of the soil and water conservation service capacity was relatively consistent, displaying an overall “higher in the east and lower in the west” spatial distribution pattern. Throughout this period, the gravity center in the Sanjiangyuan region remained in the western part of Maqin County, with increased soil and water conservation capacity towards the northwest and multidirectional extension. This result indicated the engineering projects that had been implemented had significantly improved soil and water conservation service capacity. ③ Factors, such as vegetation coverage, GDP per unit area, and grazing intensity, had considerable impacts on soil and water conservation services and the interactions between vegetation coverage and GDP per unit area, average annual rainfall, grazing intensity, and other factors explained a considerable proportion of the change. [Conclusion] It is essential to continue implementing natural forest protection projects and promote forest conservation and restoration to significantly enhance the forest stock. Furthermore, measures, such as rational grazing, construction of artificial grasslands, fencing, and reseeding, should be adopted to protect ecosystems.
[Objective] The spatial-temporal changes and their causes of soil and water conservation services in the Sanjiangyuan region were explored in order to provide scientific evidence and data support for environmental protection measures and sustainable development in the area. [Methods] The soil and water conservation service capacity of the Sanjiangyuan region from 2000 to 2020 was quantitatively assessed using the net primary productivity (NPP) method and a driver factor analysis was performed using the optimal parameter geographical detector. [Results] ① From 2000 to 2020, land use in the Sanjiangyuan region underwent significant changes. The cultivated land, grassland, water bodies, and construction land continuously expanded, whereas the forest land and unused land areas decreased. The region is mainly dominated by grassland, followed by water bodies and forest land. Over the 20 year period, vegetation coverage showed a generally stable increasing trend with an overall spatial distribution pattern of “higher in the east and lower in the west.” ② From 2000 to 2020, the soil and water conservation service capacity index followed an N-shaped trend, but overall, the index had an increasing trend over the time period with a growth rate of 26.13%, indicating a significant improvement in the soil and water conservation service capacity. The distribution of the soil and water conservation service capacity was relatively consistent, displaying an overall “higher in the east and lower in the west” spatial distribution pattern. Throughout this period, the gravity center in the Sanjiangyuan region remained in the western part of Maqin County, with increased soil and water conservation capacity towards the northwest and multidirectional extension. This result indicated the engineering projects that had been implemented had significantly improved soil and water conservation service capacity. ③ Factors, such as vegetation coverage, GDP per unit area, and grazing intensity, had considerable impacts on soil and water conservation services and the interactions between vegetation coverage and GDP per unit area, average annual rainfall, grazing intensity, and other factors explained a considerable proportion of the change. [Conclusion] It is essential to continue implementing natural forest protection projects and promote forest conservation and restoration to significantly enhance the forest stock. Furthermore, measures, such as rational grazing, construction of artificial grasslands, fencing, and reseeding, should be adopted to protect ecosystems.
Liu Shenglong, Xie Huili, Chen Lingxiu, Dai Hongxia, Zhang Jiao, Xu Mengjie, Chen Sitao, Liu Xingzhao
2025,45(1):296-305
, DOI: 10.13961/j.cnki.stbctb.2025.01.031
Abstract:
[Objective] The influence of urban parks and surrounding landscape patterns on the cold island effect in Fuzhou City, Fujian Province, was analyzed, and the cooling impacts and landscape configurations of parks with different types of cold island effect were quantified. in order to provide a scientific basis for understanding the cold island effect of urban parks and alleviating high urban temperatures. [Methods] Twenty-three parks were selected from the list of urban parks in Fuzhou City, and the radiative transfer equation was used to invert the land surface temperature based on Landsat 8 and GF-1 as well as other remote sensing data. For each park, the correlations between the scale, shape, internal and surrounding landscape components, vegetation coverage, building height, and economic development and the exerted cold island effect were analyzed. A logarithmic function curve was fitted between park area and the cumulative gradient of the cold island effect to calculate the cooling efficiency threshold. The cooling effect was used as basis to divide the types of cold island effect of parks, and the respective cooling characteristics and park configurations were analyzed. [Results] ① The heat island effect in the main urban area of Fuzhou City was significant, and the cooling effect of the parks was obvious provided noticeable cooling. ② The cold island effect of parks was significantly correlated with the scale, shape, and internal and surrounding landscape components and weakly correlated with vegetation coverage, while there were no significant correlations with building height and economic development. ③ The cooling efficiency threshold of parks in Fuzhou City was 0.22 hm2. ④ The types of cold island effect of parks were divided into strong, sub-strong, and low based on the normalized average temperature and cumulative gradient of the cold island effect. Each type hads distinct cooling effects and landscape patterns suitable for suburban, urban, and crowded areas with limited land. [Conclusion] Future park planning and layout should consider the types of cold island effect of parks and respective landscape patterns, and park scale and landscape composition should be rationally distributed to minimize the park scale and achieve maximum alleviation of the urban heat island effect.
[Objective] The influence of urban parks and surrounding landscape patterns on the cold island effect in Fuzhou City, Fujian Province, was analyzed, and the cooling impacts and landscape configurations of parks with different types of cold island effect were quantified. in order to provide a scientific basis for understanding the cold island effect of urban parks and alleviating high urban temperatures. [Methods] Twenty-three parks were selected from the list of urban parks in Fuzhou City, and the radiative transfer equation was used to invert the land surface temperature based on Landsat 8 and GF-1 as well as other remote sensing data. For each park, the correlations between the scale, shape, internal and surrounding landscape components, vegetation coverage, building height, and economic development and the exerted cold island effect were analyzed. A logarithmic function curve was fitted between park area and the cumulative gradient of the cold island effect to calculate the cooling efficiency threshold. The cooling effect was used as basis to divide the types of cold island effect of parks, and the respective cooling characteristics and park configurations were analyzed. [Results] ① The heat island effect in the main urban area of Fuzhou City was significant, and the cooling effect of the parks was obvious provided noticeable cooling. ② The cold island effect of parks was significantly correlated with the scale, shape, and internal and surrounding landscape components and weakly correlated with vegetation coverage, while there were no significant correlations with building height and economic development. ③ The cooling efficiency threshold of parks in Fuzhou City was 0.22 hm2. ④ The types of cold island effect of parks were divided into strong, sub-strong, and low based on the normalized average temperature and cumulative gradient of the cold island effect. Each type hads distinct cooling effects and landscape patterns suitable for suburban, urban, and crowded areas with limited land. [Conclusion] Future park planning and layout should consider the types of cold island effect of parks and respective landscape patterns, and park scale and landscape composition should be rationally distributed to minimize the park scale and achieve maximum alleviation of the urban heat island effect.
2025,45(1):306-316
, DOI: 10.13961/j.cnki.stbctb.2025.01.032
Abstract:
[Objective] The spatial and temporal variations in urban land green utilization efficiency and the influencing factors were investigated to provide a scientific basis for optimizing the development and protection patterns of national land space and promoting the sustainable development of urban land. [Methods] The slack-based measure-directional distance function (SBM-DDF) model was used to measure the land green utilization efficiency of urban land in Anhui Province from 2008 to 2022. Kernel density analysis and center of gravity migration models were selected to analyze the spatial and temporal variations, while the geodetector and geographic time weighted regression (GTWR) models were combined to study the factors influencing urban land utilization efficiency. [Results] ① The average value of green land utilization efficiency of urban land in Anhui Province from 2008 to 2022 was 0.77 and was divided into two phases: a straight-line decline from 2008 to 2014 and a fluctuating increase from 2015 to 2022. ② Polarization phenomena were observed in the region, with the low value of the city increasing, the high value being more stable, and the regional gap gradually expanding. The gravity center trajectory of efficiency value of the whole province moved first to southeast and then to northwest, and the improvement was more obvious in northwest than in southeast. Although it remained high in the south and low in the north, indicating unbalanced spatial characteristics. ③ The leading factors were environmental protection inputs, urban and rural structures, urban greening, environmental regulation, and industrial structure, the interaction between industrial structure and environmental protection inputs was the strongest, with a q-value of 0.82. The spatial heterogeneity of the leading factors was significant: urban greening influenced all cities positively; urban and rural structure, environmental regulation, and environmental protection inputs influenced the central and southern regions positively and the northern region negatively; and the industrial structure influenced the resource cities negatively. Industrial structure has a significant negative influence on resource-oriented cities. [Conclusion] Strict land use control, promotion of industrial structure upgrading, increasing ecological and environmental protection, strengthening overall collaborative development, and formulating differentiated development paths should be used to promote the overall improvement of green land use efficiency in the urban areas of Anhui Province.
[Objective] The spatial and temporal variations in urban land green utilization efficiency and the influencing factors were investigated to provide a scientific basis for optimizing the development and protection patterns of national land space and promoting the sustainable development of urban land. [Methods] The slack-based measure-directional distance function (SBM-DDF) model was used to measure the land green utilization efficiency of urban land in Anhui Province from 2008 to 2022. Kernel density analysis and center of gravity migration models were selected to analyze the spatial and temporal variations, while the geodetector and geographic time weighted regression (GTWR) models were combined to study the factors influencing urban land utilization efficiency. [Results] ① The average value of green land utilization efficiency of urban land in Anhui Province from 2008 to 2022 was 0.77 and was divided into two phases: a straight-line decline from 2008 to 2014 and a fluctuating increase from 2015 to 2022. ② Polarization phenomena were observed in the region, with the low value of the city increasing, the high value being more stable, and the regional gap gradually expanding. The gravity center trajectory of efficiency value of the whole province moved first to southeast and then to northwest, and the improvement was more obvious in northwest than in southeast. Although it remained high in the south and low in the north, indicating unbalanced spatial characteristics. ③ The leading factors were environmental protection inputs, urban and rural structures, urban greening, environmental regulation, and industrial structure, the interaction between industrial structure and environmental protection inputs was the strongest, with a q-value of 0.82. The spatial heterogeneity of the leading factors was significant: urban greening influenced all cities positively; urban and rural structure, environmental regulation, and environmental protection inputs influenced the central and southern regions positively and the northern region negatively; and the industrial structure influenced the resource cities negatively. Industrial structure has a significant negative influence on resource-oriented cities. [Conclusion] Strict land use control, promotion of industrial structure upgrading, increasing ecological and environmental protection, strengthening overall collaborative development, and formulating differentiated development paths should be used to promote the overall improvement of green land use efficiency in the urban areas of Anhui Province.
2025,45(1):317-326
, DOI: 10.13961/j.cnki.stbctb.2025.01.033
Abstract:
[Objective] The spatial and temporal characteristics of ecological environment quality and its driving factors in the Weihe River basin from 2000 to 2020 was analyzed in order to provide theoretical reference for the sustainable development and ecological civilization construction in the basin. [Methods] The remote sensing ecological index (RSEI) was built based on Google Earth Engine platform to dynamically evaluate the change of ecological environment quality in the Weihe River basin from 2000 to 2020 and the impact of climate, vegetation, terrain, soil and social-economic factors on ecological environment quality was explored based on the optimal parameter geographic detector model. [Results] ① From 2000 to 2020, the quality of the Weihe River basin ecological environment continuously improved and the difference in ecological environment quality within the region increased. The ecological environment quality grade was mainly poor and relatively poor, accounting for more than 60% of the total area. In 20 years, the area of ecological environment quality grade increased for medium, good, and excellent. ② The quality grade of the ecological environment had a spatial distribution pattern of “higher in the south and lower in the north, higher and lower in the east and the west”. The area of poor grade ecological environment was the largest, and 73.43% of the Weihe River basin was in the area of ecological environment quality increase, with an increase area of 1.21×105 km2. During the study period, the area where the ecological environment quality increases was increasing and the reduced area was decreasing, and the overall ecological environment quality of the research area was positively developing. The area with excellent ecological environment quality distributed along the southeast-northwest direction. [Conclusion] Rainfall, elevation, and soil organic carbon content were the main factors affecting the ecological environment quality of the Weihe River Basin. In the process of improving the ecological environment quality of the Weihe River Basin, the distribution law of slope should be fully considered to optimize the governance scheme.
[Objective] The spatial and temporal characteristics of ecological environment quality and its driving factors in the Weihe River basin from 2000 to 2020 was analyzed in order to provide theoretical reference for the sustainable development and ecological civilization construction in the basin. [Methods] The remote sensing ecological index (RSEI) was built based on Google Earth Engine platform to dynamically evaluate the change of ecological environment quality in the Weihe River basin from 2000 to 2020 and the impact of climate, vegetation, terrain, soil and social-economic factors on ecological environment quality was explored based on the optimal parameter geographic detector model. [Results] ① From 2000 to 2020, the quality of the Weihe River basin ecological environment continuously improved and the difference in ecological environment quality within the region increased. The ecological environment quality grade was mainly poor and relatively poor, accounting for more than 60% of the total area. In 20 years, the area of ecological environment quality grade increased for medium, good, and excellent. ② The quality grade of the ecological environment had a spatial distribution pattern of “higher in the south and lower in the north, higher and lower in the east and the west”. The area of poor grade ecological environment was the largest, and 73.43% of the Weihe River basin was in the area of ecological environment quality increase, with an increase area of 1.21×105 km2. During the study period, the area where the ecological environment quality increases was increasing and the reduced area was decreasing, and the overall ecological environment quality of the research area was positively developing. The area with excellent ecological environment quality distributed along the southeast-northwest direction. [Conclusion] Rainfall, elevation, and soil organic carbon content were the main factors affecting the ecological environment quality of the Weihe River Basin. In the process of improving the ecological environment quality of the Weihe River Basin, the distribution law of slope should be fully considered to optimize the governance scheme.
2025,45(1):327-336
, DOI: 10.13961/j.cnki.stbctb.2025.01.034
Abstract:
[Objective] The gradient effects of different topographic factors on land-use patterns over 23 years from 2000 to 2023 at the arsenic sandstone area of the Yellow River were analyzed in order to provide theoretical guidance for vegetation restoration and land use optimization in this area. [Methods] Using remote sensing data to extract critical topographic factors, such as elevation, slope, and topographic position, and combining these with GIS-based quantitative analysis, the gradient effects of various topographic factors on land-use patterns were analyzed, and the graded evolution of land-use types according to a comprehensive topographic index was explored. [Results] ① Grassland was the dominant land use type in the study area, and from 2000 to 2023, the areas of forestland and construction land underwent the most significant change, followed by cultivated land and unused land. Forestland increased by 10.48 km2, whereas construction land increased by 295.40 km2, mainly from the cultivated land and grassland. The cultivated and unused land areas decreased by 1,716.52 km2 and 758.89 km2, respectively, while grassland increased by 548.12 km2. ② The spatial distribution of land use in the study area exhibited distinct gradient characteristics: cultivated land, construction land, and unused land were primarily distributed in low topographic positions, forestland was mainly located in high topographic positions, and grassland was concentrated in mid-to high-elevation areas. Meanwhile, the water bodies were predominantly found in both low and high topographic positions. ③ In 2000, the highest comprehensive land use index was 220.99, and the lowest was 205.69. By 2023, the highest index was 230.17, and the lowest was 203.36. Except for Levels 1 and 2, the comprehensive land use index in 2023 was significantly lower than that in 2000. Over the past 23 years, land use changes have been closely related to human activities. [Conclusion] From 2000 to 2023, the arsenic sandstone area of the Yellow River exhibited evident topographic gradient characteristics, with significant spatiotemporal changes in land-use types along the topographic gradient. Considering the influence of local topographic factors, it is advisable to strengthen the implementation of policies, such as returning farmland to forests and grasslands, and to optimizing the land use layout continuously.
[Objective] The gradient effects of different topographic factors on land-use patterns over 23 years from 2000 to 2023 at the arsenic sandstone area of the Yellow River were analyzed in order to provide theoretical guidance for vegetation restoration and land use optimization in this area. [Methods] Using remote sensing data to extract critical topographic factors, such as elevation, slope, and topographic position, and combining these with GIS-based quantitative analysis, the gradient effects of various topographic factors on land-use patterns were analyzed, and the graded evolution of land-use types according to a comprehensive topographic index was explored. [Results] ① Grassland was the dominant land use type in the study area, and from 2000 to 2023, the areas of forestland and construction land underwent the most significant change, followed by cultivated land and unused land. Forestland increased by 10.48 km2, whereas construction land increased by 295.40 km2, mainly from the cultivated land and grassland. The cultivated and unused land areas decreased by 1,716.52 km2 and 758.89 km2, respectively, while grassland increased by 548.12 km2. ② The spatial distribution of land use in the study area exhibited distinct gradient characteristics: cultivated land, construction land, and unused land were primarily distributed in low topographic positions, forestland was mainly located in high topographic positions, and grassland was concentrated in mid-to high-elevation areas. Meanwhile, the water bodies were predominantly found in both low and high topographic positions. ③ In 2000, the highest comprehensive land use index was 220.99, and the lowest was 205.69. By 2023, the highest index was 230.17, and the lowest was 203.36. Except for Levels 1 and 2, the comprehensive land use index in 2023 was significantly lower than that in 2000. Over the past 23 years, land use changes have been closely related to human activities. [Conclusion] From 2000 to 2023, the arsenic sandstone area of the Yellow River exhibited evident topographic gradient characteristics, with significant spatiotemporal changes in land-use types along the topographic gradient. Considering the influence of local topographic factors, it is advisable to strengthen the implementation of policies, such as returning farmland to forests and grasslands, and to optimizing the land use layout continuously.
2025,45(1):337-345,356
, DOI: 10.13961/j.cnki.stbctb.2025.01.035
Abstract:
[Objective] The spatiotemporal changes and factors influencing soil conservation capacity in Linyi City, Shandong Province, before and after the implementation of the “Mountain-River Project” were investigated, in order to provide scientific support for evaluating the project’s effectiveness and future planning in the region. [Methods] Using the InVEST model, the spatiotemporal characteristics of the soil conservation capacity in Linyi City of the years 2018, 2020, and 2022 was assessed. The response relationship between the soil conservation capacity and influencing factors was analyzed from both temporal and spatial dimensions. [Results] The soil conservation capacity of Linyi City in 2018, 2020, and 2022 was 23.12, 29.62, and 53.70 t/(hm2·a), respectively. Spatially, soil conservation capacity showed a pattern of “higher in the northwest-lower in the southeast.” Among the four main influencing factors, precipitation, soil, topography, and vegetation, topography was the primary factor affecting spatial distribution, whereas interannual variation was mainly driven by precipitation. [Conclusion] The soil conservation capacity of Linyi City showed a significant upward trend with distinct spatial and interannual variations. Precipitation plays a more prominent role than ecological engineering in influencing the interannual variation in soil conservation capacity; however, the contribution of ecological engineering has increased.
[Objective] The spatiotemporal changes and factors influencing soil conservation capacity in Linyi City, Shandong Province, before and after the implementation of the “Mountain-River Project” were investigated, in order to provide scientific support for evaluating the project’s effectiveness and future planning in the region. [Methods] Using the InVEST model, the spatiotemporal characteristics of the soil conservation capacity in Linyi City of the years 2018, 2020, and 2022 was assessed. The response relationship between the soil conservation capacity and influencing factors was analyzed from both temporal and spatial dimensions. [Results] The soil conservation capacity of Linyi City in 2018, 2020, and 2022 was 23.12, 29.62, and 53.70 t/(hm2·a), respectively. Spatially, soil conservation capacity showed a pattern of “higher in the northwest-lower in the southeast.” Among the four main influencing factors, precipitation, soil, topography, and vegetation, topography was the primary factor affecting spatial distribution, whereas interannual variation was mainly driven by precipitation. [Conclusion] The soil conservation capacity of Linyi City showed a significant upward trend with distinct spatial and interannual variations. Precipitation plays a more prominent role than ecological engineering in influencing the interannual variation in soil conservation capacity; however, the contribution of ecological engineering has increased.
2025,45(1):346-356
, DOI: 10.13961/j.cnki.stbctb.2025.01.036
Abstract:
[Objective] The agglomeration characteristics and evolution trend of land use conflicts was scientifically identified to provide important reference for promoting the rational layout of territorial space and regional sustainable development. [Methods] The spatial-temporal evolution trend of land use conflict in the Wanjiang urban belt from 1990 to 2020 was quantitatively analyzed by constructing a land use conflict measurement model based on the landscape index. The distance weight matrix was determined by setting the optimal spatial threshold to explore the agglomeration effect of land use conflict more accurately. [Results] ① Significant changes occurred in the land use structure of the Wanjiang urban belt from 1990 to 2020. The area of cultivated and forest land decreased continuously, and the scale of construction land increased significantly. ② The distribution pattern of regional land use conflicts was “higher in the north and lower in the south,” with areas of weak and medium spatial conflicts occupying the main position. Serious conflict areas were concentrated in Hefei City, Wuhu City, Jin’an District of Lu’an City, and the coastal areas on both sides of the Yangtze River system. ③ The land use conflict index changed significantly in urban areas during the study period, especially in the east of Hefei City, the north of Wuhu City, and the southeast of Chuzhou City. Under the influence of urbanization, the conflict gravity center gradually shifted southward, and the serious conflict zone shifted from the northwest to the southeast. ④ 5 km was selected as the optimal distance analysis threshold. The high-high aggregation conflict zone was centered on Hefei City, while the low-low aggregation conflict zone showed no agglomeration phenomenon. [Conclusion] The land use conflict in Wanjiang urban belt has the potential to intensify, and the main conflict areas show a shifting trend. In the future, it is necessary to strengthen the rational distribution of regional land use and focus on the balance and stability between urbanization development and ecological protection.
[Objective] The agglomeration characteristics and evolution trend of land use conflicts was scientifically identified to provide important reference for promoting the rational layout of territorial space and regional sustainable development. [Methods] The spatial-temporal evolution trend of land use conflict in the Wanjiang urban belt from 1990 to 2020 was quantitatively analyzed by constructing a land use conflict measurement model based on the landscape index. The distance weight matrix was determined by setting the optimal spatial threshold to explore the agglomeration effect of land use conflict more accurately. [Results] ① Significant changes occurred in the land use structure of the Wanjiang urban belt from 1990 to 2020. The area of cultivated and forest land decreased continuously, and the scale of construction land increased significantly. ② The distribution pattern of regional land use conflicts was “higher in the north and lower in the south,” with areas of weak and medium spatial conflicts occupying the main position. Serious conflict areas were concentrated in Hefei City, Wuhu City, Jin’an District of Lu’an City, and the coastal areas on both sides of the Yangtze River system. ③ The land use conflict index changed significantly in urban areas during the study period, especially in the east of Hefei City, the north of Wuhu City, and the southeast of Chuzhou City. Under the influence of urbanization, the conflict gravity center gradually shifted southward, and the serious conflict zone shifted from the northwest to the southeast. ④ 5 km was selected as the optimal distance analysis threshold. The high-high aggregation conflict zone was centered on Hefei City, while the low-low aggregation conflict zone showed no agglomeration phenomenon. [Conclusion] The land use conflict in Wanjiang urban belt has the potential to intensify, and the main conflict areas show a shifting trend. In the future, it is necessary to strengthen the rational distribution of regional land use and focus on the balance and stability between urbanization development and ecological protection.
2025,45(1):357-369
, DOI: 10.13961/j.cnki.stbctb.2025.01.037
Abstract:
[Objective] The functional composition of the soil and water conservation ecological services in Mudanjiang City, Heilongjiang Province, China, was constructed from the perspective of ecological priority. The spatiotemporal differentiation characteristics, tradeoffs and synergies of regional soil conservation, carbon sink of soil and water conservation, and water purification capacity were explored, and the intensity of regional soil and water conservation ecological services was calculated, providing scientific basis for maintaining regional ecological stability, ensuring the sustainable development of agriculture, and improving hydrological connectivity and water quality. [Methods] The main watershed and sub-watershed of Mudanjiang City were divided using the SWAT model, and the soil and water conservation ecological service functions (soil conservation, carbon sink of soil and water conservation, and water quality purification) were quantitatively evaluated and analyzed in terms of space and time in each watershed for 2002, 2012, and 2022 using the InVEST model. The soil conservation function was analyzed using bivariate spatial autocorrelation analysis at the grid scale based on the Geoda software. We studied the tradeoff and synergistic relationships between the different service functions and their temporal changes and calculated the ecological service intensity of soil and water conservation in Mudanjiang City by combining numerical and weighting methods. The contributions of rainfall and the digital elevation model to each service function were explained using geographic detectors. [Results] The soil conservation and soil and water conservation carbon sink functions in Mudanjiang City exhibit a synergistic relationship, whereas the water quality purification function exhibits tradeoff relationships with both the soil and water conservation carbon sink and soil conservation functions. The average ecological service intensities of soil and water conservation in 2002, 2012, and 2022 were 0.327 5, 0.325 6, and 0.332 7, respectively, showing a slight decrease followed by an increase. [Conclusion] The soil and water conservation ecological service functions in Mudanjiang City improved compared to the case in the initial study period, with the average value in Suifenhe River basin being better than those in other regions and Mudanjiang River basin contributing the most to the total. The spatiotemporal heterogeneity characteristics of the service functions are affected by precipitation, topography, land use change, and vegetation coverage.
[Objective] The functional composition of the soil and water conservation ecological services in Mudanjiang City, Heilongjiang Province, China, was constructed from the perspective of ecological priority. The spatiotemporal differentiation characteristics, tradeoffs and synergies of regional soil conservation, carbon sink of soil and water conservation, and water purification capacity were explored, and the intensity of regional soil and water conservation ecological services was calculated, providing scientific basis for maintaining regional ecological stability, ensuring the sustainable development of agriculture, and improving hydrological connectivity and water quality. [Methods] The main watershed and sub-watershed of Mudanjiang City were divided using the SWAT model, and the soil and water conservation ecological service functions (soil conservation, carbon sink of soil and water conservation, and water quality purification) were quantitatively evaluated and analyzed in terms of space and time in each watershed for 2002, 2012, and 2022 using the InVEST model. The soil conservation function was analyzed using bivariate spatial autocorrelation analysis at the grid scale based on the Geoda software. We studied the tradeoff and synergistic relationships between the different service functions and their temporal changes and calculated the ecological service intensity of soil and water conservation in Mudanjiang City by combining numerical and weighting methods. The contributions of rainfall and the digital elevation model to each service function were explained using geographic detectors. [Results] The soil conservation and soil and water conservation carbon sink functions in Mudanjiang City exhibit a synergistic relationship, whereas the water quality purification function exhibits tradeoff relationships with both the soil and water conservation carbon sink and soil conservation functions. The average ecological service intensities of soil and water conservation in 2002, 2012, and 2022 were 0.327 5, 0.325 6, and 0.332 7, respectively, showing a slight decrease followed by an increase. [Conclusion] The soil and water conservation ecological service functions in Mudanjiang City improved compared to the case in the initial study period, with the average value in Suifenhe River basin being better than those in other regions and Mudanjiang River basin contributing the most to the total. The spatiotemporal heterogeneity characteristics of the service functions are affected by precipitation, topography, land use change, and vegetation coverage.
2025,45(1):370-380
, DOI: 10.13961/j.cnki.stbctb.2025.01.038
Abstract:
[Objective] Based on bibliometrics, research hotspots and trends in the field of plant-soil reinforcement were explored to provide a reference and guidance for the research status and development in this field. [Methods] Using the CNKI (China National Knowledge Infrastructure) and Web of Science (WoS) databases as data sources, a combined approach using VOSviewer and CiteSpace was employed for the visual analysis of publication volumes, countries, institutions, researchers, and keywords in the field of plant-soil reinforcement from 1993 to 2023. [Results] ① The volume of publications showed a slow increase followed by a sustained rapid growth, with the publication volume in CNKI stabilizing in recent years while that in WoS surged. ② China has produced the most research results on plant-soil reinforcement, but there was still room for improvement in research quality. Beijing Forestry University, Yunnan Agricultural University, and Inner Mongolia Agricultural University were the three major institutions in the field of plant-soil reinforcement. While the collaborative publication of literature showed that the team has close cooperation within the institution it lacks cooperation outside the institution. ③ Research in the field of plant-soil reinforcement focused on slope stability, root mechanics, and root-soil shear resistance. Keyword analysis showed that WoS emphasized erosion prediction, the Loess Plateau, and mechanical properties, whereas CNKI highlighted root morphology, drawdown zones, mechanical characteristics, self-repair, and ecological restoration as research hotspots over the past three years. [Conclusion] China has the highest research output in this field; however, there is room for improvement in research quality and collaboration among teams and institutions. Most studies have focused on herbaceous plants and have had relatively short durations. Future research should deepen the study of other plant types and longer durations. In addition, research on ecologically vulnerable areas remains limited, indicating the need to expand the scope of future research.
[Objective] Based on bibliometrics, research hotspots and trends in the field of plant-soil reinforcement were explored to provide a reference and guidance for the research status and development in this field. [Methods] Using the CNKI (China National Knowledge Infrastructure) and Web of Science (WoS) databases as data sources, a combined approach using VOSviewer and CiteSpace was employed for the visual analysis of publication volumes, countries, institutions, researchers, and keywords in the field of plant-soil reinforcement from 1993 to 2023. [Results] ① The volume of publications showed a slow increase followed by a sustained rapid growth, with the publication volume in CNKI stabilizing in recent years while that in WoS surged. ② China has produced the most research results on plant-soil reinforcement, but there was still room for improvement in research quality. Beijing Forestry University, Yunnan Agricultural University, and Inner Mongolia Agricultural University were the three major institutions in the field of plant-soil reinforcement. While the collaborative publication of literature showed that the team has close cooperation within the institution it lacks cooperation outside the institution. ③ Research in the field of plant-soil reinforcement focused on slope stability, root mechanics, and root-soil shear resistance. Keyword analysis showed that WoS emphasized erosion prediction, the Loess Plateau, and mechanical properties, whereas CNKI highlighted root morphology, drawdown zones, mechanical characteristics, self-repair, and ecological restoration as research hotspots over the past three years. [Conclusion] China has the highest research output in this field; however, there is room for improvement in research quality and collaboration among teams and institutions. Most studies have focused on herbaceous plants and have had relatively short durations. Future research should deepen the study of other plant types and longer durations. In addition, research on ecologically vulnerable areas remains limited, indicating the need to expand the scope of future research.
2025,45(1):381-392
, DOI: 10.13961/j.cnki.stbctb.2025.01.039
Abstract:
[Objective] This study aimed to clarify the spatiotemporal pattern evolution law of the coupling coordination between the recessive form of urban land use and ecological welfare performance, reveal the direction of its influencing factors, and provide a scientific basis for promoting the green development of urban agglomerations along the Lower Yellow River. [Methods] Based on panel data from 17 prefecture-level cities along the Lower Yellow River from 2012 to 2021, the comprehensive index and Super-SBM models were used to measure the recessive form of land use and ecological welfare performance. In addition, ArcGIS visualization, kernel density analysis, and a coupled coordination model were used to deply analyze the evolution trend of the recessive form of land use, the performance level of ecological welfare, and the coupling coordination degree of them in the spatial and temporal dimensions, with the influencing factors analyzed using the Tobit regression model. [Results] ① The recessive form of land use in each city was stable but improved, and the ecological welfare performance experienced a phased evolution process of “first decreasing and then increasing.” ② During the study period, the coupling coordination degree of the overall ecological welfare performance and the recessive form of land use of cities along the Lower Yellow River experienced a change from “near disharmony to barely coordination,” and tended to change to primary coordination. ③ Opening to the outside world, industrial structure, and spatial agglomeration had significant positive effects on the coupling coordination; but scientific and technological innovation and the urban environment had obvious inhibitory effects on the coupling coordination. Meanwhile, elevation, slope, and education level did not affect the coupling coordination. [Conclusion] In the future, it is necessary to promote the rational use of land according to local conditions, formulate scientific environmental protection policies, strengthen the monitoring and management of cities, strengthen the leading role of provincial capitals, and promote green coordinated development among cities.
[Objective] This study aimed to clarify the spatiotemporal pattern evolution law of the coupling coordination between the recessive form of urban land use and ecological welfare performance, reveal the direction of its influencing factors, and provide a scientific basis for promoting the green development of urban agglomerations along the Lower Yellow River. [Methods] Based on panel data from 17 prefecture-level cities along the Lower Yellow River from 2012 to 2021, the comprehensive index and Super-SBM models were used to measure the recessive form of land use and ecological welfare performance. In addition, ArcGIS visualization, kernel density analysis, and a coupled coordination model were used to deply analyze the evolution trend of the recessive form of land use, the performance level of ecological welfare, and the coupling coordination degree of them in the spatial and temporal dimensions, with the influencing factors analyzed using the Tobit regression model. [Results] ① The recessive form of land use in each city was stable but improved, and the ecological welfare performance experienced a phased evolution process of “first decreasing and then increasing.” ② During the study period, the coupling coordination degree of the overall ecological welfare performance and the recessive form of land use of cities along the Lower Yellow River experienced a change from “near disharmony to barely coordination,” and tended to change to primary coordination. ③ Opening to the outside world, industrial structure, and spatial agglomeration had significant positive effects on the coupling coordination; but scientific and technological innovation and the urban environment had obvious inhibitory effects on the coupling coordination. Meanwhile, elevation, slope, and education level did not affect the coupling coordination. [Conclusion] In the future, it is necessary to promote the rational use of land according to local conditions, formulate scientific environmental protection policies, strengthen the monitoring and management of cities, strengthen the leading role of provincial capitals, and promote green coordinated development among cities.
2025,45(1):393-404
, DOI: 10.13961/j.cnki.stbctb.2025.01.040
Abstract:
[Objective] The coupling and coordination relationship between soil and water conservation policy and agricultural eco-efficiency, and its driving factors were analyzed to provide a new perspective and thinking for further understanding of the coordination relationship between soil and water conservation policy and agricultural eco-efficiency. [Methods] An evaluation index system for soil and water conservation policy intensity and agricultural eco-efficiency was established using the Three Gorges reservoir (Chongqing section) as the research area. The coupling coordination degree model, geographical detector model, and ordinary least squares (OLS) regression were used to analyze the coupling relationship between the soil and water conservation policy and agricultural eco-efficiency, and its driving mechanism in the region from 2015 to 2022. [Results] ① There were significant differences in policy intensity and ecological efficiency among regions in the Three Gorges reservoir area (Chongqing section). The maintenance area of soil-conserving human settlements in the Fangshan Hills and parallel ridges and valleys showed strong growth momentum during policy implementation, whereas the rest of the region was relatively stable. The agricultural ecological efficiency of the urban landscape living environment maintenance area was excellent, whereas that of the Wuling Mountain water and soil conservation areas was relatively low, showing an obvious polarization trend. ② The degree of coupling coordination between soil and water conservation policies and agricultural ecological efficiency showed an overall upward trend, and the coordination degree of the urban landscape human settlement environment maintenance area and the Fangshan hilly soil conservation human settlement environment maintenance area was particularly prominent. However, there was a significant imbalance of that in Kaizhou District in the areas of soil conservation and human settlement in the parallel ridge valley of Yuzhong. ③ The input of farmland water conservation facilities was helpful in improving the coordination level, and reasonable control of the planting area could also more positively affect the coordination relationship between the soil and water conservation policy and agricultural ecological efficiency. The robustness of the regression results is confirmed using a counterfactual test. [Conclusion] To effectively maintain soil and water resources and agricultural ecological security, the Three Gorges reservoir area (Chongqing section) should adhere to the principles of local governance and regional linkages, actively guide all parties in society to participate in the formation of governance synergy, and jointly promote the development of a diversified support model combining poverty alleviation, soil conservation, and agricultural assistance.
[Objective] The coupling and coordination relationship between soil and water conservation policy and agricultural eco-efficiency, and its driving factors were analyzed to provide a new perspective and thinking for further understanding of the coordination relationship between soil and water conservation policy and agricultural eco-efficiency. [Methods] An evaluation index system for soil and water conservation policy intensity and agricultural eco-efficiency was established using the Three Gorges reservoir (Chongqing section) as the research area. The coupling coordination degree model, geographical detector model, and ordinary least squares (OLS) regression were used to analyze the coupling relationship between the soil and water conservation policy and agricultural eco-efficiency, and its driving mechanism in the region from 2015 to 2022. [Results] ① There were significant differences in policy intensity and ecological efficiency among regions in the Three Gorges reservoir area (Chongqing section). The maintenance area of soil-conserving human settlements in the Fangshan Hills and parallel ridges and valleys showed strong growth momentum during policy implementation, whereas the rest of the region was relatively stable. The agricultural ecological efficiency of the urban landscape living environment maintenance area was excellent, whereas that of the Wuling Mountain water and soil conservation areas was relatively low, showing an obvious polarization trend. ② The degree of coupling coordination between soil and water conservation policies and agricultural ecological efficiency showed an overall upward trend, and the coordination degree of the urban landscape human settlement environment maintenance area and the Fangshan hilly soil conservation human settlement environment maintenance area was particularly prominent. However, there was a significant imbalance of that in Kaizhou District in the areas of soil conservation and human settlement in the parallel ridge valley of Yuzhong. ③ The input of farmland water conservation facilities was helpful in improving the coordination level, and reasonable control of the planting area could also more positively affect the coordination relationship between the soil and water conservation policy and agricultural ecological efficiency. The robustness of the regression results is confirmed using a counterfactual test. [Conclusion] To effectively maintain soil and water resources and agricultural ecological security, the Three Gorges reservoir area (Chongqing section) should adhere to the principles of local governance and regional linkages, actively guide all parties in society to participate in the formation of governance synergy, and jointly promote the development of a diversified support model combining poverty alleviation, soil conservation, and agricultural assistance.
Display Method:
Abstract:
Absrtact:[Objective] To systematically analyze the spatio-temporal change characteristics of land use in China and provinces under different carbon emission scenarios, in order to provide data support and theoretical basis for formulating regional land use planning and policies to cope with climate change, as well as future land use planning and sustainable development in China. [Methods] Based on land use data from 2015 to 2100, combined with land use transfer matrix and dynamic attitude index, this paper analyzed the temporal and spatial characteristics of land use change in China. [Results] Under SSP126 and SSP245 scenarios, cultivated land, construction land and unused land showed an overall increase trend, while grassland and forest land decreased, and grassland decreased most significantly. Under the SSP585 scenario, cultivated land, grassland and construction land increase, while forest land and unused land decrease significantly. In terms of land use transfer, forest land was converted into cultivated land and grassland, and unused land and grassland were converted most frequently. From 2015 to 2030, the land use change is the most drastic, and the dynamic attitude under the SSP585 scenario is the highest, which is mainly manifested as the conversion of grassland and unused land into cultivated land and construction land. From 2030 to 2060, the change amplitude decreases, and the change in the western region is relatively stable, and the change in Sichuan, Gansu and Heilongjiang provinces tends to be stable under the SSP245 scenario. From 2060 to 2100, the impact of climate change will weaken, and the total change area will decrease significantly. Especially under the SSP585 scenario, the change of western provinces is still more obvious, while the change of eastern regions will slow down. [Conclusion] China's land use change will be affected by carbon emission scenario, regional economic development and urbanization process, showing significant spatio-temporal heterogeneity and regional differences.
Absrtact:[Objective] To systematically analyze the spatio-temporal change characteristics of land use in China and provinces under different carbon emission scenarios, in order to provide data support and theoretical basis for formulating regional land use planning and policies to cope with climate change, as well as future land use planning and sustainable development in China. [Methods] Based on land use data from 2015 to 2100, combined with land use transfer matrix and dynamic attitude index, this paper analyzed the temporal and spatial characteristics of land use change in China. [Results] Under SSP126 and SSP245 scenarios, cultivated land, construction land and unused land showed an overall increase trend, while grassland and forest land decreased, and grassland decreased most significantly. Under the SSP585 scenario, cultivated land, grassland and construction land increase, while forest land and unused land decrease significantly. In terms of land use transfer, forest land was converted into cultivated land and grassland, and unused land and grassland were converted most frequently. From 2015 to 2030, the land use change is the most drastic, and the dynamic attitude under the SSP585 scenario is the highest, which is mainly manifested as the conversion of grassland and unused land into cultivated land and construction land. From 2030 to 2060, the change amplitude decreases, and the change in the western region is relatively stable, and the change in Sichuan, Gansu and Heilongjiang provinces tends to be stable under the SSP245 scenario. From 2060 to 2100, the impact of climate change will weaken, and the total change area will decrease significantly. Especially under the SSP585 scenario, the change of western provinces is still more obvious, while the change of eastern regions will slow down. [Conclusion] China's land use change will be affected by carbon emission scenario, regional economic development and urbanization process, showing significant spatio-temporal heterogeneity and regional differences.
Abstract:
[Objective] To scientifically evaluate the spatio-temporal variation of agricultural carbon emissions and its main influencing factors in the Yellow River Basin, predict the future emission trend, and provide data support and decision-making reference for formulating agricultural carbon emission reduction policies and regional collaborative governance plans. [Methods] In this paper, the agricultural carbon emissions from 2001 to 2021 in nine provinces of the Yellow River Basin were selected as the research object, STIRPAT extended model was used to analyze the driving factors, and GM (1,1) model was used to forecast. [Results] There were significant differences in agricultural carbon emissions among provinces and regions in the Yellow River Basin, and agricultural carbon emissions in major grain-producing areas were significantly higher than those in other provinces. Agricultural carbon emissions in the Yellow River Basin first increased and then decreased over time, showing an overall "inverted U-shape". The quarter-on-quarter growth rate showed a fluctuating rise in the early stage, and then began to decline slowly after 2012 until a negative growth in 2017, indicating that policy intervention played an important role in agricultural carbon emission reduction. Among the driving factors of agricultural carbon emissions in the Yellow River Basin, agricultural production efficiency, economic development level, urbanization level, agricultural land management scale and agricultural mechanization level are the main factors leading to the increase of agricultural carbon emissions in the Yellow River Basin. The energy intensity of agricultural machinery has a restraining effect on carbon emissions, and technological progress may offset part of the carbon emission reduction effect due to the "rebound effect". In the future 2022-2035, agricultural carbon emissions in the Yellow River Basin may show a downward trend, but still maintain a high level, and agricultural carbon emission reduction pressure is still large. [Conclusion] The potential of agricultural carbon emission reduction in the Yellow River Basin has not been fully released, and agricultural carbon emission reduction should be further achieved by accelerating the application of new energy technologies, popularizing green and low-carbon production technologies, building a whole-chain management system of agricultural waste, promoting the optimization of agricultural structure and the innovation of the coupling model of planting and breeding, and building a collaborative development system of ecological agriculture and organic agriculture according to local conditions. At the same time, it is necessary to establish a dynamic balance mechanism between economic growth and emission reduction targets to avoid the risk of carbon emissions rebound caused by extensive development.
[Objective] To scientifically evaluate the spatio-temporal variation of agricultural carbon emissions and its main influencing factors in the Yellow River Basin, predict the future emission trend, and provide data support and decision-making reference for formulating agricultural carbon emission reduction policies and regional collaborative governance plans. [Methods] In this paper, the agricultural carbon emissions from 2001 to 2021 in nine provinces of the Yellow River Basin were selected as the research object, STIRPAT extended model was used to analyze the driving factors, and GM (1,1) model was used to forecast. [Results] There were significant differences in agricultural carbon emissions among provinces and regions in the Yellow River Basin, and agricultural carbon emissions in major grain-producing areas were significantly higher than those in other provinces. Agricultural carbon emissions in the Yellow River Basin first increased and then decreased over time, showing an overall "inverted U-shape". The quarter-on-quarter growth rate showed a fluctuating rise in the early stage, and then began to decline slowly after 2012 until a negative growth in 2017, indicating that policy intervention played an important role in agricultural carbon emission reduction. Among the driving factors of agricultural carbon emissions in the Yellow River Basin, agricultural production efficiency, economic development level, urbanization level, agricultural land management scale and agricultural mechanization level are the main factors leading to the increase of agricultural carbon emissions in the Yellow River Basin. The energy intensity of agricultural machinery has a restraining effect on carbon emissions, and technological progress may offset part of the carbon emission reduction effect due to the "rebound effect". In the future 2022-2035, agricultural carbon emissions in the Yellow River Basin may show a downward trend, but still maintain a high level, and agricultural carbon emission reduction pressure is still large. [Conclusion] The potential of agricultural carbon emission reduction in the Yellow River Basin has not been fully released, and agricultural carbon emission reduction should be further achieved by accelerating the application of new energy technologies, popularizing green and low-carbon production technologies, building a whole-chain management system of agricultural waste, promoting the optimization of agricultural structure and the innovation of the coupling model of planting and breeding, and building a collaborative development system of ecological agriculture and organic agriculture according to local conditions. At the same time, it is necessary to establish a dynamic balance mechanism between economic growth and emission reduction targets to avoid the risk of carbon emissions rebound caused by extensive development.
Abstract:
[Objective] Quantifying the proportion and composition of each factor in runoff depth, quantitatively analyzing the contribution rate of underlying surface, climate and industrial and agricultural water use change to runoff change in the source area of the Yellow River, laying a foundation for ecological environment protection and water resources development in the Yellow River basin.[Methods] Based on the distributed hydrothermal coupling model WEP-ISF model, the paper analyzed the monthly mean discharge and the dynamic changes of actual evapotranspiration, soil temperature, soil water content and runoff composition in the source area of the Yellow River in different periods, and analyzed the contribution of each influencing factor to the change of runoff by using multi-factor attribution analysis method. [Results] The results showed that the WEP-ISF model could describe the hydrological process and hydrothermal process of the Yellow River source basin well. The mean absolute percentage error between the simulated soil temperature and the interpreted soil temperature was 69.78%~171.55%, and the Nash efficiency coefficient was more than 0.70. The mean absolute percentage error between simulated and interpreted values of soil surface water content is between 13.94% and 20.97%, and the Nash efficiency coefficient exceeds 0.5. Specifically, the Nash efficiency coefficient for the simulated and measured monthly average flow is 0.80, and the mean absolute percentage error is 25.85%.The Nash efficiency coefficient and the mean absolute percentage error of the simulated evapotranspiration value and the interpreted remote sensing value were 0.80 and 53.39%, respectively. The annual average of glacier, snowmelt and fall-off water flow is 0.9mm, 14.9mm and 70.5mm, accounting for 1.0%, 17.3% and 81.7% of the source runoff depth of the Yellow River, respectively. Compared with the baseline period of 1970-1990, the annual average runoff of Tangnahai decreased by 6.675 billion m3 during 1991-2021, the changes of glacier, snowmelt and water flow were 1.48mm, -3.8mm and -13.2mm, which accounted for 9.53%, -24.48% and -85.05% of the changes of runoff depth in the source area of the Yellow River, respectively.And the contribution rates of climate, underlying surface and socio-economic water use change were 96.46%, 2.49% and 1.05%, respectively. [Conclusion] Among the many factors affecting the runoff change in the source area of the Yellow River, the climate factor is the main driving factor leading to the runoff attenuation in the source area of the Yellow River, which is manifested in the trend of increasing glacier melt water flow and decreasing trend of snowmelt runoff and runoff.
[Objective] Quantifying the proportion and composition of each factor in runoff depth, quantitatively analyzing the contribution rate of underlying surface, climate and industrial and agricultural water use change to runoff change in the source area of the Yellow River, laying a foundation for ecological environment protection and water resources development in the Yellow River basin.[Methods] Based on the distributed hydrothermal coupling model WEP-ISF model, the paper analyzed the monthly mean discharge and the dynamic changes of actual evapotranspiration, soil temperature, soil water content and runoff composition in the source area of the Yellow River in different periods, and analyzed the contribution of each influencing factor to the change of runoff by using multi-factor attribution analysis method. [Results] The results showed that the WEP-ISF model could describe the hydrological process and hydrothermal process of the Yellow River source basin well. The mean absolute percentage error between the simulated soil temperature and the interpreted soil temperature was 69.78%~171.55%, and the Nash efficiency coefficient was more than 0.70. The mean absolute percentage error between simulated and interpreted values of soil surface water content is between 13.94% and 20.97%, and the Nash efficiency coefficient exceeds 0.5. Specifically, the Nash efficiency coefficient for the simulated and measured monthly average flow is 0.80, and the mean absolute percentage error is 25.85%.The Nash efficiency coefficient and the mean absolute percentage error of the simulated evapotranspiration value and the interpreted remote sensing value were 0.80 and 53.39%, respectively. The annual average of glacier, snowmelt and fall-off water flow is 0.9mm, 14.9mm and 70.5mm, accounting for 1.0%, 17.3% and 81.7% of the source runoff depth of the Yellow River, respectively. Compared with the baseline period of 1970-1990, the annual average runoff of Tangnahai decreased by 6.675 billion m3 during 1991-2021, the changes of glacier, snowmelt and water flow were 1.48mm, -3.8mm and -13.2mm, which accounted for 9.53%, -24.48% and -85.05% of the changes of runoff depth in the source area of the Yellow River, respectively.And the contribution rates of climate, underlying surface and socio-economic water use change were 96.46%, 2.49% and 1.05%, respectively. [Conclusion] Among the many factors affecting the runoff change in the source area of the Yellow River, the climate factor is the main driving factor leading to the runoff attenuation in the source area of the Yellow River, which is manifested in the trend of increasing glacier melt water flow and decreasing trend of snowmelt runoff and runoff.
Abstract:
[Objective] Aiming at the problems of heavy soil texture, lack of nutrients and low soil biological activity of newly-created farmland in Qinba mountain area, the effects of different modifiers on the improvement of soil quality of newly cultivated land in Qinba mountain area were analyzed, so as to provide theoretical basis and technical support for the rapid improvement of soil quality of newly-created farmland and the restoration of production. [Methods] A two-year field experiment was conducted with five treatments: Control (CT), ferrous sulfate (T1), biochar (T2), microbial inoculant (T3), and composite amendment (T4). The effects of these treatments on soil quality and maize yield were evaluated across four dimensions: maize yield, soil physical structure, chemical properties, and soil enzyme activity. [Results] Compared to CT, maize yields increased by 17.31 %, 30.57 %, and 25.89 % under T2, T3, and T4 treatments, respectively. The ranking of the soil quality index for each treatment is as follows: T4 > T2 > T3 > T1 > CT. Both T2 and T4 treatments attained soil pH, bulk density, organic matter, total nitrogen, and alkali-hydrolyzed nitrogen levels that are on par with those found in high-quality cultivated land in the Qinba Mountain area. T1 improved soil bulk density to near-optimal levels, while T3 enhanced soil pH and bulk density. Correlation analysis indicated that soil organic matter was the key factor influencing soil physical properties, nutrient content, and enzyme activity, whereas low microbial activity was identified as the primary constraint on yield improvement in newly-created farmland. [Conclusion] For comprehensive soil quality enhancement, biochar (T2) and composite amendment (T4) are recommended as key technologies. However, when considering cost-effectiveness and yield improvement, microbial inoculant (T3) proves to be a practical and efficient measure for widespread application in the region.
[Objective] Aiming at the problems of heavy soil texture, lack of nutrients and low soil biological activity of newly-created farmland in Qinba mountain area, the effects of different modifiers on the improvement of soil quality of newly cultivated land in Qinba mountain area were analyzed, so as to provide theoretical basis and technical support for the rapid improvement of soil quality of newly-created farmland and the restoration of production. [Methods] A two-year field experiment was conducted with five treatments: Control (CT), ferrous sulfate (T1), biochar (T2), microbial inoculant (T3), and composite amendment (T4). The effects of these treatments on soil quality and maize yield were evaluated across four dimensions: maize yield, soil physical structure, chemical properties, and soil enzyme activity. [Results] Compared to CT, maize yields increased by 17.31 %, 30.57 %, and 25.89 % under T2, T3, and T4 treatments, respectively. The ranking of the soil quality index for each treatment is as follows: T4 > T2 > T3 > T1 > CT. Both T2 and T4 treatments attained soil pH, bulk density, organic matter, total nitrogen, and alkali-hydrolyzed nitrogen levels that are on par with those found in high-quality cultivated land in the Qinba Mountain area. T1 improved soil bulk density to near-optimal levels, while T3 enhanced soil pH and bulk density. Correlation analysis indicated that soil organic matter was the key factor influencing soil physical properties, nutrient content, and enzyme activity, whereas low microbial activity was identified as the primary constraint on yield improvement in newly-created farmland. [Conclusion] For comprehensive soil quality enhancement, biochar (T2) and composite amendment (T4) are recommended as key technologies. However, when considering cost-effectiveness and yield improvement, microbial inoculant (T3) proves to be a practical and efficient measure for widespread application in the region.
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[Objective]: A comprehensive review of research progress on soil amendments for controlling soil erosion in the southern red soil regions of China can provide a scientific basis for effectively guiding soil erosion management in the region. [Methods]: Based on RStudio and ArcGIS visualization tools, we constructed keyword combinations centered on "soil amendments," "soil erosion," and "southern red soil regions of China" to retrieve relevant literature published between 1999 and 2024 from the China National Knowledge Infrastructure and Web of Science databases. Quantitative analysis was conducted focusing on the number of publications, research institutions, journals, application frequency of amendments, experimental methods and application durations, study locations, and the evolution of keyword. [Results]: Over the past 25 years, there has been a rapid increase in the number of publications related to soil amendments for erosion control, reflecting a growing interest among researchers in this field. Straw, organic fertilizers, and biochar have emerged as the most frequently used materials due to their significant effectiveness in improving soil organic matter content, enhancing aggregate stability, and increasing water retention capacity. Related studies have primarily focused on regions with severe soil erosion, such as Jiangxi and Hunan provinces. Soil amendments can be categorized into four major types: natural amendments, synthetic amendments, natural-synthetic copolymer amendments, and biological amendments. This study summarizes the distinct mechanisms and practical effects of natural amendments, synthetic amendments, natural-synthetic copolymer amendments, and biological amendments in enhancing soil aggregate stability, erosion resistance, water retention capacity, and ecological restoration. [Conclusion]: This study systematically reviews the research progress on soil amendments for controlling soil erosion in the southern red soil regions of China, highlighting the significant roles of different types of soil amendments in regulating soil erosion, enhancing soil aggregate stability, and improving water retention capacity. Furthermore, it recommends that future research focus on the interactions between amendments and environmental factors (e.g., climate, soil types), the development of novel composite amendments, and comprehensive assessments of their long-term ecological effects to promote sustainable management of agricultural ecosystems.
[Objective]: A comprehensive review of research progress on soil amendments for controlling soil erosion in the southern red soil regions of China can provide a scientific basis for effectively guiding soil erosion management in the region. [Methods]: Based on RStudio and ArcGIS visualization tools, we constructed keyword combinations centered on "soil amendments," "soil erosion," and "southern red soil regions of China" to retrieve relevant literature published between 1999 and 2024 from the China National Knowledge Infrastructure and Web of Science databases. Quantitative analysis was conducted focusing on the number of publications, research institutions, journals, application frequency of amendments, experimental methods and application durations, study locations, and the evolution of keyword. [Results]: Over the past 25 years, there has been a rapid increase in the number of publications related to soil amendments for erosion control, reflecting a growing interest among researchers in this field. Straw, organic fertilizers, and biochar have emerged as the most frequently used materials due to their significant effectiveness in improving soil organic matter content, enhancing aggregate stability, and increasing water retention capacity. Related studies have primarily focused on regions with severe soil erosion, such as Jiangxi and Hunan provinces. Soil amendments can be categorized into four major types: natural amendments, synthetic amendments, natural-synthetic copolymer amendments, and biological amendments. This study summarizes the distinct mechanisms and practical effects of natural amendments, synthetic amendments, natural-synthetic copolymer amendments, and biological amendments in enhancing soil aggregate stability, erosion resistance, water retention capacity, and ecological restoration. [Conclusion]: This study systematically reviews the research progress on soil amendments for controlling soil erosion in the southern red soil regions of China, highlighting the significant roles of different types of soil amendments in regulating soil erosion, enhancing soil aggregate stability, and improving water retention capacity. Furthermore, it recommends that future research focus on the interactions between amendments and environmental factors (e.g., climate, soil types), the development of novel composite amendments, and comprehensive assessments of their long-term ecological effects to promote sustainable management of agricultural ecosystems.
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[Objective]To quantitatively evaluate the soil quality of artificial forest land in North China Plain in order to provide scientific basis and suggestion for soil quality improvement and diagnosis of obstacle factors in this area. [Methods] Five poplar plantations with different planting densities (1111, 833, 625, 555 and 416 trees /ha) were selected as the research objects, and samples of soil physicochemical and biological properties were collected. Based on principal component analysis (PCA), the minimum dataset (MDS) was selected, and soil quality index, sensitivity index and obstacle factor diagnosis were used to comprehensively evaluate the soil quality of plantation forest in North China Plain. [Results] Based on the results of principal component analysis, the minimum data set consisting of soil total carbon, sucrase activity, electrical conductivity, powder and available phosphorus was selected. The order of soil quality index of poplar plantation with different density was Y5 (416 plants /ha) > Y4 (555 plants /ha) > Y3 (625 plants /ha) > Y1 (1111 plants /ha) > Y2 (833 plants /ha). There was a significant correlation between the linear minimum data set and the linear total data set, and the coefficient of variation was the largest, and the linear minimum data set could be a good soil quality assessment (P<0.01). According to the results of obstacle degree model, all poplar plantations with different densities are faced with soil nutrient and water limiting obstacles, ?and organic carbon is the main factor limiting soil quality in this area. [Conclusion] The poplar plantation with 416 trees /ha has the best soil quality. All poplar plantations in North China Plain are faced with soil nutrient deficiency and water shortage. Scientific fertilization and irrigation management measures should be formulated in this region, and appropriate afforestation density should be determined in the plantation production practice to achieve sustainable soil utilization.
[Objective]To quantitatively evaluate the soil quality of artificial forest land in North China Plain in order to provide scientific basis and suggestion for soil quality improvement and diagnosis of obstacle factors in this area. [Methods] Five poplar plantations with different planting densities (1111, 833, 625, 555 and 416 trees /ha) were selected as the research objects, and samples of soil physicochemical and biological properties were collected. Based on principal component analysis (PCA), the minimum dataset (MDS) was selected, and soil quality index, sensitivity index and obstacle factor diagnosis were used to comprehensively evaluate the soil quality of plantation forest in North China Plain. [Results] Based on the results of principal component analysis, the minimum data set consisting of soil total carbon, sucrase activity, electrical conductivity, powder and available phosphorus was selected. The order of soil quality index of poplar plantation with different density was Y5 (416 plants /ha) > Y4 (555 plants /ha) > Y3 (625 plants /ha) > Y1 (1111 plants /ha) > Y2 (833 plants /ha). There was a significant correlation between the linear minimum data set and the linear total data set, and the coefficient of variation was the largest, and the linear minimum data set could be a good soil quality assessment (P<0.01). According to the results of obstacle degree model, all poplar plantations with different densities are faced with soil nutrient and water limiting obstacles, ?and organic carbon is the main factor limiting soil quality in this area. [Conclusion] The poplar plantation with 416 trees /ha has the best soil quality. All poplar plantations in North China Plain are faced with soil nutrient deficiency and water shortage. Scientific fertilization and irrigation management measures should be formulated in this region, and appropriate afforestation density should be determined in the plantation production practice to achieve sustainable soil utilization.
Abstract:
The study area is located in the arid desert area of Gansu Province, Jingtai Baidunzi Salt Marsh Wetland, in the transition zone from Tengger Desert to the Loess Plateau, and belongs to the temperate arid continental climate. To assess species diversity and collect vegetation and soil samples, zones of fenced exclusion, light grazing, and heavy grazing were established. Indicators such as plant diversity and soil physical and chemical properties were measured. Principal component analysis and the construction of a principal component grouping minimum data set (MDS) were employed to examine the influence of grazing intensity on soil quality. Results indicate that while fenced exclusion increased vegetation biomass, it decreased diversity. In the light grazing zone, the Shannon-Wiener diversity index and Margalef richness index were 11.11% and 17.86% higher, respectively, than in the heavy grazing zone, and 51.52% and 6.45% higher than in the fenced exclusion zone. The percentage of soil water-stable aggregates with particle size >0.25 mm, the average mass diameter, and the geometric mean diameter of surface soil water-stable aggregates, were highest in the no grazing zone, followed by the light grazing and heavy grazing zones. The soil fertility potential, soil fertility intensity, and overall soil quality were significantly higher in the no grazing zone compared to the heavy grazing zone. In conclusion, fenced exclusion enhances vegetation growth and soil quality, while light grazing positively impacts soil and vegetation restoration. Grazing primarily affects the shallow soil layer, providing a scientific basis for rational grazing and ecological restoration of wetlands in arid desert area.
The study area is located in the arid desert area of Gansu Province, Jingtai Baidunzi Salt Marsh Wetland, in the transition zone from Tengger Desert to the Loess Plateau, and belongs to the temperate arid continental climate. To assess species diversity and collect vegetation and soil samples, zones of fenced exclusion, light grazing, and heavy grazing were established. Indicators such as plant diversity and soil physical and chemical properties were measured. Principal component analysis and the construction of a principal component grouping minimum data set (MDS) were employed to examine the influence of grazing intensity on soil quality. Results indicate that while fenced exclusion increased vegetation biomass, it decreased diversity. In the light grazing zone, the Shannon-Wiener diversity index and Margalef richness index were 11.11% and 17.86% higher, respectively, than in the heavy grazing zone, and 51.52% and 6.45% higher than in the fenced exclusion zone. The percentage of soil water-stable aggregates with particle size >0.25 mm, the average mass diameter, and the geometric mean diameter of surface soil water-stable aggregates, were highest in the no grazing zone, followed by the light grazing and heavy grazing zones. The soil fertility potential, soil fertility intensity, and overall soil quality were significantly higher in the no grazing zone compared to the heavy grazing zone. In conclusion, fenced exclusion enhances vegetation growth and soil quality, while light grazing positively impacts soil and vegetation restoration. Grazing primarily affects the shallow soil layer, providing a scientific basis for rational grazing and ecological restoration of wetlands in arid desert area.
Abstract:
[Objective] Through the comparative analysis of water yielding capacity of the first five national parks in China, to explore the key driving force of each park, and to provide scientific basis for optimizing the ecological protection and water resource management of national parks. [Methods] Based on the InVEST model, we assessed the water yielding capacity of each national park from 2000 to 2023, combined with the coefficient of variation to analyze the stability of the water yielding capacity, and used the Partial Least Squares Path Model (PLS-PM) to quantitatively explore the functioning mechanism of the key driving force of each park. [Results] 1) From 2000 to 2023, the depth of water yield in the first national parks generally showed a fluctuating upward trend (except Hainan Tropical Rainforest National Park). Among them, Wuyishan National Park has the largest depth of water yield (1609.13 mm) and the largest increase (k=9.34), while Sanjiangyuan National Park has the smaller depth of water yield (133.89 mm) and the most moderate increase (k=0.95). 2) The stability of the water yield of each park is as follows: Sanjiangyuan National Park > Hainan Tropical Rainforest National Park > Giant Panda National Park > Wuyishan National Park > Northeastern Tiger and Leopard National Park. Park > Northeast Tiger and Leopard National Park. 3) The key driving forces of different parks differed significantly, showing different patterns of influence. Precipitation is the main positive factor affecting water yield, and it is significantly higher in Sanjiangyuan (0.9879) and Hainan Tropical Rainforest National Park (0.8328) than in the other parks; potential evapotranspiration is generally negatively correlated with the depth of water yield, which is particularly significant in the Giant Panda (-0.4581) and Wuyishan National Park (-0.3485); and the impacts of vegetation cover and topography differ in different national parks. varied among different national parks. [Conclusions] The spatial and temporal patterns of water yield capacity in the first five national parks in China from 2000 to 2023 are obvious and stable, and their key driving forces are different and spatially heterogeneous.
[Objective] Through the comparative analysis of water yielding capacity of the first five national parks in China, to explore the key driving force of each park, and to provide scientific basis for optimizing the ecological protection and water resource management of national parks. [Methods] Based on the InVEST model, we assessed the water yielding capacity of each national park from 2000 to 2023, combined with the coefficient of variation to analyze the stability of the water yielding capacity, and used the Partial Least Squares Path Model (PLS-PM) to quantitatively explore the functioning mechanism of the key driving force of each park. [Results] 1) From 2000 to 2023, the depth of water yield in the first national parks generally showed a fluctuating upward trend (except Hainan Tropical Rainforest National Park). Among them, Wuyishan National Park has the largest depth of water yield (1609.13 mm) and the largest increase (k=9.34), while Sanjiangyuan National Park has the smaller depth of water yield (133.89 mm) and the most moderate increase (k=0.95). 2) The stability of the water yield of each park is as follows: Sanjiangyuan National Park > Hainan Tropical Rainforest National Park > Giant Panda National Park > Wuyishan National Park > Northeastern Tiger and Leopard National Park. Park > Northeast Tiger and Leopard National Park. 3) The key driving forces of different parks differed significantly, showing different patterns of influence. Precipitation is the main positive factor affecting water yield, and it is significantly higher in Sanjiangyuan (0.9879) and Hainan Tropical Rainforest National Park (0.8328) than in the other parks; potential evapotranspiration is generally negatively correlated with the depth of water yield, which is particularly significant in the Giant Panda (-0.4581) and Wuyishan National Park (-0.3485); and the impacts of vegetation cover and topography differ in different national parks. varied among different national parks. [Conclusions] The spatial and temporal patterns of water yield capacity in the first five national parks in China from 2000 to 2023 are obvious and stable, and their key driving forces are different and spatially heterogeneous.
Abstract:
Abstract:[Objective]This study explored the spatiotemporal variation patterns of vegetation during the dry season and their response to drought resistance under different ecological restoration modes, aiming to provide fundamental data and theoretical support for vegetation ecological restoration in the dry-hot valley region. [Methods] The study focused on three types of restoration modes: an artificially constructed arbor-shrub-grass stereoscopic restoration terrace (ASH) that had been restored for three years, naturally restored land post artificial terrace development (NET), and naturally restored shrub-grassland (SG), with degraded land (DG) as a control. Fixed sample plots were established, and a combination of vegetation community surveys, drone monitoring, and microclimate recording was used to compare species composition, species diversity, vegetation coverage, and microclimate characteristics between different plots at the beginning and end of the dry season. [Results](1) Species Diversity: During the dry season, ASH exhibited minimal changes in species composition, high species diversity, and no obvious dominant species. NET showed high species evenness but relatively low species richness. SG experienced significant changes in species composition, with both species richness and evenness showing significant declines by the end of the season. (2) Vegetation Coverage: At the beginning of the dry season, the total fractional vegetation cover (FVC) ranked as ASH > NET > SG > DG, and this pattern remained consistent at the end of the dry season. The degree of change in FVC between the beginning and end of the dry season was greatest in NET, followed by ASH, with DG showing the least change. ASH had significantly higher coverage across all vegetation layers compared to other plots. (3) Microclimate Regulation: Microclimate Regulation: During the early and late dry seasons, the ASH vegetation type exhibits lower temperatures and higher humidity characteristics compared to other vegetation types. [Conclusion]The arbor-shrub-grass stereoscopic vegetation structure demonstrates significant advantages in regulating microclimate and maintaining ecological stability, making it suitable for promotion in regions with extreme climatic conditions, such as dry-hot valleys.
Abstract:[Objective]This study explored the spatiotemporal variation patterns of vegetation during the dry season and their response to drought resistance under different ecological restoration modes, aiming to provide fundamental data and theoretical support for vegetation ecological restoration in the dry-hot valley region. [Methods] The study focused on three types of restoration modes: an artificially constructed arbor-shrub-grass stereoscopic restoration terrace (ASH) that had been restored for three years, naturally restored land post artificial terrace development (NET), and naturally restored shrub-grassland (SG), with degraded land (DG) as a control. Fixed sample plots were established, and a combination of vegetation community surveys, drone monitoring, and microclimate recording was used to compare species composition, species diversity, vegetation coverage, and microclimate characteristics between different plots at the beginning and end of the dry season. [Results](1) Species Diversity: During the dry season, ASH exhibited minimal changes in species composition, high species diversity, and no obvious dominant species. NET showed high species evenness but relatively low species richness. SG experienced significant changes in species composition, with both species richness and evenness showing significant declines by the end of the season. (2) Vegetation Coverage: At the beginning of the dry season, the total fractional vegetation cover (FVC) ranked as ASH > NET > SG > DG, and this pattern remained consistent at the end of the dry season. The degree of change in FVC between the beginning and end of the dry season was greatest in NET, followed by ASH, with DG showing the least change. ASH had significantly higher coverage across all vegetation layers compared to other plots. (3) Microclimate Regulation: Microclimate Regulation: During the early and late dry seasons, the ASH vegetation type exhibits lower temperatures and higher humidity characteristics compared to other vegetation types. [Conclusion]The arbor-shrub-grass stereoscopic vegetation structure demonstrates significant advantages in regulating microclimate and maintaining ecological stability, making it suitable for promotion in regions with extreme climatic conditions, such as dry-hot valleys.
Abstract:
Abstract: [Objective]To explore the response mechanism of vegetation to drought, identify the temporal and spatial evolution characteristics of drought and its negative impact on vegetation NPP.[Method]Drought characteristics was quantified by Standardized Precipitation Evapotranspiration Index (SPEI) , and NPPwas estimated based on MODIS remote sensing data by Carnegie-Ames-Stanford Approach (CASA) model and annual SPEI index during 2001 to 2020 in the middle arid zone of Ningxia was calculated to explore the response characteristics and differences of NPP of different vegetation types to SPEI, and the correlation between NPP loss due to drought(?NPP) and SPEI index by using the methods of trend analysis, Mann-Kendall test and correlation analysis. [Result]The results showed that: (1) during 2001 to 2020, the SPEI index indicated that the drought trend in the study area was generally slowing down , drought was still dominant on spatial scale, but there was a trend of humidification. (2) ?NPPin the study area showed a totally decreasing trend of fluctuation; spatially, the ?NPP in the eastern part of the study area decreased significantly. (3) The correlation analysis between SPEI index and ?NPP showed that the positive correlation was dominant, but there were obvious spatial-temporal differences due to different drought grades. (4) The response of ?NPP of different vegetation types to annual SPEI was different , under severe and extreme drought stresses, the NPP loss of forest was the largest, followed by crop, and shrubs was the least. [Conclusion]In general, drought was the main factor restricting the growth of NPP in the study area. In order to improve the resistance of vegetation to drought in the study area, the complexity and diversity of vegetation structure and composition should be improved.
Abstract: [Objective]To explore the response mechanism of vegetation to drought, identify the temporal and spatial evolution characteristics of drought and its negative impact on vegetation NPP.[Method]Drought characteristics was quantified by Standardized Precipitation Evapotranspiration Index (SPEI) , and NPPwas estimated based on MODIS remote sensing data by Carnegie-Ames-Stanford Approach (CASA) model and annual SPEI index during 2001 to 2020 in the middle arid zone of Ningxia was calculated to explore the response characteristics and differences of NPP of different vegetation types to SPEI, and the correlation between NPP loss due to drought(?NPP) and SPEI index by using the methods of trend analysis, Mann-Kendall test and correlation analysis. [Result]The results showed that: (1) during 2001 to 2020, the SPEI index indicated that the drought trend in the study area was generally slowing down , drought was still dominant on spatial scale, but there was a trend of humidification. (2) ?NPPin the study area showed a totally decreasing trend of fluctuation; spatially, the ?NPP in the eastern part of the study area decreased significantly. (3) The correlation analysis between SPEI index and ?NPP showed that the positive correlation was dominant, but there were obvious spatial-temporal differences due to different drought grades. (4) The response of ?NPP of different vegetation types to annual SPEI was different , under severe and extreme drought stresses, the NPP loss of forest was the largest, followed by crop, and shrubs was the least. [Conclusion]In general, drought was the main factor restricting the growth of NPP in the study area. In order to improve the resistance of vegetation to drought in the study area, the complexity and diversity of vegetation structure and composition should be improved.
Abstract:
[Objective] This study aims to explore the spatiotemporal trends and driving forces of fractional vegetation cover (FVC) in Jiangsu Province over the past decade, providing a reference for comprehensively understanding the vegetation coverage and macro-regulating related policies in Jiangsu Province. [Methods] Using the Landsat8 data from 2013 to 2022 as the data source, annual 30m resolution NDVI images of Jiangsu Province were synthesized based on the maximum value composite method on the GEE cloud computing platform. The pixel dichotomy model was applied to estimate the vegetation cover from 2013 to 2022. Various methods, including Sen’s slope analysis, Mann-Kendall significance test, coefficient of variation (CV), and Hurst index, were used to analyze the spatiotemporal trends and characteristics of the vegetation cover. Additionally, a univariate linear regression model was constructed with FVC as the dependent variable and nighttime light data as the independent variable. Residual analysis was employed to quantify the driving forces of FVC changes and to analyze the contributions of human activities and climatic factors to FVC changes. [Results] From 2013 to 2022, the annual average FVC in Jiangsu Province was 0.648, showing a fluctuating downward trend but still predominantly consisting of very high and high FVC types. Areas with a decreasing FVC trend accounted for 51.85%, while areas with an increasing trend accounted for 45.91%. The average CV was 0.16, indicating relatively low overall fluctuation. The average Hurst index was 0.56, primarily indicating weak persistence, followed by weak anti-persistence, with an overall interwoven distribution of different types, and coexistence of degradation and improvement. Human activities positively contributed to changes in vegetation cover in 86.53% of the areas, while climate change positively contributed to changes in 71.47% of the areas. [Conclusion] Over the past decade, the overall vegetation cover in Jiangsu Province has been good, with the declining trend gradually flattening out. The vegetation cover in northern and central Jiangsu is better than in southern Jiangsu, but the degradation in northern and central Jiangsu is more severe than in southern Jiangsu. The main driving forces of the changes are the combined effects of climate change and human activities, with human activities contributing more to the increase in FVC than climate change.
[Objective] This study aims to explore the spatiotemporal trends and driving forces of fractional vegetation cover (FVC) in Jiangsu Province over the past decade, providing a reference for comprehensively understanding the vegetation coverage and macro-regulating related policies in Jiangsu Province. [Methods] Using the Landsat8 data from 2013 to 2022 as the data source, annual 30m resolution NDVI images of Jiangsu Province were synthesized based on the maximum value composite method on the GEE cloud computing platform. The pixel dichotomy model was applied to estimate the vegetation cover from 2013 to 2022. Various methods, including Sen’s slope analysis, Mann-Kendall significance test, coefficient of variation (CV), and Hurst index, were used to analyze the spatiotemporal trends and characteristics of the vegetation cover. Additionally, a univariate linear regression model was constructed with FVC as the dependent variable and nighttime light data as the independent variable. Residual analysis was employed to quantify the driving forces of FVC changes and to analyze the contributions of human activities and climatic factors to FVC changes. [Results] From 2013 to 2022, the annual average FVC in Jiangsu Province was 0.648, showing a fluctuating downward trend but still predominantly consisting of very high and high FVC types. Areas with a decreasing FVC trend accounted for 51.85%, while areas with an increasing trend accounted for 45.91%. The average CV was 0.16, indicating relatively low overall fluctuation. The average Hurst index was 0.56, primarily indicating weak persistence, followed by weak anti-persistence, with an overall interwoven distribution of different types, and coexistence of degradation and improvement. Human activities positively contributed to changes in vegetation cover in 86.53% of the areas, while climate change positively contributed to changes in 71.47% of the areas. [Conclusion] Over the past decade, the overall vegetation cover in Jiangsu Province has been good, with the declining trend gradually flattening out. The vegetation cover in northern and central Jiangsu is better than in southern Jiangsu, but the degradation in northern and central Jiangsu is more severe than in southern Jiangsu. The main driving forces of the changes are the combined effects of climate change and human activities, with human activities contributing more to the increase in FVC than climate change.
Abstract:
[Objective] To explore the wind and sand flow prevention and stabilization benefits of artificial Haloxylon ammodendron forests with different planting years, as well as to rapidly evaluate the wind and sand flow prevention and stabilization benefits, and to define the lower limit of the biomass-anti-sand flow prevention and stabilization benefits, so as to provide scientific basis for the restoration and reconstruction of desert vegetation. [Methods] In this study, the artificial Haloxylon ammodendron forests with different planting ages in the desertification area of Turpan City were used as the research object, and various indicators of wind and sand prevention and fixation benefits were monitored through the methods of field investigation, field observation and indoor analysis to compare the relationship between the indicators of wind and sand prevention and fixation benefits and the changes of biomass. [Results] (1) The windbreak effectiveness, surface roughness, surface erosion volume, and sand retention benefits of artificial Haloxylon ammodendron forests are gradually improved with the increase of the years of creation. (2) The wind speed profile in the region changed with the growth of the artificial Haloxylon ammodendron forests. The wind speed profile of the primary desert showed “L” type change characteristics, the wind speed profile of the 2-year old and 4-year old artificial Haloxylon ammodendron forests showed “I” type change characteristics, the wind speed profile of the 6a-year old and 8a-year old forests showed “J” type change characteristics. The wind speed contours of 6-year old, 8-year old and 10-year old planted Haloxylon ammodendron forests showed the opposite of “J” type changes. (3) The sand transport flux of the planted Haloxylon ammodendron forest showed a decreasing trend with the increase of the establishment period, and also showed a decreasing trend with the increase of the height. (4) In this study, the biomass-windbreak and sand fixation efficiency index model was constructed based on five kinds of Haloxylon ammodendron forests with different years of age, in which the best function model between the standing biomass index and the relationship between windbreak efficiency, soil erosion volume, surface roughness, sand transport flux, and sand blocking efficiency was the power function model, the idempotent function model, quadratic function, exponential function, and the logistic function model, and the R2 were respectively 0.651, 0.962, 0.790, 0.804, 0.925.(5) If we want to play a good windbreak and sand fixation benefit, the lower limit of standing wood biomass index of the artificial shuttle forest needs to reach 4.92kg/m2.[Conclusion] To play the role of windbreak and sand fixation of the windbreak and sand fixation forests, the planting years of the artificial Haloxylon ammodendron forest after 4 years, its windbreak and sand fixation benefit can reach a good state, and at the same time, using the At the same time, the corresponding model can be used to quickly estimate the regional indicators of windbreak and sand fixation benefits, and carry out the assessment of windbreak and sand fixation benefits. When the standing wood biomass index of the planted Haloxylon ammodendron forest reaches 4.92 kg/m2 and above, it will be able to realize its good sand-control and sand-fixation benefits.
[Objective] To explore the wind and sand flow prevention and stabilization benefits of artificial Haloxylon ammodendron forests with different planting years, as well as to rapidly evaluate the wind and sand flow prevention and stabilization benefits, and to define the lower limit of the biomass-anti-sand flow prevention and stabilization benefits, so as to provide scientific basis for the restoration and reconstruction of desert vegetation. [Methods] In this study, the artificial Haloxylon ammodendron forests with different planting ages in the desertification area of Turpan City were used as the research object, and various indicators of wind and sand prevention and fixation benefits were monitored through the methods of field investigation, field observation and indoor analysis to compare the relationship between the indicators of wind and sand prevention and fixation benefits and the changes of biomass. [Results] (1) The windbreak effectiveness, surface roughness, surface erosion volume, and sand retention benefits of artificial Haloxylon ammodendron forests are gradually improved with the increase of the years of creation. (2) The wind speed profile in the region changed with the growth of the artificial Haloxylon ammodendron forests. The wind speed profile of the primary desert showed “L” type change characteristics, the wind speed profile of the 2-year old and 4-year old artificial Haloxylon ammodendron forests showed “I” type change characteristics, the wind speed profile of the 6a-year old and 8a-year old forests showed “J” type change characteristics. The wind speed contours of 6-year old, 8-year old and 10-year old planted Haloxylon ammodendron forests showed the opposite of “J” type changes. (3) The sand transport flux of the planted Haloxylon ammodendron forest showed a decreasing trend with the increase of the establishment period, and also showed a decreasing trend with the increase of the height. (4) In this study, the biomass-windbreak and sand fixation efficiency index model was constructed based on five kinds of Haloxylon ammodendron forests with different years of age, in which the best function model between the standing biomass index and the relationship between windbreak efficiency, soil erosion volume, surface roughness, sand transport flux, and sand blocking efficiency was the power function model, the idempotent function model, quadratic function, exponential function, and the logistic function model, and the R2 were respectively 0.651, 0.962, 0.790, 0.804, 0.925.(5) If we want to play a good windbreak and sand fixation benefit, the lower limit of standing wood biomass index of the artificial shuttle forest needs to reach 4.92kg/m2.[Conclusion] To play the role of windbreak and sand fixation of the windbreak and sand fixation forests, the planting years of the artificial Haloxylon ammodendron forest after 4 years, its windbreak and sand fixation benefit can reach a good state, and at the same time, using the At the same time, the corresponding model can be used to quickly estimate the regional indicators of windbreak and sand fixation benefits, and carry out the assessment of windbreak and sand fixation benefits. When the standing wood biomass index of the planted Haloxylon ammodendron forest reaches 4.92 kg/m2 and above, it will be able to realize its good sand-control and sand-fixation benefits.
Abstract:
[Purpose] Under the "dual carbon" background, agriculture, as a significant source of carbon emissions, has substantial potential for emission reduction that cannot be overlooked. [Method] Based on provincial panel data from 30 provinces (regions) in China from 2012 to 2022, the article systematically analyzes the impact of agricultural new quality productivity on agricultural carbon emissions using econometric models such as the Kernel density model, spatial Durbin model, and spatial attenuation model. [Conclusion]: (1) Agricultural new quality productivity can significantly reduce agricultural carbon emissions. Specifically, when all control variables are included, for every 1% increase in the development level of agricultural new quality productivity, agricultural carbon emissions will decrease by 1.601%. (2) From a spatial perspective, the improvement of agricultural new quality productivity has a significant spatial spillover effect. (3) Urbanization level and government support have different moderating effects on the ability of agricultural new quality productivity to inhibit agricultural carbon emissions. (4) The carbon reduction effect of agricultural new quality productivity exhibits significant spatial heterogeneity, with more pronounced effects in western regions, major grain-producing areas, and areas northwest of the Hu Huanyong Line.
[Purpose] Under the "dual carbon" background, agriculture, as a significant source of carbon emissions, has substantial potential for emission reduction that cannot be overlooked. [Method] Based on provincial panel data from 30 provinces (regions) in China from 2012 to 2022, the article systematically analyzes the impact of agricultural new quality productivity on agricultural carbon emissions using econometric models such as the Kernel density model, spatial Durbin model, and spatial attenuation model. [Conclusion]: (1) Agricultural new quality productivity can significantly reduce agricultural carbon emissions. Specifically, when all control variables are included, for every 1% increase in the development level of agricultural new quality productivity, agricultural carbon emissions will decrease by 1.601%. (2) From a spatial perspective, the improvement of agricultural new quality productivity has a significant spatial spillover effect. (3) Urbanization level and government support have different moderating effects on the ability of agricultural new quality productivity to inhibit agricultural carbon emissions. (4) The carbon reduction effect of agricultural new quality productivity exhibits significant spatial heterogeneity, with more pronounced effects in western regions, major grain-producing areas, and areas northwest of the Hu Huanyong Line.
Abstract:
The mechanism of soil aggregate fragmentation under natural conditions was simulated in order to study the changes of aggregate stability with different straw returning methods and determine the soil structural characteristics and the relationship between organic carbon and aggregate stability. The results would provide theoretical basis for implementing reasonable erosion prevention and control techniques on sloping farmland of black soil areas. The results showed that the changes in soil aggregate stability under different straw returning measures were influenced by the fragmentation mechanism and returning methods , and fast wetting was the main mechanism for aggregate fragmentation. There was a significant difference in MWD values with fast wetting and wet stirring between aggregates of <2 mm and 2-5 mm, the aggregates stability of 2-5 mm particle in wet stirring was the highest, which indicating that higher stability was large particle aggregates in black soil and soil organic carbon was positively correlated with the stability of large particle aggregates. Size aggregates of <2 mm particle were significantly positively correlated with soil bulk density and capillary pores under moist stirring, while significantly negatively correlated with total porosity and non capillary pores. In short term the non biological factors such as soil bulk density and porosity had masked the role of straw mulching in preventing surface erosion and stabilizing aggregates. However the total porosity and non capillary porosity of straw mixed and returned soil were decreased and the stability of aggregates was shown an increasing trend.
The mechanism of soil aggregate fragmentation under natural conditions was simulated in order to study the changes of aggregate stability with different straw returning methods and determine the soil structural characteristics and the relationship between organic carbon and aggregate stability. The results would provide theoretical basis for implementing reasonable erosion prevention and control techniques on sloping farmland of black soil areas. The results showed that the changes in soil aggregate stability under different straw returning measures were influenced by the fragmentation mechanism and returning methods , and fast wetting was the main mechanism for aggregate fragmentation. There was a significant difference in MWD values with fast wetting and wet stirring between aggregates of <2 mm and 2-5 mm, the aggregates stability of 2-5 mm particle in wet stirring was the highest, which indicating that higher stability was large particle aggregates in black soil and soil organic carbon was positively correlated with the stability of large particle aggregates. Size aggregates of <2 mm particle were significantly positively correlated with soil bulk density and capillary pores under moist stirring, while significantly negatively correlated with total porosity and non capillary pores. In short term the non biological factors such as soil bulk density and porosity had masked the role of straw mulching in preventing surface erosion and stabilizing aggregates. However the total porosity and non capillary porosity of straw mixed and returned soil were decreased and the stability of aggregates was shown an increasing trend.
Abstract:
Spring overflow is one of the important ways of groundwater discharge, and it is of great significance to explore the causes of springs for the study of groundwater cycle and the evaluation of groundwater resources.By collecting samples of spring water from the Baicheng Basin, testing and analyzing them, and comprehensively applying Gibbs diagrams, PCA-APCS-MLR models, and hydrogen and oxygen isotopes, we quantitatively explored the amount of transformations between springs and other bodies of water, and analyzed the source of spring water and its causes.The results show that: (1) the hydrochemical type of spring water is mainly of HCO3·SO4·CL-Ca·Na type, and the spring water is frequently transformed with diving and river water;(2) Ca2+、Na+、Mg2+ and SO42- in the chemical components of the spring water originate from the weathering and dissolution of gypsum and other salts, and Na+ and Cl- originate from the weathering and dissolution of silicate minerals such as sodium feldspar and montmorillonite, and the influence of agriculture and industrial and mining production and human life on the nitrates in the spring water is large;(3) The δD and δ18O values of springs range -81.28‰～-50.27‰ and -12.20‰～-8.57‰, and the δD and δ18O in the southern dives and springs in the Baicheng Basin are poorer than those in the north, and the δD and δ18O in the southern dives and springs tend to be poorer due to the large amount of recharge of river water;(4) The surface water-groundwater transformation relationship in the basin is mainly the recharge of river water to submerged water and springs. In the middle reaches of the Muzati River and the upper reaches of the Kizil River, the recharge ratio of river water and submerged water to springs ranges 8.3%～50.1% and 49.9%～91.7%, respectively;(5) The springs in the Bay City Basin are mainly erosion decline springs and overflow decline springs.Atmospheric precipitation and snow and ice melt water from the high medium mountains in the northern part of the Baicheng Basin infiltrate along bedrock fissures to form groundwater, Influenced by rivers and flash flood gullies cutting through pore water aquifers of the Quaternary Loose Rock type, Diving overflows to form erosion-declining springs, mainly in the upper to middle reaches of the Muzati River;Groundwater formed in the mountainous areas of the high medium in the rivers or gullies cut aquifers exposed to form surface water, surface water infiltration to the plains again into groundwater, groundwater in the process of transport encountered in the Neozoic mudstone, sandstone, conglomerate formation of the relative isolation of the movement of the blocked water level heighten outcrops on the surface of the formation of the overflow of the falling springs, mainly located in the middle and lower reaches of the Muzati River and the lower reaches of the Kezir River.The results of the study can provide a basis for accurate evaluation of the amount of underground water resources in the Baicheng Basin.
Spring overflow is one of the important ways of groundwater discharge, and it is of great significance to explore the causes of springs for the study of groundwater cycle and the evaluation of groundwater resources.By collecting samples of spring water from the Baicheng Basin, testing and analyzing them, and comprehensively applying Gibbs diagrams, PCA-APCS-MLR models, and hydrogen and oxygen isotopes, we quantitatively explored the amount of transformations between springs and other bodies of water, and analyzed the source of spring water and its causes.The results show that: (1) the hydrochemical type of spring water is mainly of HCO3·SO4·CL-Ca·Na type, and the spring water is frequently transformed with diving and river water;(2) Ca2+、Na+、Mg2+ and SO42- in the chemical components of the spring water originate from the weathering and dissolution of gypsum and other salts, and Na+ and Cl- originate from the weathering and dissolution of silicate minerals such as sodium feldspar and montmorillonite, and the influence of agriculture and industrial and mining production and human life on the nitrates in the spring water is large;(3) The δD and δ18O values of springs range -81.28‰～-50.27‰ and -12.20‰～-8.57‰, and the δD and δ18O in the southern dives and springs in the Baicheng Basin are poorer than those in the north, and the δD and δ18O in the southern dives and springs tend to be poorer due to the large amount of recharge of river water;(4) The surface water-groundwater transformation relationship in the basin is mainly the recharge of river water to submerged water and springs. In the middle reaches of the Muzati River and the upper reaches of the Kizil River, the recharge ratio of river water and submerged water to springs ranges 8.3%～50.1% and 49.9%～91.7%, respectively;(5) The springs in the Bay City Basin are mainly erosion decline springs and overflow decline springs.Atmospheric precipitation and snow and ice melt water from the high medium mountains in the northern part of the Baicheng Basin infiltrate along bedrock fissures to form groundwater, Influenced by rivers and flash flood gullies cutting through pore water aquifers of the Quaternary Loose Rock type, Diving overflows to form erosion-declining springs, mainly in the upper to middle reaches of the Muzati River;Groundwater formed in the mountainous areas of the high medium in the rivers or gullies cut aquifers exposed to form surface water, surface water infiltration to the plains again into groundwater, groundwater in the process of transport encountered in the Neozoic mudstone, sandstone, conglomerate formation of the relative isolation of the movement of the blocked water level heighten outcrops on the surface of the formation of the overflow of the falling springs, mainly located in the middle and lower reaches of the Muzati River and the lower reaches of the Kezir River.The results of the study can provide a basis for accurate evaluation of the amount of underground water resources in the Baicheng Basin.
Abstract:
[Objective] By studying the canopy interception ability of different shrubs, this paper aims to further understand the quantitative characteristics of the hydrological and ecological functions of the shrub canopy in this region and provide a theoretical basis for screening economic shrub species beneficial to water conservation in semi-arid areas.[Methods] In this paper, six economic shrubs with development potential in western Heilongjiang Province, namely Corylus heterophylla, Lycium chinense, Hippophae rhamnoides, Prunus tomentosa, Eleutherococcus senticosus, and Rosa davurica, were taken as the research objects. Through the monitoring of 15 rainfall events from June to September 2023, the canopy interception characteristics of the six shrubs were compared and analyzed.[Results] The canopy interception capacities of the six shrubs were significantly different (P < 0.05), and more than 70% of the rainfall fell in the form of throughfall. The variation ranges of the throughfall rate, stemflow rate and canopy interception rate of the shrubs were 71.47% - 91.16% (82.14%), 2.31% - 7.46% (4.4%), and 6.56% - 23.41% (13.65%) respectively. The canopy interception rate showed the order of Prunus tomentosa > Hippophae rhamnoides > Corylus heterophylla > Rosa davurica > Eleutherococcus senticosus > Lycium chinense, with the rates being 87.89%, 1.61% and 10.50% respectively. (2) Rainfall is the key meteorological factor affecting the rainfall interception process of the shrub canopy. The throughfall amount, stemflow amount and canopy interception amount of the six shrubs all had a significant linear positive correlation with the rainfall outside the forest (P < 0.01), and there was a logarithmic function relationship between the throughfall rate, stemflow rate, interception rate and the rainfall outside the forest. Correlation analysis was conducted on meteorological factors, stand characteristics and canopy interception capacity. The interception rate was positively correlated with temperature (P < 0.05) and negatively correlated with wind speed (P < 0.01). Except that the number of branches was not significantly correlated with the throughfall rate, the other stand characteristics were significantly positively correlated with the stemflow rate and canopy interception rate, and significantly negatively correlated with the throughfall rate.[Conclusion] There are certain differences in the interception capacities of different shrubs. Prunus tomentosa, Corylus heterophylla and Hippophae rhamnoides have relatively high interception rates and stemflow rates, and have advantages in reducing rain splash erosion and conserving water sources. Lycium chinense, Eleutherococcus senticosus and Rosa davurica have high throughfall rates and have advantages in increasing the effectively utilized water under the forest canopy. Both meteorological factors and stand characteristics play important roles in the process of shrub canopy interception.
[Objective] By studying the canopy interception ability of different shrubs, this paper aims to further understand the quantitative characteristics of the hydrological and ecological functions of the shrub canopy in this region and provide a theoretical basis for screening economic shrub species beneficial to water conservation in semi-arid areas.[Methods] In this paper, six economic shrubs with development potential in western Heilongjiang Province, namely Corylus heterophylla, Lycium chinense, Hippophae rhamnoides, Prunus tomentosa, Eleutherococcus senticosus, and Rosa davurica, were taken as the research objects. Through the monitoring of 15 rainfall events from June to September 2023, the canopy interception characteristics of the six shrubs were compared and analyzed.[Results] The canopy interception capacities of the six shrubs were significantly different (P < 0.05), and more than 70% of the rainfall fell in the form of throughfall. The variation ranges of the throughfall rate, stemflow rate and canopy interception rate of the shrubs were 71.47% - 91.16% (82.14%), 2.31% - 7.46% (4.4%), and 6.56% - 23.41% (13.65%) respectively. The canopy interception rate showed the order of Prunus tomentosa > Hippophae rhamnoides > Corylus heterophylla > Rosa davurica > Eleutherococcus senticosus > Lycium chinense, with the rates being 87.89%, 1.61% and 10.50% respectively. (2) Rainfall is the key meteorological factor affecting the rainfall interception process of the shrub canopy. The throughfall amount, stemflow amount and canopy interception amount of the six shrubs all had a significant linear positive correlation with the rainfall outside the forest (P < 0.01), and there was a logarithmic function relationship between the throughfall rate, stemflow rate, interception rate and the rainfall outside the forest. Correlation analysis was conducted on meteorological factors, stand characteristics and canopy interception capacity. The interception rate was positively correlated with temperature (P < 0.05) and negatively correlated with wind speed (P < 0.01). Except that the number of branches was not significantly correlated with the throughfall rate, the other stand characteristics were significantly positively correlated with the stemflow rate and canopy interception rate, and significantly negatively correlated with the throughfall rate.[Conclusion] There are certain differences in the interception capacities of different shrubs. Prunus tomentosa, Corylus heterophylla and Hippophae rhamnoides have relatively high interception rates and stemflow rates, and have advantages in reducing rain splash erosion and conserving water sources. Lycium chinense, Eleutherococcus senticosus and Rosa davurica have high throughfall rates and have advantages in increasing the effectively utilized water under the forest canopy. Both meteorological factors and stand characteristics play important roles in the process of shrub canopy interception.
Abstract:
【Objective】In order to accurately evaluate the soil quality characteristics of different slope positions under straw mulching and no-tillage in the northeast black soil region,【Method】the minimum data sets for soil quality evaluation of straw mulching no-tillage slope land and conventional tillage slope land in the Northeast black soil region were established by principal component analysis and cluster analysis, respectively. The soil quality index of minimum data set was calculated, and the most suitable minimum data set soil quality index was selected through comparative analysis with the total data set soil quality index, and the soil quality of the experimental area was evaluated and analyzed.【Results】(1) The minimum data set for soil quality evaluation of sloping farmland in the test area was composed of total porosity, pH, organic matter, total potassium and available phosphorus. (2) The Nash coefficient and correlation coefficient ofsoil quality index in the minimum data set of principal component analysis and the soil quality index in the total data set are higher than the soil quality index in the minimum data set of cluster analysis, so it is more suitable to use the minimum data set of principal component analysis to replace the total data set for soil quality evaluation.(3) According to the minimum data set of principal component analysis, the soil quality was the best in the straw-covered no-till slope (0.661), and the worst in the traditional tilling slope (0.472). (4) The main obstacle factors of soil quality under NT treatment were bulk density (0.156) and total porosity (0.132), while the main obstacle factors of CK treatment were total phosphorus (0.151) and available potassium (0.159).【Conclusion】Principal component analysis (PCA) and membership function were used to identify soil quality characteristics under different slope positions of straw mulching no-tillage and traditional tillage. The research results can provide basis for soil quality control and ecological restoration of sloping farmland in northeast black soil region.
【Objective】In order to accurately evaluate the soil quality characteristics of different slope positions under straw mulching and no-tillage in the northeast black soil region,【Method】the minimum data sets for soil quality evaluation of straw mulching no-tillage slope land and conventional tillage slope land in the Northeast black soil region were established by principal component analysis and cluster analysis, respectively. The soil quality index of minimum data set was calculated, and the most suitable minimum data set soil quality index was selected through comparative analysis with the total data set soil quality index, and the soil quality of the experimental area was evaluated and analyzed.【Results】(1) The minimum data set for soil quality evaluation of sloping farmland in the test area was composed of total porosity, pH, organic matter, total potassium and available phosphorus. (2) The Nash coefficient and correlation coefficient ofsoil quality index in the minimum data set of principal component analysis and the soil quality index in the total data set are higher than the soil quality index in the minimum data set of cluster analysis, so it is more suitable to use the minimum data set of principal component analysis to replace the total data set for soil quality evaluation.(3) According to the minimum data set of principal component analysis, the soil quality was the best in the straw-covered no-till slope (0.661), and the worst in the traditional tilling slope (0.472). (4) The main obstacle factors of soil quality under NT treatment were bulk density (0.156) and total porosity (0.132), while the main obstacle factors of CK treatment were total phosphorus (0.151) and available potassium (0.159).【Conclusion】Principal component analysis (PCA) and membership function were used to identify soil quality characteristics under different slope positions of straw mulching no-tillage and traditional tillage. The research results can provide basis for soil quality control and ecological restoration of sloping farmland in northeast black soil region.
Abstract:
[Objective] Flood disasters are one of the most significant natural disasters in the middle reaches of the Yangtze River. Measuring the flood disaster resilience levels of the region and exploring the driving factors of their spatial heterogeneity are crucial for enhancing regional disaster resistance and achieving sustainable quality development.[Methods] This paper employs the CRITIC-Entropy Weight Combined Weighting Method and the Geographical Detector, among other methods, to construct a comprehensive flood disaster resilience evaluation index system from four dimensions: society, economy, infrastructure, and environment. It analyzes the spatiotemporal evolution and spatial heterogeneity driving factors of flood disaster resilience in the middle reaches of the Yangtze River from 2012 to 2022. [Results] (1) During the study period, the flood resilience in the middle reaches of the Yangtze River fluctuated and increased from 0.2091 to 0.2629, with only a slight decline in 2020. The structure of flood resilience evolved from “environment–society–infrastructure–economy” to “environment–society–economy–infrastructure”.(2) There are significant differences in flood resilience within the region. 95.24% of the areas are characterized by fluctuating increases. Ganzhou and Ji'an are regions with sustained growth. The differences in social resilience within the region are gradually narrowing. Except for Enshi and Xiangxi, the economic resilience levels of other regions have improved. The infrastructure resilience levels of 25 cities and prefectures have been enhanced. The environmental resilience in the northwestern part of the region is better than that in other areas.(3) The results of factor detection show that the main factors influencing the spatial differentiation of flood resilience in 2012 were population density, terrain relief, and slope. By 2022, these factors had shifted to the number of people receiving minimum living security, the number of large-scale industrial enterprises, and the end-of-year highway mileage.(4) The results of interaction factor detection show that the most influential interaction factor in 2012 was population density ∩ proportion of the tertiary industry. By 2022, it had evolved to per capita GDP ∩ end-of-year highway mileage. [Conclusion] The research results can provide references for urban flood control and disaster relief policies.
[Objective] Flood disasters are one of the most significant natural disasters in the middle reaches of the Yangtze River. Measuring the flood disaster resilience levels of the region and exploring the driving factors of their spatial heterogeneity are crucial for enhancing regional disaster resistance and achieving sustainable quality development.[Methods] This paper employs the CRITIC-Entropy Weight Combined Weighting Method and the Geographical Detector, among other methods, to construct a comprehensive flood disaster resilience evaluation index system from four dimensions: society, economy, infrastructure, and environment. It analyzes the spatiotemporal evolution and spatial heterogeneity driving factors of flood disaster resilience in the middle reaches of the Yangtze River from 2012 to 2022. [Results] (1) During the study period, the flood resilience in the middle reaches of the Yangtze River fluctuated and increased from 0.2091 to 0.2629, with only a slight decline in 2020. The structure of flood resilience evolved from “environment–society–infrastructure–economy” to “environment–society–economy–infrastructure”.(2) There are significant differences in flood resilience within the region. 95.24% of the areas are characterized by fluctuating increases. Ganzhou and Ji'an are regions with sustained growth. The differences in social resilience within the region are gradually narrowing. Except for Enshi and Xiangxi, the economic resilience levels of other regions have improved. The infrastructure resilience levels of 25 cities and prefectures have been enhanced. The environmental resilience in the northwestern part of the region is better than that in other areas.(3) The results of factor detection show that the main factors influencing the spatial differentiation of flood resilience in 2012 were population density, terrain relief, and slope. By 2022, these factors had shifted to the number of people receiving minimum living security, the number of large-scale industrial enterprises, and the end-of-year highway mileage.(4) The results of interaction factor detection show that the most influential interaction factor in 2012 was population density ∩ proportion of the tertiary industry. By 2022, it had evolved to per capita GDP ∩ end-of-year highway mileage. [Conclusion] The research results can provide references for urban flood control and disaster relief policies.
LIAO Chaoming, LI Youru, XU Binbin, Qin Yuanli, ZengShunqi, YUN Ziheng, GU Guanhai, WEI Yuanyuan, SHI Chunrou
Abstract:
The city of Qinzhou, serving as the primary construction site for the century project "Pinglu Yunhe", exploits modern remote sensing technology to generate high-precision land use/cover change (LUCC) datasets, which exert substantial implications for its national spatial planning and ecological protection and construction. This research, concentrating on the Beibu Gulf coastal area and taking Qinzhou as an exemplar, employs Google Earth Engine (GEE) and Landsat remote sensing images to construct a LUCC dataset during the period from 2012 to 2022 and analyze its temporal and spatial pattern evolution by means of a random forest model integrating spectral, texture, index, and terrain features. The study also introduces the optimal parameter geographic detector to explore the driving mechanisms. The results demonstrate that: (1) The optimized random forest model can effectively extract remote sensing information, with overall accuracies (OA) ranging from 0.88 to 0.92 and Kappa coefficients ranging from 0.86 to 0.90. The overall accuracy and Kappa coefficient of each period"s LUCC product are in line with the classification results of several 4km×4km interpretation patches and Google Earth"s high-resolution images of the same period and location, indicating that the classification results of land features are consistent with the actual land features. (2) From 2012 to 2022, the area of forest land in Qinzhou increased by 91.93km2, the area of cultivated land decreased by 284.73km2, and the area of built-up land rose by 180.05km2. The overall trend of land use and cover change is ascending. (3) During the study period, the land use and cover change in Qinzhou was mainly driven by economic factors (GDP) and terrain features (DEM and slope), with the two factors presenting a dual-factor enhancement effect on the temporal and spatial pattern evolution in the three phases of 2012-2017, 2017-2022, and 2012-2022 respectively. The interactive effect between ecological factors (NPP and precipitation) and GDP shows different degrees of dual-factor enhancement at different stages. This study can provide data support for land resource management in Qinzhou and the produced LUCC datasets can serve as a reference for guidance.
The city of Qinzhou, serving as the primary construction site for the century project "Pinglu Yunhe", exploits modern remote sensing technology to generate high-precision land use/cover change (LUCC) datasets, which exert substantial implications for its national spatial planning and ecological protection and construction. This research, concentrating on the Beibu Gulf coastal area and taking Qinzhou as an exemplar, employs Google Earth Engine (GEE) and Landsat remote sensing images to construct a LUCC dataset during the period from 2012 to 2022 and analyze its temporal and spatial pattern evolution by means of a random forest model integrating spectral, texture, index, and terrain features. The study also introduces the optimal parameter geographic detector to explore the driving mechanisms. The results demonstrate that: (1) The optimized random forest model can effectively extract remote sensing information, with overall accuracies (OA) ranging from 0.88 to 0.92 and Kappa coefficients ranging from 0.86 to 0.90. The overall accuracy and Kappa coefficient of each period"s LUCC product are in line with the classification results of several 4km×4km interpretation patches and Google Earth"s high-resolution images of the same period and location, indicating that the classification results of land features are consistent with the actual land features. (2) From 2012 to 2022, the area of forest land in Qinzhou increased by 91.93km2, the area of cultivated land decreased by 284.73km2, and the area of built-up land rose by 180.05km2. The overall trend of land use and cover change is ascending. (3) During the study period, the land use and cover change in Qinzhou was mainly driven by economic factors (GDP) and terrain features (DEM and slope), with the two factors presenting a dual-factor enhancement effect on the temporal and spatial pattern evolution in the three phases of 2012-2017, 2017-2022, and 2012-2022 respectively. The interactive effect between ecological factors (NPP and precipitation) and GDP shows different degrees of dual-factor enhancement at different stages. This study can provide data support for land resource management in Qinzhou and the produced LUCC datasets can serve as a reference for guidance.
Abstract:
[Objective] As an ecological security barrier, Inner Mongolia's agro-pastoral intertwined zone also bears a high proportion of food security, and there is a more serious conflict between ecology and arable land protection. The resilience evaluation of Inner Mongolia's agricultural and pastoral intertwined areas helps to identify the high and low levels of arable land resilience in Inner Mongolia's agricultural and pastoral intertwined areas, and carry out zonal regulation, which helps to formulate targeted countermeasures for the sustainable utilization and protection of arable land. [Based on the toughness theory, 29 flag counties in Inner Mongolia's agricultural and pastoral intertwined area are taken as the research area, and by constructing the “pressure-state-response” model, the entropy value method is utilized to comprehensively evaluate the toughness characteristics of arable land in the agricultural and pastoral intertwined area of Inner Mongolia, and based on the characteristics of combination of toughness level of arable land, the toughness subzone of the agricultural and pastoral intertwined area is divided, and subzone control and management are proposed. zoning, and put forward the zoning control path. [Results] (1)Over the past 22 years, the overall resilience level of cropland in Inner Mongolia's agricultural and pastoral intertwined belt is not high, showing a trend of high in the east and low in the west; the historical changes show that the overall resilience level is on a decreasing trend due to the influence of the climate, and that the resilience of the eastern part of the country has been restored in the near future. (2) Based on the combination of changes in the toughness level of cropland, three regions are divided. The first-level stable cultivation area should strictly abide by the red line of arable land protection, and give play to the function of functional areas for food production. The second-level monitoring and protection area needs to increase artificial inputs and improve the regional mechanization level. The tertiary conservation fallow area should adhere to the land space suitability pattern of appropriate agriculture, appropriate animal husbandry, appropriate animal husbandry, appropriate animal husbandry, and stop the uncontrolled expansion of planting industry. [Conclusion] This study integrates the toughness theory into the protection of arable land, indirectly evaluates the toughness of arable land by analyzing the stability of arable land, and directly evaluates the toughness of arable land by constructing an index system, and concludes that the toughness of arable land in the agricultural and animal husbandry areas of Inner Mongolia is generally low, and that the land remediation and wind and sand management should be strengthened to realize the “precise management” and improve the toughness of arable land.
[Objective] As an ecological security barrier, Inner Mongolia's agro-pastoral intertwined zone also bears a high proportion of food security, and there is a more serious conflict between ecology and arable land protection. The resilience evaluation of Inner Mongolia's agricultural and pastoral intertwined areas helps to identify the high and low levels of arable land resilience in Inner Mongolia's agricultural and pastoral intertwined areas, and carry out zonal regulation, which helps to formulate targeted countermeasures for the sustainable utilization and protection of arable land. [Based on the toughness theory, 29 flag counties in Inner Mongolia's agricultural and pastoral intertwined area are taken as the research area, and by constructing the “pressure-state-response” model, the entropy value method is utilized to comprehensively evaluate the toughness characteristics of arable land in the agricultural and pastoral intertwined area of Inner Mongolia, and based on the characteristics of combination of toughness level of arable land, the toughness subzone of the agricultural and pastoral intertwined area is divided, and subzone control and management are proposed. zoning, and put forward the zoning control path. [Results] (1)Over the past 22 years, the overall resilience level of cropland in Inner Mongolia's agricultural and pastoral intertwined belt is not high, showing a trend of high in the east and low in the west; the historical changes show that the overall resilience level is on a decreasing trend due to the influence of the climate, and that the resilience of the eastern part of the country has been restored in the near future. (2) Based on the combination of changes in the toughness level of cropland, three regions are divided. The first-level stable cultivation area should strictly abide by the red line of arable land protection, and give play to the function of functional areas for food production. The second-level monitoring and protection area needs to increase artificial inputs and improve the regional mechanization level. The tertiary conservation fallow area should adhere to the land space suitability pattern of appropriate agriculture, appropriate animal husbandry, appropriate animal husbandry, appropriate animal husbandry, and stop the uncontrolled expansion of planting industry. [Conclusion] This study integrates the toughness theory into the protection of arable land, indirectly evaluates the toughness of arable land by analyzing the stability of arable land, and directly evaluates the toughness of arable land by constructing an index system, and concludes that the toughness of arable land in the agricultural and animal husbandry areas of Inner Mongolia is generally low, and that the land remediation and wind and sand management should be strengthened to realize the “precise management” and improve the toughness of arable land.
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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.
Abstract:
[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.
Abstract:
[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.
Abstract:
[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.
Abstract:
[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.
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[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.
Abstract:
[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.
Abstract:
[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.
Abstract:
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.
Abstract:
[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 .
Abstract:
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。
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.
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.
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。
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.
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.
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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- 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
- Deputy Editor-in-chief：
Zhao Yongjun
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