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2024,44(6):1-11,22
, DOI: 10.13961/j.cnki.stbctb.2024.06.001
Abstract:
[Objective] The biological diversity and the anti-tensile mechanical properties of plant roots in the Ngoring Lake area were investigated, to provide data support for the effective prevention and control of geological disasters such as soil erosion and the sod layer slump of alpine grassland in the Ngoring Lake area, the source of the Yellow River, as well as a theoretical basis for the research on the failure mechanism of the sod layer. [Methods] Based on the sample survey results in the study area, single-root tensile tests were performed on the dominant herbaceous plants in the area; the differences in single-root tensile strength, single-root tensile intensity, single-root ultimate elongation and single-root modulus of elasticity of the different herbaceous plants and their relationship with the root diameter were comparatively analyzed in different root-diameter levels. [Results] The dominant herbaceous plants in the study area were Carex moorcroftii, Astragalus polycladus, Artemisia frigida, Poa annua, Leontopodium pusillum. and Lagotis brachystachya. Under the condition of root diameter range of 0.10—0.60 mm, the single root tensile strength and single root tensile intensity of the above six herbaceous plants exhibited the trend of power function growth and power function decrease, respectively, with the increase of root diameter. Furthermore, there was no significant functional relationship between the single-root ultimate elongation and single-root elastic modulus and root diameter. Considering the mechanical property indexes of single root tensile resistance, species importance value, and root type of different plant types, Poa annua exhibited the best soil fixation capacity in the Ngoring Lake area. [Conclusion] The root systems of the six dominant herbaceous plants in the study area have better soil-fixing potential, among which Poa annua has the strongest soil-fixing ability. This study’s results can provide a certain basis for the soil and water conservation work in the Ngoring Lake area.
[Objective] The biological diversity and the anti-tensile mechanical properties of plant roots in the Ngoring Lake area were investigated, to provide data support for the effective prevention and control of geological disasters such as soil erosion and the sod layer slump of alpine grassland in the Ngoring Lake area, the source of the Yellow River, as well as a theoretical basis for the research on the failure mechanism of the sod layer. [Methods] Based on the sample survey results in the study area, single-root tensile tests were performed on the dominant herbaceous plants in the area; the differences in single-root tensile strength, single-root tensile intensity, single-root ultimate elongation and single-root modulus of elasticity of the different herbaceous plants and their relationship with the root diameter were comparatively analyzed in different root-diameter levels. [Results] The dominant herbaceous plants in the study area were Carex moorcroftii, Astragalus polycladus, Artemisia frigida, Poa annua, Leontopodium pusillum. and Lagotis brachystachya. Under the condition of root diameter range of 0.10—0.60 mm, the single root tensile strength and single root tensile intensity of the above six herbaceous plants exhibited the trend of power function growth and power function decrease, respectively, with the increase of root diameter. Furthermore, there was no significant functional relationship between the single-root ultimate elongation and single-root elastic modulus and root diameter. Considering the mechanical property indexes of single root tensile resistance, species importance value, and root type of different plant types, Poa annua exhibited the best soil fixation capacity in the Ngoring Lake area. [Conclusion] The root systems of the six dominant herbaceous plants in the study area have better soil-fixing potential, among which Poa annua has the strongest soil-fixing ability. This study’s results can provide a certain basis for the soil and water conservation work in the Ngoring Lake area.
2024,44(6):12-22
, DOI: 10.13961/j.cnki.stbctb.2024.06.002
Abstract:
[Objective] The effects of different soil and water conservation measures on soil nutrients and plant diversity in open-pit coal mine dumps were explored, aiming to provide feasible technical measures for the ecological restoration of mine dumps and other abandoned lands. [Methods] Eight soil and water conservation measures combining soil and water-conservation-engineering and plant measures were deployed on the exposed slopes of the grassland open-pit coal mine discharge site, with no measures (CK) as the control. Sampling was conducted to investigate the characteristics of the plant community, as well as to determine the main physicochemical properties of the soil, compare and analyze the differences in the changes in the characteristics of the plant community, and soil properties of the different soil and water conservation measures. The redundancy method was used to analyze the correlation between plant community characteristics and soil properties. [Results] ① The soil and water conservation measures applied on the slope of the discharge site affected differently the main physicochemical properties of the soil, in which the soil quick-acting nutrient content changed significantly (p<0.05), and the soil quick-acting phosphorus content of the two measures-spreading mixed grass + ecological bag spacing 1m (Ⅱ) and spreading mixed grass + ecological bag spacing 2 m (Ⅲ)-reached 3.38 and 3.13 mg/kg, respectively. These increased by 53.6% and 42.3% compared to that of the control (CK) (2.20 mg/kg), respectively. The soil quick-effect potassium content of the three measures of spreading mixed grass + ecological bag spacing 2 m (Ⅲ), spreading mixed grass + geocell (Ⅶ), and spreading mixed grass + grass curtain (Ⅷ) was 108.25, 126.25, and 124.00 mg/kg, respectively. In contrast, the soil quick-effect potassium content of the control plot was only 53.25 mg/kg. ② The effects of soil and water conservation measures on plant community characteristics manifested mainly in the Simpson’s dominance index, which was significantly higher than that of the control (CK), except for the insignificant differences (p>0.05) between the spreading of sedge + salix psammophila sand barriers (Ⅵ) and the spreading of sedge + geocell (Ⅶ) (p<0.05). ③ The results of redundancy analysis showed that the Margalef richness, Simpson dominance index, and Shannon-Wiener diversity index were all significantly positively correlated with soil quick-acting phosphorus. The Louie evenness index was significantly positively correlated with soil total nitrogen, quick-acting potassium, and slow-acting potassium. [Conclusion] The implementation of soil and water conservation measures in open-pit coal mine dumps can improve the soil nutrient content and plant diversity, which has a positive effect on ecological restoration. The soil and water conservation measures of spreading mixed grass + ecological bag with an interval of 2 m (Ⅲ) and spreading mixed grass + salix psammophila sand barriers (Ⅵ) have a better ecological restoration effect, which can be popularized and applied as the main measures for ecological restoration of dumps in the mining area.
[Objective] The effects of different soil and water conservation measures on soil nutrients and plant diversity in open-pit coal mine dumps were explored, aiming to provide feasible technical measures for the ecological restoration of mine dumps and other abandoned lands. [Methods] Eight soil and water conservation measures combining soil and water-conservation-engineering and plant measures were deployed on the exposed slopes of the grassland open-pit coal mine discharge site, with no measures (CK) as the control. Sampling was conducted to investigate the characteristics of the plant community, as well as to determine the main physicochemical properties of the soil, compare and analyze the differences in the changes in the characteristics of the plant community, and soil properties of the different soil and water conservation measures. The redundancy method was used to analyze the correlation between plant community characteristics and soil properties. [Results] ① The soil and water conservation measures applied on the slope of the discharge site affected differently the main physicochemical properties of the soil, in which the soil quick-acting nutrient content changed significantly (p<0.05), and the soil quick-acting phosphorus content of the two measures-spreading mixed grass + ecological bag spacing 1m (Ⅱ) and spreading mixed grass + ecological bag spacing 2 m (Ⅲ)-reached 3.38 and 3.13 mg/kg, respectively. These increased by 53.6% and 42.3% compared to that of the control (CK) (2.20 mg/kg), respectively. The soil quick-effect potassium content of the three measures of spreading mixed grass + ecological bag spacing 2 m (Ⅲ), spreading mixed grass + geocell (Ⅶ), and spreading mixed grass + grass curtain (Ⅷ) was 108.25, 126.25, and 124.00 mg/kg, respectively. In contrast, the soil quick-effect potassium content of the control plot was only 53.25 mg/kg. ② The effects of soil and water conservation measures on plant community characteristics manifested mainly in the Simpson’s dominance index, which was significantly higher than that of the control (CK), except for the insignificant differences (p>0.05) between the spreading of sedge + salix psammophila sand barriers (Ⅵ) and the spreading of sedge + geocell (Ⅶ) (p<0.05). ③ The results of redundancy analysis showed that the Margalef richness, Simpson dominance index, and Shannon-Wiener diversity index were all significantly positively correlated with soil quick-acting phosphorus. The Louie evenness index was significantly positively correlated with soil total nitrogen, quick-acting potassium, and slow-acting potassium. [Conclusion] The implementation of soil and water conservation measures in open-pit coal mine dumps can improve the soil nutrient content and plant diversity, which has a positive effect on ecological restoration. The soil and water conservation measures of spreading mixed grass + ecological bag with an interval of 2 m (Ⅲ) and spreading mixed grass + salix psammophila sand barriers (Ⅵ) have a better ecological restoration effect, which can be popularized and applied as the main measures for ecological restoration of dumps in the mining area.
Li Shihui, Zhao Ximei, Wang Yuanbo, Chen Weifeng, Lu Yue, Xia Jiangbao, Chen Yinping, Zhang Zihan, Li Yiran
2024,44(6):23-30,56
, DOI: 10.13961/j.cnki.stbctb.2024.06.003
Abstract:
[Objective] The effects of planting different perennial flowers on soil salinity and nutrients in the Yellow River delta were explored, in order to provide species reference for selecting suitable perennial flowers for ecological improvement of saline soil and assist the national strategy of the Yellow River and the construction of beautiful villages in saline-alkali areas. [Methods] The bare soil without planting perennial flowers was taken as the control, the soils planted with Iris lactea, Pennisetum alopecuroides subsp. purple, Dianthus plumarius, Gaillardia pulchella, Hemerocallis hybrida, and Sedum spectabile were examined to find the effects of perennial flowers planting on the soil salt content, electrical conductivity, Na+, Cl-, available potassium, and available phosphorus content. [Results] ① The perennial flower planting showed ecological regulation effects on saline soil in the Yellow River Delta. Among them, I. lactea and P. alopecuroides significantly reduced the salt content in the 0—10 cm soil. At the same time, I. lactea also had a certain effect on reducing the salt content of 10—20 cm soil layer, and the trend of conductivity was consistent with the salt content. ② The contents of Na+ and Cl- in the 0—10 cm soils were significantly reduced by G. pulchella and D. plumarius, and the removal effect of soil Cl- by I. lactea and G. pulchella was significant. ③ Perennial flowers had no significant effect on the content of available potassium in topsoil but reduced the content of available phosphorus in the 10—20 cm soils except P. alopecuroides. [Conclusion] The improvement effect of I. lactea and P. alopecuroides on saline soil was better, and they could be given priority when selecting perennial flowers for ecological improvement of saline soil in the Yellow River delta. H. hybrida had the medium effect, whereas D. plumarius, G. pulchella and S. spectabile had poor effects.
[Objective] The effects of planting different perennial flowers on soil salinity and nutrients in the Yellow River delta were explored, in order to provide species reference for selecting suitable perennial flowers for ecological improvement of saline soil and assist the national strategy of the Yellow River and the construction of beautiful villages in saline-alkali areas. [Methods] The bare soil without planting perennial flowers was taken as the control, the soils planted with Iris lactea, Pennisetum alopecuroides subsp. purple, Dianthus plumarius, Gaillardia pulchella, Hemerocallis hybrida, and Sedum spectabile were examined to find the effects of perennial flowers planting on the soil salt content, electrical conductivity, Na+, Cl-, available potassium, and available phosphorus content. [Results] ① The perennial flower planting showed ecological regulation effects on saline soil in the Yellow River Delta. Among them, I. lactea and P. alopecuroides significantly reduced the salt content in the 0—10 cm soil. At the same time, I. lactea also had a certain effect on reducing the salt content of 10—20 cm soil layer, and the trend of conductivity was consistent with the salt content. ② The contents of Na+ and Cl- in the 0—10 cm soils were significantly reduced by G. pulchella and D. plumarius, and the removal effect of soil Cl- by I. lactea and G. pulchella was significant. ③ Perennial flowers had no significant effect on the content of available potassium in topsoil but reduced the content of available phosphorus in the 10—20 cm soils except P. alopecuroides. [Conclusion] The improvement effect of I. lactea and P. alopecuroides on saline soil was better, and they could be given priority when selecting perennial flowers for ecological improvement of saline soil in the Yellow River delta. H. hybrida had the medium effect, whereas D. plumarius, G. pulchella and S. spectabile had poor effects.
Effects of Different Washing Reagents on Removal of Soil Salt Salinity for Coastal Reclamation Zones
2024,44(6):31-38,45
, DOI: 10.13961/j.cnki.stbctb.2024.06.004
Abstract:
[Objective] The effectiveness of washing reagents in removing soil salinity was evaluated to provide theoretical guidance for soil amendments in coastal reclamation zones. [Methods] Slightly and heavily saline soils of paddy fields from the Chongming coastal reclamation zones in Shanghai City were selected as the research objects, and the effects of five types of washing reagent (potassium nitrate, iron nitrate, calcium nitrate, magnesium nitrate, and ammonium bicarbonate) concentrations and extraction times on soil salinity (Na+, K+, Ca2+, Mg2+, CO2-3, HCO-3, Cl-, and SO2-4) removal efficiency were compared and analyzed. [Results] The five washing reagents promoted the removal of Na+ and Cl- in the slightly saline soils, and the effect of potassium nitrate on Na+ removal efficiency was the most obvious, because the Na+ concentration in the eluate was increased by 9.9%—25.9% compared with that in the control. However, Cl- was more easily removed by ammonium bicarbonate, and the increase ratio was approximately 9.6%—21.2% compared with the control. Potassium nitrate (3.0 mmol/L) showed the best results, considering the removal of soil salt ions and the loss of soil nutrients (K+, Ca2+, and Mg2+). The Na+, Cl-, SO2-4, and Ca2+ concentrations in the eluate of the second washing by potassium nitrate were markedly lower than those after the first time, whereas it was not the case for HCO-3 and Mg2+. In this experiment, the five washing reagents showed negligible effects on the removal efficiency of Na+ and Cl- in the heavily saline soils because the applied concentration was much lower than the salt ion content in the soils, and the increase rates of the two ions were 0.10%—1.0% and 0.01%—-4.40%, respectively, compared with the control. [Conclusion] The types, concentrations and times of washing reagents should be determined according to the types and contents of soil salt ions when improves soil in coastal reclamation zones. The application of washing reagents could be combined with irrigation measures.
[Objective] The effectiveness of washing reagents in removing soil salinity was evaluated to provide theoretical guidance for soil amendments in coastal reclamation zones. [Methods] Slightly and heavily saline soils of paddy fields from the Chongming coastal reclamation zones in Shanghai City were selected as the research objects, and the effects of five types of washing reagent (potassium nitrate, iron nitrate, calcium nitrate, magnesium nitrate, and ammonium bicarbonate) concentrations and extraction times on soil salinity (Na+, K+, Ca2+, Mg2+, CO2-3, HCO-3, Cl-, and SO2-4) removal efficiency were compared and analyzed. [Results] The five washing reagents promoted the removal of Na+ and Cl- in the slightly saline soils, and the effect of potassium nitrate on Na+ removal efficiency was the most obvious, because the Na+ concentration in the eluate was increased by 9.9%—25.9% compared with that in the control. However, Cl- was more easily removed by ammonium bicarbonate, and the increase ratio was approximately 9.6%—21.2% compared with the control. Potassium nitrate (3.0 mmol/L) showed the best results, considering the removal of soil salt ions and the loss of soil nutrients (K+, Ca2+, and Mg2+). The Na+, Cl-, SO2-4, and Ca2+ concentrations in the eluate of the second washing by potassium nitrate were markedly lower than those after the first time, whereas it was not the case for HCO-3 and Mg2+. In this experiment, the five washing reagents showed negligible effects on the removal efficiency of Na+ and Cl- in the heavily saline soils because the applied concentration was much lower than the salt ion content in the soils, and the increase rates of the two ions were 0.10%—1.0% and 0.01%—-4.40%, respectively, compared with the control. [Conclusion] The types, concentrations and times of washing reagents should be determined according to the types and contents of soil salt ions when improves soil in coastal reclamation zones. The application of washing reagents could be combined with irrigation measures.
2024,44(6):39-45
, DOI: 10.13961/j.cnki.stbctb.2024.06.005
Abstract:
[Objective] The content and stoichiometric ratio of available trace elements in soil under different vegetation types in photovoltaic power plants were explored to provide a theoretical basis for accelerating the vegetation restoration of photovoltaic power stations in arid areas of Western China. [Methods] The soil of four vegetation types in the photovoltaic agriculture, forestry and animal husbandry demonstration base of Tumd Left Banner in Hohhot City, Inner Mongolia was taken as the research object, and the available trace elements and ecological stoichiometry characteristics of different vegetation soils were analyzed. Four vegetation types, namely natural vegetation, Pinus sylvestris, Astragalus membranaceus, and Medicago sativa, were selected to determine the nutrient status of the 0—20 cm and 20—40 cm soil layers. [Results] ① There were significant differences in the soil available trace elements among the four vegetation types, and the content of available trace elements was low. ② For the four vegetation types, the content of available trace elements in soil followed the order A. membranaceus plot > M. sativa plot > P. sylvestris plot > natural vegetation plots. ③ The chemical ratios of the soil trace element effective contents in the study area were 0.96, 31.95, 4.07, 33.50, 4.30 and 0.15 for Fe∶Mn, Fe∶Cu, Fe∶Zn, Mn∶Cu, Mn∶Zn and Cu∶Zn, respectively. ④ The soil trace nutrients in the study area were Fe, Mn, and Cu deficiencies; Fe was the main trace element limiting factor, and Mn and Cu were secondary limiting factors. [Conclusion] At the same time as vegetation restoration in this area, it is necessary to add micro-fertilizer appropriately, which can improve soil fertility to a certain extent and provide sufficient micronutrients for vegetation restoration in the study area.
[Objective] The content and stoichiometric ratio of available trace elements in soil under different vegetation types in photovoltaic power plants were explored to provide a theoretical basis for accelerating the vegetation restoration of photovoltaic power stations in arid areas of Western China. [Methods] The soil of four vegetation types in the photovoltaic agriculture, forestry and animal husbandry demonstration base of Tumd Left Banner in Hohhot City, Inner Mongolia was taken as the research object, and the available trace elements and ecological stoichiometry characteristics of different vegetation soils were analyzed. Four vegetation types, namely natural vegetation, Pinus sylvestris, Astragalus membranaceus, and Medicago sativa, were selected to determine the nutrient status of the 0—20 cm and 20—40 cm soil layers. [Results] ① There were significant differences in the soil available trace elements among the four vegetation types, and the content of available trace elements was low. ② For the four vegetation types, the content of available trace elements in soil followed the order A. membranaceus plot > M. sativa plot > P. sylvestris plot > natural vegetation plots. ③ The chemical ratios of the soil trace element effective contents in the study area were 0.96, 31.95, 4.07, 33.50, 4.30 and 0.15 for Fe∶Mn, Fe∶Cu, Fe∶Zn, Mn∶Cu, Mn∶Zn and Cu∶Zn, respectively. ④ The soil trace nutrients in the study area were Fe, Mn, and Cu deficiencies; Fe was the main trace element limiting factor, and Mn and Cu were secondary limiting factors. [Conclusion] At the same time as vegetation restoration in this area, it is necessary to add micro-fertilizer appropriately, which can improve soil fertility to a certain extent and provide sufficient micronutrients for vegetation restoration in the study area.
2024,44(6):46-56
, DOI: 10.13961/j.cnki.stbctb.20241105.001
Abstract:
[Objective] The coupling relationship between undecomposed leaf litter traits and water conservation ability of 11 major tree species in Northeast China was explored, and their water retention and water loss processes were analyzed, in order to provide theoretical basis for clarifying the water conservation ability of main tree species in this area. [Methods] A total of 11 common tree species in Northeast China were used as the research object. The water holding and loss characteristics of undecomposed leaves were determined by indoor immersion and water loss experiments, and the physical and chemical properties of 12 kinds of leaves were then determined by vernier calipers, scanners, elemental analyzers, Klason method, and concentrated acid hydrolysis sugar determination method. The relationship between leaf traits and leaf water conservation ability was analyzed using regression analysis. [Results] The maximum water holding capacity, effective retention capacity, water loss ratio, and water loss rate of undecomposed litter of 11 species showed significant differences (p<0.05). The maximum water retention rate in descending order was Tilia mandshurica, Betula platyphylla, Tilia amurensis, Larix gmelinii, Fraxinus mandshurica, Juglans mandshurica, Quercus mongolica, Populus×canadensis, Pinus sylvestris var. mongolica, Pinus koraiensis, Picea koraiensis, and it was significantly positively correlated with the specific leaf area. In addition, there was a significant negative correlation between leaf thickness and leaf shape index (p<0.05). At 24 h, the water loss rates were (from low to high) Picea koraiensis, B. platyphylla, T. amurensis, T. mandshurica, Pinus koraiensis, Q. mongolica, F. mandshurica, Populus×canadensis, Pinus sylvestris var. mongolica, L. gmelinii, and J. mandshurica. The water loss rate was significantly positively correlated with leaf length, specific leaf area, and rough degree (p<0.05). [Conclusion] Specific leaf area was the most important leaf character affecting water conservation ability of undecomposed leaf litter, followed by leaf length, leaf thickness, leaf shape index, and roughness. T. mandshurica, B. platyphylla, and T. amurensis are tree species showing an excellent water conservation capacity of undecomposed litter.
[Objective] The coupling relationship between undecomposed leaf litter traits and water conservation ability of 11 major tree species in Northeast China was explored, and their water retention and water loss processes were analyzed, in order to provide theoretical basis for clarifying the water conservation ability of main tree species in this area. [Methods] A total of 11 common tree species in Northeast China were used as the research object. The water holding and loss characteristics of undecomposed leaves were determined by indoor immersion and water loss experiments, and the physical and chemical properties of 12 kinds of leaves were then determined by vernier calipers, scanners, elemental analyzers, Klason method, and concentrated acid hydrolysis sugar determination method. The relationship between leaf traits and leaf water conservation ability was analyzed using regression analysis. [Results] The maximum water holding capacity, effective retention capacity, water loss ratio, and water loss rate of undecomposed litter of 11 species showed significant differences (p<0.05). The maximum water retention rate in descending order was Tilia mandshurica, Betula platyphylla, Tilia amurensis, Larix gmelinii, Fraxinus mandshurica, Juglans mandshurica, Quercus mongolica, Populus×canadensis, Pinus sylvestris var. mongolica, Pinus koraiensis, Picea koraiensis, and it was significantly positively correlated with the specific leaf area. In addition, there was a significant negative correlation between leaf thickness and leaf shape index (p<0.05). At 24 h, the water loss rates were (from low to high) Picea koraiensis, B. platyphylla, T. amurensis, T. mandshurica, Pinus koraiensis, Q. mongolica, F. mandshurica, Populus×canadensis, Pinus sylvestris var. mongolica, L. gmelinii, and J. mandshurica. The water loss rate was significantly positively correlated with leaf length, specific leaf area, and rough degree (p<0.05). [Conclusion] Specific leaf area was the most important leaf character affecting water conservation ability of undecomposed leaf litter, followed by leaf length, leaf thickness, leaf shape index, and roughness. T. mandshurica, B. platyphylla, and T. amurensis are tree species showing an excellent water conservation capacity of undecomposed litter.
Liang Yuxing, Yuan Zaixiang, Wang Kai, Li Rongsheng, Zhang Shaojie, Zhang Pengpeng, Chen Yong, Sun Yujie
2024,44(6):57-67,128
, DOI: 10.13961/j.cnki.stbctb.2024.06.007
Abstract:
[Objective] The characteristics of water conservation capacity of the mixed combination models of Mytilaria laosensis and Castanopsis hystrix were explored, and the best mixed combination mode of water conservation capacity was selected, in order to provided a scientific basis for the construction, operation and management of water conservation forest in Xijiang River basin. [Methods] Nine mixed plantation patterns with three mixing proportions (i.e., 1∶3, 2∶2, and 3∶1) and three mixing modes (i.e., interplant mixing, strip and row mixing, and block mixing) of M. laosensis and C. hystrix were selected, and the pure plantations of both species served as controls. The differences in the water conservation capacity of litter and soil among the eleven planting models were evaluated, and the mixed plantation with the optimal water conservation capacity was identified using an entropy weight TOPSIS (technique for order preference by similarity to an ideal solution) model. [Results] ① The biomass, natural water storage, effective water interception, and maximum water interception in the litter layer ranged from 1.17 to 4.21, 0.38 to 2.29, 5.15 to 10.58, and 6.40 to 13.37 t/hm2, respectively. These indices were positively and significantly correlated with the percentage of M. laosensis in the plantations (p<0.05). Compared to interplant mixing and block mixing, the strip and row mixing of the plantations yielded higher biomass and effective water interception in the litter layer. ② The natural moisture storage, capillary water storage, non-capillary water storage, and saturated water storage in soil at a depth of 0—30 cm ranged from 756.14 to 1 007.21, 1 130.73 to 1 388.40, 117.96 to 422.63, and 1 444.70 to 1 590.66 t/hm2, respectively. Capillary and non-capillary water storage differed significantly among the plantations and were positively correlated with the percentage of M. laosensis in the plantations (p<0.05). ③ The mixed plantation of M. laosensis and C. hystrix with a ratio of 3∶1 and strip and row mixing exhibited the optimal water conservation capacity. The water conservation capacity of the other plantations ranked as follows: pure plantation of M. laosensis, other mixed plantation patterns, and pure plantation of C. hystrix. [Conclusion] The water conservation capacity of the mixed plantation of M. laosensis and C. hystrix was, to a certain extent, better than that of each pure plantation in the young stand stage, which was influenced by the mixing proportions and modes.
[Objective] The characteristics of water conservation capacity of the mixed combination models of Mytilaria laosensis and Castanopsis hystrix were explored, and the best mixed combination mode of water conservation capacity was selected, in order to provided a scientific basis for the construction, operation and management of water conservation forest in Xijiang River basin. [Methods] Nine mixed plantation patterns with three mixing proportions (i.e., 1∶3, 2∶2, and 3∶1) and three mixing modes (i.e., interplant mixing, strip and row mixing, and block mixing) of M. laosensis and C. hystrix were selected, and the pure plantations of both species served as controls. The differences in the water conservation capacity of litter and soil among the eleven planting models were evaluated, and the mixed plantation with the optimal water conservation capacity was identified using an entropy weight TOPSIS (technique for order preference by similarity to an ideal solution) model. [Results] ① The biomass, natural water storage, effective water interception, and maximum water interception in the litter layer ranged from 1.17 to 4.21, 0.38 to 2.29, 5.15 to 10.58, and 6.40 to 13.37 t/hm2, respectively. These indices were positively and significantly correlated with the percentage of M. laosensis in the plantations (p<0.05). Compared to interplant mixing and block mixing, the strip and row mixing of the plantations yielded higher biomass and effective water interception in the litter layer. ② The natural moisture storage, capillary water storage, non-capillary water storage, and saturated water storage in soil at a depth of 0—30 cm ranged from 756.14 to 1 007.21, 1 130.73 to 1 388.40, 117.96 to 422.63, and 1 444.70 to 1 590.66 t/hm2, respectively. Capillary and non-capillary water storage differed significantly among the plantations and were positively correlated with the percentage of M. laosensis in the plantations (p<0.05). ③ The mixed plantation of M. laosensis and C. hystrix with a ratio of 3∶1 and strip and row mixing exhibited the optimal water conservation capacity. The water conservation capacity of the other plantations ranked as follows: pure plantation of M. laosensis, other mixed plantation patterns, and pure plantation of C. hystrix. [Conclusion] The water conservation capacity of the mixed plantation of M. laosensis and C. hystrix was, to a certain extent, better than that of each pure plantation in the young stand stage, which was influenced by the mixing proportions and modes.
2024,44(6):68-76
, DOI: 10.13961/j.cnki.stbctb.2024.06.008
Abstract:
[Objective] The effects of different planting densities on plant community structure, species diversity, and soil physicochemical properties of Pinus tabulaeformis plantation were studied, and the appropriate management density of soil and water conservation forest were determined to provide reference for the improvement of ecological function and sustainable development of P. tabulaeformis plantation in the arsenic sandstone area. [Methods] Taking P. tabulaeformis plantation on the slope of Xujiamen Qiangou in Xiheidai of Zhungeer Banner as the research site, the relationship between understory herbaceous plant community composition, species diversity and soil physical and chemical properties under four planting densities (950, 2 000, 3 250, 4 300 plant/hm2) was explored through field sampling and indoor investigation. [Results] ① There were 33 species from 9 families and 19 genera in the study area, and the number of plant species was the highest when the afforestation density was 3 250 plant/hm2. The understory herbaceous plant communities of P. tabulaeformis were mainly Gramineae, Compositae, Fabaceae and Rosaceae. With the increase of afforestation density, the associated dominant species transited from sunny and mesophytic species to shady species. ② The species diversity index, plant height, biomass, soil organic matter, available nitrogen, phosphorus and potassium content, and soil water content in the understory herbaceous layer were 3 250 plants/hm2>4 300 plants/hm2>950 plants/hm2>2 000 plants/hm2. ③ Afforestation density had significant effects on soil water content, organic matter and available nitrogen, phosphorus and potassium content (p<0.05), but had no significant effects on plant species diversity index (p>0.05). In the correlation analysis, soil organic matter, available nitrogen, phosphorus and potassium content were most closely related to the species diversity index of herbaceous layer. [Conclusion] The planting density of 3 250 plant/hm2 was more conducive to the growth of understory plants and the improvement of soil fertility in the arsenic sandstone area of Zhungeer Banner.
[Objective] The effects of different planting densities on plant community structure, species diversity, and soil physicochemical properties of Pinus tabulaeformis plantation were studied, and the appropriate management density of soil and water conservation forest were determined to provide reference for the improvement of ecological function and sustainable development of P. tabulaeformis plantation in the arsenic sandstone area. [Methods] Taking P. tabulaeformis plantation on the slope of Xujiamen Qiangou in Xiheidai of Zhungeer Banner as the research site, the relationship between understory herbaceous plant community composition, species diversity and soil physical and chemical properties under four planting densities (950, 2 000, 3 250, 4 300 plant/hm2) was explored through field sampling and indoor investigation. [Results] ① There were 33 species from 9 families and 19 genera in the study area, and the number of plant species was the highest when the afforestation density was 3 250 plant/hm2. The understory herbaceous plant communities of P. tabulaeformis were mainly Gramineae, Compositae, Fabaceae and Rosaceae. With the increase of afforestation density, the associated dominant species transited from sunny and mesophytic species to shady species. ② The species diversity index, plant height, biomass, soil organic matter, available nitrogen, phosphorus and potassium content, and soil water content in the understory herbaceous layer were 3 250 plants/hm2>4 300 plants/hm2>950 plants/hm2>2 000 plants/hm2. ③ Afforestation density had significant effects on soil water content, organic matter and available nitrogen, phosphorus and potassium content (p<0.05), but had no significant effects on plant species diversity index (p>0.05). In the correlation analysis, soil organic matter, available nitrogen, phosphorus and potassium content were most closely related to the species diversity index of herbaceous layer. [Conclusion] The planting density of 3 250 plant/hm2 was more conducive to the growth of understory plants and the improvement of soil fertility in the arsenic sandstone area of Zhungeer Banner.
2024,44(6):77-87
, DOI: 10.13961/j.cnki.stbctb.20240923.002
Abstract:
[Objective] The dynamic changes in soil moisture and its response to rainfall in earth-rocky mountain areas of North China were analyzed, and the characteristics and laws of its rainfall response recharge were revealed, aiming at providing a reference and theoretical basis for rational utilization of water resources and water conservation in this area. [Methods] This study focused on typical natural barren slopes in earth-rocky mountain area of North China, employing in-situ monitoring to collect real-time data on soil moisture at different slope positions for detailed analysis. The dynamic response characteristics of soil moisture to rainfall and its intrinsic patterns were studied. [Results] ① The average annual soil moisture content along the slope exhibited the following pattern: bottom slope (20.3%±5.5%) > top slope (19.5%±5.7%) > middle slope (15.9%±7.0%), and in the vertical profile, deeper soil layers had a higher moisture content than that in shallower layers. ② The response rate of soil moisture to rainfall was significantly faster in the middle slope (1.50 h) compared to that in the top (4.10 h) and bottom slopes (2.80 h), and in the vertical profile, deeper soil layers responded to rainfall more quickly than shallower layers. ③ The average rates of moisture replenishment and depletion due to rainfall were as follows: middle slope (1.4%/h, 0.3%/h) > top slope (0.9%/h, 0.2%/h) > bottom slope (0.7%/h, 0.1%/h), and in the vertical profile, the replenishment and depletion rates were higher in deeper soil layers than in shallower layers. [Conclusion] In the earth-rocky mountainous area of North China, when rainfall exceeds 2.7 mm, it can effectively recharge soil moisture on slopes. Additionally, the responses of the middle slope and deeper soil layers to rainfall were notably more rapid.
[Objective] The dynamic changes in soil moisture and its response to rainfall in earth-rocky mountain areas of North China were analyzed, and the characteristics and laws of its rainfall response recharge were revealed, aiming at providing a reference and theoretical basis for rational utilization of water resources and water conservation in this area. [Methods] This study focused on typical natural barren slopes in earth-rocky mountain area of North China, employing in-situ monitoring to collect real-time data on soil moisture at different slope positions for detailed analysis. The dynamic response characteristics of soil moisture to rainfall and its intrinsic patterns were studied. [Results] ① The average annual soil moisture content along the slope exhibited the following pattern: bottom slope (20.3%±5.5%) > top slope (19.5%±5.7%) > middle slope (15.9%±7.0%), and in the vertical profile, deeper soil layers had a higher moisture content than that in shallower layers. ② The response rate of soil moisture to rainfall was significantly faster in the middle slope (1.50 h) compared to that in the top (4.10 h) and bottom slopes (2.80 h), and in the vertical profile, deeper soil layers responded to rainfall more quickly than shallower layers. ③ The average rates of moisture replenishment and depletion due to rainfall were as follows: middle slope (1.4%/h, 0.3%/h) > top slope (0.9%/h, 0.2%/h) > bottom slope (0.7%/h, 0.1%/h), and in the vertical profile, the replenishment and depletion rates were higher in deeper soil layers than in shallower layers. [Conclusion] In the earth-rocky mountainous area of North China, when rainfall exceeds 2.7 mm, it can effectively recharge soil moisture on slopes. Additionally, the responses of the middle slope and deeper soil layers to rainfall were notably more rapid.
2024,44(6):88-96
, DOI: 10.13961/j.cnki.stbctb.2024.06.010
Abstract:
[Objective] Forest type differentiation characteristics and spatial patterns of the forest water conservation function of Giant Panda National Park in Sichuan Province were examined, in order to provide guidance for the protection of forest resources and adaptive management of water resources in this area. [Methods] Based on the results of the cadastral and special forest resources survey in the Sichuan area of Giant Panda National Park, sample plots data, and multi-source remote sensing data, the integrated storage capacity method was applied to estimate the forest water conservation function. Its characteristics under different forest types and site conditions were then analyzed. [Results] ① The extent of water conservation of the forest ecosystem in this area was 1.71×109 m3, yielding a water conservation of 1 061.27 m3/hm2 per unit area. The soil layer served as the main reservoir for water conservation. Evergreen coniferous forests exhibited the strongest water conservation function. ② There were notable spatial variations in forest water conservation function, with higher levels in Ya’an, Mianyang, and Guangyuan City and lower levels in Aba Prefecture and Deyang City. ③ The forest water conservation amount mainly concentrated in areas with altitudes ranging between (1 500, 3 500］ meters, contributing 90.10% to the total water conservation amount. In addition, the forest water conservation per unit area significantly decreased as altitude increased (p＜0.01). ④ Forests on steep slopes (35°，45°］ had the highest forest water conservation amount, with a contribution rate of 24.01%. The forest water conservation per unit area showed a trend of first increasing and then decreasing as slope steepness increased (p＜0.01). [Conclusion] Reasonably adjusting the forest resources’ structure and optimizing forest resources’ distribution of Giant Panda National Park in Sichuan Province according to local conditions would help maximize the forest water conservation function in this area.
[Objective] Forest type differentiation characteristics and spatial patterns of the forest water conservation function of Giant Panda National Park in Sichuan Province were examined, in order to provide guidance for the protection of forest resources and adaptive management of water resources in this area. [Methods] Based on the results of the cadastral and special forest resources survey in the Sichuan area of Giant Panda National Park, sample plots data, and multi-source remote sensing data, the integrated storage capacity method was applied to estimate the forest water conservation function. Its characteristics under different forest types and site conditions were then analyzed. [Results] ① The extent of water conservation of the forest ecosystem in this area was 1.71×109 m3, yielding a water conservation of 1 061.27 m3/hm2 per unit area. The soil layer served as the main reservoir for water conservation. Evergreen coniferous forests exhibited the strongest water conservation function. ② There were notable spatial variations in forest water conservation function, with higher levels in Ya’an, Mianyang, and Guangyuan City and lower levels in Aba Prefecture and Deyang City. ③ The forest water conservation amount mainly concentrated in areas with altitudes ranging between (1 500, 3 500］ meters, contributing 90.10% to the total water conservation amount. In addition, the forest water conservation per unit area significantly decreased as altitude increased (p＜0.01). ④ Forests on steep slopes (35°，45°］ had the highest forest water conservation amount, with a contribution rate of 24.01%. The forest water conservation per unit area showed a trend of first increasing and then decreasing as slope steepness increased (p＜0.01). [Conclusion] Reasonably adjusting the forest resources’ structure and optimizing forest resources’ distribution of Giant Panda National Park in Sichuan Province according to local conditions would help maximize the forest water conservation function in this area.
2024,44(6):97-105
, DOI: 10.13961/j.cnki.stbctb.2024.06.011
Abstract:
[Objective] The optimal combination of three environmental materials for soil aggregate structure and physicochemical properties improvements were examined, in order to solve the problems of poor soil structure and serious soil and water loss in the process of soil reclamation in the alpine region of Qinghai-Xizang region. [Methods] Using the Qinghai Delni Copper Mine as the research site and utilizing the local serpentine residue soil and raw soil, the effect of mixing three kinds of materials, namely binder, long fiber, and rice husk, on the soil improvement was investigated through the soil cultivation simulation orthogonal test, and the ratio of the mixed materials with the best effect was screened out. [Results] Orthogonal polar results showed that the binder had a stronger effect on soil aggregates, total porosity, field water holding capacity, and soil bulk density, whereas long fibers and rice husk had a stronger effect on pH value and total salt content. Binder incorporation increased soil bulk density but decreased soil pore space compared to the control (CK). Long fibers and rice husk significantly decreased soil pH value, increased total porosity and field water holding capacity, and suitably increased total salt content. The optimal combination for soil aggregates and pH value was A2B2C3 (binder 0.074 g/kg, long fiber 2.960 g/kg, rice husk 11.110 g/kg). Soil bulk density, total porosity, and field water holding capacity regulation were optimized using the combination A1B2C2 (binder 0.037 g/kg, long fiber 2.960 g/kg, rice husk 7.410 g/kg), and the optimal combination for total salt content was A3B1C2 (binder 0.111 g/kg, long fiber 1.480 g/kg, rice husk 7.410 g/kg). [Conclusion] The optimal formula for soil matrix restoration in the alpine mining area was obtained as A1.5B2C2, that is, binder 0.056 g/kg, long fiber 2.960 g/kg, and rice husk 7.410 g/kg as the optimal ratios, which could improve the soil structure and enhances the capacity of soil and water conservation in the alpine mining area of Qinghai-Xizang region.
[Objective] The optimal combination of three environmental materials for soil aggregate structure and physicochemical properties improvements were examined, in order to solve the problems of poor soil structure and serious soil and water loss in the process of soil reclamation in the alpine region of Qinghai-Xizang region. [Methods] Using the Qinghai Delni Copper Mine as the research site and utilizing the local serpentine residue soil and raw soil, the effect of mixing three kinds of materials, namely binder, long fiber, and rice husk, on the soil improvement was investigated through the soil cultivation simulation orthogonal test, and the ratio of the mixed materials with the best effect was screened out. [Results] Orthogonal polar results showed that the binder had a stronger effect on soil aggregates, total porosity, field water holding capacity, and soil bulk density, whereas long fibers and rice husk had a stronger effect on pH value and total salt content. Binder incorporation increased soil bulk density but decreased soil pore space compared to the control (CK). Long fibers and rice husk significantly decreased soil pH value, increased total porosity and field water holding capacity, and suitably increased total salt content. The optimal combination for soil aggregates and pH value was A2B2C3 (binder 0.074 g/kg, long fiber 2.960 g/kg, rice husk 11.110 g/kg). Soil bulk density, total porosity, and field water holding capacity regulation were optimized using the combination A1B2C2 (binder 0.037 g/kg, long fiber 2.960 g/kg, rice husk 7.410 g/kg), and the optimal combination for total salt content was A3B1C2 (binder 0.111 g/kg, long fiber 1.480 g/kg, rice husk 7.410 g/kg). [Conclusion] The optimal formula for soil matrix restoration in the alpine mining area was obtained as A1.5B2C2, that is, binder 0.056 g/kg, long fiber 2.960 g/kg, and rice husk 7.410 g/kg as the optimal ratios, which could improve the soil structure and enhances the capacity of soil and water conservation in the alpine mining area of Qinghai-Xizang region.
2024,44(6):106-117
, DOI: 10.13961/j.cnki.stbctb.2024.06.012
Abstract:
[Purpose] Field investigations were carried in the three-river-source region, to provide a reference for soil erosion prevention and control in the region. [Methods] The investigation team travelled to Guoluo, Yushu, Hainan, and Huangnan Prefectures in Qinghai Province in three separate groups from July 25 to August 20, 2023. Woodlands, grasslands, farmlands, bare lands, roads, riverbanks, and mountain gullies in these areas were surveyed and analyzed. [Results] Grassland had the most complex type of soil erosion and was subjected to the joint action of multiple camp-force erosions such as wind erosion, water erosion, freezing and thawing erosion, and gravity erosion, resulting in serious soil erosion. In addition, grassland damage by highland rodents may be another important factor in the occurrence of grassland erosion. Forestland had erosion gullies in the standing forest; however, the overall risk of erosion was low due to engineered slope protection. The foot of the slope on which the shrub land is situated was more exposed to hydraulic and gravitational erosion and was at greater risk of erosion. The farmland was spread over a small area, with mild water erosion occurred in the field. For bare ground, fine gully erosion was more intense, and soil erosion was serious. Notably, on both sides of the road, the slopes were more severely eroded, and the excavation of the project has led to the destruction of the turf, sliding under gravity, and the emergence of larger exposed surfaces, which provide conditions for the occurrence of water erosion, leading to a larger network of erosion gullies that have already formed in some areas. [Conclusion] Soil erosion in the three-river-source region of Qinghai Province is complex and varied, with the intensification of human activities and the risk of further exacerbation of soil erosion in localized areas. There is an urgent need to conduct soil and water conservation work in the new era, and there is a need to strengthen basic research on soil erosion in the region, the deployment of the network of soil and water conservation monitoring stations, and intelligent management.
[Purpose] Field investigations were carried in the three-river-source region, to provide a reference for soil erosion prevention and control in the region. [Methods] The investigation team travelled to Guoluo, Yushu, Hainan, and Huangnan Prefectures in Qinghai Province in three separate groups from July 25 to August 20, 2023. Woodlands, grasslands, farmlands, bare lands, roads, riverbanks, and mountain gullies in these areas were surveyed and analyzed. [Results] Grassland had the most complex type of soil erosion and was subjected to the joint action of multiple camp-force erosions such as wind erosion, water erosion, freezing and thawing erosion, and gravity erosion, resulting in serious soil erosion. In addition, grassland damage by highland rodents may be another important factor in the occurrence of grassland erosion. Forestland had erosion gullies in the standing forest; however, the overall risk of erosion was low due to engineered slope protection. The foot of the slope on which the shrub land is situated was more exposed to hydraulic and gravitational erosion and was at greater risk of erosion. The farmland was spread over a small area, with mild water erosion occurred in the field. For bare ground, fine gully erosion was more intense, and soil erosion was serious. Notably, on both sides of the road, the slopes were more severely eroded, and the excavation of the project has led to the destruction of the turf, sliding under gravity, and the emergence of larger exposed surfaces, which provide conditions for the occurrence of water erosion, leading to a larger network of erosion gullies that have already formed in some areas. [Conclusion] Soil erosion in the three-river-source region of Qinghai Province is complex and varied, with the intensification of human activities and the risk of further exacerbation of soil erosion in localized areas. There is an urgent need to conduct soil and water conservation work in the new era, and there is a need to strengthen basic research on soil erosion in the region, the deployment of the network of soil and water conservation monitoring stations, and intelligent management.
2024,44(6):118-128
, DOI: 10.13961/j.cnki.stbctb.2024.06.013
Abstract:
[Objective] The temporal and spatial dynamic changes of desertification in the Kubuqi Desert during 2000—2023 were investigated, aiming to provide theoretical references and basic data support for the restoration of vegetation and ecological construction. [Methods] Based on the features of Landsat remote sensing images, the spatial and temporal distribution and change trend of land desertification in the Kubuqi Desert and its surrounding areas from 2000 to 2023 were studied by using enhanced vegitation index (EVI) remote sensing index gray segmentation, land desertification degree classification, land use dynamic attitude, abundance index and importance index. [Results] The total desertification area in the Kubuqi Desert decreased from 10 694.6 km2 in 2000 to 8 837.56 km2 in 2023. The area of extreme desertification was reduced from 6 272.11 km2 to 1 461.15 km2, that of severe desertification increased from 1 773.97 km2 in 2000 to 2 874.48 km2, of moderate desertification increased from 1 372.16 km2 in 2000 to 1 965.84 km2, and of mild desertification increased from 1 276.35 km2 to 2 535.58 km2. Considering the perspective of time series, the rate of extremely severe desertification from 2000 to 2023 was 3.33%, that of severe desertification was 2.70%, of moderate desertification was 1.88%, and of mild desertification was 4.29%. The area of extremely severe desert land types decreased from 6 272.11 km2 in 2000 to 1 461.65 km2 in 2023, with a total loss area of 4 949.72 km2. From the spatial perspective, the distribution of extremely severe desert types changed from distributed over time to concentrated, becoming dominant from 2000 to 2010; the multiple-degree index of severe and moderate desertification types ranged between 7.69% and 16.15%, indicating that the long-term distribution of heavy and moderate desertification types was concentrated; mild desertification types were scattered and extensive over time. [Conclusion] From 2000 to 2023, the area of Kubuqi Desert showed a decreasing trend, and the ecological environment had been improved. In the future, the ecological restoration of this region will focus on the extremely severe desert area.
[Objective] The temporal and spatial dynamic changes of desertification in the Kubuqi Desert during 2000—2023 were investigated, aiming to provide theoretical references and basic data support for the restoration of vegetation and ecological construction. [Methods] Based on the features of Landsat remote sensing images, the spatial and temporal distribution and change trend of land desertification in the Kubuqi Desert and its surrounding areas from 2000 to 2023 were studied by using enhanced vegitation index (EVI) remote sensing index gray segmentation, land desertification degree classification, land use dynamic attitude, abundance index and importance index. [Results] The total desertification area in the Kubuqi Desert decreased from 10 694.6 km2 in 2000 to 8 837.56 km2 in 2023. The area of extreme desertification was reduced from 6 272.11 km2 to 1 461.15 km2, that of severe desertification increased from 1 773.97 km2 in 2000 to 2 874.48 km2, of moderate desertification increased from 1 372.16 km2 in 2000 to 1 965.84 km2, and of mild desertification increased from 1 276.35 km2 to 2 535.58 km2. Considering the perspective of time series, the rate of extremely severe desertification from 2000 to 2023 was 3.33%, that of severe desertification was 2.70%, of moderate desertification was 1.88%, and of mild desertification was 4.29%. The area of extremely severe desert land types decreased from 6 272.11 km2 in 2000 to 1 461.65 km2 in 2023, with a total loss area of 4 949.72 km2. From the spatial perspective, the distribution of extremely severe desert types changed from distributed over time to concentrated, becoming dominant from 2000 to 2010; the multiple-degree index of severe and moderate desertification types ranged between 7.69% and 16.15%, indicating that the long-term distribution of heavy and moderate desertification types was concentrated; mild desertification types were scattered and extensive over time. [Conclusion] From 2000 to 2023, the area of Kubuqi Desert showed a decreasing trend, and the ecological environment had been improved. In the future, the ecological restoration of this region will focus on the extremely severe desert area.
2024,44(6):129-139
, DOI: 10.13961/j.cnki.stbctb.2024.06.014
Abstract:
[Objective] The spatiotemporal changes and sustainable utilization of water resources ecological footprint were explored in the middle reaches of the Yangtze River to provide decision-making references for the sustainable utilization of water resources in this region and in other provinces, metropolitan areas, and river basins. [Methods] This study selected the Hubei, Hunan, and Jiangxi provinces in the middle reaches of the Yangtze River from 2011 to 2021 as the research subjects. Employing the water resource ecological footprint model, a spatiotemporal analysis was conducted on the ecological footprint and related indicators of the three provinces. Based on the pressure-state-response model framework, an evaluation index system for sustainable water resource utilization in the middle reaches of the Yangtze River region was developed. [Results] ① The per-capita water resource ecological footprint and ecological carrying capacity of the three provinces showed an overall increasing trend, with the ecological carrying capacity exceeding the ecological footprint, resulting in an overall ecological surplus. Jiangxi Province had the highest per-capita ecological surplus of water resources, ranging from 3.186 to 7.966, whereas Hubei Province had the lowest, ranging from 0.304 to 2.603. ② The ecological footprint of each water account in the three provinces was predominantly industrial followed by domestic. Although ecological environmental water had the smallest share, it showed the most significant increase, particularly in Hubei Province. ③ The ecological footprint of water resources per ten thousand GDP exhibited a significant downward trend, with Jiangxi Province having the highest value and Hubei Province having the lowest, and the gap between the two gradually narrowed each year. ④ The pressure, state, and response indices for sustainable water resource utilization in the three provinces generally exhibited declining, rising, and increasing trends, respectively. The comprehensive evaluation indices exhibited a fluctuating upward trend; however, the rate of increase was modest and the overall index values remained relatively low. [Conclusion] Continued efforts are required to enhance the rational use of water for industrial and domestic purposes, promote the utilization of ecological and environmental water, and develop advanced measures to achieve sustainable water resource utilization. These findings can serve as a decision-making reference for water resource sustainability in the middle reaches of the Yangtze River and other provinces, city clusters, or basin areas.
[Objective] The spatiotemporal changes and sustainable utilization of water resources ecological footprint were explored in the middle reaches of the Yangtze River to provide decision-making references for the sustainable utilization of water resources in this region and in other provinces, metropolitan areas, and river basins. [Methods] This study selected the Hubei, Hunan, and Jiangxi provinces in the middle reaches of the Yangtze River from 2011 to 2021 as the research subjects. Employing the water resource ecological footprint model, a spatiotemporal analysis was conducted on the ecological footprint and related indicators of the three provinces. Based on the pressure-state-response model framework, an evaluation index system for sustainable water resource utilization in the middle reaches of the Yangtze River region was developed. [Results] ① The per-capita water resource ecological footprint and ecological carrying capacity of the three provinces showed an overall increasing trend, with the ecological carrying capacity exceeding the ecological footprint, resulting in an overall ecological surplus. Jiangxi Province had the highest per-capita ecological surplus of water resources, ranging from 3.186 to 7.966, whereas Hubei Province had the lowest, ranging from 0.304 to 2.603. ② The ecological footprint of each water account in the three provinces was predominantly industrial followed by domestic. Although ecological environmental water had the smallest share, it showed the most significant increase, particularly in Hubei Province. ③ The ecological footprint of water resources per ten thousand GDP exhibited a significant downward trend, with Jiangxi Province having the highest value and Hubei Province having the lowest, and the gap between the two gradually narrowed each year. ④ The pressure, state, and response indices for sustainable water resource utilization in the three provinces generally exhibited declining, rising, and increasing trends, respectively. The comprehensive evaluation indices exhibited a fluctuating upward trend; however, the rate of increase was modest and the overall index values remained relatively low. [Conclusion] Continued efforts are required to enhance the rational use of water for industrial and domestic purposes, promote the utilization of ecological and environmental water, and develop advanced measures to achieve sustainable water resource utilization. These findings can serve as a decision-making reference for water resource sustainability in the middle reaches of the Yangtze River and other provinces, city clusters, or basin areas.
2024,44(6):140-148,158
, DOI: 10.13961/j.cnki.stbctb.2024.06.015
Abstract:
[Objective] The impact of changes in land use types on soil erosion amount in the control area of check dams was studied to provide a theoretical basis for the high-quality development of ecological construction in the dam control area. [Methods] The control area of the Shuiquanwan check dam in Weiyuan County, Gansu Province, was selected as the research site. The weighted average method was used to modify the soil erosion modulus from the literature, and the soil erosion amounts for different land use types in the control area were calculated. The change process and characteristics of land use types were analyzed based on remote sensing images, and the influence of changes in soil conservation measures on soil erosion was explored through Pearson correlation analysis. [Results] ① From 2005 to 2023, the main land use types in the dam-controled area of Shuiquanwan check dam were terraced fields, which accounted for more than 70%, while water bodies accounted for less than 0.1%. The transformation of land use types involved mutual changes among terraced fields, wasteland, sloping land, dredged land, and shrubland。② The total amount of soil erosion in 2005, 2010, 2018, and 2023 was 4.54×103, 3.70×103, 3.31×103 and 3.95×103 t, respectively. Soil erosion mainly occurred in sloping farmland, wasteland, dredged land, terraces, and shrubland, with wasteland exhibiting the largest annual erosion. Its proportion ranged from 41.74% to 49.46%, while residential land and roads accounted for less than 1%. ③ A significant negative correlation exists between slope-cultivated land and terrace area, with a correlation coefficient of 0.972. There was also a significant positive correlation between soil erosion and grassland area, with a correlation coefficient of 0.983. [Conclusion] The adjustment of agricultural structure and the development of agricultural technology are among the main driving factors for land use types and patterns changes. Comprehensive management of slope changes and small watersheds effectively reduces regional soil and water loss.
[Objective] The impact of changes in land use types on soil erosion amount in the control area of check dams was studied to provide a theoretical basis for the high-quality development of ecological construction in the dam control area. [Methods] The control area of the Shuiquanwan check dam in Weiyuan County, Gansu Province, was selected as the research site. The weighted average method was used to modify the soil erosion modulus from the literature, and the soil erosion amounts for different land use types in the control area were calculated. The change process and characteristics of land use types were analyzed based on remote sensing images, and the influence of changes in soil conservation measures on soil erosion was explored through Pearson correlation analysis. [Results] ① From 2005 to 2023, the main land use types in the dam-controled area of Shuiquanwan check dam were terraced fields, which accounted for more than 70%, while water bodies accounted for less than 0.1%. The transformation of land use types involved mutual changes among terraced fields, wasteland, sloping land, dredged land, and shrubland。② The total amount of soil erosion in 2005, 2010, 2018, and 2023 was 4.54×103, 3.70×103, 3.31×103 and 3.95×103 t, respectively. Soil erosion mainly occurred in sloping farmland, wasteland, dredged land, terraces, and shrubland, with wasteland exhibiting the largest annual erosion. Its proportion ranged from 41.74% to 49.46%, while residential land and roads accounted for less than 1%. ③ A significant negative correlation exists between slope-cultivated land and terrace area, with a correlation coefficient of 0.972. There was also a significant positive correlation between soil erosion and grassland area, with a correlation coefficient of 0.983. [Conclusion] The adjustment of agricultural structure and the development of agricultural technology are among the main driving factors for land use types and patterns changes. Comprehensive management of slope changes and small watersheds effectively reduces regional soil and water loss.
2024,44(6):149-158
, DOI: 10.13961/j.cnki.stbctb.2024.06.016
Abstract:
[Objective] Slope gradient data was accurately obtained to address the limitation of slope gradient underestimation using the freely downloaded 30 m resolution digital elevation model (DEM) for farmland in Northeast China, in order to provide important data support for quantitatively evaluating soil erosion in the rolling hilly regions. [Methods] A 5 cm resolution DEM was generated from drone survey images and resampled to obtain 1, 5, and 12.5 m DEM resolutions. Combined with the 30 m DEM resolution, the optimal DEM resolution for slope gradient extraction in the study area was identified. Additionally, the histogram matching method was used to establish a slope gradient conversion model between the 30 m DEM resolution and the optimal DEM resolution for each slope gradient category. [Results] ① The slope gradient distributions derived from the five DEM resolutions indicated that the 1 m and 5 m DEM resolutions exhibited a strong similarity to the slope gradient distribution of the 5 cm DEM. Given that the 5 m DEM resolution corresponds to a 1∶10,000 scale topographic map, the 5 m DEM resolution was optimal for constructing the slope gradient conversion model. ② Using the histogram matching method, a univariate linear model and a univariate quadratic non-linear model were developed for slope gradient conversion between the 30 m and 5 m DEM resolutions across different slope gradient segments. The linear conversion model was suitable for slopes less than 7°, while the non-linear model was more appropriate for slopes greater than 7°. ③ After applying both linear and non-linear conversion models, the frequency distribution of slope gradients extracted from the 30 m DEM resolution closely matched that of the 5 m DEM resolution, significantly improving covariance and correlation coefficients. This reflected that the slope gradients after conversion from the 30 m DEM resolution can accurately represent ground undulation; additionally, the optimization results from the non-linear conversion model were superior to those from the linear conversion model. [Conclusion] The 5 m DEM resolution is the optimal resolution for extracting slope data in the study area. The developed conversion model for low-to-high resolution slope gradients showed that the non-linear slope conversion model has a better optimization effect than the linear slope conversion model.
[Objective] Slope gradient data was accurately obtained to address the limitation of slope gradient underestimation using the freely downloaded 30 m resolution digital elevation model (DEM) for farmland in Northeast China, in order to provide important data support for quantitatively evaluating soil erosion in the rolling hilly regions. [Methods] A 5 cm resolution DEM was generated from drone survey images and resampled to obtain 1, 5, and 12.5 m DEM resolutions. Combined with the 30 m DEM resolution, the optimal DEM resolution for slope gradient extraction in the study area was identified. Additionally, the histogram matching method was used to establish a slope gradient conversion model between the 30 m DEM resolution and the optimal DEM resolution for each slope gradient category. [Results] ① The slope gradient distributions derived from the five DEM resolutions indicated that the 1 m and 5 m DEM resolutions exhibited a strong similarity to the slope gradient distribution of the 5 cm DEM. Given that the 5 m DEM resolution corresponds to a 1∶10,000 scale topographic map, the 5 m DEM resolution was optimal for constructing the slope gradient conversion model. ② Using the histogram matching method, a univariate linear model and a univariate quadratic non-linear model were developed for slope gradient conversion between the 30 m and 5 m DEM resolutions across different slope gradient segments. The linear conversion model was suitable for slopes less than 7°, while the non-linear model was more appropriate for slopes greater than 7°. ③ After applying both linear and non-linear conversion models, the frequency distribution of slope gradients extracted from the 30 m DEM resolution closely matched that of the 5 m DEM resolution, significantly improving covariance and correlation coefficients. This reflected that the slope gradients after conversion from the 30 m DEM resolution can accurately represent ground undulation; additionally, the optimization results from the non-linear conversion model were superior to those from the linear conversion model. [Conclusion] The 5 m DEM resolution is the optimal resolution for extracting slope data in the study area. The developed conversion model for low-to-high resolution slope gradients showed that the non-linear slope conversion model has a better optimization effect than the linear slope conversion model.
2024,44(6):159-165,193
, DOI: 10.13961/j.cnki.stbctb.2024.06.017
Abstract:
[Objective] The simulation method of flood evolution process caused by reservoir dam failures in urban areas was analyzed, in order to provide a scientific basis for risk prevention, early warning system development, and evacuation plans. [Methods] Using the upstream Jiangang and Changzhuang reservoirs in Zhengzhou City as case studies, a high-resolution digital elevation model was constructed based on GIS technology. The MIKE FLOOD coupling model was employed to integrate one-dimensional and two-dimensional models of reservoir dam failure, simulating the flood evolution process and exploring the characteristics of floods in downstream rivers and complex urban areas. [Results] Immediately following the dam failure, the peak discharge at the breach quickly reached its maximum. Peak outflow volumes from the Changzhuang and Jiangan reservoirs were 4 542.03 and 17 549.1 m3/s, respectively, with non-converging flood peaks. Portions of both banks downstream of the Jialu River, within 15.00 to 31.39 km from the Jiangan reservoir, were inundated, covering an area of 56.37 km2. One hour after the breach of the Changzhuang reservoir, riverbanks began to overflow, resulting in increased inundation areas. The Jiangan reservoir dam failure occurred 4.25 h later. 1.25 h after the Jiangan reservoir breach, inundation depths significantly increased in the original inundation area, expanding further to the maximum inundation area 1.92 h later. Following the dam breaks of the Changzhuang and Jiangan reservoirs, the floodwater level rose above the top of the south-to-north water transfer protection embankment, and a large volume of floodwater surged into the main channel of the south-to-north water transfer, generally increasing the flood flow rate. [Conclusion] The peak flood flow from the Jiangan reservoir is significantly larger than that from the Changzhuang reservoir, making its dam break more harmful. After the dam breaks, a substantial amount of floodwater enters the main channel of the south-to-north water diversion Project, increasing the risk of erosion of dikes, slopes, and inlet and outlet lock chambers. This situation seriously affects the water conveyance safety of the main canal of the south-to-north water diversion project and the safety of people’s lives and property.
[Objective] The simulation method of flood evolution process caused by reservoir dam failures in urban areas was analyzed, in order to provide a scientific basis for risk prevention, early warning system development, and evacuation plans. [Methods] Using the upstream Jiangang and Changzhuang reservoirs in Zhengzhou City as case studies, a high-resolution digital elevation model was constructed based on GIS technology. The MIKE FLOOD coupling model was employed to integrate one-dimensional and two-dimensional models of reservoir dam failure, simulating the flood evolution process and exploring the characteristics of floods in downstream rivers and complex urban areas. [Results] Immediately following the dam failure, the peak discharge at the breach quickly reached its maximum. Peak outflow volumes from the Changzhuang and Jiangan reservoirs were 4 542.03 and 17 549.1 m3/s, respectively, with non-converging flood peaks. Portions of both banks downstream of the Jialu River, within 15.00 to 31.39 km from the Jiangan reservoir, were inundated, covering an area of 56.37 km2. One hour after the breach of the Changzhuang reservoir, riverbanks began to overflow, resulting in increased inundation areas. The Jiangan reservoir dam failure occurred 4.25 h later. 1.25 h after the Jiangan reservoir breach, inundation depths significantly increased in the original inundation area, expanding further to the maximum inundation area 1.92 h later. Following the dam breaks of the Changzhuang and Jiangan reservoirs, the floodwater level rose above the top of the south-to-north water transfer protection embankment, and a large volume of floodwater surged into the main channel of the south-to-north water transfer, generally increasing the flood flow rate. [Conclusion] The peak flood flow from the Jiangan reservoir is significantly larger than that from the Changzhuang reservoir, making its dam break more harmful. After the dam breaks, a substantial amount of floodwater enters the main channel of the south-to-north water diversion Project, increasing the risk of erosion of dikes, slopes, and inlet and outlet lock chambers. This situation seriously affects the water conveyance safety of the main canal of the south-to-north water diversion project and the safety of people’s lives and property.
2024,44(6):166-176
, DOI: 10.13961/j.cnki.stbctb.2024.06.018
Abstract:
[Objective] The development characteristics of erosion gullies at black soil area in rolling hilly area in Northeast China were explored, and the influencing factors of erosion gullies in sloping farmland were revealed, in order to provide scientific basis and data support for erosion gully control in the region. [Methods] The study selected 61 typical erosion gullies on sloping farmland at Guofu Town, Baiquan County, Helongjiang Province, as research sites. Factors such as slope, aspect, altitude, and catchment area were extracted and analyzed for their effects on the morphological changes and development characteristics of gullies on sloping farmland, using drone aerial photography techniques to generate digital elevation models and based on data sources such as remote sensing images in the study area. [Results] ① The length, area, and volume of the erosion gullies in the study area showed a significant correlation with factors such as slope, altitude, and catchment area. Except for gully length, the correlation between gully morphological parameters and influencing factors ranked from large to small (i.e., catchment area > slope > altitude). ② Gully length variation and shape index showed a gradual decrease with increasing slope, reaching the maximum value within the range between 0° and 2°. Gully depth increased with increasing slope, peaking at 4° to 5°; significant variations were observed in gully development on sunny and semi-sunny slopes, with the most rapid development occurring on southwest-facing slopes. The average gully length and shape index in the study area showed a trend of first increasing and then decreasing with increasing altitude, reaching a peak in the range of 230—240 m. ③ Larger catchment areas corresponded to larger gully morphological parameters and more intense gully development. When the catchment area was within the range of >20 hm2, the variations in gully length and gully bank area reached their peak values. ④ A multivariate regression model constructed with gully morphological parameters and influencing factors showed a high degree of fit. The fitting coefficients for gully length, area, and volume were 0.73, 0.47, and 0.16, respectively. [Conclusion] The development of erosion gullies in typical areas of Baiquan County is significantly influenced by slope, aspect, catchment area, and altitude. It is recommended to prioritize erosion control measures for gullies located on slopes between 2° and 3°, facing southeast, at altitudes of 230—240 m, and with catchment areas exceeding 20 hm2.
[Objective] The development characteristics of erosion gullies at black soil area in rolling hilly area in Northeast China were explored, and the influencing factors of erosion gullies in sloping farmland were revealed, in order to provide scientific basis and data support for erosion gully control in the region. [Methods] The study selected 61 typical erosion gullies on sloping farmland at Guofu Town, Baiquan County, Helongjiang Province, as research sites. Factors such as slope, aspect, altitude, and catchment area were extracted and analyzed for their effects on the morphological changes and development characteristics of gullies on sloping farmland, using drone aerial photography techniques to generate digital elevation models and based on data sources such as remote sensing images in the study area. [Results] ① The length, area, and volume of the erosion gullies in the study area showed a significant correlation with factors such as slope, altitude, and catchment area. Except for gully length, the correlation between gully morphological parameters and influencing factors ranked from large to small (i.e., catchment area > slope > altitude). ② Gully length variation and shape index showed a gradual decrease with increasing slope, reaching the maximum value within the range between 0° and 2°. Gully depth increased with increasing slope, peaking at 4° to 5°; significant variations were observed in gully development on sunny and semi-sunny slopes, with the most rapid development occurring on southwest-facing slopes. The average gully length and shape index in the study area showed a trend of first increasing and then decreasing with increasing altitude, reaching a peak in the range of 230—240 m. ③ Larger catchment areas corresponded to larger gully morphological parameters and more intense gully development. When the catchment area was within the range of >20 hm2, the variations in gully length and gully bank area reached their peak values. ④ A multivariate regression model constructed with gully morphological parameters and influencing factors showed a high degree of fit. The fitting coefficients for gully length, area, and volume were 0.73, 0.47, and 0.16, respectively. [Conclusion] The development of erosion gullies in typical areas of Baiquan County is significantly influenced by slope, aspect, catchment area, and altitude. It is recommended to prioritize erosion control measures for gullies located on slopes between 2° and 3°, facing southeast, at altitudes of 230—240 m, and with catchment areas exceeding 20 hm2.
Utilization of Salix Psammophila Biomass Resources Based on Cultivation of Stropharia Rugosoannulata
2024,44(6):177-183
, DOI: 10.13961/j.cnki.stbctb.2024.06.019
Abstract:
[Objective] The effects of culture media containing different contents of Salix psammophila, a kind of ecological products, on the quality of Stropharia rugosoannulata were explored to provide a scientific basis for the cultivation of S. psammophila at Yulin sand area in Shaanxi Province. [Methods] Using S. psammophila branches and wheat straw as the main raw materials, four cultivation material formulas with varying S. psammophila contents were set up. The effects of different S. psammophila cultivation substrate ratios on the yield, morphological characteristics, nutritional components, and mineral and heavy metal contents of S. rugosoannulata were studied, and the experimental results were comprehensively analyzed using gray relational analysis. [Results] ① When using S. psammophila branches and wheat straw to cultivate S. rugosoannulata, the yield of S. rugosoannulata increased with increasing S. psammophila content. The pure S. psammophila sawdust added quicklime (X1) formula performed the best, with a yield of 7.42 kg/m2, which was 4.33 kg/m2 higher than that of the control (CK) group, and a biotransformation rate of 49.5%. Simultaneously, the protein content (41.5%) and mushroom shape index (0.81) in the X1 formula were 4.06% and 0.14% higher, respectively, than those in the CK group. ② Using the gray correlation method to comprehensively analyze the yield, nutritional value, mineral content, and heavy metal content, the weighted correlation between pure S. psammophila shavings and the ideal sequence was determined to be the highest at 0.818. [Conclusion] The fermented S. psammophila could be used as a cultivation material for S. rugosoannulata, that is, the problem of S. psammophila branches can be solved by cultivating S. rugosoannulata, providing new ideas for the utilization of S. psammophila resources in sandy areas.
[Objective] The effects of culture media containing different contents of Salix psammophila, a kind of ecological products, on the quality of Stropharia rugosoannulata were explored to provide a scientific basis for the cultivation of S. psammophila at Yulin sand area in Shaanxi Province. [Methods] Using S. psammophila branches and wheat straw as the main raw materials, four cultivation material formulas with varying S. psammophila contents were set up. The effects of different S. psammophila cultivation substrate ratios on the yield, morphological characteristics, nutritional components, and mineral and heavy metal contents of S. rugosoannulata were studied, and the experimental results were comprehensively analyzed using gray relational analysis. [Results] ① When using S. psammophila branches and wheat straw to cultivate S. rugosoannulata, the yield of S. rugosoannulata increased with increasing S. psammophila content. The pure S. psammophila sawdust added quicklime (X1) formula performed the best, with a yield of 7.42 kg/m2, which was 4.33 kg/m2 higher than that of the control (CK) group, and a biotransformation rate of 49.5%. Simultaneously, the protein content (41.5%) and mushroom shape index (0.81) in the X1 formula were 4.06% and 0.14% higher, respectively, than those in the CK group. ② Using the gray correlation method to comprehensively analyze the yield, nutritional value, mineral content, and heavy metal content, the weighted correlation between pure S. psammophila shavings and the ideal sequence was determined to be the highest at 0.818. [Conclusion] The fermented S. psammophila could be used as a cultivation material for S. rugosoannulata, that is, the problem of S. psammophila branches can be solved by cultivating S. rugosoannulata, providing new ideas for the utilization of S. psammophila resources in sandy areas.
2024,44(6):184-193
, DOI: 10.13961/j.cnki.stbctb.2024.06.020
Abstract:
[Objective] The quantitative characteristics of plant communities and their influencing factors under different slope positions in the Loess Plateau were investigated, so as to provide a scientific reference for the theoretical understanding of plant community construction mechanisms within the slope-gully system and for the practical guidance on the design of artificially plant communities restoration. [Methods] The study examines the composition, diversity, stability, and distribution patterns of dominant plants across five slope positions-sunny gully, sunny hill, hilltop, shady hill, and shady gully-within the forest-steppe zone of the loess hilly region under natural conditions. The structural equation model of environmental factors, soil erosion intensity, and plant diversity and stability was constructed to explore the main ecological factors affecting the construction of plant communities in different slope positions. [Results] ① In the forest-steppe zone of the loess hilly region, the sunny gully and sunny hill slopes exhibit a two-layer vertical structure predominantly composed of perennial herbs and shrubs, with dominant plants showing a dispersed distribution pattern. The hilltop had a single-layer vertical structure, mainly comprising annual and perennial herbs, where plants demonstrate a highly clustered distribution. The shady gully slope community had a three-layer vertical structure, with plants also showing a clustered distribution pattern. ② The shady gully slope had the highest species diversity, richness, and stability, whereas the sunny hill slope exhibited the lowest richness and diversity, with significant reductions of 18.4% and 26.5%, respectively, compared to the shady gully slope. The hilltop plant community showed the least stability, with an index of only 29. ③ The common key factors influencing community characteristics across different slope positions were soil erosion intensity and soil moisture. However, soil bulk density on the sunny gully slope, organic matter on the sunny and shady hill slopes, and light intensity on the hilltop and shady gully slope were the distinguishing ecological factors affecting plant community structure, stability, and diversity. [Conclusion] Vegetation restoration strategies should be tailored to the specific slope positions in the forest-steppe zone of the loess hilly region. The “fertile island” effect formed by perennial shrubs on the sunny gully slope could improve surface conditions, while micro-topographic modifications on the sunny hill slope could reduce soil erosion. On the hilltop, the introduction of drought-tolerant plants could enhance plant community structure. The shady hill and gully slopes do not require the construction of an excessively complex plant community structure, so as not to cause the degradation of the herbaceous layer under the artificial forest owing to insufficient light.
[Objective] The quantitative characteristics of plant communities and their influencing factors under different slope positions in the Loess Plateau were investigated, so as to provide a scientific reference for the theoretical understanding of plant community construction mechanisms within the slope-gully system and for the practical guidance on the design of artificially plant communities restoration. [Methods] The study examines the composition, diversity, stability, and distribution patterns of dominant plants across five slope positions-sunny gully, sunny hill, hilltop, shady hill, and shady gully-within the forest-steppe zone of the loess hilly region under natural conditions. The structural equation model of environmental factors, soil erosion intensity, and plant diversity and stability was constructed to explore the main ecological factors affecting the construction of plant communities in different slope positions. [Results] ① In the forest-steppe zone of the loess hilly region, the sunny gully and sunny hill slopes exhibit a two-layer vertical structure predominantly composed of perennial herbs and shrubs, with dominant plants showing a dispersed distribution pattern. The hilltop had a single-layer vertical structure, mainly comprising annual and perennial herbs, where plants demonstrate a highly clustered distribution. The shady gully slope community had a three-layer vertical structure, with plants also showing a clustered distribution pattern. ② The shady gully slope had the highest species diversity, richness, and stability, whereas the sunny hill slope exhibited the lowest richness and diversity, with significant reductions of 18.4% and 26.5%, respectively, compared to the shady gully slope. The hilltop plant community showed the least stability, with an index of only 29. ③ The common key factors influencing community characteristics across different slope positions were soil erosion intensity and soil moisture. However, soil bulk density on the sunny gully slope, organic matter on the sunny and shady hill slopes, and light intensity on the hilltop and shady gully slope were the distinguishing ecological factors affecting plant community structure, stability, and diversity. [Conclusion] Vegetation restoration strategies should be tailored to the specific slope positions in the forest-steppe zone of the loess hilly region. The “fertile island” effect formed by perennial shrubs on the sunny gully slope could improve surface conditions, while micro-topographic modifications on the sunny hill slope could reduce soil erosion. On the hilltop, the introduction of drought-tolerant plants could enhance plant community structure. The shady hill and gully slopes do not require the construction of an excessively complex plant community structure, so as not to cause the degradation of the herbaceous layer under the artificial forest owing to insufficient light.
2024,44(6):194-199,209
, DOI: 10.13961/j.cnki.stbctb.2024.06.021
Abstract:
[Objective] The rainfall regimes and their effects on runoff and sediment yield in the small watershed of the upper reaches of Dawen River were studied, in order to provided a theoretical basis for the predicting and early warning of flood control and soil erosion in the mountainous and hilly areas of Central and Southern Shandong Province. [Methods] The Culai Mountain watershed in the upper reaches of the Dawen River was selected as the study area. K-means clustering and multiple linear regression analysis were employed to examine different types of rainfall and their impacts on sediment yield using rainfall, runoff, and sediment yield data from 2021 to 2023. [Results] The rainfall in this basin can be divided into four types, categorized as follows: type Ⅰ features small amounts of precipitation with low intensity, type Ⅱ features medium amounts of precipitation with moderate intensity, type Ⅲ features heavy amounts of precipitation with high intensity, and type Ⅳ features extra heavy amounts of precipitation with moderate intensity. Rainfall in types Ⅲ and Ⅳ was the main source of runoff and sediment yield in this basin. [Conclusion] The Culai Mountain watershed mainly experiences light rainfall with low intensity, yet the frequency of rainstorms remains relatively high. Affected by the mountainous terrain, the Ⅳ type rainfall was significant sources of regional floods and debris flows. Rainfall Precipitation amount is the primary influencing factor for runoff and sediment production in this basin.
[Objective] The rainfall regimes and their effects on runoff and sediment yield in the small watershed of the upper reaches of Dawen River were studied, in order to provided a theoretical basis for the predicting and early warning of flood control and soil erosion in the mountainous and hilly areas of Central and Southern Shandong Province. [Methods] The Culai Mountain watershed in the upper reaches of the Dawen River was selected as the study area. K-means clustering and multiple linear regression analysis were employed to examine different types of rainfall and their impacts on sediment yield using rainfall, runoff, and sediment yield data from 2021 to 2023. [Results] The rainfall in this basin can be divided into four types, categorized as follows: type Ⅰ features small amounts of precipitation with low intensity, type Ⅱ features medium amounts of precipitation with moderate intensity, type Ⅲ features heavy amounts of precipitation with high intensity, and type Ⅳ features extra heavy amounts of precipitation with moderate intensity. Rainfall in types Ⅲ and Ⅳ was the main source of runoff and sediment yield in this basin. [Conclusion] The Culai Mountain watershed mainly experiences light rainfall with low intensity, yet the frequency of rainstorms remains relatively high. Affected by the mountainous terrain, the Ⅳ type rainfall was significant sources of regional floods and debris flows. Rainfall Precipitation amount is the primary influencing factor for runoff and sediment production in this basin.
2024,44(6):200-209
, DOI: 10.13961/j.cnki.stbctb.2024.06.022
Abstract:
[Objective] The characteristics of cultivated land changes around large cities were studied to provide a key basis for realizing the sustainable utilization of cultivated land resources and high-quality development of national space in the concentrated expansion areas of cities. [Methods] Three typical large cities in the upper, middle, and lower sections of the Yangtze River economic belt (Chengdu, Wuhan and Shanghai City) were selected as examples. Based on a land-use transfer matrix and a framework for analyzing the intensity of land-use change, it elaborated on the intensity and stability characteristics of cultivated land change around the three big cities over a long period and explored the synergistic mechanism between urban sprawl and the protection of high-quality cultivated land. [Results] ① The total area of cultivated land around the three major cities decreased continuously between 1990 and 2020, with the loss of high-quality cultivated land and the pressure to replenish cultivated land, and the loss of cultivated land in the middle of the period was the most serious. Wuhan City achieved a balance between occupation and compensation for cultivated land during the late stage. ② The big cities in the Yangtze River economic belt showed rapid land-use changes between 1990 and 2020, and only Chengdu City showed slow changes in the early period. ③ The transfer out of cultivated land and the transfer in of construction land around the big cities in the Yangtze River economic belt had been active between 1990 and 2020, whereas the transfer in of cultivated land had remained stable; the transfer out of construction land in Chengdu and Wuhan City began to be active after 2010. ④ The conversion process of cultivated land to construction land around the big cities in the Yangtze River economic belt between 1990 and 2020 showed a stable tendency systematic conversion pattern, and the transfer in of construction land mainly originated from cultivated land. [Conclusion] In the future, it will be necessary to scientifically formulate a rigid and elastic combination of cultivated land control strategies, realize the multifunctional protection of cultivated land from the perspective of regional ecological security, and establish a diversified cultivated land protection incentive system around the large cities of the Yangtze River economic belt.
[Objective] The characteristics of cultivated land changes around large cities were studied to provide a key basis for realizing the sustainable utilization of cultivated land resources and high-quality development of national space in the concentrated expansion areas of cities. [Methods] Three typical large cities in the upper, middle, and lower sections of the Yangtze River economic belt (Chengdu, Wuhan and Shanghai City) were selected as examples. Based on a land-use transfer matrix and a framework for analyzing the intensity of land-use change, it elaborated on the intensity and stability characteristics of cultivated land change around the three big cities over a long period and explored the synergistic mechanism between urban sprawl and the protection of high-quality cultivated land. [Results] ① The total area of cultivated land around the three major cities decreased continuously between 1990 and 2020, with the loss of high-quality cultivated land and the pressure to replenish cultivated land, and the loss of cultivated land in the middle of the period was the most serious. Wuhan City achieved a balance between occupation and compensation for cultivated land during the late stage. ② The big cities in the Yangtze River economic belt showed rapid land-use changes between 1990 and 2020, and only Chengdu City showed slow changes in the early period. ③ The transfer out of cultivated land and the transfer in of construction land around the big cities in the Yangtze River economic belt had been active between 1990 and 2020, whereas the transfer in of cultivated land had remained stable; the transfer out of construction land in Chengdu and Wuhan City began to be active after 2010. ④ The conversion process of cultivated land to construction land around the big cities in the Yangtze River economic belt between 1990 and 2020 showed a stable tendency systematic conversion pattern, and the transfer in of construction land mainly originated from cultivated land. [Conclusion] In the future, it will be necessary to scientifically formulate a rigid and elastic combination of cultivated land control strategies, realize the multifunctional protection of cultivated land from the perspective of regional ecological security, and establish a diversified cultivated land protection incentive system around the large cities of the Yangtze River economic belt.
2024,44(6):210-221,247
, DOI: 10.13961/j.cnki.stbctb.20240923.001
Abstract:
[Objective] The adaptive siting and layout characteristics of rural settlements in the aquatic environment and the ecological wisdom they contain from the perspective of water-related place names were analyzed to provide theoretical references and inspiration for safety and resilience planning and sustainable development of contemporary rural settlements in the context of climate change. [Methods] Settlement types were classified according to water-related names. Combining textual and spatial analyses, spatial autocorrelation, kernel density estimation, and the SCS-CN hydrological model were comprehensively applied to analyze the adaptive siting and layout characteristics of rural settlements in South Henan Province. [Results] ① The naming of rural settlements in South Henan presents significant aquatic environment orientation, and there is a certain corroborative relationship between place names and spatial patterns. ② The spatial distribution of various types of water-related settlements is significantly clustered and spatially heterogeneous, with a high degree of dependence on the unique water environment. ③ In the macro-level of adaptive siting to the water environment, rural settlements in South Henan have a strong preference for near-water siting and consideration of rain and flood risk. ④ Under the comprehensive influence of the aquatic environment, the adaptive layout features such as site utilization with storage and drainage, village layout to avoid rain and flood, and environmental transformation with consideration of defense have been formed. [Conclusion] The naming of the rural settlements in the Southern Henan region has strong water-related features, and the siting and layout fully embodies the ecological wisdom of water environment adaptation, which tends to benefit from and avoid harm, as well as low technology and ecology. In the future, the concept of water environment adaptation planning can be inherited by watersheds, town and village systems, and facilities.
[Objective] The adaptive siting and layout characteristics of rural settlements in the aquatic environment and the ecological wisdom they contain from the perspective of water-related place names were analyzed to provide theoretical references and inspiration for safety and resilience planning and sustainable development of contemporary rural settlements in the context of climate change. [Methods] Settlement types were classified according to water-related names. Combining textual and spatial analyses, spatial autocorrelation, kernel density estimation, and the SCS-CN hydrological model were comprehensively applied to analyze the adaptive siting and layout characteristics of rural settlements in South Henan Province. [Results] ① The naming of rural settlements in South Henan presents significant aquatic environment orientation, and there is a certain corroborative relationship between place names and spatial patterns. ② The spatial distribution of various types of water-related settlements is significantly clustered and spatially heterogeneous, with a high degree of dependence on the unique water environment. ③ In the macro-level of adaptive siting to the water environment, rural settlements in South Henan have a strong preference for near-water siting and consideration of rain and flood risk. ④ Under the comprehensive influence of the aquatic environment, the adaptive layout features such as site utilization with storage and drainage, village layout to avoid rain and flood, and environmental transformation with consideration of defense have been formed. [Conclusion] The naming of the rural settlements in the Southern Henan region has strong water-related features, and the siting and layout fully embodies the ecological wisdom of water environment adaptation, which tends to benefit from and avoid harm, as well as low technology and ecology. In the future, the concept of water environment adaptation planning can be inherited by watersheds, town and village systems, and facilities.
Zhang Feng, Chen Jia, Fan Pingping, Niu Yong, Fang Nufang, Wu Zeyan, Tan Tingjun, Long Wentao, Tai Liang
2024,44(6):222-236
, DOI: 10.13961/j.cnki.stbctb.2024.06.024
Abstract:
[Objective] The effects of soil erosion and sedimentation on the form, concentration, and enrichment of heavy metals were explored, and the mechanism of the influence of soil erosion and sedimentation on the form, concentration and enrichment of heavy metals were studied, in order to provide a scientific basis for the prevention and control of soil heavy metal pollution in river basins. [Methods] Based on relevant domestic and foreign studies about the influence of erosion-deposition on soil heavy metals, CiteSpace and VOSveiwer software were used to study the knowledge map of the influence of soil heavy metals during erosion-deposition and the relevant research results were systematically analyzed. [Results] ① The research on erosion-sedimentation and heavy metals has shown an upward trend in the past 30 years, increasing rapidly from 2017 to 2023, and geochemical characteristics, ecological risk assessment, source analysis, migration, and transformation are the hot spots in the research area. ② During the erosion process, rainfall promoted the transformation of heavy metals from a granular state to a dissolved state, runoff led to the spatial differentiation of soil heavy metal content, and soil aggregate and clay content in the sedimentary environment affected the distribution and enrichment of heavy metals. ③ Organic matter has dual effects on heavy metals: it can adsorb free heavy metal ions and reduce the exchange state content of heavy metals in soil. In addition, it can also have complexation with heavy metals and increase the organic binding state content of heavy metals. ④ The pH value has a significant effect on the transformation of heavy metal forms. Under acidic conditions, the complexation and precipitation of heavy metal ions are promoted. In contrast, under alkaline conditions, the positive charge on the surface of soil particles repels the positive charge carried by heavy metal ions, thus affecting the adsorption of heavy metal ions on the surface of soil particles. ⑤ Soil water affects the reduction and release of heavy metals. The higher the soil water, the greater the solubility of heavy metals, but excessive water will lead to insufficient oxygen and reduce the REDOX potential (Eh). The change of Eh directly affects the stability of iron and manganese oxides and sulfides in soil, causing changes in heavy metal concentration. [Conclusion] The occurrence forms, concentration changes, and enrichment characteristics of soil heavy metals during the erosion-deposition process are affected by various environmental factors, showing significant differences from erosion area to sedimentary area. Future studies should focus on the development of new technologies and new methods for monitoring the dynamic evolution of heavy metals during the erosion-deposition process. To provide more accurate strategies for the prevention and control of soil heavy metal pollution, a study on the internal relation mechanism of the occurrence form, concentration change, and enrichment characteristics of heavy metals during the erosion-sedimentation process and interaction effects of different factors on heavy metals during erosion-deposition should be conducted.
[Objective] The effects of soil erosion and sedimentation on the form, concentration, and enrichment of heavy metals were explored, and the mechanism of the influence of soil erosion and sedimentation on the form, concentration and enrichment of heavy metals were studied, in order to provide a scientific basis for the prevention and control of soil heavy metal pollution in river basins. [Methods] Based on relevant domestic and foreign studies about the influence of erosion-deposition on soil heavy metals, CiteSpace and VOSveiwer software were used to study the knowledge map of the influence of soil heavy metals during erosion-deposition and the relevant research results were systematically analyzed. [Results] ① The research on erosion-sedimentation and heavy metals has shown an upward trend in the past 30 years, increasing rapidly from 2017 to 2023, and geochemical characteristics, ecological risk assessment, source analysis, migration, and transformation are the hot spots in the research area. ② During the erosion process, rainfall promoted the transformation of heavy metals from a granular state to a dissolved state, runoff led to the spatial differentiation of soil heavy metal content, and soil aggregate and clay content in the sedimentary environment affected the distribution and enrichment of heavy metals. ③ Organic matter has dual effects on heavy metals: it can adsorb free heavy metal ions and reduce the exchange state content of heavy metals in soil. In addition, it can also have complexation with heavy metals and increase the organic binding state content of heavy metals. ④ The pH value has a significant effect on the transformation of heavy metal forms. Under acidic conditions, the complexation and precipitation of heavy metal ions are promoted. In contrast, under alkaline conditions, the positive charge on the surface of soil particles repels the positive charge carried by heavy metal ions, thus affecting the adsorption of heavy metal ions on the surface of soil particles. ⑤ Soil water affects the reduction and release of heavy metals. The higher the soil water, the greater the solubility of heavy metals, but excessive water will lead to insufficient oxygen and reduce the REDOX potential (Eh). The change of Eh directly affects the stability of iron and manganese oxides and sulfides in soil, causing changes in heavy metal concentration. [Conclusion] The occurrence forms, concentration changes, and enrichment characteristics of soil heavy metals during the erosion-deposition process are affected by various environmental factors, showing significant differences from erosion area to sedimentary area. Future studies should focus on the development of new technologies and new methods for monitoring the dynamic evolution of heavy metals during the erosion-deposition process. To provide more accurate strategies for the prevention and control of soil heavy metal pollution, a study on the internal relation mechanism of the occurrence form, concentration change, and enrichment characteristics of heavy metals during the erosion-sedimentation process and interaction effects of different factors on heavy metals during erosion-deposition should be conducted.
2024,44(6):237-247
, DOI: 10.13961/j.cnki.stbctb.2024.06.025
Abstract:
[Objective] The temporal and spatial variation characteristics and the factors affecting the water conservation function in Gansu Province were studied to provide a reference and basis for regional water resources management decision-making and water conservation function recovery. [Methods] The dynamic changes in water conservation on the temporal and spatial scale in Gansu Province from 2001 to 2023 were evaluated quantitatively using the InVEST model, and the influencing factors of the water conservation function were analyzed using the geographic detector. [Results] ① The average water conservation in Gansu Province from 2001 to 2023 was 9.24 mm, and the water conservation fluctuated little during different periods. The change in water conservation was consistent with the precipitation and water yield, showing an upward and then a downward trend. ② From 2001 to 2023, the average water conservation capacity of different land use types in Gansu Province was ranked as cultivated, grass, forest, urban construction, unused land, and water area. ③ Precipitation was the most important driver for the change of water conservation in Gansu Province, and the interactions between precipitation and evapotranspiration, land use type, and elevation had the most significant influence on the spatial difference of the water conservation service function in Gansu Province. [Conclusion] The overall distribution pattern of water conservation in the Gansu Province was lower in the northwest and higher in the southeast. The change in water conservation function was mainly influenced by climate factors and human activities.
[Objective] The temporal and spatial variation characteristics and the factors affecting the water conservation function in Gansu Province were studied to provide a reference and basis for regional water resources management decision-making and water conservation function recovery. [Methods] The dynamic changes in water conservation on the temporal and spatial scale in Gansu Province from 2001 to 2023 were evaluated quantitatively using the InVEST model, and the influencing factors of the water conservation function were analyzed using the geographic detector. [Results] ① The average water conservation in Gansu Province from 2001 to 2023 was 9.24 mm, and the water conservation fluctuated little during different periods. The change in water conservation was consistent with the precipitation and water yield, showing an upward and then a downward trend. ② From 2001 to 2023, the average water conservation capacity of different land use types in Gansu Province was ranked as cultivated, grass, forest, urban construction, unused land, and water area. ③ Precipitation was the most important driver for the change of water conservation in Gansu Province, and the interactions between precipitation and evapotranspiration, land use type, and elevation had the most significant influence on the spatial difference of the water conservation service function in Gansu Province. [Conclusion] The overall distribution pattern of water conservation in the Gansu Province was lower in the northwest and higher in the southeast. The change in water conservation function was mainly influenced by climate factors and human activities.
2024,44(6):248-255
, DOI: 10.13961/j.cnki.stbctb.2024.06.026
Abstract:
[Objective] The temporal and spatial variations in the soil and water conservation service functions in Hunan Province were explored, in order to provide a scientific basis for evaluating these functions and formulating a regional ecological management plan. [Methods] Three factors of net primary productivity (NPP) of vegetation, digital elevation model elevation, and soil texture distribution were selected, and the spatial and temporal distribution characteristics of soil and water conservation service functions in Hunan Province were studied based on ArcGIS for the years 2000, 2005, 2010, 2015, and 2020 using the NPP quantitative index evaluation model. [Results] ① From 2000 to 2020, the average net primary productivity of vegetation in Hunan Province ranged from 4.39 to 334.52 g/(m2·a) (calculated by C), showing an upward trend over time. Spatially, the average net primary productivity was higher in the middle and decreasing towards the edges. The elevation varied from -12 to 2,081 m, exhibiting a trend of being high in the west and low in the east, with significant fluctuations in the west and relatively gentle terrain in the east. The slope ranged from 3.3° to 76.7°, showing a trend of being higher in the west and lower in the east. The soil erodibility values ranged from 0.011 to 1.411, indicating that soil erodibility tends to be low in the middle and high towards the edges, spreading and improving from the central area to surrounding regions. ② From 2000 to 2020, the amount of soil and water conservation in Hunan Province ranged from 8.75 to 185.97 t/hm2, demonstrating an upward trend over time, primarily in general important and important regions. The area of general important region showed a downward trend over time, while the area of important region showed an upward trend, and the area of extremely important regions exhibited a downward trend. The service function of soil and water conservation transitioned from generally important and extremely important regions to important regions over time. [Conclusion] The increase in net primary productivity of vegetation is the primary reason for the enhancement of soil and water conservation service functions.
[Objective] The temporal and spatial variations in the soil and water conservation service functions in Hunan Province were explored, in order to provide a scientific basis for evaluating these functions and formulating a regional ecological management plan. [Methods] Three factors of net primary productivity (NPP) of vegetation, digital elevation model elevation, and soil texture distribution were selected, and the spatial and temporal distribution characteristics of soil and water conservation service functions in Hunan Province were studied based on ArcGIS for the years 2000, 2005, 2010, 2015, and 2020 using the NPP quantitative index evaluation model. [Results] ① From 2000 to 2020, the average net primary productivity of vegetation in Hunan Province ranged from 4.39 to 334.52 g/(m2·a) (calculated by C), showing an upward trend over time. Spatially, the average net primary productivity was higher in the middle and decreasing towards the edges. The elevation varied from -12 to 2,081 m, exhibiting a trend of being high in the west and low in the east, with significant fluctuations in the west and relatively gentle terrain in the east. The slope ranged from 3.3° to 76.7°, showing a trend of being higher in the west and lower in the east. The soil erodibility values ranged from 0.011 to 1.411, indicating that soil erodibility tends to be low in the middle and high towards the edges, spreading and improving from the central area to surrounding regions. ② From 2000 to 2020, the amount of soil and water conservation in Hunan Province ranged from 8.75 to 185.97 t/hm2, demonstrating an upward trend over time, primarily in general important and important regions. The area of general important region showed a downward trend over time, while the area of important region showed an upward trend, and the area of extremely important regions exhibited a downward trend. The service function of soil and water conservation transitioned from generally important and extremely important regions to important regions over time. [Conclusion] The increase in net primary productivity of vegetation is the primary reason for the enhancement of soil and water conservation service functions.
2024,44(6):256-268
, DOI: 10.13961/j.cnki.stbctb.20240829.001
Abstract:
[Objective] The coupling coordination relationship between economic development quality and ecological resilience, and its dynamic evolution form process were explored, and the coordination role and response mechanism of economic development and ecological protection were clarified, so as to provide theoretical reference for efficient resource allocation and urban-rural integrated development in land border areas. [Methods] The coupled coordination model and kernel density estimation were used to measure and depict the coupling relationship and distribution pattern between economic development quality and ecological resilience. Finally, the P-VAR model was employed to elaborate and verify the interactive response relationship between the two systems. [Results] ① From 2000 to 2020, the coupling coordination degree between economic development quality and ecological resilience in border areas ranged from 0.183 4 to 0.272 8, showing an “initial decline followed by an increase” evolutionary characteristic. The coupling coordination degree of each border area gradually evolved from a unimodal shape to a bimodal manifestation. ② The pulse response of ecological resilience to the quality of economic development in the northern, northwestern of China, and Xizang border areas was negatively impacted, while the pulse response of ecological resilience to the quality of economic development in the northeast, northwest, and southwest border areas of China was positively impacted. ③ The contribution rate of the quality of economic development to ecological resilience in border areas is gradually increasing, while the contribution rate of ecological resilience to the quality of economic development was gradually decreasing. The contribution rate of the interactive response between the two systems in the northwest border area was higher than that in other border areas of China. [Conclusion] There are significant regional differences in the coupling, coordination and interaction of economic development quality and ecological resilience in China’s land border areas, so it is beneficial to promote the sustainable use of economic elements and ensure the ecological security of land space in China’s land border areas.
[Objective] The coupling coordination relationship between economic development quality and ecological resilience, and its dynamic evolution form process were explored, and the coordination role and response mechanism of economic development and ecological protection were clarified, so as to provide theoretical reference for efficient resource allocation and urban-rural integrated development in land border areas. [Methods] The coupled coordination model and kernel density estimation were used to measure and depict the coupling relationship and distribution pattern between economic development quality and ecological resilience. Finally, the P-VAR model was employed to elaborate and verify the interactive response relationship between the two systems. [Results] ① From 2000 to 2020, the coupling coordination degree between economic development quality and ecological resilience in border areas ranged from 0.183 4 to 0.272 8, showing an “initial decline followed by an increase” evolutionary characteristic. The coupling coordination degree of each border area gradually evolved from a unimodal shape to a bimodal manifestation. ② The pulse response of ecological resilience to the quality of economic development in the northern, northwestern of China, and Xizang border areas was negatively impacted, while the pulse response of ecological resilience to the quality of economic development in the northeast, northwest, and southwest border areas of China was positively impacted. ③ The contribution rate of the quality of economic development to ecological resilience in border areas is gradually increasing, while the contribution rate of ecological resilience to the quality of economic development was gradually decreasing. The contribution rate of the interactive response between the two systems in the northwest border area was higher than that in other border areas of China. [Conclusion] There are significant regional differences in the coupling, coordination and interaction of economic development quality and ecological resilience in China’s land border areas, so it is beneficial to promote the sustainable use of economic elements and ensure the ecological security of land space in China’s land border areas.
2024,44(6):269-277
, DOI: 10.13961/j.cnki.stbctb.2024.06.028
Abstract:
[Objective] The balance and sustainable status of water resources supply and demand in seven river basins in China were examined aiming to provide a reference for the future development of integrated management and scientific allocation of water resources. [Methods] Using the water resources ecological footprint method, this study examined the water resources ecological footprint and ecological carrying capacity of seven river basins in China between 2014 and 2022. The status of water resource sustainability was revealed by using the sustainability evaluation index based on water resources’ ecological footprint. [Results] ① The per capita ecological footprint of water resources in China’s seven major river basins showed a downward trend, among which Songhua River, Yangtze River, Pearl River, and Haihe River accounted for 82.86%, 33.32%, 19.87%, and 12.38% of agricultural water, industrial water, domestic water, and ecological water, respectively. ② The highest per capita carrying capacity was that of the Pearl River at 19.89 hm2/person, whereas the lowest was only 0.03 hm2/person for the Haihe River. Affected by climate anomalies, the ecological carrying capacity of water resources in each basin oscillated considerably from 2020 to 2022. ③ During the study period, the Yangtze, Pearl, and Songhua rivers had a total water resources ecological surplus, with the Pearl River having the largest water resources ecological surplus of 18.21 hm2/person in 2016. The Huaihe and Liaohe rivers went from a water resources ecological deficit to a surplus. The Yellow and Haihe rivers had a water resources ecological deficit, with the Yellow River having the largest water resources ecological deficit of -0.62 hm2/person in 2015. ④ The indicators of sustainable development of water resources implied that the Yellow and Haihe rivers were under greater ecological pressure from water resources and in a state of unsustainable water resources throughout the year, whereas the Pearl River had poor water resource coordination and overall low water use efficiency. [Conclusion] Currently, the balance between the supply and demand of water resources in the Yangtze, Pearl, Songhua, Huaihe, and Liaohe rivers is maintained, whereas the demand of the Yellow and Haihe rivers is always greater than the supply. In the future, water resources planning schemes at the national and basin levels should be established to promote rational utilization of water resources and support sustainable economic and social development in the basin.
[Objective] The balance and sustainable status of water resources supply and demand in seven river basins in China were examined aiming to provide a reference for the future development of integrated management and scientific allocation of water resources. [Methods] Using the water resources ecological footprint method, this study examined the water resources ecological footprint and ecological carrying capacity of seven river basins in China between 2014 and 2022. The status of water resource sustainability was revealed by using the sustainability evaluation index based on water resources’ ecological footprint. [Results] ① The per capita ecological footprint of water resources in China’s seven major river basins showed a downward trend, among which Songhua River, Yangtze River, Pearl River, and Haihe River accounted for 82.86%, 33.32%, 19.87%, and 12.38% of agricultural water, industrial water, domestic water, and ecological water, respectively. ② The highest per capita carrying capacity was that of the Pearl River at 19.89 hm2/person, whereas the lowest was only 0.03 hm2/person for the Haihe River. Affected by climate anomalies, the ecological carrying capacity of water resources in each basin oscillated considerably from 2020 to 2022. ③ During the study period, the Yangtze, Pearl, and Songhua rivers had a total water resources ecological surplus, with the Pearl River having the largest water resources ecological surplus of 18.21 hm2/person in 2016. The Huaihe and Liaohe rivers went from a water resources ecological deficit to a surplus. The Yellow and Haihe rivers had a water resources ecological deficit, with the Yellow River having the largest water resources ecological deficit of -0.62 hm2/person in 2015. ④ The indicators of sustainable development of water resources implied that the Yellow and Haihe rivers were under greater ecological pressure from water resources and in a state of unsustainable water resources throughout the year, whereas the Pearl River had poor water resource coordination and overall low water use efficiency. [Conclusion] Currently, the balance between the supply and demand of water resources in the Yangtze, Pearl, Songhua, Huaihe, and Liaohe rivers is maintained, whereas the demand of the Yellow and Haihe rivers is always greater than the supply. In the future, water resources planning schemes at the national and basin levels should be established to promote rational utilization of water resources and support sustainable economic and social development in the basin.
2024,44(6):278-287
, DOI: 10.13961/j.cnki.stbctb.2024.06.029
Abstract:
[Objective] The changes of vegetation net primary production (NPP) and its response to climate factors were quantitatively analyzed to provide scientific reference for assessing the role of urban carbon sequestration under different climate conditions and improving urban ecosystem carbon sequestration. [Methods] Based on GEE (Google Earth Engine), the NPP of Tianjin City during 2001—2022 was calculated, and the spatial and temporal variation pattern of NPP was analyzed by Slope trend analysis, F-test, barycentric migration model, standard deviation ellipse model, and other methods. Multi-factor sensitivity analysis and correlation coefficient evaluation were used to quantitatively evaluate the NPP response characteristics under temperature, precipitation, and wind-speed changes. [Results] ① The average annual vegetation NPP in Tianjin City showed an increasing trend of fluctuation, and the fluctuation range was 53.46—96.54 g/(m2·a) (calculated by C); ② The vegetation NPP of Tianjin City is higher in the north and lower in the south, and higher in the west and lower in the east. The center of gravity is concentrated in the central region, and it gradually moved to the south during 2001—2022. ③ The response of vegetation NPP to climate factors in Tianjin City has a significant lag time of 1 month for temperature and precipitation and 3 months for wind speed. [Conclusion] The variation of NPP in Tianjin City has great spatiotemporal heterogeneity and is affected by temperature, precipitation, and wind speed, with a lag effect of 1—3 months in response to climate factors.
[Objective] The changes of vegetation net primary production (NPP) and its response to climate factors were quantitatively analyzed to provide scientific reference for assessing the role of urban carbon sequestration under different climate conditions and improving urban ecosystem carbon sequestration. [Methods] Based on GEE (Google Earth Engine), the NPP of Tianjin City during 2001—2022 was calculated, and the spatial and temporal variation pattern of NPP was analyzed by Slope trend analysis, F-test, barycentric migration model, standard deviation ellipse model, and other methods. Multi-factor sensitivity analysis and correlation coefficient evaluation were used to quantitatively evaluate the NPP response characteristics under temperature, precipitation, and wind-speed changes. [Results] ① The average annual vegetation NPP in Tianjin City showed an increasing trend of fluctuation, and the fluctuation range was 53.46—96.54 g/(m2·a) (calculated by C); ② The vegetation NPP of Tianjin City is higher in the north and lower in the south, and higher in the west and lower in the east. The center of gravity is concentrated in the central region, and it gradually moved to the south during 2001—2022. ③ The response of vegetation NPP to climate factors in Tianjin City has a significant lag time of 1 month for temperature and precipitation and 3 months for wind speed. [Conclusion] The variation of NPP in Tianjin City has great spatiotemporal heterogeneity and is affected by temperature, precipitation, and wind speed, with a lag effect of 1—3 months in response to climate factors.
2024,44(6):288-297
, DOI: 10.13961/j.cnki.stbctb.20241104.001
Abstract:
[Objective] Taking Ma’anshan City of Anhui Province, a resource-based city in transition, as the research object, the influence of urban expansion on the habitat quality of this city was studied, aiming at providing reference for realizing regional sustainable development. [Methods] Based on the Globe Land30 data in 2000, 2010 and 2020, the urban land expansion was studied by means of center of gravity analysis and standard deviation ellipse, and the habitat quality of Ma’anshan City was calculated. In addition, the PLUS model was used to simulate land use change under different scenarios to analyze the impact of urban expansion on habitat quality change. [Results] ① From 2000 to 2020, the construction land and water areas increased significantly in Ma’anshan City, while the areas of other land types decreased. ② Over the same period, habitat quality in Ma’anshan City showed a downward trend, with lower habitat quality in the central plain and higher quality in the eastern and western regions. These results indicate that the spatial distribution of habitat quality is closely related to topography, land use types, and the intensity of human activities. ③ Under three scenarios-natural development, economic development, and ecological protection-the habitat quality indices for Ma’anshan City were 0.448, 0.451, and 0.459, respectively, indicating habitat quality degradation in all scenarios. [Conclusion] Urban expansion has led to a decline in habitat quality in Ma’anshan City. The ecological protection scenario yielded the highest habitat quality index, suggesting it is the most favorable development trend.
[Objective] Taking Ma’anshan City of Anhui Province, a resource-based city in transition, as the research object, the influence of urban expansion on the habitat quality of this city was studied, aiming at providing reference for realizing regional sustainable development. [Methods] Based on the Globe Land30 data in 2000, 2010 and 2020, the urban land expansion was studied by means of center of gravity analysis and standard deviation ellipse, and the habitat quality of Ma’anshan City was calculated. In addition, the PLUS model was used to simulate land use change under different scenarios to analyze the impact of urban expansion on habitat quality change. [Results] ① From 2000 to 2020, the construction land and water areas increased significantly in Ma’anshan City, while the areas of other land types decreased. ② Over the same period, habitat quality in Ma’anshan City showed a downward trend, with lower habitat quality in the central plain and higher quality in the eastern and western regions. These results indicate that the spatial distribution of habitat quality is closely related to topography, land use types, and the intensity of human activities. ③ Under three scenarios-natural development, economic development, and ecological protection-the habitat quality indices for Ma’anshan City were 0.448, 0.451, and 0.459, respectively, indicating habitat quality degradation in all scenarios. [Conclusion] Urban expansion has led to a decline in habitat quality in Ma’anshan City. The ecological protection scenario yielded the highest habitat quality index, suggesting it is the most favorable development trend.
2024,44(6):298-307,386
, DOI: 10.13961/j.cnki.stbctb.2024.06.031
Abstract:
[Objective] The spatiotemporal variation characteristics of vegetation net primary productivity (NPP) and their influencing factors were explored in Altay region of Xinjiang, China, and the adjacent area of Mongolia to provide a reference for cross-border regional ecological protection and sustainable development. [Methods] Regression analysis was used to reveal the spatiotemporal changes in vegetation NPP in Altay region adjacent to China and Mongolia, while correlation analysis and geographical detectors were applied to explore the main influencing factors of vegetation NPP in the cross-border area. [Results] ① From 2001 to 2021, the vegetation NPP in Altay region of Xinjiang, China, showed a slight decreasing trend of 5.49 g/(m2·10 a) (calculated by carbon), while the vegetation NPP in the western part of Mongolia showed a significant increasing trend of 27.06 g/(m2·10 a, p<0.05). ② Temperature (0.49, p<0.05) and precipitation (0.31, p<0.05) were the main factors affecting vegetation NPP in Altay region of Xinjiang, China, and the western part of Mongolia, respectively. ③ The interaction between temperature and land use type had the strongest explanatory power for vegetation NPP in Altay region of Xinjiang, China (0.68, p<0.05), while the interaction between precipitation and land use type had the strongest explanatory power for vegetation NPP in the western part of Mongolia (0.37, p<0.05). [Conclusion] From 2001 to 2021, the vegetation NPP in Altay region of China had been declining yearly, while the vegetation NPP in the western part of Mongolia had been increasing yearly. The interactive drivers of temperature, precipitation, and land use types are the main influences on vegetation NPP in both the Altay region of China and the western part of Mongolia.
[Objective] The spatiotemporal variation characteristics of vegetation net primary productivity (NPP) and their influencing factors were explored in Altay region of Xinjiang, China, and the adjacent area of Mongolia to provide a reference for cross-border regional ecological protection and sustainable development. [Methods] Regression analysis was used to reveal the spatiotemporal changes in vegetation NPP in Altay region adjacent to China and Mongolia, while correlation analysis and geographical detectors were applied to explore the main influencing factors of vegetation NPP in the cross-border area. [Results] ① From 2001 to 2021, the vegetation NPP in Altay region of Xinjiang, China, showed a slight decreasing trend of 5.49 g/(m2·10 a) (calculated by carbon), while the vegetation NPP in the western part of Mongolia showed a significant increasing trend of 27.06 g/(m2·10 a, p<0.05). ② Temperature (0.49, p<0.05) and precipitation (0.31, p<0.05) were the main factors affecting vegetation NPP in Altay region of Xinjiang, China, and the western part of Mongolia, respectively. ③ The interaction between temperature and land use type had the strongest explanatory power for vegetation NPP in Altay region of Xinjiang, China (0.68, p<0.05), while the interaction between precipitation and land use type had the strongest explanatory power for vegetation NPP in the western part of Mongolia (0.37, p<0.05). [Conclusion] From 2001 to 2021, the vegetation NPP in Altay region of China had been declining yearly, while the vegetation NPP in the western part of Mongolia had been increasing yearly. The interactive drivers of temperature, precipitation, and land use types are the main influences on vegetation NPP in both the Altay region of China and the western part of Mongolia.
2024,44(6):308-317
, DOI: 10.13961/j.cnki.stbctb.2024.06.032
Abstract:
[Objective] The changes in net primary productivity (NPP) under forest management and drought disturbance in natural forest areas of Heilongjiang, Jilin, and Liaoning provinces were compared and analyzed, in order to provide scientific support for responding to climate change and achieving sustainable forest management in Northeast China. [Methods] Based on the forest NPP remote-sensing data and land use data of the three northeastern provinces from 2000 to 2022, combined with the vegetation transfer matrix, the net increment of forest NPP under the forest management strategy was obtained. In addition, based on the standardized precipitation evapotranspiration index (SPEI) from 2000 to 2022, combined with the NPP anomaly index and Pearson correlation analysis, quantitative analysis of the effects of severe drought on forest NPP in three provinces of Northeast China was conducted. [Results] ① The average annual growth rate of forest NPP in the three northeastern provinces from 2000 to 2022 was 1.54%, and the spatial distribution of NPP varied significantly. The NPP average of forest area Ⅲ was the highest, and the NPP growth trend of forest areas Ⅰ and Ⅱ was more significant. Over the past 23 years, drought in the three northeastern provinces had been mitigated, and the area of severe drought zone had gradually shrunk from a large area in the west during 2000—2002 and moved north to the northwest of Heilongjiang Province in 2008. ② As forest management continues, the increase of forest area and the conversion of low NPP vegetation to high NPP vegetation over the past 23 years in the forested areas of the three northeastern provinces were the important reasons for the growth of forest NPP at the site by 15.20 Tg (calculated by carbon), with the highest percentage of increase in the area of deciduous broadleaved forests, which amounted to 43.29%. ③ Forest NPP and SPEI for the three northeastern provinces showed a significant positive correlation (R=0.60, p<0.01) and also showed a highly significant positive correlation (p<0.01) in forest areas Ⅰ (R=0.57) and Ⅱ (R=0.79), where forest NPP decreased with drought. Heavy drought decreased forest NPP in the three northeastern provinces by 11.09 Tg during 23 years. [Conclusion] Drought disturbance under climate change and forest management affected forest NPP both negatively and positively in the three northeastern provinces, but the latter was greater than the former, and forest NPP increased. Among them, the sensitivity to drought was much higher in the Greater and Lesser Khingan Mountains forests than in the Changbai Mountain forests.
[Objective] The changes in net primary productivity (NPP) under forest management and drought disturbance in natural forest areas of Heilongjiang, Jilin, and Liaoning provinces were compared and analyzed, in order to provide scientific support for responding to climate change and achieving sustainable forest management in Northeast China. [Methods] Based on the forest NPP remote-sensing data and land use data of the three northeastern provinces from 2000 to 2022, combined with the vegetation transfer matrix, the net increment of forest NPP under the forest management strategy was obtained. In addition, based on the standardized precipitation evapotranspiration index (SPEI) from 2000 to 2022, combined with the NPP anomaly index and Pearson correlation analysis, quantitative analysis of the effects of severe drought on forest NPP in three provinces of Northeast China was conducted. [Results] ① The average annual growth rate of forest NPP in the three northeastern provinces from 2000 to 2022 was 1.54%, and the spatial distribution of NPP varied significantly. The NPP average of forest area Ⅲ was the highest, and the NPP growth trend of forest areas Ⅰ and Ⅱ was more significant. Over the past 23 years, drought in the three northeastern provinces had been mitigated, and the area of severe drought zone had gradually shrunk from a large area in the west during 2000—2002 and moved north to the northwest of Heilongjiang Province in 2008. ② As forest management continues, the increase of forest area and the conversion of low NPP vegetation to high NPP vegetation over the past 23 years in the forested areas of the three northeastern provinces were the important reasons for the growth of forest NPP at the site by 15.20 Tg (calculated by carbon), with the highest percentage of increase in the area of deciduous broadleaved forests, which amounted to 43.29%. ③ Forest NPP and SPEI for the three northeastern provinces showed a significant positive correlation (R=0.60, p<0.01) and also showed a highly significant positive correlation (p<0.01) in forest areas Ⅰ (R=0.57) and Ⅱ (R=0.79), where forest NPP decreased with drought. Heavy drought decreased forest NPP in the three northeastern provinces by 11.09 Tg during 23 years. [Conclusion] Drought disturbance under climate change and forest management affected forest NPP both negatively and positively in the three northeastern provinces, but the latter was greater than the former, and forest NPP increased. Among them, the sensitivity to drought was much higher in the Greater and Lesser Khingan Mountains forests than in the Changbai Mountain forests.
2024,44(6):318-327
, DOI: 10.13961/j.cnki.stbctb.2024.06.033
Abstract:
[Objective] A logical system of “connotation interpretation, identification and evaluation, and regulation and resolution” of land use conflicts was constructed to explore the spatial types and pattern conflicts in Yancheng City, Jiangsu Province from 2010 to 2022 and to provide references for the optimization of territorial spatial layout and marine ecological environment protection. [Methods] Taking Yancheng City as an example, the spatial type and pattern conflict index were constructed based on the scale characteristics of conflicts and the landscape ecology model based on the land profit data for 2010, 2015, and 2022, respectively, to identify the spatial units and intensities of land use conflicts at the three scales of Yancheng City: City, district or county, and grid. It also revealed the conflict of interest in the social and economic background, putting forward the regulation and optimization measures. [Results] ① Owing to the strict protection of ecological space, spatial development would mainly occupy agricultural space. Coastal areas and counties would present more complex conflicts of interest due to the promotion of coastal economic development strategy and ecological protection. ② The spatial pattern conflicts in Yancheng City from 2010 to 2022 were mainly found in the western inland region and the coastal land of Dafeng District, which were related to the high ecological risk of land use change driven by lake wetland protection and coastal economic development. ③ The Yancheng City should focus on coordinating the main contradictions between economic development and basic farmland protection, and there was a need to standardize the conflict of interests on land use for the smooth promotion of coastal economic development strategy. [Conclusion] From 2010 to 2022, the ecological space of Yancheng City had been controlled strictly. The pressure of cultivated land protection in the city was relatively larger, and the contradiction of coastal development was relatively complicated. The conflict between economic development and agricultural protection should be solved in the whole city, and the conflict between port economy, aquaculture development and beach wetland protection should be coordinated in the coastal area.
[Objective] A logical system of “connotation interpretation, identification and evaluation, and regulation and resolution” of land use conflicts was constructed to explore the spatial types and pattern conflicts in Yancheng City, Jiangsu Province from 2010 to 2022 and to provide references for the optimization of territorial spatial layout and marine ecological environment protection. [Methods] Taking Yancheng City as an example, the spatial type and pattern conflict index were constructed based on the scale characteristics of conflicts and the landscape ecology model based on the land profit data for 2010, 2015, and 2022, respectively, to identify the spatial units and intensities of land use conflicts at the three scales of Yancheng City: City, district or county, and grid. It also revealed the conflict of interest in the social and economic background, putting forward the regulation and optimization measures. [Results] ① Owing to the strict protection of ecological space, spatial development would mainly occupy agricultural space. Coastal areas and counties would present more complex conflicts of interest due to the promotion of coastal economic development strategy and ecological protection. ② The spatial pattern conflicts in Yancheng City from 2010 to 2022 were mainly found in the western inland region and the coastal land of Dafeng District, which were related to the high ecological risk of land use change driven by lake wetland protection and coastal economic development. ③ The Yancheng City should focus on coordinating the main contradictions between economic development and basic farmland protection, and there was a need to standardize the conflict of interests on land use for the smooth promotion of coastal economic development strategy. [Conclusion] From 2010 to 2022, the ecological space of Yancheng City had been controlled strictly. The pressure of cultivated land protection in the city was relatively larger, and the contradiction of coastal development was relatively complicated. The conflict between economic development and agricultural protection should be solved in the whole city, and the conflict between port economy, aquaculture development and beach wetland protection should be coordinated in the coastal area.
2024,44(6):328-338
, DOI: 10.13961/j.cnki.stbctb.2024.06.034
Abstract:
[Objective] The stages and regional differences in the industrial ecological level of the Hohhot-Baotou-Ordos-Yulin urban agglomeration were measured to understand the shortcomings of the industrial ecological level and formulate more scientific countermeasures and suggestions for the development of the urban agglomeration. [Methods] The evaluation index of industrial ecology was constructed by considering the following two aspects: industrial economic system and ecological environment system. The entropy method was employed to measure the level of industrial ecology in each city of the Hohhot-Baotou-Ordos-Yulin urban agglomeration from 2012 to 2021. The coupling coordination model was then used to analyze the degree of coupling and coordination between the industrial economic system and the ecological environment system in urban agglomeration. Finally, the fixed-effect model was utilized to analyze the influencing factors. [Results] ① From 2012 to 2021, the overall level of industrial ecology in the cities affected by Hohhot-Baotou-Ordos-Yulin urban agglomeration showed a fluctuating upward trend, and from the perspective of the average level for prefectures and cities, the development of industrial ecology level was unbalanced. ② From 2012 to 2021, the coupling degree of the industrial economic system and the ecological environment system of each city in the urban agglomerations was in the advanced coupling stage of dynamic change. The degree of coordination between cities had improved to varying degrees, but it was still poorly coordinated. In addition, the rate of development of coupling coordination was slow. ③ By analyzing the influencing factors of industrial ecology using the fixed-effect model, the results showed that the levels of economic development, opening to the outside world, technological innovation, comprehensive utilization of waste, and government regulation and control had a significant positive effect on the level of industrial ecology, whereas the industrial structure had a significant inhibitory effect on the level of industrial ecology. [Conclusion] The level of industrial ecology and coupling coordination degree of Hohhot-Baotou-Ordos-Yulin urban agglomeration requires significant enhancement. It is necessary to optimize the industrial structure and cultivate a diversified industrial system; promote circular development and improve the level of waste utilization; increase investment in innovation and enhance social innovation capabilities. Meanwhile, goveronment departments should actively participate, and give full play to the role of supervision.
[Objective] The stages and regional differences in the industrial ecological level of the Hohhot-Baotou-Ordos-Yulin urban agglomeration were measured to understand the shortcomings of the industrial ecological level and formulate more scientific countermeasures and suggestions for the development of the urban agglomeration. [Methods] The evaluation index of industrial ecology was constructed by considering the following two aspects: industrial economic system and ecological environment system. The entropy method was employed to measure the level of industrial ecology in each city of the Hohhot-Baotou-Ordos-Yulin urban agglomeration from 2012 to 2021. The coupling coordination model was then used to analyze the degree of coupling and coordination between the industrial economic system and the ecological environment system in urban agglomeration. Finally, the fixed-effect model was utilized to analyze the influencing factors. [Results] ① From 2012 to 2021, the overall level of industrial ecology in the cities affected by Hohhot-Baotou-Ordos-Yulin urban agglomeration showed a fluctuating upward trend, and from the perspective of the average level for prefectures and cities, the development of industrial ecology level was unbalanced. ② From 2012 to 2021, the coupling degree of the industrial economic system and the ecological environment system of each city in the urban agglomerations was in the advanced coupling stage of dynamic change. The degree of coordination between cities had improved to varying degrees, but it was still poorly coordinated. In addition, the rate of development of coupling coordination was slow. ③ By analyzing the influencing factors of industrial ecology using the fixed-effect model, the results showed that the levels of economic development, opening to the outside world, technological innovation, comprehensive utilization of waste, and government regulation and control had a significant positive effect on the level of industrial ecology, whereas the industrial structure had a significant inhibitory effect on the level of industrial ecology. [Conclusion] The level of industrial ecology and coupling coordination degree of Hohhot-Baotou-Ordos-Yulin urban agglomeration requires significant enhancement. It is necessary to optimize the industrial structure and cultivate a diversified industrial system; promote circular development and improve the level of waste utilization; increase investment in innovation and enhance social innovation capabilities. Meanwhile, goveronment departments should actively participate, and give full play to the role of supervision.
2024,44(6):339-352
, DOI: 10.13961/j.cnki.stbctb.20241014.001
Abstract:
[Objective] The ecological performance of the Yellow River basin in Shanxi Province was evaluated to provide theoretical support and a decision-making basis for sustainable development of the region. [Methods] Using the Yellow River basin in Shanxi Province as the research area, a theoretical framework was constructed based on the “pressure-state-response” model, and the spatial-temporal interaction of ecological performance from 2010 to 2020 was evaluated using InVEST, SFA, and the coupling coordination degree. According to the current situation and spatial distribution characteristics of the ecological performance level, ecological performance optimization zoning was conducted from bottom to top. [Results] ① From 2010 to 2020, the ecosystem services index of the Yellow River basin in Shanxi Province increased by 2.27%, and the spatial distribution was “north-south, high and low,” forming a double-core pattern mainly in the Lüliang Mountains and Taiyue-Zhongtiao Mountains. ② From 2010 to 2020, the ecological efficiency of the Yellow River basin in Shanxi Province increased by 43.48%, and the spatial distribution was “lower in the center and higher in the periphery.” ③ From 2010 to 2020, the ecological performance of the Yellow River basin in Shanxi Province increased by 35.29%, with a spatial distribution of “lower in the center and higher in the periphery.” ④ Based on the characteristics of spatial differentiation of ecological performance, the study area was divided into ecological performance remodeling, ecological performance improvement, ecological performance buffer, ecological performance enhancement, and ecological performance conservation areas, and the targeted ecological performance improvement paths were proposed. [Conclusion] The ecological performance of the Yellow River basin in Shanxi Province is generally poor and is still in the primary stage of high-quality development. In future, it will be necessary to explore new paths and support points suitable for a high degree of coordination between ecological protection and economic development in the region.
[Objective] The ecological performance of the Yellow River basin in Shanxi Province was evaluated to provide theoretical support and a decision-making basis for sustainable development of the region. [Methods] Using the Yellow River basin in Shanxi Province as the research area, a theoretical framework was constructed based on the “pressure-state-response” model, and the spatial-temporal interaction of ecological performance from 2010 to 2020 was evaluated using InVEST, SFA, and the coupling coordination degree. According to the current situation and spatial distribution characteristics of the ecological performance level, ecological performance optimization zoning was conducted from bottom to top. [Results] ① From 2010 to 2020, the ecosystem services index of the Yellow River basin in Shanxi Province increased by 2.27%, and the spatial distribution was “north-south, high and low,” forming a double-core pattern mainly in the Lüliang Mountains and Taiyue-Zhongtiao Mountains. ② From 2010 to 2020, the ecological efficiency of the Yellow River basin in Shanxi Province increased by 43.48%, and the spatial distribution was “lower in the center and higher in the periphery.” ③ From 2010 to 2020, the ecological performance of the Yellow River basin in Shanxi Province increased by 35.29%, with a spatial distribution of “lower in the center and higher in the periphery.” ④ Based on the characteristics of spatial differentiation of ecological performance, the study area was divided into ecological performance remodeling, ecological performance improvement, ecological performance buffer, ecological performance enhancement, and ecological performance conservation areas, and the targeted ecological performance improvement paths were proposed. [Conclusion] The ecological performance of the Yellow River basin in Shanxi Province is generally poor and is still in the primary stage of high-quality development. In future, it will be necessary to explore new paths and support points suitable for a high degree of coordination between ecological protection and economic development in the region.
2024,44(6):353-365
, DOI: 10.13961/j.cnki.stbctb.2024.06.036
Abstract:
[Objective] The spatiotemporal evolution characteristics of ecosystem carbon storage and habitat quality and the main driving factors of spatial differentiation in Hebei Province were explored to provide a more reliable reference basis for improving regional carbon sequestration capacity and ecological environment governance. [Methods] Based on the land-use transfer matrix, the status of land-use change in Hebei Province from 2000 to 2020 was analyzed. The PLUS-InVEST-Geodector model was used to estimate the carbon storage and habitat quality of the ecosystem in Hebei Province from 2000 to 2030, and the spatio-temporal changes and driving factors were also analyzed. The change pattern of its spatial and temporal changes and driving factors were analyzed. [Results] ① The carbon stock in Hebei province decreased by 13.45 Tg (calculated by carbon) from 2000 to 2020, and the areas with decreasing carbon stock were mostly concentrated in the Bashang Plateau area, the North China Plain, and the southeastern hilly areas. ② In 2030, the carbon stock under the natural development scenario will decrease by 6.37 Tg compared with that in 2020. The carbon stock under the economic development scenario will decrease by 21.73 Tg, and that under the sustainable development scenario will increase by 3.65 Tg. ③ The habitat quality index showed a gradual downward trend over time from 2000 to 2020. The main land categories of lowest and lower grade habitat quality were construction land and cropland, while that of higher and highest grade habitat quality were grassland and forest land. ④ The habitat quality index of Hebei Province in 2030 varies under different scenarios, with sustainable development (0.463 9) > natural development (0.454 2) > economic development (0.450 0). ⑤ The strongest explanatory factors for the spatial variations in carbon stock and habitat quality were slope and elevation. [Conclusion] Carbon stock and habitat quality were affected by both natural geographic factors and socioeconomic factors. The land use pattern under the sustainable development scenario can help to improve the carbon stock and habitat quality of the ecosystem in Hebei Province.
[Objective] The spatiotemporal evolution characteristics of ecosystem carbon storage and habitat quality and the main driving factors of spatial differentiation in Hebei Province were explored to provide a more reliable reference basis for improving regional carbon sequestration capacity and ecological environment governance. [Methods] Based on the land-use transfer matrix, the status of land-use change in Hebei Province from 2000 to 2020 was analyzed. The PLUS-InVEST-Geodector model was used to estimate the carbon storage and habitat quality of the ecosystem in Hebei Province from 2000 to 2030, and the spatio-temporal changes and driving factors were also analyzed. The change pattern of its spatial and temporal changes and driving factors were analyzed. [Results] ① The carbon stock in Hebei province decreased by 13.45 Tg (calculated by carbon) from 2000 to 2020, and the areas with decreasing carbon stock were mostly concentrated in the Bashang Plateau area, the North China Plain, and the southeastern hilly areas. ② In 2030, the carbon stock under the natural development scenario will decrease by 6.37 Tg compared with that in 2020. The carbon stock under the economic development scenario will decrease by 21.73 Tg, and that under the sustainable development scenario will increase by 3.65 Tg. ③ The habitat quality index showed a gradual downward trend over time from 2000 to 2020. The main land categories of lowest and lower grade habitat quality were construction land and cropland, while that of higher and highest grade habitat quality were grassland and forest land. ④ The habitat quality index of Hebei Province in 2030 varies under different scenarios, with sustainable development (0.463 9) > natural development (0.454 2) > economic development (0.450 0). ⑤ The strongest explanatory factors for the spatial variations in carbon stock and habitat quality were slope and elevation. [Conclusion] Carbon stock and habitat quality were affected by both natural geographic factors and socioeconomic factors. The land use pattern under the sustainable development scenario can help to improve the carbon stock and habitat quality of the ecosystem in Hebei Province.
2024,44(6):366-376
, DOI: 10.13961/j.cnki.stbctb.2024.06.037
Abstract:
[Objective] The characteristics of carbon emissions from cultivated land use and their decoupling relationship with grain yield were investigated to provide a scientific basis for coordinating the reduction of carbon emissions from cultivated land use and grain security in the North China Plain. [Methods] Based on data from 45 cities in Shandong, Hebei, and Henan provinces in the North China Plain from 2001 to 2021, the spatial and temporal evolution and influencing factors of carbon emissions from cultivated land use and the decoupling relationship between these emissions and grain yield were analyzed using the carbon emission coefficient method, spatial autocorrelation analysis, spatial Durbin model, and Tapio decoupling model. [Results] ① From 2001 to 2021, the total carbon emissions from cultivated land use in the three provinces of the North China Plain exhibited an inverted U-shaped pattern, with fertilizer as the main carbon source, accounting for 51.67% of the total emissions. The total carbon emissions from cultivated land use in Shandong and Henan provinces were higher than those in Hebei Province, and the carbon emission structure differed among the three provinces. ② Spatially, the carbon emissions from cultivated land use in the three provinces of the North China Plain generally shifted from a high-carbon stage to a low-carbon stage, with notable differences in carbon emission levels among different cities. ③ The carbon emissions from cultivated land use generally showed positive spatial agglomeration characteristics, and the degree of agglomeration tended to strengthen, with spatial coherence expanding in high-high type clustering areas, while low-low type clustering areas were more dispersed. ④ The agricultural economic level, rural electricity consumption, and fertilizer application intensity had positive effects on carbon emissions from cultivated land use, while the urbanization level had negative effects. The urbanization level and rural electricity consumption had positive spatial spillover effects, while the agricultural economic level had negative spatial spillover effects. ⑤ The decoupling state between carbon emissions from cultivated land use and grain yield shifted from mainly weak decoupling with expansive negative decoupling to mainly strong decoupling with recessive decoupling. [Conclusion] Organic fertilizers and precise fertilization techniques should be encouraged to use; emission reduction measures should be formulated according to the different carbon emission structures of each province; the adaptability of grain varieties should be enhanced, and inter-regional coordination and interaction should be strengthened.
[Objective] The characteristics of carbon emissions from cultivated land use and their decoupling relationship with grain yield were investigated to provide a scientific basis for coordinating the reduction of carbon emissions from cultivated land use and grain security in the North China Plain. [Methods] Based on data from 45 cities in Shandong, Hebei, and Henan provinces in the North China Plain from 2001 to 2021, the spatial and temporal evolution and influencing factors of carbon emissions from cultivated land use and the decoupling relationship between these emissions and grain yield were analyzed using the carbon emission coefficient method, spatial autocorrelation analysis, spatial Durbin model, and Tapio decoupling model. [Results] ① From 2001 to 2021, the total carbon emissions from cultivated land use in the three provinces of the North China Plain exhibited an inverted U-shaped pattern, with fertilizer as the main carbon source, accounting for 51.67% of the total emissions. The total carbon emissions from cultivated land use in Shandong and Henan provinces were higher than those in Hebei Province, and the carbon emission structure differed among the three provinces. ② Spatially, the carbon emissions from cultivated land use in the three provinces of the North China Plain generally shifted from a high-carbon stage to a low-carbon stage, with notable differences in carbon emission levels among different cities. ③ The carbon emissions from cultivated land use generally showed positive spatial agglomeration characteristics, and the degree of agglomeration tended to strengthen, with spatial coherence expanding in high-high type clustering areas, while low-low type clustering areas were more dispersed. ④ The agricultural economic level, rural electricity consumption, and fertilizer application intensity had positive effects on carbon emissions from cultivated land use, while the urbanization level had negative effects. The urbanization level and rural electricity consumption had positive spatial spillover effects, while the agricultural economic level had negative spatial spillover effects. ⑤ The decoupling state between carbon emissions from cultivated land use and grain yield shifted from mainly weak decoupling with expansive negative decoupling to mainly strong decoupling with recessive decoupling. [Conclusion] Organic fertilizers and precise fertilization techniques should be encouraged to use; emission reduction measures should be formulated according to the different carbon emission structures of each province; the adaptability of grain varieties should be enhanced, and inter-regional coordination and interaction should be strengthened.
2024,44(6):377-386
, DOI: 10.13961/j.cnki.stbctb.2024.06.038
Abstract:
[Objective] The changes of soil biomes and organic matter in typical forest park areas of Eastern Zhejiang Province were studied to lay a foundation for improving soil structure and increasing soil organic matter content in this area. [Methods] Detecting aggregate (0.25—2 mm), micro aggregate (0.053—0.25 mm), big aggregate (>2 mm), and powder clay (<0.053 mm) in the content of organic carbon, microbial biomass carbon and nitrogen content, the influence of soil aggregate stability, and microbes using wet sieving method under different land utilization way of forest land, orchard, vegetable land, and waste land to provide a scientific basis for formation pattern and regulation of soil organic carbon pool. [Results] ① The results showed that the distribution trend of the components of the aggregates of different soil particle sizes was consistent under different land-use patterns. The mean weight diameter (MWDS) and geometric mean diameter (GMD) of 0—10 cm soil under different land use ways were higher than those of the 10—20 cm soil layer. The MWDS and GMD of both types of soil were roughly characterized by forest land > wasteland > orchard > vegetable land; forest land and wasteland showed no significant difference (p>0.05), and neither did orchards and vegetable land (p>0.05); this demonstrates the influence of different ways of land use on soil aggregate stability, mainly in the surface soil. ② For soils under different land-use patterns, each grain size trend of organic carbon content is consistent, and the basic performance is big aggregate > micro aggregate > middle aggregate > powder and clay; for the 0—10 cm soil layer, each particle’s size distribution of organic carbon content was higher than that of 10—20 cm soil layer, and the organic carbon content of forest land > wasteland > orchard > vegetable land for the 0—10 cm and 10—20 cm soil is significantly higher than that of forest land and wasteland orchards and vegetable land (p<0.05), whereas orchards and vegetable land show no significant difference (p>0.05). ③ Soils under different land-use patterns of each particle size of microbial biomass carbon and nitrogen variation trend are consistent, and the basic performance is big aggregate > micro aggregate > middle aggregate > powder and clay; for the 0—10 cm soil layer, the soil’s microbial biomass carbon and nitrogen content were higher than those of the 10—20 cm soil layer, and the microbial biomass carbon and nitrogen content of 0—10 cm and 10—20 cm soil is generally characterized by forest land > wasteland > orchard > vegetable land, significantly higher than that of forest land and wasteland orchards and vegetable land (p<0.05), whereas orchards and vegetable land show no significant difference (p>0.05). [Conclusion] Overall, the organic carbon, microbial biomass carbon, and nitrogen of the forest land and wasteland aggregate were higher than those of the orchard and vegetable land; thus, forest land and wasteland were more conducive to the accumulation of soil organic carbon and could promote soil carbon sequestration.
[Objective] The changes of soil biomes and organic matter in typical forest park areas of Eastern Zhejiang Province were studied to lay a foundation for improving soil structure and increasing soil organic matter content in this area. [Methods] Detecting aggregate (0.25—2 mm), micro aggregate (0.053—0.25 mm), big aggregate (>2 mm), and powder clay (<0.053 mm) in the content of organic carbon, microbial biomass carbon and nitrogen content, the influence of soil aggregate stability, and microbes using wet sieving method under different land utilization way of forest land, orchard, vegetable land, and waste land to provide a scientific basis for formation pattern and regulation of soil organic carbon pool. [Results] ① The results showed that the distribution trend of the components of the aggregates of different soil particle sizes was consistent under different land-use patterns. The mean weight diameter (MWDS) and geometric mean diameter (GMD) of 0—10 cm soil under different land use ways were higher than those of the 10—20 cm soil layer. The MWDS and GMD of both types of soil were roughly characterized by forest land > wasteland > orchard > vegetable land; forest land and wasteland showed no significant difference (p>0.05), and neither did orchards and vegetable land (p>0.05); this demonstrates the influence of different ways of land use on soil aggregate stability, mainly in the surface soil. ② For soils under different land-use patterns, each grain size trend of organic carbon content is consistent, and the basic performance is big aggregate > micro aggregate > middle aggregate > powder and clay; for the 0—10 cm soil layer, each particle’s size distribution of organic carbon content was higher than that of 10—20 cm soil layer, and the organic carbon content of forest land > wasteland > orchard > vegetable land for the 0—10 cm and 10—20 cm soil is significantly higher than that of forest land and wasteland orchards and vegetable land (p<0.05), whereas orchards and vegetable land show no significant difference (p>0.05). ③ Soils under different land-use patterns of each particle size of microbial biomass carbon and nitrogen variation trend are consistent, and the basic performance is big aggregate > micro aggregate > middle aggregate > powder and clay; for the 0—10 cm soil layer, the soil’s microbial biomass carbon and nitrogen content were higher than those of the 10—20 cm soil layer, and the microbial biomass carbon and nitrogen content of 0—10 cm and 10—20 cm soil is generally characterized by forest land > wasteland > orchard > vegetable land, significantly higher than that of forest land and wasteland orchards and vegetable land (p<0.05), whereas orchards and vegetable land show no significant difference (p>0.05). [Conclusion] Overall, the organic carbon, microbial biomass carbon, and nitrogen of the forest land and wasteland aggregate were higher than those of the orchard and vegetable land; thus, forest land and wasteland were more conducive to the accumulation of soil organic carbon and could promote soil carbon sequestration.
2024,44(6):387-398
, DOI: 10.13961/j.cnki.stbctb.2024.06.039
Abstract:
[Objective] The temporal and spatial evolution patterns of regional agricultural carbon budgets and carbon emission fairness were investigated, in order to provide scientific references for formulating differentiated emission reduction and carbon sequestration strategies. [Methods] Based on the agricultural statistical data of Shaanxi Province from 2000 to 2020, this study estimated the carbon budget of cultivated land in the province for 21 consecutive years using the carbon emission coefficient method. A carbon emission fairness evaluation model was constructed to analyze the carbon-emission fairness of cultivated land in Shaanxi Province from two aspects: ecological carrying capacity and economic efficiency coefficient. [Results] ① The total carbon emission of cultivated land in Shaanxi Province increased first and then decreased during 2000—2020, and the carbon emission intensity increased by 48.15%, with chemical fertilizers as the main source of carbon emissions. ② The total carbon absorption continued to rise, with an average annual growth rate of carbon absorption intensity of 13.67%, in which vegetables having the highest contribution to carbon absorption. ③ Both carbon emissions and carbon absorption showed a high distribution pattern in Central Shaanxi Province and a low one in Northern and Southern Shaanxi, with the ecological carrying capacity of cultivated land carbon emissions being Southern Shaanxi > Central Shaanxi > Northern Shaanxi and the agricultural economic efficiency being Southern Shaanxi > Northern Shaanxi > Central Shaanxi. The results of carbon emission fairness cluster analysis showed that Southern Shaanxi and Xi’an shared the pressure of carbon emission reduction of cultivated land for other regions of Shaanxi Province to a certain extent, while Tongchuan City, Baoji City, Yulin City, and Weinan City regions increased the pressure of carbon emission reduction of cultivated land. [Conclusion] The dynamics and fairness of cultivated land carbon budget in Shaanxi Province vary greatly among different regions; thus, differentiated emission reduction strategies should be developed and improved according to different regional conditions.
[Objective] The temporal and spatial evolution patterns of regional agricultural carbon budgets and carbon emission fairness were investigated, in order to provide scientific references for formulating differentiated emission reduction and carbon sequestration strategies. [Methods] Based on the agricultural statistical data of Shaanxi Province from 2000 to 2020, this study estimated the carbon budget of cultivated land in the province for 21 consecutive years using the carbon emission coefficient method. A carbon emission fairness evaluation model was constructed to analyze the carbon-emission fairness of cultivated land in Shaanxi Province from two aspects: ecological carrying capacity and economic efficiency coefficient. [Results] ① The total carbon emission of cultivated land in Shaanxi Province increased first and then decreased during 2000—2020, and the carbon emission intensity increased by 48.15%, with chemical fertilizers as the main source of carbon emissions. ② The total carbon absorption continued to rise, with an average annual growth rate of carbon absorption intensity of 13.67%, in which vegetables having the highest contribution to carbon absorption. ③ Both carbon emissions and carbon absorption showed a high distribution pattern in Central Shaanxi Province and a low one in Northern and Southern Shaanxi, with the ecological carrying capacity of cultivated land carbon emissions being Southern Shaanxi > Central Shaanxi > Northern Shaanxi and the agricultural economic efficiency being Southern Shaanxi > Northern Shaanxi > Central Shaanxi. The results of carbon emission fairness cluster analysis showed that Southern Shaanxi and Xi’an shared the pressure of carbon emission reduction of cultivated land for other regions of Shaanxi Province to a certain extent, while Tongchuan City, Baoji City, Yulin City, and Weinan City regions increased the pressure of carbon emission reduction of cultivated land. [Conclusion] The dynamics and fairness of cultivated land carbon budget in Shaanxi Province vary greatly among different regions; thus, differentiated emission reduction strategies should be developed and improved according to different regional conditions.
2024,44(6):399-408
, DOI: 10.13961/j.cnki.stbctb.2024.06.040
Abstract:
[Objective] The characteristics of water supply and demand for major crops in Yan’an City were investigated to provide references for the water requirements of crops and the structure of crop planting in the region. [Methods] Based on daily meteorological observation data from meteorological stations in the Yan’an City (from 2000 to 2020), the FAO-56 formula and crop coefficient method were used to study the characteristics of water requirements, effective precipitation, and irrigation water demand during the growth period of major crops (spring maize, spring millet, potatoes, and winter wheat) in the region. [Results] From 2000 to 2020, spring maize in the Yan’an City had the highest water requirement and effective precipitation during the mid-growing stage, which were 247.85 mm and 68.34 mm, respectively, with a water deficit increasing at a rate of 6.61 mm per decade. Potatoes also had the highest water requirement and effective precipitation during the mid-growing stage, which were 288.83 mm and 89.53 mm, respectively, with a water deficit increasing at a rate of 5.75 mm per decade. Meanwhile, spring millet had the highest water requirement and effective precipitation during the mid-growing stage, which were 248.29 mm and 71.68 mm, respectively, with a water deficit decreasing at a rate of -7.0 mm per decade. Winter wheat had the highest water requirement during the rapid development stage, at 192.98 mm, with effective precipitation peaking in the early growth stage at 31.14 mm; the water deficit increased at a rate of 9.94 mm per decade. This indicates that even when effective precipitation reaches its peak, water demand for crop growth remains deficient. [Conclusion] The planting area of spring maize should be reduced, and that of spring millet and potatoes should be expanded, to improve the structure of crop planting. Additionally, increasing on-farm water collection measures can enhance the efficiency of rainwater resource utilization, ensuring sustainable development of food production in the Yan’an City.
[Objective] The characteristics of water supply and demand for major crops in Yan’an City were investigated to provide references for the water requirements of crops and the structure of crop planting in the region. [Methods] Based on daily meteorological observation data from meteorological stations in the Yan’an City (from 2000 to 2020), the FAO-56 formula and crop coefficient method were used to study the characteristics of water requirements, effective precipitation, and irrigation water demand during the growth period of major crops (spring maize, spring millet, potatoes, and winter wheat) in the region. [Results] From 2000 to 2020, spring maize in the Yan’an City had the highest water requirement and effective precipitation during the mid-growing stage, which were 247.85 mm and 68.34 mm, respectively, with a water deficit increasing at a rate of 6.61 mm per decade. Potatoes also had the highest water requirement and effective precipitation during the mid-growing stage, which were 288.83 mm and 89.53 mm, respectively, with a water deficit increasing at a rate of 5.75 mm per decade. Meanwhile, spring millet had the highest water requirement and effective precipitation during the mid-growing stage, which were 248.29 mm and 71.68 mm, respectively, with a water deficit decreasing at a rate of -7.0 mm per decade. Winter wheat had the highest water requirement during the rapid development stage, at 192.98 mm, with effective precipitation peaking in the early growth stage at 31.14 mm; the water deficit increased at a rate of 9.94 mm per decade. This indicates that even when effective precipitation reaches its peak, water demand for crop growth remains deficient. [Conclusion] The planting area of spring maize should be reduced, and that of spring millet and potatoes should be expanded, to improve the structure of crop planting. Additionally, increasing on-farm water collection measures can enhance the efficiency of rainwater resource utilization, ensuring sustainable development of food production in the Yan’an City.
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Soil organic carbon (SOC) sequestration is one of the effective ways to mitigate global climate change, and large-scale vegetation restoration has profoundly changed this process. Clarifying the changes of soil carbon sequestration and its driving factors in the process of ecological restoration in fragile areas has important reference value for ecological management and carbon sequestration and emission reduction.In this study, we analyzed the changes of SOC sequestration and its driving factors during the process of vegetation restoration (planted forest, planted shrub and abandoned grassland) on the arid and semi-arid Loess Plateau by synthesizing 100 peer-reviewed publications (935 observations and 55 sites) published between 1992 and 2020. The results showed that 1) the rate of SOC sequestration for planted forest and shrub was 0.30 Mg C / (ha·yr), which was higher than that of abandoned grassland (0.10 Mg C / (ha·yr)). In addition, the rate of evergreen tree species (0.45 Mg C ha-1yr-1) was higher than that of deciduous tree species (0.33 Mg C / (ha·yr)), but the latter had higher SOC sequestration amount. After 51 years, the evergreen tree species may have greater carbon sequestration benefit; 2) The SOC sequestration rate increased with precipitation, but the change degree was affected by vegetation types and restoration years; 3) Regionally, SOC sequestration rate continued to increase (<30yr) and thereafter stabilized (>30yr). The average SOC sequestration rates in 0-10yr, 10-20yr, 20-30yr and >30yr were 0.02, 0.13, 0.19 and 0.18 Mg C / (ha·yr), respectively; (4) Overall, the main influencing factors of SOC sequestration was different in various restoration stages. Generally speaking, the SOC sequestration is mainly regulated by climatic factors (precipitation and temperature). The relative importance of precipitation, temperature, restoration age, vegetation types and initial SOC stock were 31.8%, 16.3%, 17.7%, 15.9% and 18.3%, respectively. Finally, we suggest that a sustainable ecological restoration model based on SOC sequestration rate and capacity should be established, and the amount and quality of vegetation should be increased through sustainable scientific management, which will effectively increase the amount of SOC sequestration in ecologically fragile areas.
Soil organic carbon (SOC) sequestration is one of the effective ways to mitigate global climate change, and large-scale vegetation restoration has profoundly changed this process. Clarifying the changes of soil carbon sequestration and its driving factors in the process of ecological restoration in fragile areas has important reference value for ecological management and carbon sequestration and emission reduction.In this study, we analyzed the changes of SOC sequestration and its driving factors during the process of vegetation restoration (planted forest, planted shrub and abandoned grassland) on the arid and semi-arid Loess Plateau by synthesizing 100 peer-reviewed publications (935 observations and 55 sites) published between 1992 and 2020. The results showed that 1) the rate of SOC sequestration for planted forest and shrub was 0.30 Mg C / (ha·yr), which was higher than that of abandoned grassland (0.10 Mg C / (ha·yr)). In addition, the rate of evergreen tree species (0.45 Mg C ha-1yr-1) was higher than that of deciduous tree species (0.33 Mg C / (ha·yr)), but the latter had higher SOC sequestration amount. After 51 years, the evergreen tree species may have greater carbon sequestration benefit; 2) The SOC sequestration rate increased with precipitation, but the change degree was affected by vegetation types and restoration years; 3) Regionally, SOC sequestration rate continued to increase (<30yr) and thereafter stabilized (>30yr). The average SOC sequestration rates in 0-10yr, 10-20yr, 20-30yr and >30yr were 0.02, 0.13, 0.19 and 0.18 Mg C / (ha·yr), respectively; (4) Overall, the main influencing factors of SOC sequestration was different in various restoration stages. Generally speaking, the SOC sequestration is mainly regulated by climatic factors (precipitation and temperature). The relative importance of precipitation, temperature, restoration age, vegetation types and initial SOC stock were 31.8%, 16.3%, 17.7%, 15.9% and 18.3%, respectively. Finally, we suggest that a sustainable ecological restoration model based on SOC sequestration rate and capacity should be established, and the amount and quality of vegetation should be increased through sustainable scientific management, which will effectively increase the amount of SOC sequestration in ecologically fragile areas.
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Abstract：[Objective] To analyze the response of soil aggregate grain size composition and stability and the organic carbon content of all levels of aggregates to the simulated warming, and to provide a scientific basis for the dynamic change of soil structure stability and carbon storage capacity of the oil pine plantation forest in Daqingshan, Inner Mongolia, in the context of climate warming. [Methods] The 0~40 cm soil of the oil pine plantation forest in Daqingshan, Inner Mongolia, was used as the study object, based on a 4a year-round simulated field warming experiment, the soil was divided into three grain sizes of >0.25 mm, 0.25~0.053 mm and <0.053 mm by wet sieving method, and the organic carbon content in the agglomerates of each grain size was measured. [Results] (1)The soils in this study area have microaggregate as the dominant grain size, and warming decreased the soil macroaggregate content and microaggregate content in all soil horizons, whereas the powdered clayey aggregate content showed a significant increase in all soil horizons, by 14.92%, 14.01%, and 13.84%, respectively; (2) Compared to the control, both soil mean weight diameter (MWD) and geometric mean diameter (GMD) were significantly reduced by warming, with MWD decreasing by 5.93%, 3.66%, and 5.68%, respectively, and GMD decreasing by 8.83%, 8.41%, and 10.63%, respectively, in all soil horizons; (3) In both treatments, the highest organic carbon content was found in soil powder and clay particles, and the warming increased the organic carbon content in powder and clay agglomerates but decreased that in macro- and micro-agglomerates; the total organic carbon content of the surface soil increased after the warming, while the organic carbon content of the soil layers from 10~20 cm and from 20~40 cm decreased; (4) The organic carbon contribution of soil powdery clay aggregates was the largest under warming conditions; compared with the control, the organic carbon contribution of soil powdery clay aggregates increased by 44.39%, 39.60%, and 43.31% in each soil stratum after warming; followed by micro-aggregates, and soil macro-aggregates had the lowest organic carbon contribution. [Conclusions] It was found that warming led to changes in soil aggregate composition, destabilized soil aggregates, and reduced organic carbon content in macro- and micro-aggregates, suggesting that warming is not conducive to the physical conservation of soil organic carbon.
Abstract：[Objective] To analyze the response of soil aggregate grain size composition and stability and the organic carbon content of all levels of aggregates to the simulated warming, and to provide a scientific basis for the dynamic change of soil structure stability and carbon storage capacity of the oil pine plantation forest in Daqingshan, Inner Mongolia, in the context of climate warming. [Methods] The 0~40 cm soil of the oil pine plantation forest in Daqingshan, Inner Mongolia, was used as the study object, based on a 4a year-round simulated field warming experiment, the soil was divided into three grain sizes of >0.25 mm, 0.25~0.053 mm and <0.053 mm by wet sieving method, and the organic carbon content in the agglomerates of each grain size was measured. [Results] (1)The soils in this study area have microaggregate as the dominant grain size, and warming decreased the soil macroaggregate content and microaggregate content in all soil horizons, whereas the powdered clayey aggregate content showed a significant increase in all soil horizons, by 14.92%, 14.01%, and 13.84%, respectively; (2) Compared to the control, both soil mean weight diameter (MWD) and geometric mean diameter (GMD) were significantly reduced by warming, with MWD decreasing by 5.93%, 3.66%, and 5.68%, respectively, and GMD decreasing by 8.83%, 8.41%, and 10.63%, respectively, in all soil horizons; (3) In both treatments, the highest organic carbon content was found in soil powder and clay particles, and the warming increased the organic carbon content in powder and clay agglomerates but decreased that in macro- and micro-agglomerates; the total organic carbon content of the surface soil increased after the warming, while the organic carbon content of the soil layers from 10~20 cm and from 20~40 cm decreased; (4) The organic carbon contribution of soil powdery clay aggregates was the largest under warming conditions; compared with the control, the organic carbon contribution of soil powdery clay aggregates increased by 44.39%, 39.60%, and 43.31% in each soil stratum after warming; followed by micro-aggregates, and soil macro-aggregates had the lowest organic carbon contribution. [Conclusions] It was found that warming led to changes in soil aggregate composition, destabilized soil aggregates, and reduced organic carbon content in macro- and micro-aggregates, suggesting that warming is not conducive to the physical conservation of soil organic carbon.
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[Objective] In order to investigate the effect of microbial (EM) agents with fly ash dosing on the physicochemical properties of windswept soils in mine dumps. [Methods] In this study, the wind-sand soil of the discharge site of the Manlailiang open-pit mine in Ordos City was selected as the research object, and the method of field potting test was used. Based on the two-factor complete test, four levels of EM microbial agents to wind-sand soil weight ratios of 0 g/kg, 0.1 g/kg, 0.2 g/kg, 0.3 g/kg, and four levels of fly ash to wind-sand soil weight ratios of 0 g/kg, 25 g/kg, 50 g/kg, and 75 g/kg were set, and the mixing of EM microbial agents and fly ash with the sandy soil was carried out at different ratios. To study the effect of different dosages of amendments on the physicochemical properties of soil at the mine discharge site and to calculate the soil quality index. [Results] ① The application of EM microbial agents and fly ash significantly improved the soil physicochemical properties relative to T1 (CK). The effect of mixed application of EM microbial agents and fly ash on soil physicochemical properties was better than that of single application of EM microbial agents or fly ash, and the improvement of soil physicochemical properties was better with the increase of the addition of fly ash in different application ratios. ② When the EM microbial agents is 0.2g/kg and the fly ash is 75g/kg, the improvement in soil quality is most significant. The soil quality index is 0.78, which is a fertile grade with an increase of 147% compared to CK. ③ The growth and photosynthetic indicators of Corethrodendron fruticosum are closely related to the physical and chemical properties of the soil. Mantel analysis showed that the growth and photosynthetic indicators of C. fruticosum are driven by soil total nitrogen and organic matter. [Conclusion] Mixed application of two amendment materials significantly improves the soil quality of windswept soils in mine dumping sites relative to single application of amendment materials. The research results can provide guidance and technical support for soil improvement in mining areas.
[Objective] In order to investigate the effect of microbial (EM) agents with fly ash dosing on the physicochemical properties of windswept soils in mine dumps. [Methods] In this study, the wind-sand soil of the discharge site of the Manlailiang open-pit mine in Ordos City was selected as the research object, and the method of field potting test was used. Based on the two-factor complete test, four levels of EM microbial agents to wind-sand soil weight ratios of 0 g/kg, 0.1 g/kg, 0.2 g/kg, 0.3 g/kg, and four levels of fly ash to wind-sand soil weight ratios of 0 g/kg, 25 g/kg, 50 g/kg, and 75 g/kg were set, and the mixing of EM microbial agents and fly ash with the sandy soil was carried out at different ratios. To study the effect of different dosages of amendments on the physicochemical properties of soil at the mine discharge site and to calculate the soil quality index. [Results] ① The application of EM microbial agents and fly ash significantly improved the soil physicochemical properties relative to T1 (CK). The effect of mixed application of EM microbial agents and fly ash on soil physicochemical properties was better than that of single application of EM microbial agents or fly ash, and the improvement of soil physicochemical properties was better with the increase of the addition of fly ash in different application ratios. ② When the EM microbial agents is 0.2g/kg and the fly ash is 75g/kg, the improvement in soil quality is most significant. The soil quality index is 0.78, which is a fertile grade with an increase of 147% compared to CK. ③ The growth and photosynthetic indicators of Corethrodendron fruticosum are closely related to the physical and chemical properties of the soil. Mantel analysis showed that the growth and photosynthetic indicators of C. fruticosum are driven by soil total nitrogen and organic matter. [Conclusion] Mixed application of two amendment materials significantly improves the soil quality of windswept soils in mine dumping sites relative to single application of amendment materials. The research results can provide guidance and technical support for soil improvement in mining areas.
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[Objective] To measure the characteristics of rural revitalization level change in China's drylands from 2000 to 2022, to reveal the development trend of rural revitalization level and subsystems in China's drylands from multiple perspectives, and to explore the spatial heterogeneity and potential causes of its formation. [Methods] We constructed an evaluation index system from five aspects, including industrial prosperity, ecological livability, civilized rural culture, effective governance, and affluent life, and applied the entropy weight method and Dagum's Gini coefficient method to assess the level of rural revitalization in China's drylands, and analyze the dominant factors of its spatial heterogeneity. [Results] ① The level of rural revitalization in China's drylands in 2022 is relatively low compared with the national average, at 0.343, with obvious differences in the revitalization levels of various subsystems, among which the level of ecological livability is the highest; the level of effective governance is the lowest, but with the largest annual growth rate and increase; and the growth rate of living affluence is slower and the increase is the smallest. Rural revitalization index was “high in the east and low in the west” distribution characteristics, low-value areas accounted for the highest proportion, 55.10%, high-value areas accounted for only 18.36%; ② China's rural revitalization level of arid zones in different climatic types of zones varies significantly. The rural revitalization indexes of sub-humid arid zones are relatively high, and the development potential of semi-arid zones and arid zone jurisdictions is greater; ③ There are obvious differences in rural revitalization characteristics between different city type zones. All indices of rural revitalization in mega-city jurisdictions are at the leading level, and mega-city jurisdictions have the highest annual growth rate, while medium-sized and small city jurisdictions are lagging behind in rural revitalization, with an expanding trend; affluent living and ecological livability are the main factors leading to the differences among the five subsystems of the city-type districts. [Conclusion] China's drylands need to focus on the advantages of rural location and natural ecological characteristics, and formulate precise policies to promote regional rural development according to local conditions.
[Objective] To measure the characteristics of rural revitalization level change in China's drylands from 2000 to 2022, to reveal the development trend of rural revitalization level and subsystems in China's drylands from multiple perspectives, and to explore the spatial heterogeneity and potential causes of its formation. [Methods] We constructed an evaluation index system from five aspects, including industrial prosperity, ecological livability, civilized rural culture, effective governance, and affluent life, and applied the entropy weight method and Dagum's Gini coefficient method to assess the level of rural revitalization in China's drylands, and analyze the dominant factors of its spatial heterogeneity. [Results] ① The level of rural revitalization in China's drylands in 2022 is relatively low compared with the national average, at 0.343, with obvious differences in the revitalization levels of various subsystems, among which the level of ecological livability is the highest; the level of effective governance is the lowest, but with the largest annual growth rate and increase; and the growth rate of living affluence is slower and the increase is the smallest. Rural revitalization index was “high in the east and low in the west” distribution characteristics, low-value areas accounted for the highest proportion, 55.10%, high-value areas accounted for only 18.36%; ② China's rural revitalization level of arid zones in different climatic types of zones varies significantly. The rural revitalization indexes of sub-humid arid zones are relatively high, and the development potential of semi-arid zones and arid zone jurisdictions is greater; ③ There are obvious differences in rural revitalization characteristics between different city type zones. All indices of rural revitalization in mega-city jurisdictions are at the leading level, and mega-city jurisdictions have the highest annual growth rate, while medium-sized and small city jurisdictions are lagging behind in rural revitalization, with an expanding trend; affluent living and ecological livability are the main factors leading to the differences among the five subsystems of the city-type districts. [Conclusion] China's drylands need to focus on the advantages of rural location and natural ecological characteristics, and formulate precise policies to promote regional rural development according to local conditions.
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[ Objective ] To explore the law of soil wind erosion in degraded bare patches of alpine meadow, and to provide scientific basis for vegetation restoration and ecological environment protection in degraded meadow area. [ Methods ] In this study, we selected the bald patches formed by the degradation of plateau pika activity in Henan County, Qinghai Province as the research object. Under the three wind speeds of 9,12 and 15 m / s, the degraded bald patches with different vegetation coverage ( 0 %, 20 %, 40 %, 60 %, 80 % ) were subjected to in-situ simulated wind erosion experiments to explore the effects of vegetation coverage on soil wind erosion under different wind speeds. [ Results ] ① The soil wind erosion rate of degraded bare land showed a trend of rapid decline and then tended to be gentle over time ( p < 0.05 ). ② Under the wind erosion test with a total duration of 60 min, the first 10 min is the sensitive period of soil wind erosion rate change. Under the three wind speeds, there was a significant negative exponential function relationship between vegetation coverage and total sediment discharge ( R2 = 0.98 ). The greater the absolute value of the exponential coefficient, the weaker the inhibitory effect of vegetation coverage on wind erosion at higher wind speeds.③ With the increase of vegetation coverage, the sediment transport in the height range of 0-5cm decreased significantly, and the sediment transport of each vegetation coverage decreased gradually with the increase of height. [ Conclusion ] Increasing vegetation coverage can effectively reduce the wind erosion rate and sand transport height, but at higher wind speeds, the inhibition effect of vegetation coverage on wind erosion is significantly weakened, and the key threshold of vegetation coverage to inhibit soil wind erosion is about 40 %. With the continuous increase of vegetation coverage, the marginal benefit of wind erosion reduction gradually decreases.
[ Objective ] To explore the law of soil wind erosion in degraded bare patches of alpine meadow, and to provide scientific basis for vegetation restoration and ecological environment protection in degraded meadow area. [ Methods ] In this study, we selected the bald patches formed by the degradation of plateau pika activity in Henan County, Qinghai Province as the research object. Under the three wind speeds of 9,12 and 15 m / s, the degraded bald patches with different vegetation coverage ( 0 %, 20 %, 40 %, 60 %, 80 % ) were subjected to in-situ simulated wind erosion experiments to explore the effects of vegetation coverage on soil wind erosion under different wind speeds. [ Results ] ① The soil wind erosion rate of degraded bare land showed a trend of rapid decline and then tended to be gentle over time ( p < 0.05 ). ② Under the wind erosion test with a total duration of 60 min, the first 10 min is the sensitive period of soil wind erosion rate change. Under the three wind speeds, there was a significant negative exponential function relationship between vegetation coverage and total sediment discharge ( R2 = 0.98 ). The greater the absolute value of the exponential coefficient, the weaker the inhibitory effect of vegetation coverage on wind erosion at higher wind speeds.③ With the increase of vegetation coverage, the sediment transport in the height range of 0-5cm decreased significantly, and the sediment transport of each vegetation coverage decreased gradually with the increase of height. [ Conclusion ] Increasing vegetation coverage can effectively reduce the wind erosion rate and sand transport height, but at higher wind speeds, the inhibition effect of vegetation coverage on wind erosion is significantly weakened, and the key threshold of vegetation coverage to inhibit soil wind erosion is about 40 %. With the continuous increase of vegetation coverage, the marginal benefit of wind erosion reduction gradually decreases.
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[Objective] To assess the land use change and carbon storage change in the future under different scenarios in the Xiaoxing'an Mountains region of Heilongjiang Province, in order to optimize ecosystem services and provide scientific reference for the construction of the northern ecological security barrier.[Method] Based on land use data from 2000, 2010, and 2020, simulate the land use changes in the Xiaoxing'an Mountains region for the year 2030, and assess the carbon storage under three different scenarios: natural development, ecological protection, and urban development.[Result]① Between 2000 and 2020, the land use pattern in the Xiaoxing'an Mountains region of Heilongjiang Province underwent significant changes, with forests and grasslands continuously shrinking, especially forests, which mainly transitioned into cultivated land. ② The carbon storage in the Xiaoxing'an Mountains region of Heilongjiang Province in 2000, 2010, and 2020 was 220415.25×10?t, 220200.94×10?t, and 219139.71×10?t, respectively, showing a trend of annual decline. ③ From the perspective of carbon sequestration, by 2030, the ecological protection scenario is significantly advantageous compared to the natural development scenario, with an increase of 1932.98×10?t, effectively alleviating the downward trend of carbon storage, providing a strong basis and guidance for subsequent policy-making.[Conclusion] The future should continue with scientific ecological policies to maintain the ecological security of the Xiaoxing'an Mountains region in Heilongjiang Province, enhance carbon sink capacity, and help build a northern ecological security barrier.
[Objective] To assess the land use change and carbon storage change in the future under different scenarios in the Xiaoxing'an Mountains region of Heilongjiang Province, in order to optimize ecosystem services and provide scientific reference for the construction of the northern ecological security barrier.[Method] Based on land use data from 2000, 2010, and 2020, simulate the land use changes in the Xiaoxing'an Mountains region for the year 2030, and assess the carbon storage under three different scenarios: natural development, ecological protection, and urban development.[Result]① Between 2000 and 2020, the land use pattern in the Xiaoxing'an Mountains region of Heilongjiang Province underwent significant changes, with forests and grasslands continuously shrinking, especially forests, which mainly transitioned into cultivated land. ② The carbon storage in the Xiaoxing'an Mountains region of Heilongjiang Province in 2000, 2010, and 2020 was 220415.25×10?t, 220200.94×10?t, and 219139.71×10?t, respectively, showing a trend of annual decline. ③ From the perspective of carbon sequestration, by 2030, the ecological protection scenario is significantly advantageous compared to the natural development scenario, with an increase of 1932.98×10?t, effectively alleviating the downward trend of carbon storage, providing a strong basis and guidance for subsequent policy-making.[Conclusion] The future should continue with scientific ecological policies to maintain the ecological security of the Xiaoxing'an Mountains region in Heilongjiang Province, enhance carbon sink capacity, and help build a northern ecological security barrier.
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[Objective] To explore the effects of conservation tillage on soil carbon dioxide (CO2) and methane (CH4) emissions in dry farmland in the semi-arid region of the Loess Plateau of central Gansu Province, and to describe the characteristics of changes in the emissions of the two and the main factors affecting them. [Methods] In this study, no-tillage (NT), traditional tillage + straw mulch (CTS), and no-tillage + straw mulch (NTS) were used to collect and measure CO2 and CH4 emission fluxes in spring wheat soil by stat,ic camera box and gas chromatography. The relevant environmental factors and wheat yield were measured at the same time. [Results] The results showed that: (1) Compared with CT treatment, the cumulative CO2 emissions of NT, CTS, and NTS treatment increased by 15.67%, 17.34%, and 1.52%, respectively, and the cumulative CH4 absorption increased by 16.26%, 11.95%, and 0.16%. In addition, compared with traditional tillage, conservation tillage can effectively reduce global warming potential, reduce greenhouse gas emission intensity, and significantly increase wheat yields. (2) Soil organic carbon (SOC) and microbial carbon (MBC) contents under conservation tillage were higher than those under traditional tillage, and SOC and MBC contents of each treatment showed a decreasing trend with the deepening of the soil layer. (3) Correlation analysis shows that soil temperature and SOC were positively correlated with CO2 emission flux (P < 0.001) and negatively correlated with CH4 absorption flux (P < 0.001), while soil water content was negatively correlated with CO2 emission flux (P < 0.001). There was a significant positive correlation with CH4 absorption flux (P < 0.001). Redundancy analysis showed that soil temperature, soil water content, and SOC were the key driving factors affecting soil carbon flux. [Conclusion] Compared with traditional tillage, conservation tillage studied in this paper can slow down greenhouse gas emissions in the study area, reduce the contribution to the greenhouse effect, and significantly increase wheat yield, among which NTS treatment has a better performance. Combining ecological benefits and economic benefits, no-tillage and straw mulching can be prioritized as tillage measures to increase production and reduce emissions.
[Objective] To explore the effects of conservation tillage on soil carbon dioxide (CO2) and methane (CH4) emissions in dry farmland in the semi-arid region of the Loess Plateau of central Gansu Province, and to describe the characteristics of changes in the emissions of the two and the main factors affecting them. [Methods] In this study, no-tillage (NT), traditional tillage + straw mulch (CTS), and no-tillage + straw mulch (NTS) were used to collect and measure CO2 and CH4 emission fluxes in spring wheat soil by stat,ic camera box and gas chromatography. The relevant environmental factors and wheat yield were measured at the same time. [Results] The results showed that: (1) Compared with CT treatment, the cumulative CO2 emissions of NT, CTS, and NTS treatment increased by 15.67%, 17.34%, and 1.52%, respectively, and the cumulative CH4 absorption increased by 16.26%, 11.95%, and 0.16%. In addition, compared with traditional tillage, conservation tillage can effectively reduce global warming potential, reduce greenhouse gas emission intensity, and significantly increase wheat yields. (2) Soil organic carbon (SOC) and microbial carbon (MBC) contents under conservation tillage were higher than those under traditional tillage, and SOC and MBC contents of each treatment showed a decreasing trend with the deepening of the soil layer. (3) Correlation analysis shows that soil temperature and SOC were positively correlated with CO2 emission flux (P < 0.001) and negatively correlated with CH4 absorption flux (P < 0.001), while soil water content was negatively correlated with CO2 emission flux (P < 0.001). There was a significant positive correlation with CH4 absorption flux (P < 0.001). Redundancy analysis showed that soil temperature, soil water content, and SOC were the key driving factors affecting soil carbon flux. [Conclusion] Compared with traditional tillage, conservation tillage studied in this paper can slow down greenhouse gas emissions in the study area, reduce the contribution to the greenhouse effect, and significantly increase wheat yield, among which NTS treatment has a better performance. Combining ecological benefits and economic benefits, no-tillage and straw mulching can be prioritized as tillage measures to increase production and reduce emissions.
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[Objective] Rainfall erosivity is an important index to evaluate soil erosion, to solve the problems of spatial differentiation and poor accuracy in estimating rainfall erosivity by meteorological stations and satellite precipitation products. [Methods] This research developed a station-satellite fusion calculation method of rainfall erosivity based on the rainfall data of 96 meteorological stations and precipitation products of GPM IMERG and ERA5. The rainfall erosivity of Jiangsu Province from 2001 to 2023 was reconstructed, and its erosivity density and prone area division were further studied. [Results]① This method was reliable because the fusion rainfall erosivity had a higher correlation coefficient, lower deviation, and lower root mean square error compared with rainfall erosivity calculated by satellite and station. This method will capture the high value of rainfall erosivity and reduce uncertainty and error. ② The mean annual rainfall erosivity in Jiangsu Province from 2001 to 2023 was 4709.39 MJ·mm/(hm2·h·a) and the spatial distribution was low in the north and high in the south. Seasonal rainfall ?erosivity was obviously different: more in summer and less in winter, and the same in spring and autumn. ③ The annual rainfall erosivity in Jiangsu Province showed an increasing trend from 2001 to 2023. The climate tendency rate showed a significant increasing trend in the south of Jiangsu Province and an insignificant decreasing trend in the north in spring and summer, which was the opposite in winter. ④ The annual erosivity density of Jiangsu Province was 4.96 MJ/(hm2·h), and the spatial distribution was high in the north and low in the south. The most vulnerable areas of rainfall erosivity were the east of Xuzhou, the north of Lianyungang, the west of Zhenjiang and the northern part of Nanjing. The less vulnerable areas were Yangzhou, Taizhou and the eastern part of Nantong. [Conclusion] The research can provide scientific basis for regional rainfall erosion prediction, soil loss prevention and soil and water conservation measures.
[Objective] Rainfall erosivity is an important index to evaluate soil erosion, to solve the problems of spatial differentiation and poor accuracy in estimating rainfall erosivity by meteorological stations and satellite precipitation products. [Methods] This research developed a station-satellite fusion calculation method of rainfall erosivity based on the rainfall data of 96 meteorological stations and precipitation products of GPM IMERG and ERA5. The rainfall erosivity of Jiangsu Province from 2001 to 2023 was reconstructed, and its erosivity density and prone area division were further studied. [Results]① This method was reliable because the fusion rainfall erosivity had a higher correlation coefficient, lower deviation, and lower root mean square error compared with rainfall erosivity calculated by satellite and station. This method will capture the high value of rainfall erosivity and reduce uncertainty and error. ② The mean annual rainfall erosivity in Jiangsu Province from 2001 to 2023 was 4709.39 MJ·mm/(hm2·h·a) and the spatial distribution was low in the north and high in the south. Seasonal rainfall ?erosivity was obviously different: more in summer and less in winter, and the same in spring and autumn. ③ The annual rainfall erosivity in Jiangsu Province showed an increasing trend from 2001 to 2023. The climate tendency rate showed a significant increasing trend in the south of Jiangsu Province and an insignificant decreasing trend in the north in spring and summer, which was the opposite in winter. ④ The annual erosivity density of Jiangsu Province was 4.96 MJ/(hm2·h), and the spatial distribution was high in the north and low in the south. The most vulnerable areas of rainfall erosivity were the east of Xuzhou, the north of Lianyungang, the west of Zhenjiang and the northern part of Nanjing. The less vulnerable areas were Yangzhou, Taizhou and the eastern part of Nantong. [Conclusion] The research can provide scientific basis for regional rainfall erosion prediction, soil loss prevention and soil and water conservation measures.
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[Objective] Soil anti-erodibility is an important parameter to characterize the ability of soil to resist erosion. The study of anti-erodibility on red soil can provide important basic data and reference for the prevention and control of soil erosion in red soil region and the rational development and utilization of red soil resources. [Methods] In this manuscript, the typical red soil in Weishui River Basin of Hunan Province was taken as the research object. A total of 16 types of red soil, including dry land, paddy field, garden land, and forestland, which were derived from four typical soil parent materials, such as Quaternary red clay, sandstone, plate shale, and granite, were selected to study the differences in anti-erodibility of red soils with different parent materials and land use types. [Results] Land use types significantly (P < 0.05) affected red soil anti-erodibility, the anti-erodibility and water stability indexes of paddy field, garden land, and forestland were significantly (P < 0.05) higher than those of dry land. There was no significant (P > 0.05) difference in the anti-erodibility of red soil derived from different parent materials, and the interaction between them and land use types on anti-erodibility was not obvious. In addition, land use types also significantly (P < 0.05) changed the contents of water-stable aggregate (WSA0.25) and soil organic matter, WSA0.25 of forest land was significantly (P < 0.05) higher than that that of dry land, and the soil organic matter content in paddy soil was significantly (P < 0.05) higher than that that of dry land, garden land, and forestland. However, the effect of parent materials on WSA0.25 was not significantly (P > 0.05), while significantly (P < 0.05) changed the contents of organic matter and clay in red soil, which were significantly (P < 0.05) lower in soil derived from granite than that derived from the other three parent materials. Correlation analysis showed that the anti-erodibility and water-stable indexes were significantly (P < 0.05) correlated with WSA0.25 and soil organic matter. [Conclusion] Both land use types and parent materials can affect the anti-erodibility of red soil by changing WSA0.25 and soil organic matter, but the effect of land use types on anti-erodibility was significantly stronger than that of parent material. Therefore, it should be based on the optimization of adjustment and layout about land use types for the prevention and control of soil and water loss in red soil, taking into account soil parent materials.
[Objective] Soil anti-erodibility is an important parameter to characterize the ability of soil to resist erosion. The study of anti-erodibility on red soil can provide important basic data and reference for the prevention and control of soil erosion in red soil region and the rational development and utilization of red soil resources. [Methods] In this manuscript, the typical red soil in Weishui River Basin of Hunan Province was taken as the research object. A total of 16 types of red soil, including dry land, paddy field, garden land, and forestland, which were derived from four typical soil parent materials, such as Quaternary red clay, sandstone, plate shale, and granite, were selected to study the differences in anti-erodibility of red soils with different parent materials and land use types. [Results] Land use types significantly (P < 0.05) affected red soil anti-erodibility, the anti-erodibility and water stability indexes of paddy field, garden land, and forestland were significantly (P < 0.05) higher than those of dry land. There was no significant (P > 0.05) difference in the anti-erodibility of red soil derived from different parent materials, and the interaction between them and land use types on anti-erodibility was not obvious. In addition, land use types also significantly (P < 0.05) changed the contents of water-stable aggregate (WSA0.25) and soil organic matter, WSA0.25 of forest land was significantly (P < 0.05) higher than that that of dry land, and the soil organic matter content in paddy soil was significantly (P < 0.05) higher than that that of dry land, garden land, and forestland. However, the effect of parent materials on WSA0.25 was not significantly (P > 0.05), while significantly (P < 0.05) changed the contents of organic matter and clay in red soil, which were significantly (P < 0.05) lower in soil derived from granite than that derived from the other three parent materials. Correlation analysis showed that the anti-erodibility and water-stable indexes were significantly (P < 0.05) correlated with WSA0.25 and soil organic matter. [Conclusion] Both land use types and parent materials can affect the anti-erodibility of red soil by changing WSA0.25 and soil organic matter, but the effect of land use types on anti-erodibility was significantly stronger than that of parent material. Therefore, it should be based on the optimization of adjustment and layout about land use types for the prevention and control of soil and water loss in red soil, taking into account soil parent materials.
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[Objective] Clarify the quantity and distribution of coal resources in Ningdong coal electricity base, analyze the spatio-temporal evolution and distribution characteristics of water and soil resources, analyze the current situation of development and utilization management of major resources in Ningdong Base, and build the resource-ecology-security integrated management framework of large coal electricity base in Ningdong.[Methods] Based on multi-source data, through the network analysis of growth rate, land transfer matrix and land use transfer matrix, this paper studies the distribution characteristics and spatiotemporal changes of coal-land and water resources in Ningdong Base from 2003 to 2023. In view of regional water resources management, this paper defines the surface water and groundwater extraction and water supply capacity of Ningdong, and analyzes the changes of land resources development and utilization in Ningdong through the utilization rate of land resources. [Results] ①The coal mines in the Ningdong large-scale coal-fired electricity base are mainly concentrated in the central and northern regions, with an average annual growth rate of 5.89% in coal production from 2003 to 2023. The water resources of Ningdong Base are mainly distributed in the northern and central parts of the base, and the water area has increased from 21.45km2 in 2003 to 45.66km2 in 2023. The land use of Ningdong Base is mainly grassland, but the area has been decreasing year by year. The area of industrial and residential land has increased the most significantly, from 48.26 km2 in 2003 to 280.28 km2 in 2023. ②The water consumption of Ningdong Base is mainly industrial water consumption, and the industrial water consumption is mainly coal, coal-fired electricity, and coal chemical industries. The total underground water supply capacity is 0.624 × 108 m3·a-1, and the supply and demand of water resources utilization are unbalanced; The utilization level of land resources has significantly increased from 6.14% in 2003 to 18.42% in 2023. [Conclusion] From 2003 to 2023, the coal production of Ningdong Coal and Electricity Base showed a steady upward trend, and the supply and demand of water resources in Ningdong coal base is unbalanced, but the utilization of land resources is significantly improved. Coal development affects the utilization of water and land resources, the change of mining scale and distribution, and brings about the change of water demand and land occupation. Water resources provide support for coal and land use, and their distribution and utilization pattern affect development activities. Land use change affects water distribution and coal mining, and the three interact and restrict each other.
[Objective] Clarify the quantity and distribution of coal resources in Ningdong coal electricity base, analyze the spatio-temporal evolution and distribution characteristics of water and soil resources, analyze the current situation of development and utilization management of major resources in Ningdong Base, and build the resource-ecology-security integrated management framework of large coal electricity base in Ningdong.[Methods] Based on multi-source data, through the network analysis of growth rate, land transfer matrix and land use transfer matrix, this paper studies the distribution characteristics and spatiotemporal changes of coal-land and water resources in Ningdong Base from 2003 to 2023. In view of regional water resources management, this paper defines the surface water and groundwater extraction and water supply capacity of Ningdong, and analyzes the changes of land resources development and utilization in Ningdong through the utilization rate of land resources. [Results] ①The coal mines in the Ningdong large-scale coal-fired electricity base are mainly concentrated in the central and northern regions, with an average annual growth rate of 5.89% in coal production from 2003 to 2023. The water resources of Ningdong Base are mainly distributed in the northern and central parts of the base, and the water area has increased from 21.45km2 in 2003 to 45.66km2 in 2023. The land use of Ningdong Base is mainly grassland, but the area has been decreasing year by year. The area of industrial and residential land has increased the most significantly, from 48.26 km2 in 2003 to 280.28 km2 in 2023. ②The water consumption of Ningdong Base is mainly industrial water consumption, and the industrial water consumption is mainly coal, coal-fired electricity, and coal chemical industries. The total underground water supply capacity is 0.624 × 108 m3·a-1, and the supply and demand of water resources utilization are unbalanced; The utilization level of land resources has significantly increased from 6.14% in 2003 to 18.42% in 2023. [Conclusion] From 2003 to 2023, the coal production of Ningdong Coal and Electricity Base showed a steady upward trend, and the supply and demand of water resources in Ningdong coal base is unbalanced, but the utilization of land resources is significantly improved. Coal development affects the utilization of water and land resources, the change of mining scale and distribution, and brings about the change of water demand and land occupation. Water resources provide support for coal and land use, and their distribution and utilization pattern affect development activities. Land use change affects water distribution and coal mining, and the three interact and restrict each other.
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[Objective] Exploring the distribution and differences of grain new quality productivity and its coupled coordination in grain functional areas is of great significance for promoting the development of grain new quality productivity and guaranteeing food security in China. [Methods] Based on the panel data of 30 provinces in China from 2012 to 2022, the entropy-TOPSIS method, Dagum Gini coefficient and coupled coordination degree model were applied to measure the level of grain new quality productivity, the degree of obstacles and the degree of coupled coordination. [Results] (1) The level of new grain productivity in China has been growing steadily, and it has been improved in all grain functional areas, but there is a development pattern of “grain main marketing area > grain main production area > grain production and marketing balance area”; in terms of dimensions, scientific and technological productivity and digital productivity have increased significantly in the whole country and in all grain functional areas, while the green productivity has been relatively stable and needs to be developed; (2) The level of new grain productivity has been improved by the entropy-TOPSIS method, the Dagum Gini coefficient and the coupling coordination degree model. (2) The overall gap in the level of new quality productivity of grain in China has gradually widened, and the differences within the main grain marketing areas and the inter-regional differences between the main grain marketing areas and the balance of production and marketing areas are the largest, and the inter-regional differences have become the main source of the overall differences in the new quality productivity of grain; (3) The level of coupling and coordination of the new quality productivity of grain in China has gradually increased, and it has been transformed from the low degree of coupling and coordination to the medium degree of coupling and coordination, but the coupling and coordination in the balance of production and marketing areas has been reduced to the medium degree of coupling and coordination. production and marketing balance area is still relatively low; (4) the spatial structure of grain new quality productivity coupling and coordination shows a high degree of aggregation to the main grain production area and the main grain marketing area, and the significant cold spot area is concentrated in the production and marketing balance area. [Conclusion] Accordingly, it is recommended to increase R&D investment in grain production and marketing balance zones, focus on promoting the development of green productivity, and encourage spatial linkage between production and marketing balance zones and grain main marketing zones and main marketing zones, in order to promote the overall coupled and coordinated development of grain new quality productivity.
[Objective] Exploring the distribution and differences of grain new quality productivity and its coupled coordination in grain functional areas is of great significance for promoting the development of grain new quality productivity and guaranteeing food security in China. [Methods] Based on the panel data of 30 provinces in China from 2012 to 2022, the entropy-TOPSIS method, Dagum Gini coefficient and coupled coordination degree model were applied to measure the level of grain new quality productivity, the degree of obstacles and the degree of coupled coordination. [Results] (1) The level of new grain productivity in China has been growing steadily, and it has been improved in all grain functional areas, but there is a development pattern of “grain main marketing area > grain main production area > grain production and marketing balance area”; in terms of dimensions, scientific and technological productivity and digital productivity have increased significantly in the whole country and in all grain functional areas, while the green productivity has been relatively stable and needs to be developed; (2) The level of new grain productivity has been improved by the entropy-TOPSIS method, the Dagum Gini coefficient and the coupling coordination degree model. (2) The overall gap in the level of new quality productivity of grain in China has gradually widened, and the differences within the main grain marketing areas and the inter-regional differences between the main grain marketing areas and the balance of production and marketing areas are the largest, and the inter-regional differences have become the main source of the overall differences in the new quality productivity of grain; (3) The level of coupling and coordination of the new quality productivity of grain in China has gradually increased, and it has been transformed from the low degree of coupling and coordination to the medium degree of coupling and coordination, but the coupling and coordination in the balance of production and marketing areas has been reduced to the medium degree of coupling and coordination. production and marketing balance area is still relatively low; (4) the spatial structure of grain new quality productivity coupling and coordination shows a high degree of aggregation to the main grain production area and the main grain marketing area, and the significant cold spot area is concentrated in the production and marketing balance area. [Conclusion] Accordingly, it is recommended to increase R&D investment in grain production and marketing balance zones, focus on promoting the development of green productivity, and encourage spatial linkage between production and marketing balance zones and grain main marketing zones and main marketing zones, in order to promote the overall coupled and coordinated development of grain new quality productivity.
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[Objective] The Milan Gobi area of the Golmud-Korla Railway is located in the alluvial and alluvial Gobi in front of Altun Mountain, where the effective prevention and control of the hazards caused by gobi wind-blown sand is one of the key problems to be solved in railway safety operation. [Methods] This study analyzed the regional wind conditions, monitored the amount of sand transported along the line, observed the protection efficiency of the test section of the protection system, and finally, put forward the appropriate configuration model of the protection system. [Results] The research shows that the Milan Gobi area of the Golmud-Korla Railway is a high wind energy environment, the main sand driving winds are NE and ENE, and the annual sand transport volume reaches 2.15-3.45 m3/m. The main sand source of the railway sand damage caused by the sand flowing dunes on the Gobi are mainly medium sand and fine sand, while the sand particles within 40cm below the surface of the Gobi are mainly fine sand. After construction damage, it is easy to generate sand and become a new sand source. The results show that the sand resistance rates of single HDPE plate, reed bundle and galvanized chicken wire barrier are 96.42%, 93.85% and 76.60%, and the sand resistance rates of double fences are 97.95%, 98.71% and 92.78%, respectively. The sand resistance rates of the whole protection system are above 95%. Although the amount of sand deposited in the zigzag sand barrier is large, the corner of the zigzag barrier is easily buried by sand deposited. [Conclusion] The sand control system which combines linear HDPE board sand barrier with reed bundle large grid is suitable for the sand control system configuration mode in Milan Gobi area of the Golmud-Korla Railway. The research results are of great significance to ensure the safe operation of the Golmud-Korla Railway.
[Objective] The Milan Gobi area of the Golmud-Korla Railway is located in the alluvial and alluvial Gobi in front of Altun Mountain, where the effective prevention and control of the hazards caused by gobi wind-blown sand is one of the key problems to be solved in railway safety operation. [Methods] This study analyzed the regional wind conditions, monitored the amount of sand transported along the line, observed the protection efficiency of the test section of the protection system, and finally, put forward the appropriate configuration model of the protection system. [Results] The research shows that the Milan Gobi area of the Golmud-Korla Railway is a high wind energy environment, the main sand driving winds are NE and ENE, and the annual sand transport volume reaches 2.15-3.45 m3/m. The main sand source of the railway sand damage caused by the sand flowing dunes on the Gobi are mainly medium sand and fine sand, while the sand particles within 40cm below the surface of the Gobi are mainly fine sand. After construction damage, it is easy to generate sand and become a new sand source. The results show that the sand resistance rates of single HDPE plate, reed bundle and galvanized chicken wire barrier are 96.42%, 93.85% and 76.60%, and the sand resistance rates of double fences are 97.95%, 98.71% and 92.78%, respectively. The sand resistance rates of the whole protection system are above 95%. Although the amount of sand deposited in the zigzag sand barrier is large, the corner of the zigzag barrier is easily buried by sand deposited. [Conclusion] The sand control system which combines linear HDPE board sand barrier with reed bundle large grid is suitable for the sand control system configuration mode in Milan Gobi area of the Golmud-Korla Railway. The research results are of great significance to ensure the safe operation of the Golmud-Korla Railway.
Abstract:
This study advances the in-situ monitoring of suspended sediment, building upon previous equipment development to design experimental protocols and validate laboratory models. The Luoyugou section of the Tianshui Soil and Water Conservation Monitoring Station served as the field test site. We conducted a comparative analysis between automatically collected field data and manually measured sediment concentrations to evaluate system errors and their sources. The results show that in laboratory simulations with varying sediment concentration gradients, the quantum dot spectral suspended sediment measurement system achieved a correlation coefficient of 0.998 with manual monitoring data. During sporadic rainfall-runoff events in the field, the system maintained a high correlation coefficient of 0.984. The monitoring equipment has shown improved environmental adaptability and reliability of results both in artificial simulation experiment and field experiment, and has relatively good applied basic of automatic monitoring of suspended sediment in soil and water conservation.
This study advances the in-situ monitoring of suspended sediment, building upon previous equipment development to design experimental protocols and validate laboratory models. The Luoyugou section of the Tianshui Soil and Water Conservation Monitoring Station served as the field test site. We conducted a comparative analysis between automatically collected field data and manually measured sediment concentrations to evaluate system errors and their sources. The results show that in laboratory simulations with varying sediment concentration gradients, the quantum dot spectral suspended sediment measurement system achieved a correlation coefficient of 0.998 with manual monitoring data. During sporadic rainfall-runoff events in the field, the system maintained a high correlation coefficient of 0.984. The monitoring equipment has shown improved environmental adaptability and reliability of results both in artificial simulation experiment and field experiment, and has relatively good applied basic of automatic monitoring of suspended sediment in soil and water conservation.
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[Objective]This paper conducts a comprehensive analysis of the changes in cultivated land use patterns in Yunnan Province from multiple perspectives, classifies the risk levels of cultivated land use, and provides a basis for cultivated land protection policies and management strategies in the study area, while also offering references for cultivated land protection in other regions. [Methods] Utilizing land use survey data from 2011 and ?2021, and adopting a "quantity-quality-ecology" tripartite perspective, we comprehensively analyzed the characteristics of changes in cultivated land use patterns by employing landscape indices and the Pressure-State-Response (PSR) model. Based on the state space model, we categorized the risk levels of cultivated land use. [Results] (1)Regional variations were observed in the changes of cultivated land quantity in Yunnan Province from 2011 to 2021, with districts and counties exhibiting significant changes displaying a distribution pattern characterized by "overall scattered and local aggregation"; (2)The degree of cultivated land fragmentation intensified, agglomeration weakened, and patch shapes became more regular; The average soil layer thickness of cultivated land decreased, the content of soil organic matter and cation exchange capacity increased, and the PD of cultivated land increased by 1.251, AI and MSI decreased by 5.672% and 0.055, indicating that the degree of farmland fragmentation increased, the agglomeration weakened, and the patch shape tended to be regular; (3)The overall level of ecological security of cultivated land declined, revealing a spatial pattern of "high in the south, low in the north, and polarized in the middle"; (4)Based on the dynamic changes in cultivated land, we conducted risk zoning for cultivated land use in Yunnan Province and proposed regulatory suggestions. [Conclusion]The research results clarified the change characteristics of the quantity, quality and ecological security pattern of cultivated land in Yunnan Province, measured the risk of cultivated land use and provided control measures, which provided a certain scientific basis for the sustainable development of cultivated land and food security in Yunnan Province.
[Objective]This paper conducts a comprehensive analysis of the changes in cultivated land use patterns in Yunnan Province from multiple perspectives, classifies the risk levels of cultivated land use, and provides a basis for cultivated land protection policies and management strategies in the study area, while also offering references for cultivated land protection in other regions. [Methods] Utilizing land use survey data from 2011 and ?2021, and adopting a "quantity-quality-ecology" tripartite perspective, we comprehensively analyzed the characteristics of changes in cultivated land use patterns by employing landscape indices and the Pressure-State-Response (PSR) model. Based on the state space model, we categorized the risk levels of cultivated land use. [Results] (1)Regional variations were observed in the changes of cultivated land quantity in Yunnan Province from 2011 to 2021, with districts and counties exhibiting significant changes displaying a distribution pattern characterized by "overall scattered and local aggregation"; (2)The degree of cultivated land fragmentation intensified, agglomeration weakened, and patch shapes became more regular; The average soil layer thickness of cultivated land decreased, the content of soil organic matter and cation exchange capacity increased, and the PD of cultivated land increased by 1.251, AI and MSI decreased by 5.672% and 0.055, indicating that the degree of farmland fragmentation increased, the agglomeration weakened, and the patch shape tended to be regular; (3)The overall level of ecological security of cultivated land declined, revealing a spatial pattern of "high in the south, low in the north, and polarized in the middle"; (4)Based on the dynamic changes in cultivated land, we conducted risk zoning for cultivated land use in Yunnan Province and proposed regulatory suggestions. [Conclusion]The research results clarified the change characteristics of the quantity, quality and ecological security pattern of cultivated land in Yunnan Province, measured the risk of cultivated land use and provided control measures, which provided a certain scientific basis for the sustainable development of cultivated land and food security in Yunnan Province.
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Abstract: [Objective]It is crucial to clarify the seepage law of granite colluvial soil for engineering construction, agricultural activities, ecological restoration and geological disaster prevention in the area. [Methods] In this paper, the constant head permeability tests of granite colluvial soil under different initial dry densities are carried out, and the seepage characteristics of granite colluvial soil under low hydraulic gradient are studied. [Results] The results indicate that granite colluvial soil have different degrees of fluctuation characteristics under low hydraulic gradient. The permeability coefficient increases with the hydraulic gradient under all dry density conditions. When the hydraulic gradient reaches the critical hydraulic gradient icr, the permeability coefficient remains basically unchanged, and the permeability coefficient at this moment decreases logarithmically with the increase of dry density. And the critical hydraulic gradient of the transition fluctuates greatly under low dry density conditions. While the dry density is greater than 1.5g / cm3, the critical hydraulic gradient icr increases linearly with the dry density. [Conclusion] The saturated seepage of granite residual soil under different dry density conditions has fluctuation characteristics under low hydraulic gradient. Then, the prediction equations of critical hydraulic gradient and permeability coefficient in the linear seepage stage of granite colluvial soil under different dry density conditions are clarified. Combined with pore seepage theory, the reasons of fluctuation seepage and its transformation of granite colluvial soil under low hydraulic gradient is preliminarily discussed. The research results provide a new viewpoint for the study of seepage process of granite colluvial soil and provide a reference for consolidation analysis and seepage stability calculation of granite colluvial soil.
Abstract: [Objective]It is crucial to clarify the seepage law of granite colluvial soil for engineering construction, agricultural activities, ecological restoration and geological disaster prevention in the area. [Methods] In this paper, the constant head permeability tests of granite colluvial soil under different initial dry densities are carried out, and the seepage characteristics of granite colluvial soil under low hydraulic gradient are studied. [Results] The results indicate that granite colluvial soil have different degrees of fluctuation characteristics under low hydraulic gradient. The permeability coefficient increases with the hydraulic gradient under all dry density conditions. When the hydraulic gradient reaches the critical hydraulic gradient icr, the permeability coefficient remains basically unchanged, and the permeability coefficient at this moment decreases logarithmically with the increase of dry density. And the critical hydraulic gradient of the transition fluctuates greatly under low dry density conditions. While the dry density is greater than 1.5g / cm3, the critical hydraulic gradient icr increases linearly with the dry density. [Conclusion] The saturated seepage of granite residual soil under different dry density conditions has fluctuation characteristics under low hydraulic gradient. Then, the prediction equations of critical hydraulic gradient and permeability coefficient in the linear seepage stage of granite colluvial soil under different dry density conditions are clarified. Combined with pore seepage theory, the reasons of fluctuation seepage and its transformation of granite colluvial soil under low hydraulic gradient is preliminarily discussed. The research results provide a new viewpoint for the study of seepage process of granite colluvial soil and provide a reference for consolidation analysis and seepage stability calculation of granite colluvial soil.
HUANG Zixuan, HUANG Yuhan, WEI Juan, CHEN Fengting, TAN Qingfang, CHANG Zhiyong, HUANG Youping, LIU Weiyan, WANG Lehan
Abstract:
Abstract: [Objective] This study aims to reveal the influence of different initial moisture contents and rainfall intensities on the splashing characteristics and splashing process of red soil macroaggregates. [Methods] The red soil macroaggregates (2~5 mm) were selected as the research object. Artificial simulated rainfall experiments were content to explore the variation patterns of splash erosion and splash erosion rate with four rainfall intensities (30, 60, 90, 140 mm·h-1) and four initial moisture contents (10 %, 20 %, 30 %, saturation ) . [Results] Under the same initial moisture content, the ranges of splash erosion variation for macroaggregates of red soil at four different rainfall intensities were from 0.05 to 0.27 g, from 0.03 to 0.19 g, from 0.16 to 1.41 g, and from 0.03 to 1.48 g. At the same rainfall intensity, the splash erosion of aggregates under saturated initial moisture conditions all increased significantly (p＜0.05). At the four rainfall intensities, the splash erosion of aggregates under saturated initial moisture conditions increased by 1.5, 1.11, 3.8, 3.21 times, respectively, compared to the sum of the splash erosion under unsaturated initial moisture conditions (10%, 20%, and 30%). The initial moisture content, rainfall intensity and their interaction all exert direct positive effects on the splash erosion of aggregates, with effect sizes of 0.646, 0.415, and 0.361.[Conclusion] At the initial moisture content of 20 %, the increase in rainfall intensity had not significantly affected the splash erosion of red soil macroaggregates. Under other initial moisture content conditions, the splash erosion of red soil macroaggregates was sensitive to changes in rainfall intensity at the same initial moisture content. This sensitivity was particularly evident during conditions of heavy rainfall (90 mm·h?1) or extreme rainstorm (140 mm·h?1). Under these conditions, the macroaggregates of red soil had been more susceptible to the impact of splash erosion. At the same rainfall intensity, saturated initial moisture content had intensified the occurrence and severity of splash erosion. The initial moisture content and rainfall intensity showed a significant positive correlation with changes in red soil macroaggregates. Additionally, the impact of initial moisture content on splash erosion was greater than that of rainfall intensity and their interaction, serving as a key factor influencing the splash erosion. Our research results provide insights into the splash erosion process of red soil macroaggregates. Furthermore, these findings can provide a reference for developing effective measures to prevent and control soil erosion on slope farmland of red soil.
Abstract: [Objective] This study aims to reveal the influence of different initial moisture contents and rainfall intensities on the splashing characteristics and splashing process of red soil macroaggregates. [Methods] The red soil macroaggregates (2~5 mm) were selected as the research object. Artificial simulated rainfall experiments were content to explore the variation patterns of splash erosion and splash erosion rate with four rainfall intensities (30, 60, 90, 140 mm·h-1) and four initial moisture contents (10 %, 20 %, 30 %, saturation ) . [Results] Under the same initial moisture content, the ranges of splash erosion variation for macroaggregates of red soil at four different rainfall intensities were from 0.05 to 0.27 g, from 0.03 to 0.19 g, from 0.16 to 1.41 g, and from 0.03 to 1.48 g. At the same rainfall intensity, the splash erosion of aggregates under saturated initial moisture conditions all increased significantly (p＜0.05). At the four rainfall intensities, the splash erosion of aggregates under saturated initial moisture conditions increased by 1.5, 1.11, 3.8, 3.21 times, respectively, compared to the sum of the splash erosion under unsaturated initial moisture conditions (10%, 20%, and 30%). The initial moisture content, rainfall intensity and their interaction all exert direct positive effects on the splash erosion of aggregates, with effect sizes of 0.646, 0.415, and 0.361.[Conclusion] At the initial moisture content of 20 %, the increase in rainfall intensity had not significantly affected the splash erosion of red soil macroaggregates. Under other initial moisture content conditions, the splash erosion of red soil macroaggregates was sensitive to changes in rainfall intensity at the same initial moisture content. This sensitivity was particularly evident during conditions of heavy rainfall (90 mm·h?1) or extreme rainstorm (140 mm·h?1). Under these conditions, the macroaggregates of red soil had been more susceptible to the impact of splash erosion. At the same rainfall intensity, saturated initial moisture content had intensified the occurrence and severity of splash erosion. The initial moisture content and rainfall intensity showed a significant positive correlation with changes in red soil macroaggregates. Additionally, the impact of initial moisture content on splash erosion was greater than that of rainfall intensity and their interaction, serving as a key factor influencing the splash erosion. Our research results provide insights into the splash erosion process of red soil macroaggregates. Furthermore, these findings can provide a reference for developing effective measures to prevent and control soil erosion on slope farmland of red soil.
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Abstract: [Objective] To clarify the changes in urban resilience and land use efficiency in Guangdong Province from 2013 to 2022, identify the spatiotemporal evolution patterns of their coupling coordination state and aggregation characteristics, with the aim of providing a scientific basis for promoting the coordinated development of resilient urban construction and intensive land use in the region.[Methods]The regional variations and evolutionary patterns in the coupling coordination between urban resilience and land use efficiency among 21 prefecture-level cities in Guangdong Province were analyzed using comprehensive evaluation methods, which encompassed the entropy weight method, the CRITIC method, the super-efficiency SBM model, the coupling coordination degree model, and the spatial autocorrelation model.[Results](1)During the study period, urban resilience in Guangdong Province continued to strengthen, with an increase of 43.21%. There are differences in the level of urban resilience construction among the cities, with a spatial distribution pattern of "gradually decreasing from the core to the periphery."(2) The fluctuation of land use efficiency has increased, rising from 0.57 to 0.65. However, land use has not reached DEA optimality, and most prefecture-level cities exhibit significant interannual volatility in land use efficiency, showing a spatial distribution pattern of "higher in the Pearl River Delta, lower in northern Guangdong, higher in western Guangdong, and lower in eastern Guangdong."(3) The overall coupling between urban resilience and land use efficiency is favorable and stable, exhibiting a sturdy and positive correlation. The coupling coordination level across the province has undergone an enhancement, transitioning from the initial coordination stage to the intermediate coordination stage. (4) Spatially, there exists a positive correlation in the coupling coordination between urban resilience and land use efficiency; however, localized agglomeration characteristics are not prominent.[Conclusion]Strengthen the linkage between resilient city construction and land spatial planning, optimize policy orientation, focus on unified coordination of regional planning, promote complementary advantages between cities, enhance agglomeration efficiency, and promote coordinated regional development.
Abstract: [Objective] To clarify the changes in urban resilience and land use efficiency in Guangdong Province from 2013 to 2022, identify the spatiotemporal evolution patterns of their coupling coordination state and aggregation characteristics, with the aim of providing a scientific basis for promoting the coordinated development of resilient urban construction and intensive land use in the region.[Methods]The regional variations and evolutionary patterns in the coupling coordination between urban resilience and land use efficiency among 21 prefecture-level cities in Guangdong Province were analyzed using comprehensive evaluation methods, which encompassed the entropy weight method, the CRITIC method, the super-efficiency SBM model, the coupling coordination degree model, and the spatial autocorrelation model.[Results](1)During the study period, urban resilience in Guangdong Province continued to strengthen, with an increase of 43.21%. There are differences in the level of urban resilience construction among the cities, with a spatial distribution pattern of "gradually decreasing from the core to the periphery."(2) The fluctuation of land use efficiency has increased, rising from 0.57 to 0.65. However, land use has not reached DEA optimality, and most prefecture-level cities exhibit significant interannual volatility in land use efficiency, showing a spatial distribution pattern of "higher in the Pearl River Delta, lower in northern Guangdong, higher in western Guangdong, and lower in eastern Guangdong."(3) The overall coupling between urban resilience and land use efficiency is favorable and stable, exhibiting a sturdy and positive correlation. The coupling coordination level across the province has undergone an enhancement, transitioning from the initial coordination stage to the intermediate coordination stage. (4) Spatially, there exists a positive correlation in the coupling coordination between urban resilience and land use efficiency; however, localized agglomeration characteristics are not prominent.[Conclusion]Strengthen the linkage between resilient city construction and land spatial planning, optimize policy orientation, focus on unified coordination of regional planning, promote complementary advantages between cities, enhance agglomeration efficiency, and promote coordinated regional development.
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[Objective] The relationship between climate change and soil carbon sequestration capacity was explored to reveal the effects of temperature, carbon dioxide (CO2) concentration and precipitation on soil organic carbon and its component pool, and provided a theoretical basis for improving soil carbon sequestration capacity under the background of global climate change. [Method] Using meta-analysis method, a total of 44 relevant literatures were screened and 281 research sample data were collected. Soil active and inert organic carbon components were characterized by Particulate organic carbon (POC) and Mineral associated organic carbon (MAOC), respectively. The effects of climate change on soil carbon stock and its stability were analyzed. [Result] ①There was a significant negative correlation between atmospheric CO2 concentration and soil POC and MAOC contents (P<0.05). POC content decreased with increasing air temperature, while MAOC content increased slightly. POC was more sensitive to air temperature change than MAOC. Soil POC was positively correlated with precipitation increase and negatively correlated with precipitation decrease, while soil MAOC content was opposite. ②The increase of air temperature, CO2 concentration and the decrease of precipitation decreased the concentration of soil total organic carbon, while the increase of precipitation increased the concentration of soil total organic carbon. ③The response of soil organic carbon and its components to the change of climate factors is obviously affected by soil depth and soil type. [Conclusion] The influence of climate factors on soil organic carbon and its component content is obviously different, and the change of climate factors will reduce the storage or stability of soil organic carbon pool, and weaken the soil carbon sequestration capacity. The study contributes to further understanding of the impact of global climate change on soil carbon sequestration capacity.
[Objective] The relationship between climate change and soil carbon sequestration capacity was explored to reveal the effects of temperature, carbon dioxide (CO2) concentration and precipitation on soil organic carbon and its component pool, and provided a theoretical basis for improving soil carbon sequestration capacity under the background of global climate change. [Method] Using meta-analysis method, a total of 44 relevant literatures were screened and 281 research sample data were collected. Soil active and inert organic carbon components were characterized by Particulate organic carbon (POC) and Mineral associated organic carbon (MAOC), respectively. The effects of climate change on soil carbon stock and its stability were analyzed. [Result] ①There was a significant negative correlation between atmospheric CO2 concentration and soil POC and MAOC contents (P<0.05). POC content decreased with increasing air temperature, while MAOC content increased slightly. POC was more sensitive to air temperature change than MAOC. Soil POC was positively correlated with precipitation increase and negatively correlated with precipitation decrease, while soil MAOC content was opposite. ②The increase of air temperature, CO2 concentration and the decrease of precipitation decreased the concentration of soil total organic carbon, while the increase of precipitation increased the concentration of soil total organic carbon. ③The response of soil organic carbon and its components to the change of climate factors is obviously affected by soil depth and soil type. [Conclusion] The influence of climate factors on soil organic carbon and its component content is obviously different, and the change of climate factors will reduce the storage or stability of soil organic carbon pool, and weaken the soil carbon sequestration capacity. The study contributes to further understanding of the impact of global climate change on soil carbon sequestration capacity.
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Abstract: 【Objectives】To clarify the influences of diverse irrigation treatments on gaseous nitrogen loss and nitrogen cycle functional genes within the facility cucumber ecosystem. 【Methods】 Facility cucumbers were chosen as the research subjects for a field experiment. The experimental designs were traditional irrigation (100% IWD), 25% water-saving irrigation (75% IWD), and 50% water-saving irrigation (50% IWD). Through in-situ field monitoring experiments, continuous observations and records of N2O emissions and ammonia volatilization from the soil of facility cucumbers were made respectively using the static chamber - gas chromatography method and the ventilation absorption method. The nitrogen cycle functional genes were determined by high-throughput qPCR gene chip technology. 【Results】 (1) Among the various irrigation treatments, the cumulative emissions of N2O were 100% IWD > 75% IWD (p < 0.05), and 100% IWD > 50% IWD (p < 0.05). (2) The cumulative ammonia volatilization was 75% IWD > 50% IWD > 100% IWD (p < 0.05). (3) The overall abundance of nitrogen cycle functional genes in the soil underwent a significant change (PERMANOVA F = 241.82, p = 0.001). (4) The cucumber yield was 100% IWD > 75% IWD > 50% IWD (p < 0.05). 【Conclusion】 In the facility cucumber ecosystem, compared with the traditional irrigation treatment, 75% IWD can save 25% of irrigation water resources while reducing N2O emissions (by 25% - 50%), but this leads to an increase in ammonia volatilization (by approximately 5%). 50% IWD can save more irrigation water resources and, while ensuring the promotion of reducing N2O emissions (by 25% - 50%), it causes a small increase in ammonia volatilization (by approximately 10%). Water-saving by 75% and 50% can effectively reduce N2O emissions while ensuring water conservation. In the facility cucumber ecosystem, compared with traditional irrigation, 75% IWD and 50% IWD can effectively reduce the relative abundance of denitrification genes (narG, nirK1, nirK2, nirK3, nirS1, and nirS2 genes), but 50% IWD significantly increases the relative abundance of nitrification genes (amoA2, amoB, and nxrA genes). In the facility cucumber ecosystem, compared with traditional irrigation, 75% IWD and 50% IWD can effectively save water and reduce N2O emissions while ensuring the yield.
Abstract: 【Objectives】To clarify the influences of diverse irrigation treatments on gaseous nitrogen loss and nitrogen cycle functional genes within the facility cucumber ecosystem. 【Methods】 Facility cucumbers were chosen as the research subjects for a field experiment. The experimental designs were traditional irrigation (100% IWD), 25% water-saving irrigation (75% IWD), and 50% water-saving irrigation (50% IWD). Through in-situ field monitoring experiments, continuous observations and records of N2O emissions and ammonia volatilization from the soil of facility cucumbers were made respectively using the static chamber - gas chromatography method and the ventilation absorption method. The nitrogen cycle functional genes were determined by high-throughput qPCR gene chip technology. 【Results】 (1) Among the various irrigation treatments, the cumulative emissions of N2O were 100% IWD > 75% IWD (p < 0.05), and 100% IWD > 50% IWD (p < 0.05). (2) The cumulative ammonia volatilization was 75% IWD > 50% IWD > 100% IWD (p < 0.05). (3) The overall abundance of nitrogen cycle functional genes in the soil underwent a significant change (PERMANOVA F = 241.82, p = 0.001). (4) The cucumber yield was 100% IWD > 75% IWD > 50% IWD (p < 0.05). 【Conclusion】 In the facility cucumber ecosystem, compared with the traditional irrigation treatment, 75% IWD can save 25% of irrigation water resources while reducing N2O emissions (by 25% - 50%), but this leads to an increase in ammonia volatilization (by approximately 5%). 50% IWD can save more irrigation water resources and, while ensuring the promotion of reducing N2O emissions (by 25% - 50%), it causes a small increase in ammonia volatilization (by approximately 10%). Water-saving by 75% and 50% can effectively reduce N2O emissions while ensuring water conservation. In the facility cucumber ecosystem, compared with traditional irrigation, 75% IWD and 50% IWD can effectively reduce the relative abundance of denitrification genes (narG, nirK1, nirK2, nirK3, nirS1, and nirS2 genes), but 50% IWD significantly increases the relative abundance of nitrification genes (amoA2, amoB, and nxrA genes). In the facility cucumber ecosystem, compared with traditional irrigation, 75% IWD and 50% IWD can effectively save water and reduce N2O emissions while ensuring the yield.
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[Objective] To comprehensively analyze the variability and persistence of runoff in Bailong River, Gansu Province, and quantitatively analyze the contribution rate of climate and human activities to annual runoff change, so as to provide theoretical basis for water resources planning and management in Bailong River Basin. [Methods] Based on the annual and monthly rainfall and runoff data of Baiyun Station, Zhouqu Station, Wudu Station and Bikou Station in Bailong River Basin from 1961 to 2021, this paper used Mann-Kendall trend, sliding T test, R/S analysis and double accumulation curve to study the evolution characteristics of Bailong River runoff and analyze its causes. [Results] (1) The annual runoff of Bailong River stations showed a decreasing trend to different degrees. And loss from upstream to downstream showed a trend of increase (present bikou stand [-3.07×108m3·(10 a)-1] > wudu [-1.49×108m3·(10 a)-1] > zhouqu station [-1.49×108m3·(10 a)-1] > baiyun stand [-0.34×108m3·(10 a)-1]of the linear tendency rate); (2) The maximum monthly runoff in the upper reaches of Bailong River occurred in September, and in the middle and lower reaches in July, with the maximum annual runoff extreme ratio at Wudu Station; (3) The abrupt change points of runoff mainly occurred in 1969 and 1994, and the change rates of abrupt runoff at all stations were negative, that is, the runoff was higher than the annual average before the abrupt change, and the reverse after the abrupt change; (4) Hurst index indicates that runoff will continue to decline in the middle and lower reaches of Bailong River in the future (H=0.53~0.77); (5) The contribution rate of climate change to the reduction of watershed runoff is 94.85%, and the contribution rate of human activities is 5.15%. [Conclusion] The research results provide a basis for systematically grasping the characteristics of runoff evolution in Bailong River.
[Objective] To comprehensively analyze the variability and persistence of runoff in Bailong River, Gansu Province, and quantitatively analyze the contribution rate of climate and human activities to annual runoff change, so as to provide theoretical basis for water resources planning and management in Bailong River Basin. [Methods] Based on the annual and monthly rainfall and runoff data of Baiyun Station, Zhouqu Station, Wudu Station and Bikou Station in Bailong River Basin from 1961 to 2021, this paper used Mann-Kendall trend, sliding T test, R/S analysis and double accumulation curve to study the evolution characteristics of Bailong River runoff and analyze its causes. [Results] (1) The annual runoff of Bailong River stations showed a decreasing trend to different degrees. And loss from upstream to downstream showed a trend of increase (present bikou stand [-3.07×108m3·(10 a)-1] > wudu [-1.49×108m3·(10 a)-1] > zhouqu station [-1.49×108m3·(10 a)-1] > baiyun stand [-0.34×108m3·(10 a)-1]of the linear tendency rate); (2) The maximum monthly runoff in the upper reaches of Bailong River occurred in September, and in the middle and lower reaches in July, with the maximum annual runoff extreme ratio at Wudu Station; (3) The abrupt change points of runoff mainly occurred in 1969 and 1994, and the change rates of abrupt runoff at all stations were negative, that is, the runoff was higher than the annual average before the abrupt change, and the reverse after the abrupt change; (4) Hurst index indicates that runoff will continue to decline in the middle and lower reaches of Bailong River in the future (H=0.53~0.77); (5) The contribution rate of climate change to the reduction of watershed runoff is 94.85%, and the contribution rate of human activities is 5.15%. [Conclusion] The research results provide a basis for systematically grasping the characteristics of runoff evolution in Bailong River.
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Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
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[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
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[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
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[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
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[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
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[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
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[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
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.
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[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.
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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.
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[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.
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[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
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[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
Abstract:
[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.
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Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
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[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
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Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
Abstract:
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
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[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.
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。
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.
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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：
Qiao Dianxin
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