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2024,44(1):1-8,19
, DOI: 10.13961/j.cnki.stbctb.2024.01.001
Abstract:
[Objective] The ecology of open-pit coal mine areas is fragile and water resources are scarce. Therefore, the use of microorganisms for mine reclamation has become a research hotspot with regard to ecological reconstruction of mining areas. The effects of soil inoculation with arbuscular mycorrhizal fungi (AMF) on maize root growth and water use charateristics under the conditions of a reconstructed soil sponge ecological structure in an open-pit mine dump were determined in order to provide a scientific basis for the implementation of ecological agriculture in mining areas.[Methods] A soil column simulation experiment was conducted in a laboratory. Three treatments were evaluated:a bare soil column (CK), maize without bacterial inoculation (NM), and maize with bacterial inoculation (AM). The stable hydrogen and oxygen isotope tracer technique was used to study water use characteristics by maize roots.[Results] ① The AMF treatment increased maize root growth and changed maize root distribution. Total root length, total root surface area, total root volume, and number of root tips for the AM treatment were 19.3 %, 14.8 %, 9.1 %, and 34.0 %, respectively, higher than observed for the NM treatment. The proportions of fine roots smaller than 0.3 mm and coarse roots larger than 0.7 mm for the AM treatment were 3.2 % and 3.5 %, respectively, higher than for the NM group. ② AMF changed water use characteristics by maize roots by depth. The proportion of water used by maize for the AM treatment from the 0-20 cm soil layer was 5.5 % higher than for the NM treatment. ③ The moisture content of the 0-20 cm soil layer of the AM treatment was significantly lower than for the NM treatment. The moisture content of saturated clay layer of the CK treatment was higher than for the NM treatment, which was higher than for the AM treatment. AMF improved the ability of maize roots to absorb water, and affected the release of water in the clay layer.[Conclusion] AMF inoculation of a reconstructed soil sponge structure in an open-pit mine dump can promote maize root development, improve maize water utilization strategy, and make full use of the water stored in the water layer in the sponge structure.
[Objective] The ecology of open-pit coal mine areas is fragile and water resources are scarce. Therefore, the use of microorganisms for mine reclamation has become a research hotspot with regard to ecological reconstruction of mining areas. The effects of soil inoculation with arbuscular mycorrhizal fungi (AMF) on maize root growth and water use charateristics under the conditions of a reconstructed soil sponge ecological structure in an open-pit mine dump were determined in order to provide a scientific basis for the implementation of ecological agriculture in mining areas.[Methods] A soil column simulation experiment was conducted in a laboratory. Three treatments were evaluated:a bare soil column (CK), maize without bacterial inoculation (NM), and maize with bacterial inoculation (AM). The stable hydrogen and oxygen isotope tracer technique was used to study water use characteristics by maize roots.[Results] ① The AMF treatment increased maize root growth and changed maize root distribution. Total root length, total root surface area, total root volume, and number of root tips for the AM treatment were 19.3 %, 14.8 %, 9.1 %, and 34.0 %, respectively, higher than observed for the NM treatment. The proportions of fine roots smaller than 0.3 mm and coarse roots larger than 0.7 mm for the AM treatment were 3.2 % and 3.5 %, respectively, higher than for the NM group. ② AMF changed water use characteristics by maize roots by depth. The proportion of water used by maize for the AM treatment from the 0-20 cm soil layer was 5.5 % higher than for the NM treatment. ③ The moisture content of the 0-20 cm soil layer of the AM treatment was significantly lower than for the NM treatment. The moisture content of saturated clay layer of the CK treatment was higher than for the NM treatment, which was higher than for the AM treatment. AMF improved the ability of maize roots to absorb water, and affected the release of water in the clay layer.[Conclusion] AMF inoculation of a reconstructed soil sponge structure in an open-pit mine dump can promote maize root development, improve maize water utilization strategy, and make full use of the water stored in the water layer in the sponge structure.
2024,44(1):9-19
, DOI: 10.13961/j.cnki.stbctb.2024.01.002
Abstract:
[Objective] The coastal area of the Yellow River is one of the areas experiencing the most severe soil and water loss. The soil moisture and vegetation community characteristics of riparian-sand-fixing forest belt in sandy areas were studied under different zone spacing, and the belt spacing under the optimal allocation mode was determined in order to provide the basis for the construction of row and belt afforestation of riparian sand-fixing forest belt in sandy areas.[Methods] The study was conducted on sand-fixation forest belts with different band spacings at Xiliugou, Dalat Banner, Ordos City, Inner Mongolia. Soil sampling and vegetation surveys were carried out in the sand-fixation forest sample plots with different band spacings of 8 m, 16 m, 22 m, and 28 m. Soil physical properties and vegetation community characteristics were analyzed. The correlation between soil moisture and vegetation was also determined.[Results] ① The soil moisture and vegetation index of different sand-fixation forest belts increased with increasing band spacing. ② The soil moisture for different soil layers in the 0-100 cm soil layer in various zones of the band spacing also increased with the increasing horizontal spacing, and the change tended to be stable after 11 m. ③ Soil moisture in different zones was positively correlated with vegetation index in general, but the evenness index and richness index were different. The greater the band spacing, the better the vegetation restoration effect, and the peak value of the restoration effect was approximately reached when the band spacing was 22 m.[Conclusion] The vegetation restoration effect increased with increasing sand-fixation forest belt band spacing when sandy land was treated with a low coverage row-type sand-fixation forest, but it is not always that the wider the band spacing, the better the vegetation restoration effect. The 22 m band spacing had the best vegetation restoration effect of all of the row-type sand-fixation forest band spacings, and the near-natural restoration effect on sandy land was the best.
[Objective] The coastal area of the Yellow River is one of the areas experiencing the most severe soil and water loss. The soil moisture and vegetation community characteristics of riparian-sand-fixing forest belt in sandy areas were studied under different zone spacing, and the belt spacing under the optimal allocation mode was determined in order to provide the basis for the construction of row and belt afforestation of riparian sand-fixing forest belt in sandy areas.[Methods] The study was conducted on sand-fixation forest belts with different band spacings at Xiliugou, Dalat Banner, Ordos City, Inner Mongolia. Soil sampling and vegetation surveys were carried out in the sand-fixation forest sample plots with different band spacings of 8 m, 16 m, 22 m, and 28 m. Soil physical properties and vegetation community characteristics were analyzed. The correlation between soil moisture and vegetation was also determined.[Results] ① The soil moisture and vegetation index of different sand-fixation forest belts increased with increasing band spacing. ② The soil moisture for different soil layers in the 0-100 cm soil layer in various zones of the band spacing also increased with the increasing horizontal spacing, and the change tended to be stable after 11 m. ③ Soil moisture in different zones was positively correlated with vegetation index in general, but the evenness index and richness index were different. The greater the band spacing, the better the vegetation restoration effect, and the peak value of the restoration effect was approximately reached when the band spacing was 22 m.[Conclusion] The vegetation restoration effect increased with increasing sand-fixation forest belt band spacing when sandy land was treated with a low coverage row-type sand-fixation forest, but it is not always that the wider the band spacing, the better the vegetation restoration effect. The 22 m band spacing had the best vegetation restoration effect of all of the row-type sand-fixation forest band spacings, and the near-natural restoration effect on sandy land was the best.
2024,44(1):20-28,39
, DOI: 10.13961/j.cnki.stbctb.20231009.001
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water loss on abandoned dreg field of production and construction projects. The runoff and sediment redution effects of various vegetation restoration patterns in an abandoned dreg field were studied to 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 patterns (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 patterns 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 patterns, 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 loss on abandoned dreg field of production and construction projects. The runoff and sediment redution effects of various vegetation restoration patterns in an abandoned dreg field were studied to 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 patterns (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 patterns 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 patterns, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6 % and 95.5 % respectively.
2024,44(1):29-39
, DOI: 10.13961/j.cnki.stbctb.2024.01.004
Abstract:
[Objective] The relationship between grassland community and functional group quantity changes under grazing disturbance and soil wind erosion in grasslands was analyzed, and the influence of different functional groups on grassland erosion processes were determined to provide a theoretical basis for the rational use and protection of desert grasslands.[Methods] The study was conducted on desert grasslands of Stipa breviflora in Inner Mongolia. A completely randomized experiment was conducted with three grazing treatments:control (CK), moderate grazing (MG), and heavy grazing (HG). Sand transport and functional group characteristics under different treatments were determined.[Results] ① The height, coverage, and aboveground biomass of each functional group generally declined as grazing intensity increased. Appropriate grazing significantly increased the Simpson dominance index and the Shannon-Wiener diversity index. ② Differences in sand transport among different grazing treatments were significant. Sand transport related to different heights followed the order of HG>MG>CK, and sand transport rate decreased significantly as height increased under the same grazing treatment. ③ There was an exponential negative correlation between height, coverage of each functional group, and sand transport, with the height changes of perennial grasses and perennial forbs having a more significant impact on sand transport. Aboveground biomass of each functional group was negatively correlated with sand transport, with the highest fitting degree observed between the biomass of perennial grasses and sand transport.[Conclusion] Overgrazing significantly affected functional group characteristics and reduced the windbreak and sand-fixing capacity of grasslands. Grazing intensity of desert grasslands in Inner Mongolia should be limited to moderate levels or below.
[Objective] The relationship between grassland community and functional group quantity changes under grazing disturbance and soil wind erosion in grasslands was analyzed, and the influence of different functional groups on grassland erosion processes were determined to provide a theoretical basis for the rational use and protection of desert grasslands.[Methods] The study was conducted on desert grasslands of Stipa breviflora in Inner Mongolia. A completely randomized experiment was conducted with three grazing treatments:control (CK), moderate grazing (MG), and heavy grazing (HG). Sand transport and functional group characteristics under different treatments were determined.[Results] ① The height, coverage, and aboveground biomass of each functional group generally declined as grazing intensity increased. Appropriate grazing significantly increased the Simpson dominance index and the Shannon-Wiener diversity index. ② Differences in sand transport among different grazing treatments were significant. Sand transport related to different heights followed the order of HG>MG>CK, and sand transport rate decreased significantly as height increased under the same grazing treatment. ③ There was an exponential negative correlation between height, coverage of each functional group, and sand transport, with the height changes of perennial grasses and perennial forbs having a more significant impact on sand transport. Aboveground biomass of each functional group was negatively correlated with sand transport, with the highest fitting degree observed between the biomass of perennial grasses and sand transport.[Conclusion] Overgrazing significantly affected functional group characteristics and reduced the windbreak and sand-fixing capacity of grasslands. Grazing intensity of desert grasslands in Inner Mongolia should be limited to moderate levels or below.
2024,44(1):40-49,85
, DOI: 10.13961/j.cnki.stbctb.2024.01.005
Abstract:
[Objective] The soil water characteristics of the mixture of landslide gravel soil and local sedimentary cohesive soil in different proportions in Jiuzhai Valley after the "8·8" earthquake in 2017, were analyzed, and the best improved gravel soil suitable for plant growth in the study area was selected in order to provide scientific basis for ecological environment restoration after earthquake in Jiuzhai Valley region.[Methods] A local clay soil from Jiuzhai Valley and gravel soil from the Jiuzhai Valley region were mixed at different volume ratios, and soil water characteristics were investigated by soil water characteristic curve test, water constant test, and soil column test to investigate the soil water characteristics under the different mixing ratios in order to select soil mixing ratios suitable for plant growth.[Results] ① The van Genuchten model was able to fit the soil-water characteristic curve of the improved gravel soil well, and the soil air-entry value increased as the proportion of clay soil increased. The parameter α characterized the state of the air-entry value to a certain extent. ② The improved gravel soil increased the water absorption coefficient, wilting coefficient, field water-holding capacity and saturated water content as the proportion of clay soil increased. The water availability and maximum effective water volume of the gravel soil increased by 22.26 %~50.00 % with the addition of clay soil (compared with the gravel soil), and the maximum effective water volume similarly increased by 70.96 %~131.46 %. ③ Of the three models evaluated, the Philip model simulated soil water infiltration the best, and the size of the uptake rate (S) can represent the change trend of the initial infiltration rate to a certain extent.[Conclusion] Comprehensive comparisons of the water characteristics of different ratios of improved gravel soil showed that, when the overlying soil layer is a water storage layer, a gravel soil to clay soil ratio of 7:3 can be selected as the optimal ratio for improved gravel soil. When the overlying soil layer is a non-storage layer that is not capable of storing water, a gravel soil to clay soil ratio of 3:7 can be selected as the optimal ratio for improved gravel soil.
[Objective] The soil water characteristics of the mixture of landslide gravel soil and local sedimentary cohesive soil in different proportions in Jiuzhai Valley after the "8·8" earthquake in 2017, were analyzed, and the best improved gravel soil suitable for plant growth in the study area was selected in order to provide scientific basis for ecological environment restoration after earthquake in Jiuzhai Valley region.[Methods] A local clay soil from Jiuzhai Valley and gravel soil from the Jiuzhai Valley region were mixed at different volume ratios, and soil water characteristics were investigated by soil water characteristic curve test, water constant test, and soil column test to investigate the soil water characteristics under the different mixing ratios in order to select soil mixing ratios suitable for plant growth.[Results] ① The van Genuchten model was able to fit the soil-water characteristic curve of the improved gravel soil well, and the soil air-entry value increased as the proportion of clay soil increased. The parameter α characterized the state of the air-entry value to a certain extent. ② The improved gravel soil increased the water absorption coefficient, wilting coefficient, field water-holding capacity and saturated water content as the proportion of clay soil increased. The water availability and maximum effective water volume of the gravel soil increased by 22.26 %~50.00 % with the addition of clay soil (compared with the gravel soil), and the maximum effective water volume similarly increased by 70.96 %~131.46 %. ③ Of the three models evaluated, the Philip model simulated soil water infiltration the best, and the size of the uptake rate (S) can represent the change trend of the initial infiltration rate to a certain extent.[Conclusion] Comprehensive comparisons of the water characteristics of different ratios of improved gravel soil showed that, when the overlying soil layer is a water storage layer, a gravel soil to clay soil ratio of 7:3 can be selected as the optimal ratio for improved gravel soil. When the overlying soil layer is a non-storage layer that is not capable of storing water, a gravel soil to clay soil ratio of 3:7 can be selected as the optimal ratio for improved gravel soil.
2024,44(1):50-56
, DOI: 10.13961/j.cnki.stbctb.2024.01.006
Abstract:
[Objective] The effects of soil straw hole injection on soil moisture content and crop growth were studied to provide a theoretical basis for increasing rainwater storage capacity and improving water use efficiency in dry farmland.[Methods] A field trial of a maize-wheat rotation was carried out, with four treatments including conventional tillage (CK), and soil straw hole injection of 2 holes/m2 (T1), 4 holes/m2 (T2), and 8 holes/m2 (T3).[Results] All three hole injection treatments increased the surface soil moisture during the entire experimental period. The T2 and T3 treatments increased the deep soil moisture content at harvest time, and the moisture content in the 60-80 cm soil layer increased 29.19 % and 28.18 %, respectively, compared with CK at the end of the experiment. Soil straw hole injection treatments increased plant height, yield, biomass, precipitation use efficiency, and water use efficiency. The T2 and T3 treatments had the most obvious effect on soil moisture and crop growth, with no significant difference between them.[Conclusion] Water retention and yield were increased by soil straw hole injection treatments. Considering the cost and effects, soil straw hole injection of 4 holes/m2 (T2) is recommended.
[Objective] The effects of soil straw hole injection on soil moisture content and crop growth were studied to provide a theoretical basis for increasing rainwater storage capacity and improving water use efficiency in dry farmland.[Methods] A field trial of a maize-wheat rotation was carried out, with four treatments including conventional tillage (CK), and soil straw hole injection of 2 holes/m2 (T1), 4 holes/m2 (T2), and 8 holes/m2 (T3).[Results] All three hole injection treatments increased the surface soil moisture during the entire experimental period. The T2 and T3 treatments increased the deep soil moisture content at harvest time, and the moisture content in the 60-80 cm soil layer increased 29.19 % and 28.18 %, respectively, compared with CK at the end of the experiment. Soil straw hole injection treatments increased plant height, yield, biomass, precipitation use efficiency, and water use efficiency. The T2 and T3 treatments had the most obvious effect on soil moisture and crop growth, with no significant difference between them.[Conclusion] Water retention and yield were increased by soil straw hole injection treatments. Considering the cost and effects, soil straw hole injection of 4 holes/m2 (T2) is recommended.
2024,44(1):57-67
, DOI: 10.13961/j.cnki.stbctb.20231120.001
Abstract:
[Objective] Lingjiang River is an important river basin in Southern Zhejiang Province, which is typical and representative. The hydrochemical characteristics, evolutionary mechanism and irrigation suitability of surface water at Lingjiang River basin were analyzed in order to provide scientific basis for agricultural irrigation, ecological protection and high-quality development in this region.[Methods] Mathematical statistics, Piper three-line graphs, principal component analysis, and ion ratio were used to analyze the hydrochemical statistics and identify the causes of the surface water in the basin. The suitability of surface water for irrigation was evaluated by constructing Wilcox diagrams and USSL diagrams.[Results] ① The hydrochemical types of surface water at Lingjiang River basin were spatially zoned, and the hydrochemical types from HCO3-Ca type to Cl-Na type transitioned from the middle and upper reaches (zone Ⅰ) to the lower reaches of the Wenhuang Plain (zone Ⅱ) to the estuary of Taizhou Bay (zone Ⅲ). ② The hydrochemical characteristics of the surface water in zone Ⅰ were mainly affected by the dissolution of silicate rock during rock weathering, and were affected to a lesser extent by the dissolution of carbonate karst. The hydrochemical characteristics of surface water in zone Ⅱ were mainly affected by the dissolution of silicate rock. The hydrochemical characteristics of surface water in zone Ⅲ were mainly affected by the dissolution of evaporative salt rocks. ③ The K+ and Na+ of the surface water in zones Ⅰ and Ⅱ were mainly from the dissolution of silicate minerals. Ca2+, Mg2+, HCO-3, and SO2-4 mainly resulted from the dissolution of silicate rock, and a small amount resulted from the dissolution of carbonate rock, NO-3 was mainly derived from human activities. ④ The surface water in zones Ⅰ and Ⅱ was suitable for agricultural irrigation, while the surface water in zone Ⅲ was poorly suited for irrigation, and could easily cause saline-alkali damage.[Conclusion] The hydrochemical components of surface water at Lingjiang River basin were affected by natural dissolution and human activities. The surface water in the river network area of the middle and upper reaches and lower reaches of the Wenhuang Plain is suitable for agricultural irrigation, while the surface water in the estuary of Taizhou Bay is prone to saline-alkali damage. Attention should be paid to the planning of agricultural irrigation and ecological protection and high-quality development.
[Objective] Lingjiang River is an important river basin in Southern Zhejiang Province, which is typical and representative. The hydrochemical characteristics, evolutionary mechanism and irrigation suitability of surface water at Lingjiang River basin were analyzed in order to provide scientific basis for agricultural irrigation, ecological protection and high-quality development in this region.[Methods] Mathematical statistics, Piper three-line graphs, principal component analysis, and ion ratio were used to analyze the hydrochemical statistics and identify the causes of the surface water in the basin. The suitability of surface water for irrigation was evaluated by constructing Wilcox diagrams and USSL diagrams.[Results] ① The hydrochemical types of surface water at Lingjiang River basin were spatially zoned, and the hydrochemical types from HCO3-Ca type to Cl-Na type transitioned from the middle and upper reaches (zone Ⅰ) to the lower reaches of the Wenhuang Plain (zone Ⅱ) to the estuary of Taizhou Bay (zone Ⅲ). ② The hydrochemical characteristics of the surface water in zone Ⅰ were mainly affected by the dissolution of silicate rock during rock weathering, and were affected to a lesser extent by the dissolution of carbonate karst. The hydrochemical characteristics of surface water in zone Ⅱ were mainly affected by the dissolution of silicate rock. The hydrochemical characteristics of surface water in zone Ⅲ were mainly affected by the dissolution of evaporative salt rocks. ③ The K+ and Na+ of the surface water in zones Ⅰ and Ⅱ were mainly from the dissolution of silicate minerals. Ca2+, Mg2+, HCO-3, and SO2-4 mainly resulted from the dissolution of silicate rock, and a small amount resulted from the dissolution of carbonate rock, NO-3 was mainly derived from human activities. ④ The surface water in zones Ⅰ and Ⅱ was suitable for agricultural irrigation, while the surface water in zone Ⅲ was poorly suited for irrigation, and could easily cause saline-alkali damage.[Conclusion] The hydrochemical components of surface water at Lingjiang River basin were affected by natural dissolution and human activities. The surface water in the river network area of the middle and upper reaches and lower reaches of the Wenhuang Plain is suitable for agricultural irrigation, while the surface water in the estuary of Taizhou Bay is prone to saline-alkali damage. Attention should be paid to the planning of agricultural irrigation and ecological protection and high-quality development.
2024,44(1):68-75
, DOI: 10.13961/j.cnki.stbctb.2024.01.008
Abstract:
[Objective] The effects of Polyacrylamide (PAM) applicated in separation and sediment yield process of sandy soil developed from granite parent material were determined, and the concentration threshold of PAM to increase erosion resistance of sandy soil was clarified to provide a basis for the control of Benggang erosion.[Method] Sandy soil developed from granite parent materials in Benggang erosion areas was selected. Five levels of PAM application concentrations (0 %, 1 %, 3 %, 5 %, 7 %) were set. Through runoff scouring simulation experiments, the response patterns of sediment yield rate, detachment rate, and rill erodibility of sandy soils to PAM concentration under different hydraulic conditions were studied.[Results] ① PAM significantly reduced sediment yield, detachment rate, and rill erodibility, but dramatically increased critical shear strength (p<0.01). Additionally, the sediment yield reduction effect of PAM showed a decreasing and stabilizing trend with increasing scouring time, but gradually increased with increasing application concentration, with the most pronounced average sediment reduction effect observed when PAM concentration was within 5 %. ② There was a highly significant negative correlation between soil detachment rate and PAM application concentration (p<0.001). However, as PAM application concentration increased, the rate of decrease in soil detachment rate gradually slowed down, and the effect of PAM (F=37.39, p<0.001) on soil detachment and sediment yield processes was greater than the shear strength of runoff (F=15.38, p<0.001). ③ The ratio of rill erodibility between the PAM-treated groups and the control showed a quadratic function relationship with PAM concentration (R2=0.996, p<0.001), and the efficiency of reducing rill erodibility was most significant at 5 % PAM.[Conclusion] The application of PAM effectively reduced the sediment yield rate, detachment rate, and rill erodibility of granite-derived sandy soil and increased its critical shear force. The improvement effect of PAM application showed a continuous increasing trend when the PAM application concentration was below 5 %. However, when the PAM application concentration exceeded 5 %, the improvement effect showed only a slight change. Therefore, 5 % should be considered as the concentration threshold for PAM to improve the erosion resistance of granite-derived sandy soil.
[Objective] The effects of Polyacrylamide (PAM) applicated in separation and sediment yield process of sandy soil developed from granite parent material were determined, and the concentration threshold of PAM to increase erosion resistance of sandy soil was clarified to provide a basis for the control of Benggang erosion.[Method] Sandy soil developed from granite parent materials in Benggang erosion areas was selected. Five levels of PAM application concentrations (0 %, 1 %, 3 %, 5 %, 7 %) were set. Through runoff scouring simulation experiments, the response patterns of sediment yield rate, detachment rate, and rill erodibility of sandy soils to PAM concentration under different hydraulic conditions were studied.[Results] ① PAM significantly reduced sediment yield, detachment rate, and rill erodibility, but dramatically increased critical shear strength (p<0.01). Additionally, the sediment yield reduction effect of PAM showed a decreasing and stabilizing trend with increasing scouring time, but gradually increased with increasing application concentration, with the most pronounced average sediment reduction effect observed when PAM concentration was within 5 %. ② There was a highly significant negative correlation between soil detachment rate and PAM application concentration (p<0.001). However, as PAM application concentration increased, the rate of decrease in soil detachment rate gradually slowed down, and the effect of PAM (F=37.39, p<0.001) on soil detachment and sediment yield processes was greater than the shear strength of runoff (F=15.38, p<0.001). ③ The ratio of rill erodibility between the PAM-treated groups and the control showed a quadratic function relationship with PAM concentration (R2=0.996, p<0.001), and the efficiency of reducing rill erodibility was most significant at 5 % PAM.[Conclusion] The application of PAM effectively reduced the sediment yield rate, detachment rate, and rill erodibility of granite-derived sandy soil and increased its critical shear force. The improvement effect of PAM application showed a continuous increasing trend when the PAM application concentration was below 5 %. However, when the PAM application concentration exceeded 5 %, the improvement effect showed only a slight change. Therefore, 5 % should be considered as the concentration threshold for PAM to improve the erosion resistance of granite-derived sandy soil.
2024,44(1):76-85
, DOI: 10.13961/j.cnki.stbctb.2024.01.009
Abstract:
[Objective] The variation characteristics of wildfires and determine the correlation between the number of wildfires and soil moisture at different depths were analyzed in order to provide a scientific basis for evaluating the construction of ecological civilization and human production and life.[Methods] We used SNPP/ⅦRS satellite fire monitoring, fire site, and SMAP soil moisture data with statistical methods to analyze the change characteristics of wildfires on the Indo-China Peninsula from 2016 to 2021, and to explore the correlation between number of wildfires and soil moisture at 0-5 cm and 0-100 cm under different dry and wet conditions.[Results] ① Wildfires and burned areas on the Indo-China Peninsula mainly occurred from February to April in a year. The number of wildfires and burned areas had a high consistency in spatial and temporal distribution, mostly being concentrated in the border area between Western Myanmar and India, the area east of Central Myanmar, and Northern Laos. ② From February to April, fires mainly occurred in forest land, shrub land, and cultivated land, and were prone to occur in regions where the normalized difference vegetation indices (NDVI) were as below:0.2
[Objective] The variation characteristics of wildfires and determine the correlation between the number of wildfires and soil moisture at different depths were analyzed in order to provide a scientific basis for evaluating the construction of ecological civilization and human production and life.[Methods] We used SNPP/ⅦRS satellite fire monitoring, fire site, and SMAP soil moisture data with statistical methods to analyze the change characteristics of wildfires on the Indo-China Peninsula from 2016 to 2021, and to explore the correlation between number of wildfires and soil moisture at 0-5 cm and 0-100 cm under different dry and wet conditions.[Results] ① Wildfires and burned areas on the Indo-China Peninsula mainly occurred from February to April in a year. The number of wildfires and burned areas had a high consistency in spatial and temporal distribution, mostly being concentrated in the border area between Western Myanmar and India, the area east of Central Myanmar, and Northern Laos. ② From February to April, fires mainly occurred in forest land, shrub land, and cultivated land, and were prone to occur in regions where the normalized difference vegetation indices (NDVI) were as below:0.2
2024,44(1):86-96
, DOI: 10.13961/j.cnki.stbctb.2024.01.010
Abstract:
[Objective] Developing condition and early warning research was studied with regard to the security of Shaanxi regional innovation ecosystem in order to provide a theoretical basis for the safe development of Shaanxi regional innovation ecosystem.[Methods] A security measurement index system of the regional innovation ecosystem was constructed based on the niche perspective that included the four dimensions of openness, growth, synergy, and sustainability. The security status of the regional innovation ecosystem in Shaanxi Province from 2011 to 2020 was measured and analyzed by using a niche suitability model. The BP neural network model was used to predict the evolution trend of the regional innovation ecosystem security alarm in Shaanxi Province from 2020 to 2024.[Results] ① The security status of the regional innovation ecosystem in Shaanxi Province showed a steady increase during 2011-2020, indicating that regional innovation development had a good foundation and potential. ② The security status of the regional innovation ecosystem in Shaanxi Province would continue to improve from 2020 to 2024, but the status would still be lower in the north and south and higher in the central part of the province.[Conclusion] The security status of Shaanxi regional innovation ecosystem showed an overall good evolution trend, but relevant measures to further narrow the gap between regions should be applied so as to achieve safe development of Shaanxi regional innovation ecosystem will still be required.
[Objective] Developing condition and early warning research was studied with regard to the security of Shaanxi regional innovation ecosystem in order to provide a theoretical basis for the safe development of Shaanxi regional innovation ecosystem.[Methods] A security measurement index system of the regional innovation ecosystem was constructed based on the niche perspective that included the four dimensions of openness, growth, synergy, and sustainability. The security status of the regional innovation ecosystem in Shaanxi Province from 2011 to 2020 was measured and analyzed by using a niche suitability model. The BP neural network model was used to predict the evolution trend of the regional innovation ecosystem security alarm in Shaanxi Province from 2020 to 2024.[Results] ① The security status of the regional innovation ecosystem in Shaanxi Province showed a steady increase during 2011-2020, indicating that regional innovation development had a good foundation and potential. ② The security status of the regional innovation ecosystem in Shaanxi Province would continue to improve from 2020 to 2024, but the status would still be lower in the north and south and higher in the central part of the province.[Conclusion] The security status of Shaanxi regional innovation ecosystem showed an overall good evolution trend, but relevant measures to further narrow the gap between regions should be applied so as to achieve safe development of Shaanxi regional innovation ecosystem will still be required.
2024,44(1):97-108
, DOI: 10.13961/j.cnki.stbctb.2024.01.011
Abstract:
[Objective] The health status of the living community of mountains-rivers-forests-farmlands-lakes-grasslands in source area of Qiantang River of Zhejiang Province were analyzed in order to provide scientific reference for land spatial planning and ecological management.[Methods] Based on life community theory and VOR (vitality-organization-resilience) ecological model theory, a health evaluation index system of life communities was constructed. Using 3S technologies and socioeconomic statistics, the health status of the life community in the Qiantang River source area was evaluated and graded (with the county as the evaluation unit).[Results] ① The life community health index of Chunan County in 2020 was classified as healthy, but the life community health indexes of Jiande City, Kaihua County, and Changshan County were classified as sub-healthy. ② From 2015 to 2020, the overall life community health index of the Qiantang River source area showed an upward trend, and the upward trend decreased in the following order:Jiande>Changshan>Chun'an>Kaihua. ③ Among the four counties (cities) in the Qiantang River source area in 2020, Changshan County had the best health status for the mountains-rivers-forests-farmlands-lakes-grasslands subsystem, while Chun'an County had the worst health status. Chun'an County had the best health status for the ecosystem subsystem, while Changshan County had the worst health status. ④ The structure and ecological service function of the forests and farmlands subsystems in the Qiantang River source area needs to be improved and optimized. ⑤ The ecological restoration pilot project in the Qiantang River source area had played a positive role in improving the health status of the life community to some degree.[Conclusion] The ecological restoration pilot project of mountains-rivers-forests-farmlands-lakes-grasslands in the Qiantang River source area has achieved various stages of results. The four counties (cities) should next carry out relevant restoration work to address the different problems of the mountains, rivers, forests, farmlands, and lakes subsystems. At the same time, governments should carry out comprehensive planning and ecological renovation in order to achieve more scientifically integrated governance, health management, and sustainable management for the mountains-rivers-forests-farmlands-lakes-grasslands community system.
[Objective] The health status of the living community of mountains-rivers-forests-farmlands-lakes-grasslands in source area of Qiantang River of Zhejiang Province were analyzed in order to provide scientific reference for land spatial planning and ecological management.[Methods] Based on life community theory and VOR (vitality-organization-resilience) ecological model theory, a health evaluation index system of life communities was constructed. Using 3S technologies and socioeconomic statistics, the health status of the life community in the Qiantang River source area was evaluated and graded (with the county as the evaluation unit).[Results] ① The life community health index of Chunan County in 2020 was classified as healthy, but the life community health indexes of Jiande City, Kaihua County, and Changshan County were classified as sub-healthy. ② From 2015 to 2020, the overall life community health index of the Qiantang River source area showed an upward trend, and the upward trend decreased in the following order:Jiande>Changshan>Chun'an>Kaihua. ③ Among the four counties (cities) in the Qiantang River source area in 2020, Changshan County had the best health status for the mountains-rivers-forests-farmlands-lakes-grasslands subsystem, while Chun'an County had the worst health status. Chun'an County had the best health status for the ecosystem subsystem, while Changshan County had the worst health status. ④ The structure and ecological service function of the forests and farmlands subsystems in the Qiantang River source area needs to be improved and optimized. ⑤ The ecological restoration pilot project in the Qiantang River source area had played a positive role in improving the health status of the life community to some degree.[Conclusion] The ecological restoration pilot project of mountains-rivers-forests-farmlands-lakes-grasslands in the Qiantang River source area has achieved various stages of results. The four counties (cities) should next carry out relevant restoration work to address the different problems of the mountains, rivers, forests, farmlands, and lakes subsystems. At the same time, governments should carry out comprehensive planning and ecological renovation in order to achieve more scientifically integrated governance, health management, and sustainable management for the mountains-rivers-forests-farmlands-lakes-grasslands community system.
2024,44(1):109-117
, DOI: 10.13961/j.cnki.stbctb.2024.01.012
Abstract:
[Objective] The prediction accuracy of a regional landslide stability evaluation model was improved to solve the shortcomings of over-prediction caused by over-simplification of the landslide occurrence mechanism and the mechanical mechanism based on the static physical model of the traditional landslide stability analysis, and to determine the typical spatial-temporal variability and uncertainty of model parameters.[Methods] The data assimilation method of ensemble Kalman filtering was used to construct a regional landslide data assimilation scheme based on the TRIGRS model and SBAS-InSAR observation data in the area around the North Ring Road of Lanzhou City, Gansu Province. The coefficients of safety (Fs) in the model were assimilated, and the model parameters for the internal friction angle were updated. Then landslide stability was corrected and root-mean-square deviation (RMSD) was used to test the accuracy of the assimilated values.[Results] After assimilation, the landslide safety coefficient of the study area was significantly greater than the coefficient value predicted by the model, and the percentage of unstable area was reduced from 12 % to 7 %, which was closer to the actual observed value. The test gradually corrected the internal friction angle parameter towards the observed value, and realized the dynamic updating of the model parameters. The root-mean-square deviation decreased from 0.33 to about 0.04.[Conclusion] The data assimilation method based on the ensemble Kalman filter effectively corrected the model stability prediction results so that the actual situation of landslides in the current region was more accurately reflected with greater prediction accuracy.
[Objective] The prediction accuracy of a regional landslide stability evaluation model was improved to solve the shortcomings of over-prediction caused by over-simplification of the landslide occurrence mechanism and the mechanical mechanism based on the static physical model of the traditional landslide stability analysis, and to determine the typical spatial-temporal variability and uncertainty of model parameters.[Methods] The data assimilation method of ensemble Kalman filtering was used to construct a regional landslide data assimilation scheme based on the TRIGRS model and SBAS-InSAR observation data in the area around the North Ring Road of Lanzhou City, Gansu Province. The coefficients of safety (Fs) in the model were assimilated, and the model parameters for the internal friction angle were updated. Then landslide stability was corrected and root-mean-square deviation (RMSD) was used to test the accuracy of the assimilated values.[Results] After assimilation, the landslide safety coefficient of the study area was significantly greater than the coefficient value predicted by the model, and the percentage of unstable area was reduced from 12 % to 7 %, which was closer to the actual observed value. The test gradually corrected the internal friction angle parameter towards the observed value, and realized the dynamic updating of the model parameters. The root-mean-square deviation decreased from 0.33 to about 0.04.[Conclusion] The data assimilation method based on the ensemble Kalman filter effectively corrected the model stability prediction results so that the actual situation of landslides in the current region was more accurately reflected with greater prediction accuracy.
2024,44(1):118-126
, DOI: 10.13961/j.cnki.stbctb.2024.01.013
Abstract:
[Objective] The purposes of this study were to provide a scientific foundation for the prevention and control of agricultural non-point source pollution, and to promote coordinated development between agriculture and animal husbandry by calculating and analyzing livestock manure load of farmland and land carrying capacity.[Methods] We considered the comprehensive utilization rate of livestock and poultry waste, and employed the method of the pollution generation and discharge coefficient and the method of the nutrient-balance to separately calculate livestock manure load of farmland and land carrying capacity in different regions of Hunan Province in 2020. The spatial layout of livestock and poultry breeding and the distribution of manure pollution were analyzed by utilizing data regarding livestock manure and crop yield in Hunan Province.[Results] A total of 4.27×107 pigs were bred in Hunan Province in 2020, with significant variation across regions. The loads of livestock and poultry manure, TN, and TP on farmland in Hunan Province were 19.04 t/hm2, 94.85 kg/hm2, and 24.99 kg/hm2, respectively, and the cultivated land load alert levels all exceeded level Ⅱ, posing a slight threat to the farmland environment. At least two farmland load warning levels in Yongzhou, Loudi, Huaihua, and Chenzhou City reached level Ⅲ or above, indicating a heightened environmental risk. The maximum land carrying capacity of livestock and poultry breeding land was 1.23×108 pig equivalents, but the currently raised pig equivalents only accounted for 37.18 % of this value. This result indicated that there was significant potential for increasing the livestock breeding capacity in various cities, with seven cities (Changde, Yiyang, Yueyang, Shaoyang, Changsha, Yongzhou, and Hengyang City) capable of breeding more than 5.00×106 pig equivalents. Given the absence of breeding overload within these regions, crop managers in woodland and orchards in Yongzhou, Loudi, Huaihua, and Chenzhou City were encouraged to increase their application of organic fertilizers and manure absorption to lower the risk of farmland pollution.[Conclusion] Overall, the risk posed by livestock and poultry breeding to the farmland environment in Hunan Province remains relatively low, suggesting substantial potential for future industry expansion. However, certain regions are facing farmland pollution risks, thus necessitating a redirection in manure disposal to lessen the pressure of manure absorption on farmland, thereby promoting sustainable agricultural development.
[Objective] The purposes of this study were to provide a scientific foundation for the prevention and control of agricultural non-point source pollution, and to promote coordinated development between agriculture and animal husbandry by calculating and analyzing livestock manure load of farmland and land carrying capacity.[Methods] We considered the comprehensive utilization rate of livestock and poultry waste, and employed the method of the pollution generation and discharge coefficient and the method of the nutrient-balance to separately calculate livestock manure load of farmland and land carrying capacity in different regions of Hunan Province in 2020. The spatial layout of livestock and poultry breeding and the distribution of manure pollution were analyzed by utilizing data regarding livestock manure and crop yield in Hunan Province.[Results] A total of 4.27×107 pigs were bred in Hunan Province in 2020, with significant variation across regions. The loads of livestock and poultry manure, TN, and TP on farmland in Hunan Province were 19.04 t/hm2, 94.85 kg/hm2, and 24.99 kg/hm2, respectively, and the cultivated land load alert levels all exceeded level Ⅱ, posing a slight threat to the farmland environment. At least two farmland load warning levels in Yongzhou, Loudi, Huaihua, and Chenzhou City reached level Ⅲ or above, indicating a heightened environmental risk. The maximum land carrying capacity of livestock and poultry breeding land was 1.23×108 pig equivalents, but the currently raised pig equivalents only accounted for 37.18 % of this value. This result indicated that there was significant potential for increasing the livestock breeding capacity in various cities, with seven cities (Changde, Yiyang, Yueyang, Shaoyang, Changsha, Yongzhou, and Hengyang City) capable of breeding more than 5.00×106 pig equivalents. Given the absence of breeding overload within these regions, crop managers in woodland and orchards in Yongzhou, Loudi, Huaihua, and Chenzhou City were encouraged to increase their application of organic fertilizers and manure absorption to lower the risk of farmland pollution.[Conclusion] Overall, the risk posed by livestock and poultry breeding to the farmland environment in Hunan Province remains relatively low, suggesting substantial potential for future industry expansion. However, certain regions are facing farmland pollution risks, thus necessitating a redirection in manure disposal to lessen the pressure of manure absorption on farmland, thereby promoting sustainable agricultural development.
2024,44(1):127-135
, DOI: 10.13961/j.cnki.stbctb.2024.01.014
Abstract:
[Objective] Refined survey and mapping data were used to simulate urban rainfall and runoff processes in order to activate land resource data assets and to promote precise urban flood risk management and control.[Methods] The study was conducted in the Panyu District of Guangzhou City. The SCS-CN runoff model and GIS technology were used to simulate the depth of urban flood inundation under different intensity rainstorm situations on the basis of high-precision topographic and architectural data in order to quantitatively analyze the characteristics of inundation risk in the study area. Additionally, a loss experience model of disaster-bearing bodies was used to assess flood loss risk and to identify highly vulnerable areas.[Results] ① The flood inundation risk area in Panyu District was spatially clustered with rivers and low-lying urban areas, and the streets and towns near the Shiqiao-Shawan watershed and the Sanzhixiang-Dashi watershed had higher inundation risks. ② Agricultural land and construction land were expected to be most severely affected as the intensities of rainstorms increased. ③ For the case of a 100-year rainstorm, four planning management units in Panyu District were at high risk of loss, and their losses mainly came from residential buildings, while the units facing medium risk of loss were mainly associated with agricultural land inundation.[Conclusion] Refined survey and mapping data can effectively identify the distribution of high loss areas that are prone to potential inundation. These results are in line with the actual situation. The study results can provide advance research and planning support for urban flood control and sponge city development and construction.
[Objective] Refined survey and mapping data were used to simulate urban rainfall and runoff processes in order to activate land resource data assets and to promote precise urban flood risk management and control.[Methods] The study was conducted in the Panyu District of Guangzhou City. The SCS-CN runoff model and GIS technology were used to simulate the depth of urban flood inundation under different intensity rainstorm situations on the basis of high-precision topographic and architectural data in order to quantitatively analyze the characteristics of inundation risk in the study area. Additionally, a loss experience model of disaster-bearing bodies was used to assess flood loss risk and to identify highly vulnerable areas.[Results] ① The flood inundation risk area in Panyu District was spatially clustered with rivers and low-lying urban areas, and the streets and towns near the Shiqiao-Shawan watershed and the Sanzhixiang-Dashi watershed had higher inundation risks. ② Agricultural land and construction land were expected to be most severely affected as the intensities of rainstorms increased. ③ For the case of a 100-year rainstorm, four planning management units in Panyu District were at high risk of loss, and their losses mainly came from residential buildings, while the units facing medium risk of loss were mainly associated with agricultural land inundation.[Conclusion] Refined survey and mapping data can effectively identify the distribution of high loss areas that are prone to potential inundation. These results are in line with the actual situation. The study results can provide advance research and planning support for urban flood control and sponge city development and construction.
2024,44(1):136-146
, DOI: 10.13961/j.cnki.stbctb.2024.01.015
Abstract:
[Objective] Based on the ERA5 reanalysis of precipitation data from 1950 to 2022, the spatiotemporal variation characteristics of precipitation in the water source area and water receiving area of the south-to-north water transfer project were explored in order to ensure the feasibility and sustainability of inter-basin water transfer, and provide a scientific reference for water resource scheduling and operation management of the middle route project of south-to-north water diversion project.[Methods] The Mann-Kendall test, wavelet analysis, cloud model, and Copula function were used to analyze the trend of precipitation change and the characteristics of drought-waterlogging encounters in the water source area and the water receiving area.[Results] ① During 1950-2022, annual precipitation in the water source area and the water receiving area of the south-to-north water diversion project has decreased by 34.75 mm/(10 yr) and 39.35 mm/(10 yr), respectively. The annual precipitation in the water source area and the water receiving area exhibited a main cycle of 43 years and 55 years, respectively; ② Precipitation in the subordinate cloud map was unevenly distributed and discretely dispersed in summer, while precipitation distribution was uniform and concentrated in winter; ③ The unfavorable water diversion encounter frequencies for the flood season and the non-flood season were 23.15 % and 25.92 %, respectively.[Conclusion] Annual precipitation in both the water source area and the water receiving area showed a decreasing trend. The alternating change of precipitation between the wet season and the dry season in the source area was significant. The probability of asynchronous drought-waterlogging was greater than that of synchronization, and the frequency of simultaneous drought in the north and the south was relatively low, which increased the safety and reliability of water diversion projects. These research results provide a theoretical basis for the formulation of relevant policies and technical guidance for the middle route project of the south-to-north water diversion project, and will be helpful in project planning and management, thereby improving the efficiency and sustainability of water resource utilization.
[Objective] Based on the ERA5 reanalysis of precipitation data from 1950 to 2022, the spatiotemporal variation characteristics of precipitation in the water source area and water receiving area of the south-to-north water transfer project were explored in order to ensure the feasibility and sustainability of inter-basin water transfer, and provide a scientific reference for water resource scheduling and operation management of the middle route project of south-to-north water diversion project.[Methods] The Mann-Kendall test, wavelet analysis, cloud model, and Copula function were used to analyze the trend of precipitation change and the characteristics of drought-waterlogging encounters in the water source area and the water receiving area.[Results] ① During 1950-2022, annual precipitation in the water source area and the water receiving area of the south-to-north water diversion project has decreased by 34.75 mm/(10 yr) and 39.35 mm/(10 yr), respectively. The annual precipitation in the water source area and the water receiving area exhibited a main cycle of 43 years and 55 years, respectively; ② Precipitation in the subordinate cloud map was unevenly distributed and discretely dispersed in summer, while precipitation distribution was uniform and concentrated in winter; ③ The unfavorable water diversion encounter frequencies for the flood season and the non-flood season were 23.15 % and 25.92 %, respectively.[Conclusion] Annual precipitation in both the water source area and the water receiving area showed a decreasing trend. The alternating change of precipitation between the wet season and the dry season in the source area was significant. The probability of asynchronous drought-waterlogging was greater than that of synchronization, and the frequency of simultaneous drought in the north and the south was relatively low, which increased the safety and reliability of water diversion projects. These research results provide a theoretical basis for the formulation of relevant policies and technical guidance for the middle route project of the south-to-north water diversion project, and will be helpful in project planning and management, thereby improving the efficiency and sustainability of water resource utilization.
2024,44(1):147-157
, DOI: 10.13961/j.cnki.stbctb.2024.01.016
Abstract:
[Objective] Runoff and sediment characteristics of three rivers in China were compared based on data updated dynamically, in order to provide a basis for basin development and management.[Methods] Runoff and sediment data for the Yellow River (Lijin station), Yangtze River (Datong station), and Pearl River (Gaoyao, Shijiao, Boluo stations) from 1960 to 2020 were used with the moving average method, the Pettitt test method, the double mass curve method, and the wavelet transform method to study the trend, mutagenicity, and periodicity characteristics of runoff and sediment fluxes. Additionally, the cross wavelet transform and wavelet coherence spectrum were used to investigate the resonance period and coherence of runoff and sediment flux.[Results] The runoff and sediment fluxes of the Yellow River, Yangtze River and Pearl River into seas have undergone significant declines during the past 60 years. Runoff and sediment discharge of the Yellow River decreased in 1986, and the sediment volume decreased abruptly again in 1997. Runoff of the Yangtze River and Pearl River fluctuated and the sediment discharge decreased abruptly in 1992 and 1999, respectively. The runoff and sediment changes for the three rivers were characterized by significant interannual and interdecadal cycles. Specifically, the interdecadal co-evolution cycles of runoff and sediment in the Yellow River, Yangtze River, and Pearl River were concentrated before 1980, 1990, and 2000, respectively, and the interannual co-evolution cycle was five years, with frequent "abundance-depletion" transitions. The results of the cross wavelet analysis showed that the runoff and sediment of the three rivers exhibited a significant 1-3 year resonance cycle with predominantly positive phase evolution during 1965-1975.[Conclusion] The runoff and sediment fluxes into the sea of the three major rivers of China were characterized by significant trend, mutagenicity, and periodicity. Effective watershed development and management could be more effective based on these results.
[Objective] Runoff and sediment characteristics of three rivers in China were compared based on data updated dynamically, in order to provide a basis for basin development and management.[Methods] Runoff and sediment data for the Yellow River (Lijin station), Yangtze River (Datong station), and Pearl River (Gaoyao, Shijiao, Boluo stations) from 1960 to 2020 were used with the moving average method, the Pettitt test method, the double mass curve method, and the wavelet transform method to study the trend, mutagenicity, and periodicity characteristics of runoff and sediment fluxes. Additionally, the cross wavelet transform and wavelet coherence spectrum were used to investigate the resonance period and coherence of runoff and sediment flux.[Results] The runoff and sediment fluxes of the Yellow River, Yangtze River and Pearl River into seas have undergone significant declines during the past 60 years. Runoff and sediment discharge of the Yellow River decreased in 1986, and the sediment volume decreased abruptly again in 1997. Runoff of the Yangtze River and Pearl River fluctuated and the sediment discharge decreased abruptly in 1992 and 1999, respectively. The runoff and sediment changes for the three rivers were characterized by significant interannual and interdecadal cycles. Specifically, the interdecadal co-evolution cycles of runoff and sediment in the Yellow River, Yangtze River, and Pearl River were concentrated before 1980, 1990, and 2000, respectively, and the interannual co-evolution cycle was five years, with frequent "abundance-depletion" transitions. The results of the cross wavelet analysis showed that the runoff and sediment of the three rivers exhibited a significant 1-3 year resonance cycle with predominantly positive phase evolution during 1965-1975.[Conclusion] The runoff and sediment fluxes into the sea of the three major rivers of China were characterized by significant trend, mutagenicity, and periodicity. Effective watershed development and management could be more effective based on these results.
2024,44(1):158-171
, DOI: 10.13961/j.cnki.stbctb.20231127.001
Abstract:
[Objective] The intensity of spatial conflicts was measured and ways to strengthen the management of territorial space conflicts were determined at county scale, and the utilization of territorial space was optimized in different regions in order to provide new ideas for the sustainable development and utilization of territorial space at the county level.[Methods] Taking Yihuang County in Jiangxi Province for example, the three methods of landscape ecological index model, exploitable intensity analysis, and land use status and suitability evaluation were used in conjunction with guidance provided from the comprehensive perspective of "grasp landscape pattern-clarify development intensity-determine suitability-realize function optimization" to construct a comprehensive spatial conflict measurement model. Impact type areas with significant spatial conflicts coupled with regional bases at the township scale were identified, and functional optimization measures were proposed.[Results] ① At Yihuang County from 2010 to 2020, urbanization expanded and the accommodation degree of ecological space declined. The main change trend was that the agricultural production space and ecological space were transferred to the industrial and mining production space and the urban living space. ② From 2010 to 2020, the intensity of regional conflicts intensified, and there were significant differences in intensity and distribution in different periods and regions. The controllable space was mainly located in the southern part of the study area. The mild and moderate conflicts were evenly distributed in the region. The severe conflicts were mainly located in the northern, central, and eastern areas. ③ According to the analysis of development intensity and the causes of conflict, the towns and villages could be divided into three categories:disadvantaged areas of terrain development, intensive areas of urban development, and concentrated areas of nature protection, which are the key points of spatial function optimization; ④ At the township scale, there were differences in the distribution of spatial conflict types, and the conflict areas followed the order of agricultural space and ecological space conflict > urban space and ecological space conflict > urban space conflict > agricultural space conflict; ⑤ From the comprehensive conflict measurement model, it can be concluded that there were eight kinds of comprehensive conflict combinations within the region, which could be divided into five conflict types after merging:disorderly urban expansion, urban scale expansion, improper urban planning, overall development lag and urban development lag.[Conclusion] The intensity of spatial conflicts in Yihuang County increased during 2010 to 2020, and regional ecological security and food security were constantly challenged. Therefore, regional control of spatial conflicts should be strengthened to optimize the development and utilization of regional territorial space resources.
[Objective] The intensity of spatial conflicts was measured and ways to strengthen the management of territorial space conflicts were determined at county scale, and the utilization of territorial space was optimized in different regions in order to provide new ideas for the sustainable development and utilization of territorial space at the county level.[Methods] Taking Yihuang County in Jiangxi Province for example, the three methods of landscape ecological index model, exploitable intensity analysis, and land use status and suitability evaluation were used in conjunction with guidance provided from the comprehensive perspective of "grasp landscape pattern-clarify development intensity-determine suitability-realize function optimization" to construct a comprehensive spatial conflict measurement model. Impact type areas with significant spatial conflicts coupled with regional bases at the township scale were identified, and functional optimization measures were proposed.[Results] ① At Yihuang County from 2010 to 2020, urbanization expanded and the accommodation degree of ecological space declined. The main change trend was that the agricultural production space and ecological space were transferred to the industrial and mining production space and the urban living space. ② From 2010 to 2020, the intensity of regional conflicts intensified, and there were significant differences in intensity and distribution in different periods and regions. The controllable space was mainly located in the southern part of the study area. The mild and moderate conflicts were evenly distributed in the region. The severe conflicts were mainly located in the northern, central, and eastern areas. ③ According to the analysis of development intensity and the causes of conflict, the towns and villages could be divided into three categories:disadvantaged areas of terrain development, intensive areas of urban development, and concentrated areas of nature protection, which are the key points of spatial function optimization; ④ At the township scale, there were differences in the distribution of spatial conflict types, and the conflict areas followed the order of agricultural space and ecological space conflict > urban space and ecological space conflict > urban space conflict > agricultural space conflict; ⑤ From the comprehensive conflict measurement model, it can be concluded that there were eight kinds of comprehensive conflict combinations within the region, which could be divided into five conflict types after merging:disorderly urban expansion, urban scale expansion, improper urban planning, overall development lag and urban development lag.[Conclusion] The intensity of spatial conflicts in Yihuang County increased during 2010 to 2020, and regional ecological security and food security were constantly challenged. Therefore, regional control of spatial conflicts should be strengthened to optimize the development and utilization of regional territorial space resources.
2024,44(1):172-180,192
, DOI: 10.13961/j.cnki.stbctb.2024.01.018
Abstract:
[Objective] The characteristics of the spatial dynamics of wind erosion at Wuwei City, Gansu Province and the controlled area of wind erosion and its prevention countermeasures were determined in order to provide scientific references for implementing measures to prevent wind erosion, conserve soil and water, and use ecological environmental construction practices in the city.[Methods] Multi-source geographic information data, applied remote sensing, a geographic information system (ArcGIS), and other technical means were used with the revised wind erosion equation (RWEQ) to calculate the five-period wind erosion modulus of Wuwei City from 2000 to 2020 to obtain the distribution of the regional wind erosion area, change characteristics, etc. These results were combined with a superposition analysis of spatial elements (such as the distribution of key construction projects) to put forward the principles of the city's wind erosion manageable area delineation and to apply them to delineate the manageable area of wind erosion at Wuwei City.[Results] RWEQ was able to estimate the multi-year wind erosion modulus at Wuwei City[5 788.98 t/(km2·yr)], with a multi-year average soil wind erosion of 1.92×108 t. The model exhibited an overall decreasing and occasionally increasing trend over time, and the wind erosion intensity level was obviously weakened. Wind erosion intensity exhibited obvious spatial heterogeneity that was mainly located in Minqin County, Liangzhou District, and Gulang County. According to the multi-element superimposed wind erosion zoning management program, Wuwei City can manage a total of 2 872.66 km2 of wind erosion area, of which 1 468.48 km2 was at Minqin County, 708.75 km2 was at Liangzhou District, and 695.43 km2 was at Gulang County.[Conclusion] Wind erosion sub-area management should be the focus of wind erosion prevention and soil and water conservation in Wuwei City. According to the results of the wind erosion sub-area management division, for different administrative divisions, the flat Gobi desert area with low slope in the northern part of Minqin County is the key area of regional concern. Management measures should be based on the prevention of wind and sand erosion and the restoration of vegetation cover, and attention should be given to controlling the impact of man-made engineering and construction disturbances to make clear the scope of the regional management. Liangzhou District should focus on using a combination of engineering measures and biological measures, combined with governmental management. Gulang County should focus on closure measures and protecting natural vegetation. At the same time, special attention in the Gobi desert area should be given to the implementation of wind and sand erosion prevention and ecological restoration measures for construction activities such as large-scale photovoltaic power plants.
[Objective] The characteristics of the spatial dynamics of wind erosion at Wuwei City, Gansu Province and the controlled area of wind erosion and its prevention countermeasures were determined in order to provide scientific references for implementing measures to prevent wind erosion, conserve soil and water, and use ecological environmental construction practices in the city.[Methods] Multi-source geographic information data, applied remote sensing, a geographic information system (ArcGIS), and other technical means were used with the revised wind erosion equation (RWEQ) to calculate the five-period wind erosion modulus of Wuwei City from 2000 to 2020 to obtain the distribution of the regional wind erosion area, change characteristics, etc. These results were combined with a superposition analysis of spatial elements (such as the distribution of key construction projects) to put forward the principles of the city's wind erosion manageable area delineation and to apply them to delineate the manageable area of wind erosion at Wuwei City.[Results] RWEQ was able to estimate the multi-year wind erosion modulus at Wuwei City[5 788.98 t/(km2·yr)], with a multi-year average soil wind erosion of 1.92×108 t. The model exhibited an overall decreasing and occasionally increasing trend over time, and the wind erosion intensity level was obviously weakened. Wind erosion intensity exhibited obvious spatial heterogeneity that was mainly located in Minqin County, Liangzhou District, and Gulang County. According to the multi-element superimposed wind erosion zoning management program, Wuwei City can manage a total of 2 872.66 km2 of wind erosion area, of which 1 468.48 km2 was at Minqin County, 708.75 km2 was at Liangzhou District, and 695.43 km2 was at Gulang County.[Conclusion] Wind erosion sub-area management should be the focus of wind erosion prevention and soil and water conservation in Wuwei City. According to the results of the wind erosion sub-area management division, for different administrative divisions, the flat Gobi desert area with low slope in the northern part of Minqin County is the key area of regional concern. Management measures should be based on the prevention of wind and sand erosion and the restoration of vegetation cover, and attention should be given to controlling the impact of man-made engineering and construction disturbances to make clear the scope of the regional management. Liangzhou District should focus on using a combination of engineering measures and biological measures, combined with governmental management. Gulang County should focus on closure measures and protecting natural vegetation. At the same time, special attention in the Gobi desert area should be given to the implementation of wind and sand erosion prevention and ecological restoration measures for construction activities such as large-scale photovoltaic power plants.
2024,44(1):181-192
, DOI: 10.13961/j.cnki.stbctb.2024.01.019
Abstract:
[Objective] Different soil remediation treatment needs in the Changchun-Jilin-Tumen region were determined and the characteristics of supply and demand were matched based on the spatio-temporal variations of soil conservation service founction in the region in order to provide a scientific basis for promoting the effective implementation of regional soil ecological protection.[Methods] The InVEST model was used to quantitatively assess the soil conservation service functions of cities and counties in the Changchun-Jilin-Tumen region in 2000, 2010, 2020. The relationship between the supply and demand of soil conservation services and their spatial and temporal changes were analyzed in order to identify the priority areas in need of targeted management and to formulate soil remediation strategies.[Results] From 2000 to 2020, the soil conservation intensity of the Changchun-Jilin-Tumen region ranged from 0.00 to 2 590.42 t/km2; the erosion reduction service function ranged from 0.00 to 1 544.23 t/km2, and the sediment retention service function ranged from 0.00 to 2 452.20 t/km2, with significant differences in soil conservation service levels between regions and obvious spatial and temporal differentiation characteristics. The supply and demand matching situation in the study area was relatively balanced, and there was no low supply and high demand matching type. There were four matching types between supply and demand of regional soil conservation services:Soil conservation services were sustainable when supply and demand increased simultaneously and when supply increased and demand decreased; Soil conservation services were not sustainable when both supply and demand decreased and demand increased while supply decreased. The proportion of unsustainable areas in need of treatment increased over time, accounting for 68.15 % (erosion reduction) and 72.57 % (sediment retention) by 2020, concentrated in the east and west parts of the study area. In the middle part of the study area, the soil retention service was significantly weakened.[Conclusion] In the study area, the spatio-temporal variations in soil conservation service founction were obvious, and the central-eastern part, eastern tail end, and western part of the Changchun-Jilin-Tumen region were identified as the soil sensitive area, soil fragile area, and soil restoration area, respectively. Soil ecological management work in these areas should focus on soil remediation, soil conservation, and soil restoration, respectively.
[Objective] Different soil remediation treatment needs in the Changchun-Jilin-Tumen region were determined and the characteristics of supply and demand were matched based on the spatio-temporal variations of soil conservation service founction in the region in order to provide a scientific basis for promoting the effective implementation of regional soil ecological protection.[Methods] The InVEST model was used to quantitatively assess the soil conservation service functions of cities and counties in the Changchun-Jilin-Tumen region in 2000, 2010, 2020. The relationship between the supply and demand of soil conservation services and their spatial and temporal changes were analyzed in order to identify the priority areas in need of targeted management and to formulate soil remediation strategies.[Results] From 2000 to 2020, the soil conservation intensity of the Changchun-Jilin-Tumen region ranged from 0.00 to 2 590.42 t/km2; the erosion reduction service function ranged from 0.00 to 1 544.23 t/km2, and the sediment retention service function ranged from 0.00 to 2 452.20 t/km2, with significant differences in soil conservation service levels between regions and obvious spatial and temporal differentiation characteristics. The supply and demand matching situation in the study area was relatively balanced, and there was no low supply and high demand matching type. There were four matching types between supply and demand of regional soil conservation services:Soil conservation services were sustainable when supply and demand increased simultaneously and when supply increased and demand decreased; Soil conservation services were not sustainable when both supply and demand decreased and demand increased while supply decreased. The proportion of unsustainable areas in need of treatment increased over time, accounting for 68.15 % (erosion reduction) and 72.57 % (sediment retention) by 2020, concentrated in the east and west parts of the study area. In the middle part of the study area, the soil retention service was significantly weakened.[Conclusion] In the study area, the spatio-temporal variations in soil conservation service founction were obvious, and the central-eastern part, eastern tail end, and western part of the Changchun-Jilin-Tumen region were identified as the soil sensitive area, soil fragile area, and soil restoration area, respectively. Soil ecological management work in these areas should focus on soil remediation, soil conservation, and soil restoration, respectively.
2024,44(1):193-205
, DOI: 10.13961/j.cnki.stbctb.2024.01.020
Abstract:
[Objective] A high-precision geological hazard susceptibility evaluation model was determined for the three districts (counties) of Lishi, Shilou, and Liulin in Lüliang City, Shanxi Province in Luliang mountaionous area in order to provide auxiliary decision-making support for regional planning in the area.[Methods] Based on a geographic information system, a sample of 525 historical hazard points and 500 randomly selected non-hazard points in the region were used, and 19 influencing factors of geological hazard were selected. Geographic detectors (GD) were used to judge the relative importance of each factor. Correlation tests and filtering index factors were determined on the Jupyter Notebook platform. Based on the information method (IM), a method was proposed to calculate the amount of information provided by disaster points combined with the amount of information provided by non-disaster points to obtain the improved information method (IIM), and to calculate the weight with the help of the spatial heterogeneity q value of geographic detectors. Six evaluation systems (GD-IIM, GD-IM, GD-CF, IM, CF, and IIM) were established using the certainty factor (CF). The natural breakpoint classification method was used to divide the susceptibility into five, four, and three levels, and the accuracy of the partition results was verified by the seed cell area index (SCAI). The accuracy of the model results was compared with the ROC curve.[Results] After SCAI testing, the models were divided into four levels (very low, low, high, and very high) that met the rationality requirements. The success rate and prediction rate of disaster susceptibility evaluation by the GD-IIM model reached 90.5 % and 85.5 %, respectively. The IIM model exhibited 2 %~4 % greater accuracy than the traditional IM and CF statistical methods.[Conclusion] The bivariate statistical method coupled with geographic detectors produced more accurate results in constructing the vulnerability evaluation prediction model in the study area. Model construction that considered the non-disaster point information was more accurate than the IM model that considered only the disaster point information model. The improved model was suitable for local model construction.
[Objective] A high-precision geological hazard susceptibility evaluation model was determined for the three districts (counties) of Lishi, Shilou, and Liulin in Lüliang City, Shanxi Province in Luliang mountaionous area in order to provide auxiliary decision-making support for regional planning in the area.[Methods] Based on a geographic information system, a sample of 525 historical hazard points and 500 randomly selected non-hazard points in the region were used, and 19 influencing factors of geological hazard were selected. Geographic detectors (GD) were used to judge the relative importance of each factor. Correlation tests and filtering index factors were determined on the Jupyter Notebook platform. Based on the information method (IM), a method was proposed to calculate the amount of information provided by disaster points combined with the amount of information provided by non-disaster points to obtain the improved information method (IIM), and to calculate the weight with the help of the spatial heterogeneity q value of geographic detectors. Six evaluation systems (GD-IIM, GD-IM, GD-CF, IM, CF, and IIM) were established using the certainty factor (CF). The natural breakpoint classification method was used to divide the susceptibility into five, four, and three levels, and the accuracy of the partition results was verified by the seed cell area index (SCAI). The accuracy of the model results was compared with the ROC curve.[Results] After SCAI testing, the models were divided into four levels (very low, low, high, and very high) that met the rationality requirements. The success rate and prediction rate of disaster susceptibility evaluation by the GD-IIM model reached 90.5 % and 85.5 %, respectively. The IIM model exhibited 2 %~4 % greater accuracy than the traditional IM and CF statistical methods.[Conclusion] The bivariate statistical method coupled with geographic detectors produced more accurate results in constructing the vulnerability evaluation prediction model in the study area. Model construction that considered the non-disaster point information was more accurate than the IM model that considered only the disaster point information model. The improved model was suitable for local model construction.
2024,44(1):206-217
, DOI: 10.13961/j.cnki.stbctb.20231030.001
Abstract:
[Objective] The main grain producing areas have an important strategic position in achieving stable grain production and supply. The cultivated land use efficiency and its spatiotemporal evolution characteristics in the main grain producing areas were studied to promoting the efficient use of cultivated land resources in the main grain producing areas, and ensuring food security and realizing sustainable agricultural development.[Methods] The two-stage dynamic network DEA model was innovatively used to measure cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020. The spatial and temporal evolution characteristics of cultivated land use efficiency were analyzed by ArcGIS visualization technology and kernel density estimation. The Tobit model was constructed to explore the influencing factors of cultivated land utilization efficiency.[Results] The overall efficiency level of the main grain producing area from 2010 to 2020 was characterized as "small decline-rapid rise-fluctuating growth", and the overall efficiency level was low and still had great capacity for improvement. The efficiency level of the production stage was always higher than that of the consumption stage. The gap between the efficiency levels of the two stages had a tendency to further increase. The increase in cultivated land utilization efficiency in the main grain producing area was influenced by the combined effect of the efficiency levels during the two stages, with the production stage being the main driver of efficiency improvement. Resistance to improvement came from the efficiency during the consumption stage. By region, cultivated land utilization efficiency followed the order of Songhua River basin>Yangtze River basin>Yellow River basin, with significant regional imbalance. From the spatial point of view, the overall efficiency and high value areas of production stage efficiency were spatially distributed from northeast to southwest, and gradually formed a spatial pattern of "high-high" clustering and "low-low" clustering. The high value areas of consumption stage efficiency showed a discrete distribution pattern, and did not show the development trend of convergence in the direction of improvement. The external influencing factors of the overall, production, and consumption stages were different, involving the level of socio-economic development, urban and rural development, science and technology, and agricultural infrastructure construction. There were significant differences in the intensity and direction of different factors on the overall and sub-stage cultivated land use efficiency in different regions.[Conclusion] In the future, the main grain producing areas should not only explore the path of regional differentiated cultivated land use, strengthen cooperation among prefecture-level cities, but also focus on the convergence speed of efficiency improvement in consumption stage and the coordination with the efficiency gap in production stage while improving the efficiency of production stage.
[Objective] The main grain producing areas have an important strategic position in achieving stable grain production and supply. The cultivated land use efficiency and its spatiotemporal evolution characteristics in the main grain producing areas were studied to promoting the efficient use of cultivated land resources in the main grain producing areas, and ensuring food security and realizing sustainable agricultural development.[Methods] The two-stage dynamic network DEA model was innovatively used to measure cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020. The spatial and temporal evolution characteristics of cultivated land use efficiency were analyzed by ArcGIS visualization technology and kernel density estimation. The Tobit model was constructed to explore the influencing factors of cultivated land utilization efficiency.[Results] The overall efficiency level of the main grain producing area from 2010 to 2020 was characterized as "small decline-rapid rise-fluctuating growth", and the overall efficiency level was low and still had great capacity for improvement. The efficiency level of the production stage was always higher than that of the consumption stage. The gap between the efficiency levels of the two stages had a tendency to further increase. The increase in cultivated land utilization efficiency in the main grain producing area was influenced by the combined effect of the efficiency levels during the two stages, with the production stage being the main driver of efficiency improvement. Resistance to improvement came from the efficiency during the consumption stage. By region, cultivated land utilization efficiency followed the order of Songhua River basin>Yangtze River basin>Yellow River basin, with significant regional imbalance. From the spatial point of view, the overall efficiency and high value areas of production stage efficiency were spatially distributed from northeast to southwest, and gradually formed a spatial pattern of "high-high" clustering and "low-low" clustering. The high value areas of consumption stage efficiency showed a discrete distribution pattern, and did not show the development trend of convergence in the direction of improvement. The external influencing factors of the overall, production, and consumption stages were different, involving the level of socio-economic development, urban and rural development, science and technology, and agricultural infrastructure construction. There were significant differences in the intensity and direction of different factors on the overall and sub-stage cultivated land use efficiency in different regions.[Conclusion] In the future, the main grain producing areas should not only explore the path of regional differentiated cultivated land use, strengthen cooperation among prefecture-level cities, but also focus on the convergence speed of efficiency improvement in consumption stage and the coordination with the efficiency gap in production stage while improving the efficiency of production stage.
2024,44(1):218-226,237
, DOI: 10.13961/j.cnki.stbctb.2024.01.022
Abstract:
[Objective] The status and spatial distribution of soil erosion in hilly areas were determined in order to provide a theoretical basis for limiting local soil erosion and improving soil conservation practices.[Methods] The study was conducted at Zhangjiajie City, Hunan Province in the hilly area of Southeast China. The revised universal soil loss equation (RUSLE) and geoprobe were used to to determine the spatial and temporal changes of soil erosion characteristics and to determine the driving factors of soil erosion.[Results] ① Average soil erosion values at Zhangjiajie City in 2000, 2010, and 2020 were 1.03×107, 2.05×107, and 6.74×106 t/a. Average soil erosion over the 20-yr study period initially increased and then decreased. ② Soil erosion was dominated by forest erosion. Other land feature types showed different degrees of erosion, in which erosion was mainly concentrated in the 8°-35° slope area. Erosion intensity increased with increasing slope. ③ Soil erosion in the study area was affected by vegetation cover, slope, soil properties, and elevation. The most obvious factor affecting erosion was vegetation cover. The strongest interaction factor influencing erosion was found to be between slope and vegetation cover.[Conclusion] The distribution of soil erosion at Zhangjiajie City had obvious spatial and temporal differences. Soil and water conservation should be carried out reasonably on the premise of ensuring ecological security in the future.
[Objective] The status and spatial distribution of soil erosion in hilly areas were determined in order to provide a theoretical basis for limiting local soil erosion and improving soil conservation practices.[Methods] The study was conducted at Zhangjiajie City, Hunan Province in the hilly area of Southeast China. The revised universal soil loss equation (RUSLE) and geoprobe were used to to determine the spatial and temporal changes of soil erosion characteristics and to determine the driving factors of soil erosion.[Results] ① Average soil erosion values at Zhangjiajie City in 2000, 2010, and 2020 were 1.03×107, 2.05×107, and 6.74×106 t/a. Average soil erosion over the 20-yr study period initially increased and then decreased. ② Soil erosion was dominated by forest erosion. Other land feature types showed different degrees of erosion, in which erosion was mainly concentrated in the 8°-35° slope area. Erosion intensity increased with increasing slope. ③ Soil erosion in the study area was affected by vegetation cover, slope, soil properties, and elevation. The most obvious factor affecting erosion was vegetation cover. The strongest interaction factor influencing erosion was found to be between slope and vegetation cover.[Conclusion] The distribution of soil erosion at Zhangjiajie City had obvious spatial and temporal differences. Soil and water conservation should be carried out reasonably on the premise of ensuring ecological security in the future.
2024,44(1):227-237
, DOI: 10.13961/j.cnki.stbctb.2024.01.023
Abstract:
[Objective] The spatial and temporal evolution of land use in Chongqing City were analyzed, and the relationship between the evolution characteristics of land use transformation and landscape pattern response and urbanization was explored in order to provide data support for ecological-production-living spaces land planning and sustainable development of urbanization in Chongqing City.[Methods] A land use classification criteria was constructed based on the perspective of the functional classification of ecological-productional-living spaces; utilizing land remote sensing images and nighttime lighting data in 2000, 2010, and 2020; and adopting the transfer matrix, correlation analysis, and regression analysis methods.[Results] ① From 2000 to 2020, the productional and ecological space of Chongqing City generally decreased, and the living space continued to expand. From 2000 to 2010, the productional and ecological space decreased by 191.87 km2 and 252.95 km2, respectively, and the living space increased by 446.03 km2. From 2010 to 2020, the productional space decreased by 13.76 km2, ecological space decreased by 324.05 km2, and living space increased by 314.87 km2. ② The shift of productional functions to living functions was more obvious in Chongqing City. As urbanization intensified, ecological space shifted significantly to productional space, and the shift in function was obviously gathered in the central region of Chongqing City. ③ The spatial landscape fragmentation of Chongqing City decreased, the landscape complexity gradually increased, and the forest, grass, and water ecological space dominated. ④ There were differences in the influence of land use area changes on nighttime light in 2000-2010 and in 2010-2020. In 2000, changes in urban living space and rural living space played a dominant role in influencing changes in nighttime light, while changes in industrial production space and urban living space in 2020 had a stronger influence on changes in nighttime light.[Conclusion] Various types of space in Chongqing City have been transformed into each other, and the relationship between changes in different ecological-productional-living spaces types and urbanization has been utilized to promote the coordinated development of land planning and urbanization.
[Objective] The spatial and temporal evolution of land use in Chongqing City were analyzed, and the relationship between the evolution characteristics of land use transformation and landscape pattern response and urbanization was explored in order to provide data support for ecological-production-living spaces land planning and sustainable development of urbanization in Chongqing City.[Methods] A land use classification criteria was constructed based on the perspective of the functional classification of ecological-productional-living spaces; utilizing land remote sensing images and nighttime lighting data in 2000, 2010, and 2020; and adopting the transfer matrix, correlation analysis, and regression analysis methods.[Results] ① From 2000 to 2020, the productional and ecological space of Chongqing City generally decreased, and the living space continued to expand. From 2000 to 2010, the productional and ecological space decreased by 191.87 km2 and 252.95 km2, respectively, and the living space increased by 446.03 km2. From 2010 to 2020, the productional space decreased by 13.76 km2, ecological space decreased by 324.05 km2, and living space increased by 314.87 km2. ② The shift of productional functions to living functions was more obvious in Chongqing City. As urbanization intensified, ecological space shifted significantly to productional space, and the shift in function was obviously gathered in the central region of Chongqing City. ③ The spatial landscape fragmentation of Chongqing City decreased, the landscape complexity gradually increased, and the forest, grass, and water ecological space dominated. ④ There were differences in the influence of land use area changes on nighttime light in 2000-2010 and in 2010-2020. In 2000, changes in urban living space and rural living space played a dominant role in influencing changes in nighttime light, while changes in industrial production space and urban living space in 2020 had a stronger influence on changes in nighttime light.[Conclusion] Various types of space in Chongqing City have been transformed into each other, and the relationship between changes in different ecological-productional-living spaces types and urbanization has been utilized to promote the coordinated development of land planning and urbanization.
2024,44(1):238-246,283
, DOI: 10.13961/j.cnki.stbctb.2024.01.024
Abstract:
[Objective] The impacts of land use on terrestrial ecosystems are important for current global change research. The impacts of land use change on fractional vegetation coverage (FVC) were analyzed scientificaly to improve coordinated development of the social economy and ecological environmental quality while balancing development of the regional economy, in order to provide a reference for government departments to use in protecting and restoring regional ecological management.[Methods] Hubei Province was selected as the research area. Landsat remote sensing images and land use remote sensing data from 2000 and 2020 were obtained, and methods such as spatial processing of remote sensing data, a pixel binary model, and a land use transfer matrix were used. The temporal and spatial changes in FVC, land use type changes, and their effects on FVC in Hubei Province were analyzed.[Results] ① From 2000 to 2020, the area of cultivated land, grassland, and unused land in Hubei Province decreased, the area of water and construction land increased, and the area of forest land remained basically unchanged. The land use area sizes followed the order of forest land > cultivated land > water area > construction land > grassland > unused land; ② The average FVC in Hubei Province increased by 6.50 %. The average FVC of forest land, cultivated land, grassland, and unused land increased, while the average FVC of construction land decreased. ③ FVC in Hubei Province showed an overall increasing trend. The areas with increased FVC were mainly concentrated in the west and southeast parts of Hubei Province. Some areas also experienced vegetation degradation, mainly concentrated in the central and southern parts of Hubei Province and some areas in Northern Xiangyang. ④ During the FVC transfer process resulting from changes in land use types, the transfer process between higher FVC and high FVC areas of cultivated land was the most intense. The FVC transfer amount in forest land accounted for 47.87 % of the total transfer amount, while the FVC transfer amount for grassland accounted for only a small proportion of the total transfer amount (3.40 %).[Conclusion] Land use changes in Hubei Province were great from 2000 to 2020, resulting in an overall increase in FVC over time.
[Objective] The impacts of land use on terrestrial ecosystems are important for current global change research. The impacts of land use change on fractional vegetation coverage (FVC) were analyzed scientificaly to improve coordinated development of the social economy and ecological environmental quality while balancing development of the regional economy, in order to provide a reference for government departments to use in protecting and restoring regional ecological management.[Methods] Hubei Province was selected as the research area. Landsat remote sensing images and land use remote sensing data from 2000 and 2020 were obtained, and methods such as spatial processing of remote sensing data, a pixel binary model, and a land use transfer matrix were used. The temporal and spatial changes in FVC, land use type changes, and their effects on FVC in Hubei Province were analyzed.[Results] ① From 2000 to 2020, the area of cultivated land, grassland, and unused land in Hubei Province decreased, the area of water and construction land increased, and the area of forest land remained basically unchanged. The land use area sizes followed the order of forest land > cultivated land > water area > construction land > grassland > unused land; ② The average FVC in Hubei Province increased by 6.50 %. The average FVC of forest land, cultivated land, grassland, and unused land increased, while the average FVC of construction land decreased. ③ FVC in Hubei Province showed an overall increasing trend. The areas with increased FVC were mainly concentrated in the west and southeast parts of Hubei Province. Some areas also experienced vegetation degradation, mainly concentrated in the central and southern parts of Hubei Province and some areas in Northern Xiangyang. ④ During the FVC transfer process resulting from changes in land use types, the transfer process between higher FVC and high FVC areas of cultivated land was the most intense. The FVC transfer amount in forest land accounted for 47.87 % of the total transfer amount, while the FVC transfer amount for grassland accounted for only a small proportion of the total transfer amount (3.40 %).[Conclusion] Land use changes in Hubei Province were great from 2000 to 2020, resulting in an overall increase in FVC over time.
2024,44(1):247-258
, DOI: 10.13961/j.cnki.stbctb.20230925.001
Abstract:
[Objective] The ecological product values (EPV) in Hebei Province were evaluated and the driving factors of their spatial change were also explored, in order 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 3.80×1011 yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 4.20×1011 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) in Hebei Province were evaluated and the driving factors of their spatial change were also explored, in order 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 3.80×1011 yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 4.20×1011 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.
2024,44(1):259-270
, DOI: 10.13961/j.cnki.stbctb.2024.01.026
Abstract:
[Objective] While financial proceeds from mining can promote the local economy, mining also has a profound impact on the surrounding ecological environmental quality. The ecological status of mines and their surrounding areas were monitored and quantitatively evaluated based on multi-source and long time-series remote sensing data to serve for green mine construction and sustainable development, and also play a positive demonstration role with regard to ecological restoration and management of mine areas.[Methods] This study was conducted at intelligent mine sites and its surrounding area (within 5 km) in Yongjing County, Gansu Province. Multi-spectral remote sensing images acquired by the Landsat series of satellites for five periods from 2009 to 2022 were used with high-resolution remote sensing images from the high-resolution series satellites and the planet series satellites during the same period to monitor and identify the important surface changes and time nodes of the mine and its surrounding area. The spatial and temporal distribution pattern, variation characteristics, and influencing factors of ecological quality in this region during this time period were also systematically determined.[Results] ① The ecological quality of intelligent mine areas in Yongjing County continuously declined from 2009 to 2019, and the remained stable after 2019. The mining area had little impact on the ecological quality of the surrounding area. ② The spatial-temporal change analysis of the remote sensing ecological index for the mining areas at Yongjing County indicated that changes in greenness and heat indicators were more significant than changes in dryness and humidity indicators. ③ The preliminary work of backfilling, leveling, and trimming slopes for land reclamation at abandoned mine sites can significantly increase the remote sensing ecological index value.[Conclusion] The remote sensing ecological index can objectively reflect the actual state of the ecological quality of a mining area. Actions such as land reclamation of abandoned mines and the transformation of surface operations to underground operations in mining areas can effectively solve the problem of continuously declining ecological quality in mining areas.
[Objective] While financial proceeds from mining can promote the local economy, mining also has a profound impact on the surrounding ecological environmental quality. The ecological status of mines and their surrounding areas were monitored and quantitatively evaluated based on multi-source and long time-series remote sensing data to serve for green mine construction and sustainable development, and also play a positive demonstration role with regard to ecological restoration and management of mine areas.[Methods] This study was conducted at intelligent mine sites and its surrounding area (within 5 km) in Yongjing County, Gansu Province. Multi-spectral remote sensing images acquired by the Landsat series of satellites for five periods from 2009 to 2022 were used with high-resolution remote sensing images from the high-resolution series satellites and the planet series satellites during the same period to monitor and identify the important surface changes and time nodes of the mine and its surrounding area. The spatial and temporal distribution pattern, variation characteristics, and influencing factors of ecological quality in this region during this time period were also systematically determined.[Results] ① The ecological quality of intelligent mine areas in Yongjing County continuously declined from 2009 to 2019, and the remained stable after 2019. The mining area had little impact on the ecological quality of the surrounding area. ② The spatial-temporal change analysis of the remote sensing ecological index for the mining areas at Yongjing County indicated that changes in greenness and heat indicators were more significant than changes in dryness and humidity indicators. ③ The preliminary work of backfilling, leveling, and trimming slopes for land reclamation at abandoned mine sites can significantly increase the remote sensing ecological index value.[Conclusion] The remote sensing ecological index can objectively reflect the actual state of the ecological quality of a mining area. Actions such as land reclamation of abandoned mines and the transformation of surface operations to underground operations in mining areas can effectively solve the problem of continuously declining ecological quality in mining areas.
2024,44(1):271-283
, DOI: 10.13961/j.cnki.stbctb.2024.01.027
Abstract:
[Objective] The dynamic changes in grassland habitat quality and its influencing factors in Xilingol League, Inner Mongolia were studied to provide a scientific theoretical basis for the formulation of ecological environmental protection policies and high-quality development in this area.[Methods] The remote sensing ecological index (RSEI) was constructed by using the Google Earth Engine (GEE) platform and MODIS data to evaluate the habitat quality of the study area. Spatial heterogeneity and influencing factors of RSEI were analyzed by using the Moran index and geographic detector.[Results] ① The results demonstrated a temporal change in habitat quality in the study area, with quality initially deteriorating and later improving from 2000 to 2021. The ecological environment significantly improved over time. Habitat quality was better in the typical steppe of central China and the meadow steppe of Eastern China, while it was worse in the desert steppe of Western China. ② The global Moran's I for the five-year study period exceeded 0.935, indicating a strong positive spatial correlation in the distribution of RSEI within the study area, primarily characterized by high-high and low-low cluster patterns. ③ The geodetector results showed that greenness was the main factor affecting RSEI. The most significant influence on ecological environmental quality was the interaction between model factors and natural factors, followed by the coupling of model factors and socio-economic factors.[Conclusion] The areas of high-value habitat quality in the eastern region of the Xilingol League should continue to strengthen protection of the ecological environment, and the areas of low-value habitat quality in the west should focus on restoration and management of desert grasslands and on curbing the eastward expansion of desert.
[Objective] The dynamic changes in grassland habitat quality and its influencing factors in Xilingol League, Inner Mongolia were studied to provide a scientific theoretical basis for the formulation of ecological environmental protection policies and high-quality development in this area.[Methods] The remote sensing ecological index (RSEI) was constructed by using the Google Earth Engine (GEE) platform and MODIS data to evaluate the habitat quality of the study area. Spatial heterogeneity and influencing factors of RSEI were analyzed by using the Moran index and geographic detector.[Results] ① The results demonstrated a temporal change in habitat quality in the study area, with quality initially deteriorating and later improving from 2000 to 2021. The ecological environment significantly improved over time. Habitat quality was better in the typical steppe of central China and the meadow steppe of Eastern China, while it was worse in the desert steppe of Western China. ② The global Moran's I for the five-year study period exceeded 0.935, indicating a strong positive spatial correlation in the distribution of RSEI within the study area, primarily characterized by high-high and low-low cluster patterns. ③ The geodetector results showed that greenness was the main factor affecting RSEI. The most significant influence on ecological environmental quality was the interaction between model factors and natural factors, followed by the coupling of model factors and socio-economic factors.[Conclusion] The areas of high-value habitat quality in the eastern region of the Xilingol League should continue to strengthen protection of the ecological environment, and the areas of low-value habitat quality in the west should focus on restoration and management of desert grasslands and on curbing the eastward expansion of desert.
2024,44(1):284-292
, DOI: 10.13961/j.cnki.stbctb.2024.01.028
Abstract:
[Objective] The changes of ecological environmental quality were analyzed at Shenmu City of Shaanxi Province, an important area for ecological protection and construction in the Yellow River basin, in order to provide a scientific basis for ecological environmental management, restoration, and green development in this resource-based city.[Methods] Landsat remote sensing images in 2010, 2015, and 2020 were selected, and the remote sensing ecological index (RSEI) was constructed as an ecological environmental evaluation index by using the principal component analysis method to analyze the spatial and temporal evolution pattern of ecological environmental quality in Shenmu City. The ecological environmental driving mechanism in the area was determined by Geodetector.[Results] ① The ecological environmental quality of Shenmu City deteriorated over time, with the decline in RSEI reaching 12.47 %, decreasing the fastest from 2010 to 2015. The area with poor ecological environmental quality in Shenmu City increased by 15.29 %. ② The ecological environmental quality in Shenmu City deteriorated first in the sandy area in the northwest (enhanced by wind), and then shifted to the southeast and northeast where the elevation was lower. Meanwhile, the dominant ecological environmental quality in Shenmu City was categorized as poor and fair. The area of those two categories occupied 67.09 % of the total area of Shenmu City. ③ The four indicator factors of vegetation cover and greenness, humidity, dryness, and heat were identified as significant drivers of ecological environmental quality in Shenmu City. Vegetation cover was the main driver of ecological environmental quality, accounting for 62.40 % of the variation in ecological environmental quality. The multi-factor interactions also all indicated synergistic enhancement, and the interaction between night light, population density, heat, and vegetation coverage was the strongest.[Conclusion] The overall ecological environmental quality in Shenmu City has been deteriorating over time. Although the previous degradation has been contained, the area of deteriorating ecological environmental quality is gradually expanding. Increasing vegetation cover can effectively enhance the ecological environmental quality in Shenmu City. Therefore, ecological protection measures such as vegetation greening should be further implemented to improve the ecological environmental quality in Shenmu City.
[Objective] The changes of ecological environmental quality were analyzed at Shenmu City of Shaanxi Province, an important area for ecological protection and construction in the Yellow River basin, in order to provide a scientific basis for ecological environmental management, restoration, and green development in this resource-based city.[Methods] Landsat remote sensing images in 2010, 2015, and 2020 were selected, and the remote sensing ecological index (RSEI) was constructed as an ecological environmental evaluation index by using the principal component analysis method to analyze the spatial and temporal evolution pattern of ecological environmental quality in Shenmu City. The ecological environmental driving mechanism in the area was determined by Geodetector.[Results] ① The ecological environmental quality of Shenmu City deteriorated over time, with the decline in RSEI reaching 12.47 %, decreasing the fastest from 2010 to 2015. The area with poor ecological environmental quality in Shenmu City increased by 15.29 %. ② The ecological environmental quality in Shenmu City deteriorated first in the sandy area in the northwest (enhanced by wind), and then shifted to the southeast and northeast where the elevation was lower. Meanwhile, the dominant ecological environmental quality in Shenmu City was categorized as poor and fair. The area of those two categories occupied 67.09 % of the total area of Shenmu City. ③ The four indicator factors of vegetation cover and greenness, humidity, dryness, and heat were identified as significant drivers of ecological environmental quality in Shenmu City. Vegetation cover was the main driver of ecological environmental quality, accounting for 62.40 % of the variation in ecological environmental quality. The multi-factor interactions also all indicated synergistic enhancement, and the interaction between night light, population density, heat, and vegetation coverage was the strongest.[Conclusion] The overall ecological environmental quality in Shenmu City has been deteriorating over time. Although the previous degradation has been contained, the area of deteriorating ecological environmental quality is gradually expanding. Increasing vegetation cover can effectively enhance the ecological environmental quality in Shenmu City. Therefore, ecological protection measures such as vegetation greening should be further implemented to improve the ecological environmental quality in Shenmu City.
2024,44(1):293-302,313
, DOI: 10.13961/j.cnki.stbctb.20230925.002
Abstract:
[Objective] The spatiotemporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county scale 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 of 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 mainly into construction land, forest land and grassland. ③ The gravity center 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 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" agglomeration played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" agglomeration shifting from the southeast to the northwest, and the "low-low" agglomeration shifting from the southeast to the northwest. The "high-high" agglomeration shifted from the southeastern region to the northwestern region, and the number of "low-low" agglomeration decreased.[Conclusion] The degree of non-agricultural land in Fujian Province is deepening, the degree of spatial aggregation is strengthening and the center of gravity of non-agricultural land is gradually moving to Northwest China. In order to ensure food security and take into account economic development, reasonable measures should be taken to protect cultivated land and realize sustainable development of cultivated land resources.
[Objective] The spatiotemporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county scale 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 of 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 mainly into construction land, forest land and grassland. ③ The gravity center 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 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" agglomeration played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" agglomeration shifting from the southeast to the northwest, and the "low-low" agglomeration shifting from the southeast to the northwest. The "high-high" agglomeration shifted from the southeastern region to the northwestern region, and the number of "low-low" agglomeration decreased.[Conclusion] The degree of non-agricultural land in Fujian Province is deepening, the degree of spatial aggregation is strengthening and the center of gravity of non-agricultural land is gradually moving to Northwest China. In order to ensure food security and take into account economic development, reasonable measures should be taken to protect cultivated land and realize sustainable development of cultivated land resources.
2024,44(1):303-313
, DOI: 10.13961/j.cnki.stbctb.2024.01.030
Abstract:
[Objective] Based on the land use data of five periods in Jiangxi Province from 2000 to 2020, the spatial and temporal evolution characteristics of habitat quality and the main factors of regional habitat quality change were studied, in order to provide references for land use planning and regional ecosystem service optimization in Jiangxi Province.[Methods] The InVEST habitat quality assessment model was used to measure the spatial habitat quality level in Jiangxi Province. The global Moran's I index was used to analyze the spatiotemporal correlation of habitat quality. The Geodetector model was used to capture the dominant factors affecting habitat quality.[Results] ① From 2000 to 2020, the overall habitat quality in Jiangxi Province was at a relatively high level, but showed a slow downward trend. ② The habitat quality in Jiangxi Province had a high spatial positive correlation, and the spatial distribution differences gradually increased. ③ In the natural socio-economic driving system, the proportion of forest land in land use type factors was the main controlling factor affecting habitat quality. The interactions between each driving factor were nonlinear enhancements, with the greatest interaction observed between the distance from construction land and the proportion of cultivated land.[Conclusion] The overall habitat quality level in Jiangxi Province was relatively high, with significant spatial distribution differences. Habitat quality level was mainly influenced by land use types.
[Objective] Based on the land use data of five periods in Jiangxi Province from 2000 to 2020, the spatial and temporal evolution characteristics of habitat quality and the main factors of regional habitat quality change were studied, in order to provide references for land use planning and regional ecosystem service optimization in Jiangxi Province.[Methods] The InVEST habitat quality assessment model was used to measure the spatial habitat quality level in Jiangxi Province. The global Moran's I index was used to analyze the spatiotemporal correlation of habitat quality. The Geodetector model was used to capture the dominant factors affecting habitat quality.[Results] ① From 2000 to 2020, the overall habitat quality in Jiangxi Province was at a relatively high level, but showed a slow downward trend. ② The habitat quality in Jiangxi Province had a high spatial positive correlation, and the spatial distribution differences gradually increased. ③ In the natural socio-economic driving system, the proportion of forest land in land use type factors was the main controlling factor affecting habitat quality. The interactions between each driving factor were nonlinear enhancements, with the greatest interaction observed between the distance from construction land and the proportion of cultivated land.[Conclusion] The overall habitat quality level in Jiangxi Province was relatively high, with significant spatial distribution differences. Habitat quality level was mainly influenced by land use types.
2024,44(1):314-325
, DOI: 10.13961/j.cnki.stbctb.20231212.001
Abstract:
[Objective] A coupling and coordination model of sustainable intensification and scale of cultivated land was studied to provide scientific basis for formulating policies such as territorial spatial planning, rural revitalization and cultivated land protection.[Methods] Actual land use for a study area in Inner Mongolia was used to construct an evaluation index system of sustainable intensification and scale of cultivated land by the entropy method, and the sustainable intensification and scale of cultivated land were measured by the multi-factor comprehensive analysis method. A coupling and coordination analysis was carried out according to the evaluation results. Based on the evaluation results and regional status reported in the study area, we put forward specific suggestions for the utilization and protection of cultivated land in Inner Mongolia.[Results] The comprehensive level of cultivated land intensification in Inner Mongolia from 2006 to 2021 was between 0.218 and 0.370, showing an overall upward trend. The level of cultivated land intensification was higher in the east and west, and lower in the central region. The differences in cultivated land intensification level among all of the cities were small, and the utilization degree and output effect of cultivated land had a significant influence on the level of cultivated land intensification. The comprehensive level of cultivated land scale fluctuated between 0.433 and 0.532, showing a trend of initially increasing and then decreasing. The spatial distribution characteristics were irregular. There was a large difference in the scale level of cultivated land among the cities, and the shape and area of cultivated land patches had a high contribution to the scale level of cultivated land. During the past 15 years, the coupling degree of cultivated land intensification and scale in Inner Mongolia gradually developed from the run-in stage to the high-level run-in stage, and the coupling degree of cultivated land intensification and scale continued to increase. The coupling degree of cultivated land intensification and scale has advanced from the verge of disharmony and barely coordinated to primary coordination and intermediate coordination. However, 33.33 % of cities were still in the barely coordinated stage, and the spatial distribution pattern was generally higher in the eastern and western regions and lower in the central region.[Conclusion] There is room for optimizing the cultivated land utilization level in Inner Mongolia. More attention should be given to the scientific utilization of cultivated land, improving the planting environment, and attaching equal importance to the utilization and protection of cultivated land to promote sustainable and high-quality agricultural development in Inner Mongolia.
[Objective] A coupling and coordination model of sustainable intensification and scale of cultivated land was studied to provide scientific basis for formulating policies such as territorial spatial planning, rural revitalization and cultivated land protection.[Methods] Actual land use for a study area in Inner Mongolia was used to construct an evaluation index system of sustainable intensification and scale of cultivated land by the entropy method, and the sustainable intensification and scale of cultivated land were measured by the multi-factor comprehensive analysis method. A coupling and coordination analysis was carried out according to the evaluation results. Based on the evaluation results and regional status reported in the study area, we put forward specific suggestions for the utilization and protection of cultivated land in Inner Mongolia.[Results] The comprehensive level of cultivated land intensification in Inner Mongolia from 2006 to 2021 was between 0.218 and 0.370, showing an overall upward trend. The level of cultivated land intensification was higher in the east and west, and lower in the central region. The differences in cultivated land intensification level among all of the cities were small, and the utilization degree and output effect of cultivated land had a significant influence on the level of cultivated land intensification. The comprehensive level of cultivated land scale fluctuated between 0.433 and 0.532, showing a trend of initially increasing and then decreasing. The spatial distribution characteristics were irregular. There was a large difference in the scale level of cultivated land among the cities, and the shape and area of cultivated land patches had a high contribution to the scale level of cultivated land. During the past 15 years, the coupling degree of cultivated land intensification and scale in Inner Mongolia gradually developed from the run-in stage to the high-level run-in stage, and the coupling degree of cultivated land intensification and scale continued to increase. The coupling degree of cultivated land intensification and scale has advanced from the verge of disharmony and barely coordinated to primary coordination and intermediate coordination. However, 33.33 % of cities were still in the barely coordinated stage, and the spatial distribution pattern was generally higher in the eastern and western regions and lower in the central region.[Conclusion] There is room for optimizing the cultivated land utilization level in Inner Mongolia. More attention should be given to the scientific utilization of cultivated land, improving the planting environment, and attaching equal importance to the utilization and protection of cultivated land to promote sustainable and high-quality agricultural development in Inner Mongolia.
2024,44(1):326-334
, DOI: 10.13961/j.cnki.stbctb.2024.01.032
Abstract:
[Objective] The characteristics of vegetation dynamic changes and their response relationship with potential impact factors in the Aksu River basin were determined in order to provide a theoretical basis for ecological environmental protection and governance in arid areas.[Methods] Based on MODIS normalized difference vegetation index (NDVI), climate, topography, soil type, and land use data, the dynamics and driving mechanisms of vegetation changes in Aksu River basin from 2000 to 2020 were analyzed using trend analysis and geographical detector methods.[Results] ① The NDVI of the Aksu River basin showed a significant increasing trend from 2000 to 2020, with a growth rate of 0.003 2/yr. The growth rate in the anthropogenic areas was significantly larger than in the non-anthropogenic areas. ② There were temporal and spatial differences in the explanatory power of potential factors for NDVI changes. Land use conversion was an important driving factor for NDVI changes in anthropogenic areas. Elevation, soil type, distance from glacier snowpack, and distance from water bodies were important driving factors for NDVI changes in non-anthropogenic areas. Interaction among factors increased the explanatory power of NDVI changes, and land use conversion interacting with soil type had the strongest explanatory power of NDVI changes in the anthropogenic areas. The interaction among background factors, distance from recharge water sources and other factors was an important combination of factors for NDVI changes in the anthropogenic areas. ③ More than 10 % of the area of the Aksu River basin in 2000-2020 underwent land use conversion, mainly in the form of mutual conversion of bare land and grassland, and a significant increase in the area of cropland, woodland, shrubland, and man-made land surface.[Conclusion] The spatial and temporal characteristics and driving mechanism of NDVI change in human activity area and non-human activity area in Aksu River basin are different. It is necessary to manage the Aksu River basin reasonably according to local conditions to promote the benign development of ecological environment in the basin.
[Objective] The characteristics of vegetation dynamic changes and their response relationship with potential impact factors in the Aksu River basin were determined in order to provide a theoretical basis for ecological environmental protection and governance in arid areas.[Methods] Based on MODIS normalized difference vegetation index (NDVI), climate, topography, soil type, and land use data, the dynamics and driving mechanisms of vegetation changes in Aksu River basin from 2000 to 2020 were analyzed using trend analysis and geographical detector methods.[Results] ① The NDVI of the Aksu River basin showed a significant increasing trend from 2000 to 2020, with a growth rate of 0.003 2/yr. The growth rate in the anthropogenic areas was significantly larger than in the non-anthropogenic areas. ② There were temporal and spatial differences in the explanatory power of potential factors for NDVI changes. Land use conversion was an important driving factor for NDVI changes in anthropogenic areas. Elevation, soil type, distance from glacier snowpack, and distance from water bodies were important driving factors for NDVI changes in non-anthropogenic areas. Interaction among factors increased the explanatory power of NDVI changes, and land use conversion interacting with soil type had the strongest explanatory power of NDVI changes in the anthropogenic areas. The interaction among background factors, distance from recharge water sources and other factors was an important combination of factors for NDVI changes in the anthropogenic areas. ③ More than 10 % of the area of the Aksu River basin in 2000-2020 underwent land use conversion, mainly in the form of mutual conversion of bare land and grassland, and a significant increase in the area of cropland, woodland, shrubland, and man-made land surface.[Conclusion] The spatial and temporal characteristics and driving mechanism of NDVI change in human activity area and non-human activity area in Aksu River basin are different. It is necessary to manage the Aksu River basin reasonably according to local conditions to promote the benign development of ecological environment in the basin.
2024,44(1):335-345
, DOI: 10.13961/j.cnki.stbctb.2024.01.033
Abstract:
[Objective] The changes and impact of regional ecosystem services and ecological risks were studied in order to provide decision-making support for the rational utilization of land resources and ecological restoration of territorial space.[Methods] Landsat remote sensing images were used with the random forest classification method of the GEE (Google Earth Engine) platform to extract land use change information for Kunming City, Yunnan Province from 1990 to 2020. A spatial dynamic change analysis was carried out based on the interpretation results. The equivalent factor method was used to estimate ecosystem service values. An ecological risk model was used to determine the change in ecological risk over time. The correlation between ecosystem service value and ecological risk was calculated with a bivariate spatial autocorrelation model.[Results] ① Among the land use types in Kunming City from 1990 to 2020, forest land and grassland occupied the largest area, the area of construction land increased significantly, and the area of cultivated land, grassland, and forest land decreased. ② The value of ecosystem services in Kunming City showed an overall upward trend over time, with a total increase of 3.08×108 yuan. The effective implementation of ecological protection policies increased the value of ecosystem services. Ecological risks during the study period were mainly classified as medium and low risks, and accounted for 79 % of the total area. The overall average ecosystem service value decreased by 0.12, indicating that urban economic development had developed with little impact on the environment. ③ Ecological risk had a certain impact on the change of ecosystem service value, and with the passage of time, the area of high-value and high-risk areas gradually decreased, and the area of low-value and low-risk areas gradually increased, without obvious extremes.[Conclusion] The combination of regional ecosystem service value and ecological risk can better characterize changes in ecological environment of Kunming City caused by human activities, and provide decision-making and management references for environmental protection and high-quality sustainable development. effectively prevent ecological risks, and make the economic development and environmental protection of Kunming City develop to a benign situation.
[Objective] The changes and impact of regional ecosystem services and ecological risks were studied in order to provide decision-making support for the rational utilization of land resources and ecological restoration of territorial space.[Methods] Landsat remote sensing images were used with the random forest classification method of the GEE (Google Earth Engine) platform to extract land use change information for Kunming City, Yunnan Province from 1990 to 2020. A spatial dynamic change analysis was carried out based on the interpretation results. The equivalent factor method was used to estimate ecosystem service values. An ecological risk model was used to determine the change in ecological risk over time. The correlation between ecosystem service value and ecological risk was calculated with a bivariate spatial autocorrelation model.[Results] ① Among the land use types in Kunming City from 1990 to 2020, forest land and grassland occupied the largest area, the area of construction land increased significantly, and the area of cultivated land, grassland, and forest land decreased. ② The value of ecosystem services in Kunming City showed an overall upward trend over time, with a total increase of 3.08×108 yuan. The effective implementation of ecological protection policies increased the value of ecosystem services. Ecological risks during the study period were mainly classified as medium and low risks, and accounted for 79 % of the total area. The overall average ecosystem service value decreased by 0.12, indicating that urban economic development had developed with little impact on the environment. ③ Ecological risk had a certain impact on the change of ecosystem service value, and with the passage of time, the area of high-value and high-risk areas gradually decreased, and the area of low-value and low-risk areas gradually increased, without obvious extremes.[Conclusion] The combination of regional ecosystem service value and ecological risk can better characterize changes in ecological environment of Kunming City caused by human activities, and provide decision-making and management references for environmental protection and high-quality sustainable development. effectively prevent ecological risks, and make the economic development and environmental protection of Kunming City develop to a benign situation.
2024,44(1):346-356
, DOI: 10.13961/j.cnki.stbctb.2024.01.034
Abstract:
[Objective] The spatio-temporal variation characteristics of vegetation cover since returning farmland to forest were systematically analyzed. The potential of vegetation restoration were evaluated, in order to provide scientific theoretical basis and implementation suggestions for the sustainable development of ecological environment construction in Shaanxi Province.[Methods] The spatial and temporal variations of fractional vegetation cover (FVC) were investigated from 2000 to 2020 based on MODIS NDVI data, the Sen+Mann-Kendall method and Hurst index. Vegetation restoration potential was assessed by using the 'similar habitat method' in Shaanxi Province, as well as in three subregions of the Loess Plateau, Qinling-Bashan Mountain, and the Guanzhong Plain.[Results] ① The average growth rate of FVC in Shaanxi Province was 0.002 9/a from 2000 to 2020, and 74.58 % of the area had increased in FVC. Areas of significant and slight FVC increase were detected in the Loess Plateau and Qinling-Bashan Mountain where 84.46 % and 74.40 % of the areas, respectively, showed increased FVC. Slight FVC degradation trends were detected in the Guanzhong Plain where 64.56 % of the area, showed decreased FVC. ② The areas showing persistent increase in FVC accounted for 19.80 % of the entire Shaanxi Province, and accounted for 27.83 % and 13.68 % in the Loess Plateau and Qinling-Bashan Mountain, respectively. The area showing persistent decreases in FVC were predominantly in the Guanzhong Plain. ③ For the Loess Plateau region, greater vegetation recovery potential areas were detected in the northern area and the transitional area with the Guanzhong Plain, and the vegetation recovery potential was low in the Ziwuling forest area. Low vegetation recovery potentials were found in the Qinling-Bashan Mountain and Guanzhong Plain areas because of the high vegetation coverage background and the high rate of urbanization, respectively.[Conclusion] Shaanxi Province experienced significant FVC increases during 2000-2020 due to it being a key region of ecological project implementation. However, the heterogeneous spatial-temporal variation of FVC was affected by climate, topography, plant species, and human activities. The growth rate of vegetation restoration in Shaanxi Province tended to slow down, the continuous improvement ability has been lower, and the vegetation cover tended to be stable. However, the northwest region of the Loess Plateau and its border with Guanzhong Plain still has a large potential for vegetation cover restoration.
[Objective] The spatio-temporal variation characteristics of vegetation cover since returning farmland to forest were systematically analyzed. The potential of vegetation restoration were evaluated, in order to provide scientific theoretical basis and implementation suggestions for the sustainable development of ecological environment construction in Shaanxi Province.[Methods] The spatial and temporal variations of fractional vegetation cover (FVC) were investigated from 2000 to 2020 based on MODIS NDVI data, the Sen+Mann-Kendall method and Hurst index. Vegetation restoration potential was assessed by using the 'similar habitat method' in Shaanxi Province, as well as in three subregions of the Loess Plateau, Qinling-Bashan Mountain, and the Guanzhong Plain.[Results] ① The average growth rate of FVC in Shaanxi Province was 0.002 9/a from 2000 to 2020, and 74.58 % of the area had increased in FVC. Areas of significant and slight FVC increase were detected in the Loess Plateau and Qinling-Bashan Mountain where 84.46 % and 74.40 % of the areas, respectively, showed increased FVC. Slight FVC degradation trends were detected in the Guanzhong Plain where 64.56 % of the area, showed decreased FVC. ② The areas showing persistent increase in FVC accounted for 19.80 % of the entire Shaanxi Province, and accounted for 27.83 % and 13.68 % in the Loess Plateau and Qinling-Bashan Mountain, respectively. The area showing persistent decreases in FVC were predominantly in the Guanzhong Plain. ③ For the Loess Plateau region, greater vegetation recovery potential areas were detected in the northern area and the transitional area with the Guanzhong Plain, and the vegetation recovery potential was low in the Ziwuling forest area. Low vegetation recovery potentials were found in the Qinling-Bashan Mountain and Guanzhong Plain areas because of the high vegetation coverage background and the high rate of urbanization, respectively.[Conclusion] Shaanxi Province experienced significant FVC increases during 2000-2020 due to it being a key region of ecological project implementation. However, the heterogeneous spatial-temporal variation of FVC was affected by climate, topography, plant species, and human activities. The growth rate of vegetation restoration in Shaanxi Province tended to slow down, the continuous improvement ability has been lower, and the vegetation cover tended to be stable. However, the northwest region of the Loess Plateau and its border with Guanzhong Plain still has a large potential for vegetation cover restoration.
2024,44(1):357-367
, DOI: 10.13961/j.cnki.stbctb.20230828.001
Abstract:
[Objective] Soil erosion is an important environmental problem of globality, which seriously restricts human production and life. Soil maintenance conservation founction was quantitative studied to formulate the regional soil and water conservation measures, and provide scientific basis for the functional partition planning and governance of Harbin City.[Methods] Based on the InVEST model sediment delivery ratio module, this study evaluated the soil erosion and soil conservation in 2000, 2010 and 2020 in Harbin, analyzed the spatial aggregation type of soil conservation with the help of spatial autocorrelation, and used the optimal geographic detector to reveal the driving forces of spatial heterogeneity.[Results] ① In 2000, 2010 and 2020, the soil conservation in Harbin City was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of decreasing first and then increasing, and the overall spatial distribution pattern of "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation, mainly "low-low aggregation" and "high-high aggregation" types, the "low-low aggregation" type area showed a downward trend, while the "high-high aggregation" type showed a decreasing and then rising trend. ③ Elevation, precipitation and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin City, with average explanatory forces of 0.225 9, 0.198 9 and 0.180 4, respectively, and the interaction between slope and precipitation and other factors was the strongest explanatory interaction factor in the study area.[Conclusion] Water and soil management in the western part of Harbin City and along the Songhua River should be strengthened, while good water and soil conditions in the north and east of the city should be maintained to avoid large-scale human disturbance activities.
[Objective] Soil erosion is an important environmental problem of globality, which seriously restricts human production and life. Soil maintenance conservation founction was quantitative studied to formulate the regional soil and water conservation measures, and provide scientific basis for the functional partition planning and governance of Harbin City.[Methods] Based on the InVEST model sediment delivery ratio module, this study evaluated the soil erosion and soil conservation in 2000, 2010 and 2020 in Harbin, analyzed the spatial aggregation type of soil conservation with the help of spatial autocorrelation, and used the optimal geographic detector to reveal the driving forces of spatial heterogeneity.[Results] ① In 2000, 2010 and 2020, the soil conservation in Harbin City was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of decreasing first and then increasing, and the overall spatial distribution pattern of "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation, mainly "low-low aggregation" and "high-high aggregation" types, the "low-low aggregation" type area showed a downward trend, while the "high-high aggregation" type showed a decreasing and then rising trend. ③ Elevation, precipitation and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin City, with average explanatory forces of 0.225 9, 0.198 9 and 0.180 4, respectively, and the interaction between slope and precipitation and other factors was the strongest explanatory interaction factor in the study area.[Conclusion] Water and soil management in the western part of Harbin City and along the Songhua River should be strengthened, while good water and soil conditions in the north and east of the city should be maintained to avoid large-scale human disturbance activities.
Yan Feng, Liu Xin, Pang Jiao, Dai Pengyu, Xu Jiayin, An Xiaoming, Shen Lin, Chen Yongxia, Chen Yaheng
2024,44(1):368-377
, DOI: 10.13961/j.cnki.stbctb.2024.01.036
Abstract:
[Objective] An ecological compensation model taking into account regional background differences was established to further clarify the spatial and temporal differentiation pattern of ecological compensation and its leading driving factors in the Beijing-Tianjin-Hebei region, in order to provide to a reference for government departments to formulate environmental protection and macroeconomic policies.[Methods] Based on a modified carbon deficit, a reasonable ecological compensation framework was constructed using model construction, spatial correlation analysis, and GeoDetector technology, etc. The spatial and temporal variability pattern, spatial autocorrelation, driver ranking, and interaction of ecological compensation in the Beijing-Tianjin-Hebei region during the period of 2007 to 2020 were analyzed and investigated.[Results] ① Carbon emissions in the Beijing-Tianjin-Hebei region from 2007 to 2020 showed a pattern of "increasing and then decreasing" over time, and carbon sequestration generally showed a trend of continuous increase. ② The carbon deficit in the Beijing-Tianjin-Hebei region before the amendment showed a U-shaped pattern with high carbon deficits in the east, south, and west, and low carbon deficits in the north. After the amendment, the carbon deficits were higher in the east, south, and west due to low carbon deficits in the north. After the amendment, the carbon deficits were more evenly distributed in space and time due to the local differences between regions. ③ The cold spot area of the ecological compensation amount was basically located in the Northeast Beijing-Tianjin-Hebei region, and the hot spot area was located in the Southwest Beijing-Tianjin-Hebei region. There were individual cold and hot spot areas between the two areas. The hot spot area was moving to the northeast, while the cold spot area was moving towards the southwest. ④ The main factors affecting the change of ecological compensation amount were different in different years, and the main factors affecting the change of the ecological compensation amount were different. Compensation amount changed in different years. The main factors affecting the changes in ecological compensation in the Beijing-Tianjin-Hebei region in 2007, 2012, 2017, and 2020 were tertiary industry output, financial revenue, secondary industry output, and per capita gross domestic product, respectively. The interactive influence of the factors leading to the changes in ecological compensation was different in different years. The interaction effect showed the repeated effect of decreasing each other and then increasing each other. The interaction effect was different in different years.[Conclusion] The ecological compensation model that takes into account regional background differences has a certain fairness to the analysis of the spatio-temporal differentiation pattern of ecological compensation and its leading driving factors in the Beijing-Tianjin-Hebei region, and provides more accurate guidance and suggestions for government departments to formulate environmental protection and macroeconomic policies.
[Objective] An ecological compensation model taking into account regional background differences was established to further clarify the spatial and temporal differentiation pattern of ecological compensation and its leading driving factors in the Beijing-Tianjin-Hebei region, in order to provide to a reference for government departments to formulate environmental protection and macroeconomic policies.[Methods] Based on a modified carbon deficit, a reasonable ecological compensation framework was constructed using model construction, spatial correlation analysis, and GeoDetector technology, etc. The spatial and temporal variability pattern, spatial autocorrelation, driver ranking, and interaction of ecological compensation in the Beijing-Tianjin-Hebei region during the period of 2007 to 2020 were analyzed and investigated.[Results] ① Carbon emissions in the Beijing-Tianjin-Hebei region from 2007 to 2020 showed a pattern of "increasing and then decreasing" over time, and carbon sequestration generally showed a trend of continuous increase. ② The carbon deficit in the Beijing-Tianjin-Hebei region before the amendment showed a U-shaped pattern with high carbon deficits in the east, south, and west, and low carbon deficits in the north. After the amendment, the carbon deficits were higher in the east, south, and west due to low carbon deficits in the north. After the amendment, the carbon deficits were more evenly distributed in space and time due to the local differences between regions. ③ The cold spot area of the ecological compensation amount was basically located in the Northeast Beijing-Tianjin-Hebei region, and the hot spot area was located in the Southwest Beijing-Tianjin-Hebei region. There were individual cold and hot spot areas between the two areas. The hot spot area was moving to the northeast, while the cold spot area was moving towards the southwest. ④ The main factors affecting the change of ecological compensation amount were different in different years, and the main factors affecting the change of the ecological compensation amount were different. Compensation amount changed in different years. The main factors affecting the changes in ecological compensation in the Beijing-Tianjin-Hebei region in 2007, 2012, 2017, and 2020 were tertiary industry output, financial revenue, secondary industry output, and per capita gross domestic product, respectively. The interactive influence of the factors leading to the changes in ecological compensation was different in different years. The interaction effect showed the repeated effect of decreasing each other and then increasing each other. The interaction effect was different in different years.[Conclusion] The ecological compensation model that takes into account regional background differences has a certain fairness to the analysis of the spatio-temporal differentiation pattern of ecological compensation and its leading driving factors in the Beijing-Tianjin-Hebei region, and provides more accurate guidance and suggestions for government departments to formulate environmental protection and macroeconomic policies.
2024,44(1):378-388
, DOI: 10.13961/j.cnki.stbctb.20240008.002
Abstract:
[Objective] The change characteristics and dynamic evolution trend of carbon neutral effect in 30 provinces (municipalities and regions) in China from 2000 to 2020 were analyzed, and the characteristics and internal motivation mechanism of ecological environment in agriculture and rural area were quantitatively revealed, in order to provide theoretical basis for further promoting the process of "carbon neutral" in agriculture and rural areas of China.[Methods] Based on the perspective of large agricultural production systems, 37 types of carbon sources and 28 types of carbon sinks were selected by the emission coefficient method to calculate the carbon neutrality effect for agriculture and rural areas in 30 provinces (municipalities and regions) in China during 2000-2020. The spatial and temporal distribution characteristics of the carbon neutrality effect were determined, and its dynamic evolution characteristics were observed by the Kernel-Density method.[Results] ① The carbon neutral effect in China's agriculture and rural areas increased steadily over time, with an average annual increase of 2.79 %. The overall growth rate fluctuated, and the growth rate of carbon sinks was significantly faster than the growth rate of carbon emissions. ② The spatial imbalance of the carbon neutral effect in China's agriculture and rural areas increased significantly, showing a distribution pattern of "lower in the middle and higher in the periphery". The difference between provinces was obvious:the top 10 provinces (municipalities and regions) accounted for 66.42 % of the national carbon neutral effect, while the bottom 10 provinces (municipalities and regions) accounted for only 4.72 % of the national carbon neutrality effect. ③ The level of the carbon neutrality effect showed a distribution trend of "central region > eastern region > western region", and there were great differences between different regions. The planting industry was the largest source of emission reduction and sink increase. ④ The center of the carbon neutrality effect density function curve in China's agriculture and rural areas had shifted to the right as a whole, and the spatial gap between provinces (municipalities and regions) has gradually expanded. Unbalanced regional development was observed.[Conclusion] Low-carbon economy and modern agriculture are intertwined. All regions should formulate carbon neutral development plans in agriculture and rural areas according to local conditions, bring about an inter-regional carbon neutral coordination mechanism, and accelerate the process of carbon neutral in agriculture and in rural areas.
[Objective] The change characteristics and dynamic evolution trend of carbon neutral effect in 30 provinces (municipalities and regions) in China from 2000 to 2020 were analyzed, and the characteristics and internal motivation mechanism of ecological environment in agriculture and rural area were quantitatively revealed, in order to provide theoretical basis for further promoting the process of "carbon neutral" in agriculture and rural areas of China.[Methods] Based on the perspective of large agricultural production systems, 37 types of carbon sources and 28 types of carbon sinks were selected by the emission coefficient method to calculate the carbon neutrality effect for agriculture and rural areas in 30 provinces (municipalities and regions) in China during 2000-2020. The spatial and temporal distribution characteristics of the carbon neutrality effect were determined, and its dynamic evolution characteristics were observed by the Kernel-Density method.[Results] ① The carbon neutral effect in China's agriculture and rural areas increased steadily over time, with an average annual increase of 2.79 %. The overall growth rate fluctuated, and the growth rate of carbon sinks was significantly faster than the growth rate of carbon emissions. ② The spatial imbalance of the carbon neutral effect in China's agriculture and rural areas increased significantly, showing a distribution pattern of "lower in the middle and higher in the periphery". The difference between provinces was obvious:the top 10 provinces (municipalities and regions) accounted for 66.42 % of the national carbon neutral effect, while the bottom 10 provinces (municipalities and regions) accounted for only 4.72 % of the national carbon neutrality effect. ③ The level of the carbon neutrality effect showed a distribution trend of "central region > eastern region > western region", and there were great differences between different regions. The planting industry was the largest source of emission reduction and sink increase. ④ The center of the carbon neutrality effect density function curve in China's agriculture and rural areas had shifted to the right as a whole, and the spatial gap between provinces (municipalities and regions) has gradually expanded. Unbalanced regional development was observed.[Conclusion] Low-carbon economy and modern agriculture are intertwined. All regions should formulate carbon neutral development plans in agriculture and rural areas according to local conditions, bring about an inter-regional carbon neutral coordination mechanism, and accelerate the process of carbon neutral in agriculture and in rural areas.
2024,44(1):389-398,420
, DOI: 10.13961/j.cnki.stbctb.20240019.002
Abstract:
[Objective] The carbon emission efficiency of grain production was determined for 74 cities in the five provinces of Huang-Huai-Hai region, and spatial differentiation and dynamic evolution were quantified in light of the "double carbon" goals development strategy and goals. The current situation of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region was analyzed in order to promote green and low-carbon grain production in the region.[Methods] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure carbon emissions and carbon emission efficiencies of grain production for 74 cities in the five provinces of Huang-Huai-Hai region from 2011 to 2020. The spatial differentiation and dynamic evolution of carbon emission efficiency of grain production were then determined by means of the Theil index and kernel density estimation.[Results] ① Carbon emissions of grain production in the five provinces and cities of Huang-Huai-Hai region during the study period showed a fluctuating downward trend with an "M" shape, but the decline was slow. The use of chemical fertilizers was the main cause of grain carbon emissions. ② The carbon emission efficiency of grain production in the five provinces and cities of Huang-Huai-Hai region initially decreased and then increased. 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 cities had higher efficiency values, while Huangshan, Weihai, and other cities had lower efficiency values. ③ The spatial differences of the carbon emission efficiency of grain production was on the rise, and the differences within the region were the main factor affecting the overall difference, among which the difference between cities in Henan Province was the most significant. ④ During the sample investigation period, the core density curve changed from a "single-peak shape" to a "double-peak shape" where the main peak showed a fluctuating rise and a slight shift to the right, and the secondary peak maximum was smaller, indicating that the overall level of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region had increased, regional differences had increased, and the region showed a multi-polar trend.[Conclusion] The overall level of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region was low, and there were obvious spatial differentiation characteristics. In the future, all regions should reduce the input of materials such as chemical fertilizers, and adopt the strategy of "counterpart assistance" to promote the positive interaction of grain production technology in various regions so as to narrow regional differences in the carbon emission efficiency of grain production among regions.
[Objective] The carbon emission efficiency of grain production was determined for 74 cities in the five provinces of Huang-Huai-Hai region, and spatial differentiation and dynamic evolution were quantified in light of the "double carbon" goals development strategy and goals. The current situation of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region was analyzed in order to promote green and low-carbon grain production in the region.[Methods] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure carbon emissions and carbon emission efficiencies of grain production for 74 cities in the five provinces of Huang-Huai-Hai region from 2011 to 2020. The spatial differentiation and dynamic evolution of carbon emission efficiency of grain production were then determined by means of the Theil index and kernel density estimation.[Results] ① Carbon emissions of grain production in the five provinces and cities of Huang-Huai-Hai region during the study period showed a fluctuating downward trend with an "M" shape, but the decline was slow. The use of chemical fertilizers was the main cause of grain carbon emissions. ② The carbon emission efficiency of grain production in the five provinces and cities of Huang-Huai-Hai region initially decreased and then increased. 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 cities had higher efficiency values, while Huangshan, Weihai, and other cities had lower efficiency values. ③ The spatial differences of the carbon emission efficiency of grain production was on the rise, and the differences within the region were the main factor affecting the overall difference, among which the difference between cities in Henan Province was the most significant. ④ During the sample investigation period, the core density curve changed from a "single-peak shape" to a "double-peak shape" where the main peak showed a fluctuating rise and a slight shift to the right, and the secondary peak maximum was smaller, indicating that the overall level of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region had increased, regional differences had increased, and the region showed a multi-polar trend.[Conclusion] The overall level of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region was low, and there were obvious spatial differentiation characteristics. In the future, all regions should reduce the input of materials such as chemical fertilizers, and adopt the strategy of "counterpart assistance" to promote the positive interaction of grain production technology in various regions so as to narrow regional differences in the carbon emission efficiency of grain production among regions.
2024,44(1):399-409,431
, DOI: 10.13961/j.cnki.stbctb.20231023.001
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 with λ 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 with λ 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.
2024,44(1):410-420
, DOI: 10.13961/j.cnki.stbctb.2024.01.040
Abstract:
[Objective] The land use change and its impact on carbon storage was studied from 2005 to 2020, and the land use pattern and carbon storage in the Pearl River Delta in 2035 were simulated and predicted, in order to provide a scientific basis for the territorial spatial planning and ecological decision-making under the dual carbon goal in the Pearl River delta region.[Methods] Based on land use data for four periods from 2005 to 2020, land use change and carbon storage evolution in the Pearl River delta urban agglomeration were analyzed by using the PLUS model and the InVEST model. The spatial pattern of land use and the carbon storage change trend in 2035 were predicted.[Results] ①From 2005 to 2020, carbon stocks initially increased and then decreased. The increased area of forest land, construction land, and unused land increased carbon stocks by 4.82×107 t, and the decreased area of cultivated land, grassland and water area decreased carbon stocks by 5.10×107 t. ② In 2035, with an expected increase of construction land and forest land, carbon storage will increase by 5.75×107 t compared with 2020, and the ecological environment will improve. ③ Carbon storage showed a spatial distribution pattern of "higher in the surrounding areas and lower in the middle" that was significantly consistent with the spatial distribution of land use, i.e., the high-value carbon storage areas were concentrated in forest land, cultivated land, and grassland, and the low-value carbon storage areas were concentrated in construction land.[Conclusion] With the needs of future urban development, government departments should carry out comprehensive land development and utilization, adopt ecological restoration measures based on biological and engineering technology, and improve regional carbon sequestration capacity so as to achieve carbon neutrality.
[Objective] The land use change and its impact on carbon storage was studied from 2005 to 2020, and the land use pattern and carbon storage in the Pearl River Delta in 2035 were simulated and predicted, in order to provide a scientific basis for the territorial spatial planning and ecological decision-making under the dual carbon goal in the Pearl River delta region.[Methods] Based on land use data for four periods from 2005 to 2020, land use change and carbon storage evolution in the Pearl River delta urban agglomeration were analyzed by using the PLUS model and the InVEST model. The spatial pattern of land use and the carbon storage change trend in 2035 were predicted.[Results] ①From 2005 to 2020, carbon stocks initially increased and then decreased. The increased area of forest land, construction land, and unused land increased carbon stocks by 4.82×107 t, and the decreased area of cultivated land, grassland and water area decreased carbon stocks by 5.10×107 t. ② In 2035, with an expected increase of construction land and forest land, carbon storage will increase by 5.75×107 t compared with 2020, and the ecological environment will improve. ③ Carbon storage showed a spatial distribution pattern of "higher in the surrounding areas and lower in the middle" that was significantly consistent with the spatial distribution of land use, i.e., the high-value carbon storage areas were concentrated in forest land, cultivated land, and grassland, and the low-value carbon storage areas were concentrated in construction land.[Conclusion] With the needs of future urban development, government departments should carry out comprehensive land development and utilization, adopt ecological restoration measures based on biological and engineering technology, and improve regional carbon sequestration capacity so as to achieve carbon neutrality.
2024,44(1):421-431
, DOI: 10.13961/j.cnki.stbctb.20240019.003
Abstract:
[Objective] The carbon emission effect on changes of the productional-living-ecological functions was determined in order to provide a reference for territorial and spatial planning meeting the "dual carbon" goals of "carbon peak" and "carbon neutrality".[Methods] The evaluation assignment method, the energy consumption method, and a geographical weighted regression model were used to determine the spatial-temporal evolution characteristics of the productional-living-ecological functions and their effects on carbon emissions in Liaoning Province from 2005 to 2020.[Results] ① The spatial distribution pattern of the productional-living-ecological functions in Liaoning Province did not change much from 2005 to 2020. Most of the areas were dominated by productional and ecological functions, the living function areas expanded significantly, and the spatial differences mainly occurred between the central urban area 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 differences became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities. ③ The overall correlations between the productional-living-ecological functions and carbon emissions were strong. The spatial differences were obvious and the influencing 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 clearly define the main functions of the land and promote regional cooperation on the basis of their own advantages and resource endowments so as to realize carbon emission reductions over the entire region.
[Objective] The carbon emission effect on changes of the productional-living-ecological functions was determined in order to provide a reference for territorial and spatial planning meeting the "dual carbon" goals of "carbon peak" and "carbon neutrality".[Methods] The evaluation assignment method, the energy consumption method, and a geographical weighted regression model were used to determine the spatial-temporal evolution characteristics of the productional-living-ecological functions and their effects on carbon emissions in Liaoning Province from 2005 to 2020.[Results] ① The spatial distribution pattern of the productional-living-ecological functions in Liaoning Province did not change much from 2005 to 2020. Most of the areas were dominated by productional and ecological functions, the living function areas expanded significantly, and the spatial differences mainly occurred between the central urban area 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 differences became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities. ③ The overall correlations between the productional-living-ecological functions and carbon emissions were strong. The spatial differences were obvious and the influencing 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 clearly define the main functions of the land and promote regional cooperation on the basis of their own advantages and resource endowments so as to realize carbon emission reductions over the entire region.
2024,44(1):432-442
, DOI: 10.13961/j.cnki.stbctb.20240019.001
Abstract:
[Objective] Changes in land use and carbon storage in Maowei Sea of Guangxi Zhuang Autonomous Region were analyzed in order to provide a scientific basis for increasing its carbon sink capacity and improving its ecological value.[Methods] The supervised classification method was used to interpret and extract remote sensing image data for Maowei Sea in 2009, 2015, and 2021. ArcGIS and the InVEST model were used to analyze spatiotemporal changes in land use and carbon storage in Maowei Sea.[Results] ① The land use types in Maowei Sea mainly showed the distribution characteristics of "large settlement, small mixed residence". The areas of cultivated land, shallow sea waters, and fishery breeding areas decreased, and the areas of mangrove wetlands, building land, forest grassland, and silty tidal flats increased from 2009 to 2021. ② Carbon storage initially decreased and then increased over time. Changes in net carbon sequestration and its net present value in Maowei Sea were, respectively, -1.10×105 tons and -1.37×108 yuan, 3.77×104 tons and 4.66×107 yuan, and -7.29×104 tons and -9.01×107 yuan in 2009-2015, 2015-2021 and 2009-2021. ③ The conversion from high carbon sequestration land use types (fishery breeding areas and forest and grasslands) to low carbon sequestration land use types (building land) in Maowei Sea in 2009-2021 caused the largest carbon storage loss, reaching 2.85×105 t. The conversion to fishery breeding areas increased carbon storage by 1.81×105 t.[Conclusion] Accelerating the conversion and upgrading of farming methods, increasing the proliferation of mangrove forests in terrestrial and aquatic forested areas, and accelerating the construction of forest cities will promote carbon sequestration and sustainable development in Maowei Sea.
[Objective] Changes in land use and carbon storage in Maowei Sea of Guangxi Zhuang Autonomous Region were analyzed in order to provide a scientific basis for increasing its carbon sink capacity and improving its ecological value.[Methods] The supervised classification method was used to interpret and extract remote sensing image data for Maowei Sea in 2009, 2015, and 2021. ArcGIS and the InVEST model were used to analyze spatiotemporal changes in land use and carbon storage in Maowei Sea.[Results] ① The land use types in Maowei Sea mainly showed the distribution characteristics of "large settlement, small mixed residence". The areas of cultivated land, shallow sea waters, and fishery breeding areas decreased, and the areas of mangrove wetlands, building land, forest grassland, and silty tidal flats increased from 2009 to 2021. ② Carbon storage initially decreased and then increased over time. Changes in net carbon sequestration and its net present value in Maowei Sea were, respectively, -1.10×105 tons and -1.37×108 yuan, 3.77×104 tons and 4.66×107 yuan, and -7.29×104 tons and -9.01×107 yuan in 2009-2015, 2015-2021 and 2009-2021. ③ The conversion from high carbon sequestration land use types (fishery breeding areas and forest and grasslands) to low carbon sequestration land use types (building land) in Maowei Sea in 2009-2021 caused the largest carbon storage loss, reaching 2.85×105 t. The conversion to fishery breeding areas increased carbon storage by 1.81×105 t.[Conclusion] Accelerating the conversion and upgrading of farming methods, increasing the proliferation of mangrove forests in terrestrial and aquatic forested areas, and accelerating the construction of forest cities will promote carbon sequestration and sustainable development in Maowei Sea.
2024,44(1):443-452
, DOI: 10.13961/j.cnki.stbctb.2024.01.043
Abstract:
[Objective] The impacts of land use/cover changes on carbon storage and ecosystem vulnerability in regional ecosystems were determined in order to provide a reference for regional green low-carbon and sustainable development of ecosystems.[Methods] The ecosystem carbon storage and its spatial distribution pattern were quantitatively analyzed by using land use/cover data for the core economic zone of the Central Guizhou urban agglomeration in 2000, 2010, and 2020 with the InVEST model and a land use transfer matrix. A potential impact index (PI) was used to assess the vulnerability of regional ecosystem services.[Results] ① Land use/cover changes in the core economic zone of the Central Guizhou urban agglomeration showed that cultivated land and forest land continued to decline from 2000 to 2020, and construction land continued to increase. Land use/cover changes in the study area were mainly manifested as the transfer of cultivated land, forest land, and grassland to other land use types, among which 3 339.35 and 3 669.15 km2 of land were transferred from 2000 to 2010 and 2010 to 2020, respectively. The conversion of forest land to grassland was the main transfer type during the first period, and the conversion of arable land to construction land was the main transfer type in the second period. ② Regional carbon storage decreased from 2000 to 2020 (from 4.42×107 to 4.33×107 t), with a cumulative decrease of 9.40×105 t. The conversion of forest land to grassland was the main reason for the reduction in carbon storage. The carbon storage density in each year was higher in the west and east, and lower in the middle portion of the study area. There was no significant change in the high density area during the past 20 years, while the low density area spreading from the central area to the periphery. ③ The core economic zone of the Central Guizhou urban agglomeration was the main source of carbon from 2000 to 2020, with the land use degree index increasing by 2.83, and PI index being -0.04 and -0.31, respectively, showing negative potential impact and increasing vulnerability.[Conclusion] Increasing forest land, controlling forest land conversion to other uses, and expanding construction land are important means for promoting regional green, low-carbon, stable, and sustainable development of ecosystems.
[Objective] The impacts of land use/cover changes on carbon storage and ecosystem vulnerability in regional ecosystems were determined in order to provide a reference for regional green low-carbon and sustainable development of ecosystems.[Methods] The ecosystem carbon storage and its spatial distribution pattern were quantitatively analyzed by using land use/cover data for the core economic zone of the Central Guizhou urban agglomeration in 2000, 2010, and 2020 with the InVEST model and a land use transfer matrix. A potential impact index (PI) was used to assess the vulnerability of regional ecosystem services.[Results] ① Land use/cover changes in the core economic zone of the Central Guizhou urban agglomeration showed that cultivated land and forest land continued to decline from 2000 to 2020, and construction land continued to increase. Land use/cover changes in the study area were mainly manifested as the transfer of cultivated land, forest land, and grassland to other land use types, among which 3 339.35 and 3 669.15 km2 of land were transferred from 2000 to 2010 and 2010 to 2020, respectively. The conversion of forest land to grassland was the main transfer type during the first period, and the conversion of arable land to construction land was the main transfer type in the second period. ② Regional carbon storage decreased from 2000 to 2020 (from 4.42×107 to 4.33×107 t), with a cumulative decrease of 9.40×105 t. The conversion of forest land to grassland was the main reason for the reduction in carbon storage. The carbon storage density in each year was higher in the west and east, and lower in the middle portion of the study area. There was no significant change in the high density area during the past 20 years, while the low density area spreading from the central area to the periphery. ③ The core economic zone of the Central Guizhou urban agglomeration was the main source of carbon from 2000 to 2020, with the land use degree index increasing by 2.83, and PI index being -0.04 and -0.31, respectively, showing negative potential impact and increasing vulnerability.[Conclusion] Increasing forest land, controlling forest land conversion to other uses, and expanding construction land are important means for promoting regional green, low-carbon, stable, and sustainable development of ecosystems.
2024,44(1):453-464
, DOI: 10.13961/j.cnki.stbctb.20231024.001
Abstract:
[Objective] The changes in blue-green space land use were predicted and their impacts on carbon storage in Daxing'an Mountains were analyzed in order provide scientific strategic for realizing the "dual-carbon" goal guidance references.[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. ③ The 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 to protect the blue-green space and to improve the structural integrity of forest land and grassland so as to achieve the "dual-carbon" strategic goal in the Daxing'an Mountaions.
[Objective] The changes in blue-green space land use were predicted and their impacts on carbon storage in Daxing'an Mountains were analyzed in order provide scientific strategic for realizing the "dual-carbon" goal guidance references.[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. ③ The 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 to protect the blue-green space and to improve the structural integrity of forest land and grassland so as to achieve the "dual-carbon" strategic goal in the Daxing'an Mountaions.
2024,44(1):465-476
, DOI: 10.13961/j.cnki.stbctb.20240019.004
Abstract:
[Objective] The influence of land use change patterns on the spatial distribution of carbon sinks for the Inner Mongolia section of the Yellow River basin was investigated, and the main driving factors behind the spatial distribution of carbon sinks were identified in order to provide a basis for directing ecological spatial development and for developing sink enhancement policies in the study area.[Methods] The study was conducted for the Inner Mongolia section of the Yellow River basin. InVEST-FLUS model was used to analyze changes in the carbon sink capacity during each period of the study based on land use data from 2000, 2010, and 2020. The patterns of carbon stock changes were simulated in 2040 under three different scenarios (natural development, ecological conservation and agricultural priority), and identified the main driving factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes.[Results] ① From 2000 to 2020, carbon storage for the Mongolia section of the Yellow River basin initially increased and then decreased, with an overall increase of 8.63×106 t. Subsurface biological carbon storage increased by 3.91×106 t and soil carbon storage increased by 2.28×106 t. ② Carbon storage continued to decrease by 3.92×106 t for the future natural development scenario, but increased by 2.21×107 t for the ecological protection scenario, which was higher than for the agricultural priority scenario (4.99×106 t). Soil carbon storage was the key factor causing the incremental difference. ③ The unbalanced distributions of mean annual rainfall and mean annual temperature were the main factors causing differences in the various carbon pools for the Mongolia 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. Future attention should be given to preventing and controlling desertification, and to promoting forest and grassland construction so as to improve the regional ecological security pattern and carbon sink enhancement policies.
[Objective] The influence of land use change patterns on the spatial distribution of carbon sinks for the Inner Mongolia section of the Yellow River basin was investigated, and the main driving factors behind the spatial distribution of carbon sinks were identified in order to provide a basis for directing ecological spatial development and for developing sink enhancement policies in the study area.[Methods] The study was conducted for the Inner Mongolia section of the Yellow River basin. InVEST-FLUS model was used to analyze changes in the carbon sink capacity during each period of the study based on land use data from 2000, 2010, and 2020. The patterns of carbon stock changes were simulated in 2040 under three different scenarios (natural development, ecological conservation and agricultural priority), and identified the main driving factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes.[Results] ① From 2000 to 2020, carbon storage for the Mongolia section of the Yellow River basin initially increased and then decreased, with an overall increase of 8.63×106 t. Subsurface biological carbon storage increased by 3.91×106 t and soil carbon storage increased by 2.28×106 t. ② Carbon storage continued to decrease by 3.92×106 t for the future natural development scenario, but increased by 2.21×107 t for the ecological protection scenario, which was higher than for the agricultural priority scenario (4.99×106 t). Soil carbon storage was the key factor causing the incremental difference. ③ The unbalanced distributions of mean annual rainfall and mean annual temperature were the main factors causing differences in the various carbon pools for the Mongolia 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. Future attention should be given to preventing and controlling desertification, and to promoting forest and grassland construction so as to improve the regional ecological security pattern and carbon sink enhancement policies.
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Abstract:
[Objective] Slight rainfall and dew are important water resources shouldn’t ignore in the arid regions, the utilization of which is still a difficult issue in the world. [Methods] The experimentation inclouded four treatments: ordinary polyethylene film mulch (T1), high-density polyethylene film mulch (T2), polytetrafluoroethylene film mulch (T3), and bare soil (T4), to optimize the slope of catchment surface, and to study the effects of slight rainfall and dew on soil moisture under different treatment conditions. [Results] The results showed that: (1) during the study period, the total amount of multi-year single rainfall of less than 5 mm accounted for 29.8% of the annual rainfall, and the single rainfall of less than 5 mm in April-July, the critical fertility period of the crop, accounted for 33.2% of the rainfall in this stage; the annual average dew amount was 31.68 mm, accounting for 13.2% of the multi-year average rainfall, and the amount of dew in April-July, the critical fertility period of the crop, was 11.89 mm, accounting for 10.5%; (2) the soil water content of each treatment at 5cm, 15cm depth with same order as T3>T1>T2>T4; (3) the depth of influence on the soil moisture was 15cm when the rainfall were 5mm, 4mm, 3mm and 2mm, and the soil water content of T2 treatment was largest, the change range of soil moisture was above 5cm when rainfall equal to 1mm, and the variation of soil moisture of T2 treatment was significantly. (4) The effect of dew on soil moisture is mainly above 5cm, and when the dew amount was 0.8mm, the increase amount of soil water of T1, T2, T3 and T4 was 0.6%, 1.6%, 4%, 0.2%, respectively. [Conclusion] It can be seen that T3 treatment can effectively collect the slight rainfall and dew to improve the soil moisture, and as a reference option for rainfall and dew utilization in the central arid zone of Ningxia.
[Objective] Slight rainfall and dew are important water resources shouldn’t ignore in the arid regions, the utilization of which is still a difficult issue in the world. [Methods] The experimentation inclouded four treatments: ordinary polyethylene film mulch (T1), high-density polyethylene film mulch (T2), polytetrafluoroethylene film mulch (T3), and bare soil (T4), to optimize the slope of catchment surface, and to study the effects of slight rainfall and dew on soil moisture under different treatment conditions. [Results] The results showed that: (1) during the study period, the total amount of multi-year single rainfall of less than 5 mm accounted for 29.8% of the annual rainfall, and the single rainfall of less than 5 mm in April-July, the critical fertility period of the crop, accounted for 33.2% of the rainfall in this stage; the annual average dew amount was 31.68 mm, accounting for 13.2% of the multi-year average rainfall, and the amount of dew in April-July, the critical fertility period of the crop, was 11.89 mm, accounting for 10.5%; (2) the soil water content of each treatment at 5cm, 15cm depth with same order as T3>T1>T2>T4; (3) the depth of influence on the soil moisture was 15cm when the rainfall were 5mm, 4mm, 3mm and 2mm, and the soil water content of T2 treatment was largest, the change range of soil moisture was above 5cm when rainfall equal to 1mm, and the variation of soil moisture of T2 treatment was significantly. (4) The effect of dew on soil moisture is mainly above 5cm, and when the dew amount was 0.8mm, the increase amount of soil water of T1, T2, T3 and T4 was 0.6%, 1.6%, 4%, 0.2%, respectively. [Conclusion] It can be seen that T3 treatment can effectively collect the slight rainfall and dew to improve the soil moisture, and as a reference option for rainfall and dew utilization in the central arid zone of Ningxia.
Abstract:
[Objective] It is essential to examine the nutrient content and ecological stoichiometric characteristics of plants across various altitudinal gradients in fragile forest ecosystems within arid regions in order to understand nutrient management in these ecosystems. [Methods] This study focused on the dominant plant species at five distinct altitudinal levels, namely, 1730, 1799, 2025, 2487, and 2544 m, within the Helan Mountains National Nature Reserve. The variations and correlations of carbon (C), nitrogen (N), and phosphorus (P) contents, and stoichiometric features in leaves, fine roots, and soil along these gradients were analyzed. [Results] The results of the study follow: (1) Soil organic carbon (SOC) displayed a unimodal pattern with altitude, peaking at 2487 m (42.92 g·kg-1). High-altitude soil total nitrogen (TN) levels, namely, 2025, 2487, and 2544 m, were significantly greater than those at the middle and low altitudes, namely 1730 and 1799 m, respectively, while total phosphorus (TP) remained relatively stable. The ratios of C:P and N:P initially increased prior to decreasing with altitude. (2) There was no significant change in leaf and fine root C across altitudes, but P content increased with altitude. Fine root N content progressively declined with altitude, while leaf N exhibited a fluctuating trend. At high altitudes, the N:P ratio in plant leaves and fine roots was less than 14, but at low altitudes, the ratio exceeded 16. (3) Nutrient concentrations in plant leaves were significantly higher than those in fine roots. (4) Correlation analyses revealed that leaf C was positively correlated with soil SOC, TN, C:P, and N:P. In contrast, leaf N and fine root N significantly decreased as soil SOC, TN, C:P, and N:P increased, and the relationship between leaf and fine root P and soil TP was insignificant. [Conclusion] Plant growth at high altitudes is mainly limited by N, but at low altitudes, it is limited by P. Leaves of dominant plant species at different altitudes exhibit higher nutrient content compared to fine roots, and variations in soil nutrient supply due to altitude influence the N, P, and stoichiometric characteristics of plants in the Helan Mountains.
[Objective] It is essential to examine the nutrient content and ecological stoichiometric characteristics of plants across various altitudinal gradients in fragile forest ecosystems within arid regions in order to understand nutrient management in these ecosystems. [Methods] This study focused on the dominant plant species at five distinct altitudinal levels, namely, 1730, 1799, 2025, 2487, and 2544 m, within the Helan Mountains National Nature Reserve. The variations and correlations of carbon (C), nitrogen (N), and phosphorus (P) contents, and stoichiometric features in leaves, fine roots, and soil along these gradients were analyzed. [Results] The results of the study follow: (1) Soil organic carbon (SOC) displayed a unimodal pattern with altitude, peaking at 2487 m (42.92 g·kg-1). High-altitude soil total nitrogen (TN) levels, namely, 2025, 2487, and 2544 m, were significantly greater than those at the middle and low altitudes, namely 1730 and 1799 m, respectively, while total phosphorus (TP) remained relatively stable. The ratios of C:P and N:P initially increased prior to decreasing with altitude. (2) There was no significant change in leaf and fine root C across altitudes, but P content increased with altitude. Fine root N content progressively declined with altitude, while leaf N exhibited a fluctuating trend. At high altitudes, the N:P ratio in plant leaves and fine roots was less than 14, but at low altitudes, the ratio exceeded 16. (3) Nutrient concentrations in plant leaves were significantly higher than those in fine roots. (4) Correlation analyses revealed that leaf C was positively correlated with soil SOC, TN, C:P, and N:P. In contrast, leaf N and fine root N significantly decreased as soil SOC, TN, C:P, and N:P increased, and the relationship between leaf and fine root P and soil TP was insignificant. [Conclusion] Plant growth at high altitudes is mainly limited by N, but at low altitudes, it is limited by P. Leaves of dominant plant species at different altitudes exhibit higher nutrient content compared to fine roots, and variations in soil nutrient supply due to altitude influence the N, P, and stoichiometric characteristics of plants in the Helan Mountains.
Abstract:
[Objective] Assess the welfare effects of farmers’ participation in soil conservation is of great significance to the sustainable development of regional soil conservation. [Methods] A welfare evaluation index system was constructed based on the capability theory. Selecting the counties involved in soil conservation projects within the Three Gorges Reservoir area as examples, the present study explores the welfare effects of farmers’ participation in soil conservation in the study area using methods including propensity score matching, fuzzy comprehensive evaluation, and quantile regression. [Results] 1) After participating in soil conservation, the welfare index of farming and living environment were 0.523 and 0.614 respectively. The level of residents’ happiness index of farmers was high, and the subjective well-being indexes, for example, income satisfaction, are above 0.5. 2) A marked difference in welfare outcomes between farmers who participated in soil conservation and those who did not participate was identified, the total fuzzy welfare index of participating farmers is greater than that of non-participating farmers. 3) Soil conservation projects comprehensively improve the welfare level of farmers from the aspects of economic, social and ecological, with the welfare effect of 2.75% ~ 2.80%. 4) The higher the degree of farmers’ participation in soil conservation, the better the overall welfare level of the farmers’ families. The total welfare generated by farmers’ spontaneous soil conservation behaviors is greater than that generated by government-guided soil conservations, and the government-guided welfare is more significant in terms of crop yield, and farming environments. Cultivated land area is the main factor affecting the farmers’ participation in soil conservation welfare. [Conclusion] It is concluded that, the promotion and training of soil conservation technology should be strengthened, and regional characteristics should be considered when implementing soil conservation measures, so as to improve farmers’ participation in soil conservation and ensure that more farmers benefit from soil conservation.
[Objective] Assess the welfare effects of farmers’ participation in soil conservation is of great significance to the sustainable development of regional soil conservation. [Methods] A welfare evaluation index system was constructed based on the capability theory. Selecting the counties involved in soil conservation projects within the Three Gorges Reservoir area as examples, the present study explores the welfare effects of farmers’ participation in soil conservation in the study area using methods including propensity score matching, fuzzy comprehensive evaluation, and quantile regression. [Results] 1) After participating in soil conservation, the welfare index of farming and living environment were 0.523 and 0.614 respectively. The level of residents’ happiness index of farmers was high, and the subjective well-being indexes, for example, income satisfaction, are above 0.5. 2) A marked difference in welfare outcomes between farmers who participated in soil conservation and those who did not participate was identified, the total fuzzy welfare index of participating farmers is greater than that of non-participating farmers. 3) Soil conservation projects comprehensively improve the welfare level of farmers from the aspects of economic, social and ecological, with the welfare effect of 2.75% ~ 2.80%. 4) The higher the degree of farmers’ participation in soil conservation, the better the overall welfare level of the farmers’ families. The total welfare generated by farmers’ spontaneous soil conservation behaviors is greater than that generated by government-guided soil conservations, and the government-guided welfare is more significant in terms of crop yield, and farming environments. Cultivated land area is the main factor affecting the farmers’ participation in soil conservation welfare. [Conclusion] It is concluded that, the promotion and training of soil conservation technology should be strengthened, and regional characteristics should be considered when implementing soil conservation measures, so as to improve farmers’ participation in soil conservation and ensure that more farmers benefit from soil conservation.
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] To analyze the changes in land cover and carbon stock of the Hangzhou Chengxi Sci-tech Innovation Corridor through high-resolution remote sensing images, the development trend of carbon stock is predicted under the constraints of the "three zones and three lines" achievements, which would provide scientific basis for the optimization of national land space and ecological development of the new urban center. [Methods] Based on four periods of land cover data from 2010, 2015, 2020, and 2023, the GeoSoS-FLUS model was used to simulate the changes in land cover under five different scenarios, i.e., the natural development, the extreme construction and development scenario, the extreme agricultural production, the ecological function services, and the urban-rural integration development in 2035. The model was used as the framework to calculate the changes in carbon stock under the simulated scenarios from 2010 to 2023 and from 2023 to 2035, respectively. [Results] ①Chengxi Sci-tech Innovation Corridor showed an increasing trend in carbon stock from 2010 to 2023, with a total change of 1,077.24 tC, where the carbon stock of vegetation, soil, and water were increased to approximately 913.67 tC, 566.18 tC, and 240.84 tC; ②The internal type transformation of cultivated land resulted in a decrease of 119.33 tC in soil carbon stock, while the internal type transformation of forest land accounted for 39.50% of the total change in carbon stock; ③In the natural growth scenario and ecological function service scenario, forest land growth was relatively significant, while in the extreme construction and development scenario and extreme agricultural production scenario, the land cover types are more stable. In the urban-rural integration development scenario, through reasonable replacement between cultivated land, forest land, grassland and other land cover types, other land cover types have obtained greater development space; ④In 2023-2035, under the natural growth scenario, carbon stock will rise by 898.74 tC. Under the extreme construction and development scenario, it will increase by 538.58 tC. Under the extreme agricultural production scenario, it will increase by 517.45 tC. Under the ecological service scenario, it will increase by 813.09 tC. Under the urban-rural integration development scenario, it will increase by 356.91 tC. [Conclusion] Development under the constraint of control lines could effectively guarantee the carbon sequestration capacity of cities. Reasonable transformation of land cover types and internal structural adjustments can provide more space for the development of new urban centers.
[Objective] To analyze the changes in land cover and carbon stock of the Hangzhou Chengxi Sci-tech Innovation Corridor through high-resolution remote sensing images, the development trend of carbon stock is predicted under the constraints of the "three zones and three lines" achievements, which would provide scientific basis for the optimization of national land space and ecological development of the new urban center. [Methods] Based on four periods of land cover data from 2010, 2015, 2020, and 2023, the GeoSoS-FLUS model was used to simulate the changes in land cover under five different scenarios, i.e., the natural development, the extreme construction and development scenario, the extreme agricultural production, the ecological function services, and the urban-rural integration development in 2035. The model was used as the framework to calculate the changes in carbon stock under the simulated scenarios from 2010 to 2023 and from 2023 to 2035, respectively. [Results] ①Chengxi Sci-tech Innovation Corridor showed an increasing trend in carbon stock from 2010 to 2023, with a total change of 1,077.24 tC, where the carbon stock of vegetation, soil, and water were increased to approximately 913.67 tC, 566.18 tC, and 240.84 tC; ②The internal type transformation of cultivated land resulted in a decrease of 119.33 tC in soil carbon stock, while the internal type transformation of forest land accounted for 39.50% of the total change in carbon stock; ③In the natural growth scenario and ecological function service scenario, forest land growth was relatively significant, while in the extreme construction and development scenario and extreme agricultural production scenario, the land cover types are more stable. In the urban-rural integration development scenario, through reasonable replacement between cultivated land, forest land, grassland and other land cover types, other land cover types have obtained greater development space; ④In 2023-2035, under the natural growth scenario, carbon stock will rise by 898.74 tC. Under the extreme construction and development scenario, it will increase by 538.58 tC. Under the extreme agricultural production scenario, it will increase by 517.45 tC. Under the ecological service scenario, it will increase by 813.09 tC. Under the urban-rural integration development scenario, it will increase by 356.91 tC. [Conclusion] Development under the constraint of control lines could effectively guarantee the carbon sequestration capacity of cities. Reasonable transformation of land cover types and internal structural adjustments can provide more space for the development of new urban centers.
Abstract:
[Objective] This article selects purple soil improved by collapse deposits as the research object, explores the application prospects of using collapse deposits as a new type of soil improvement material, analyzes the nutrient changes in the soil after improvement by collapse deposits, and uses weighted grey correlation analysis to evaluate the quality of the improved soil. The aim is to turn unused collapse deposits into treasures and provide new ideas for local collapse deposit utilization and purple soil improvement work. [Result] Under the same fertility irrigation level, compared to the blank control group (Y0), adding collapse deposits can significantly improve the nutrient content of shallow soil (0-20cm). The average content of total nitrogen in this layer of soil increased by 3.26-10.60%, the average content of total phosphorus increased by 10.61-43.33%, the average content of organic matter increased by 9.14-24.12%, the average content of alkali hydrolyzed nitrogen increased by 5.76-12.73%, the average content of available phosphorus increased by 24.75-46.22%, the average content of available potassium increased by 16.21-28.96%, and the EC value increased by 11.32% -27.41%. Different treatment schemes had no significant effect on soil pH value; Through the AHP grey correlation analysis evaluation model, the soil quality of each treatment group was preliminarily evaluated. It was found that within the shallow soil range of 0-20 cm, the grey correlation degree of each treatment group was ranked as Y2>Y3>Y4>Y1>Y0>Y5; Within the deep soil range of 20-40cm, the grey correlation degree of each treatment group is ranked as Y5>Y4>Y3>Y2>Y1>Y0. Based on the above analysis results, it is indicated that the appropriate proportion of composite treatment between landslide deposits and soil can have a certain improvement effect on the nutrient content of purple soil.
[Objective] This article selects purple soil improved by collapse deposits as the research object, explores the application prospects of using collapse deposits as a new type of soil improvement material, analyzes the nutrient changes in the soil after improvement by collapse deposits, and uses weighted grey correlation analysis to evaluate the quality of the improved soil. The aim is to turn unused collapse deposits into treasures and provide new ideas for local collapse deposit utilization and purple soil improvement work. [Result] Under the same fertility irrigation level, compared to the blank control group (Y0), adding collapse deposits can significantly improve the nutrient content of shallow soil (0-20cm). The average content of total nitrogen in this layer of soil increased by 3.26-10.60%, the average content of total phosphorus increased by 10.61-43.33%, the average content of organic matter increased by 9.14-24.12%, the average content of alkali hydrolyzed nitrogen increased by 5.76-12.73%, the average content of available phosphorus increased by 24.75-46.22%, the average content of available potassium increased by 16.21-28.96%, and the EC value increased by 11.32% -27.41%. Different treatment schemes had no significant effect on soil pH value; Through the AHP grey correlation analysis evaluation model, the soil quality of each treatment group was preliminarily evaluated. It was found that within the shallow soil range of 0-20 cm, the grey correlation degree of each treatment group was ranked as Y2>Y3>Y4>Y1>Y0>Y5; Within the deep soil range of 20-40cm, the grey correlation degree of each treatment group is ranked as Y5>Y4>Y3>Y2>Y1>Y0. Based on the above analysis results, it is indicated that the appropriate proportion of composite treatment between landslide deposits and soil can have a certain improvement effect on the nutrient content of purple soil.
Abstract:
Abstract: [Objective] The construction of photovoltaic (PV) arrays in desert areas interferes with surface erosion and accretion processes, to better understand the structural characteristics of the near-surface airflow field and wind-sand flow under the disturbance of PV arrays. [Methods] In this study, the vertical distribution of wind speed, wind velocity flow field and wind-sand flow structure of PV arrays (front edge of electric panels, back edge of electric panels and midline between arrays) and control points were observed in the field by using the gradient wind speed observation equipment, and the airflow field and sand transport characteristics of different locations inside and outside the power plant were compared and analyzed. [Results] (1) The overall wind speed inside the power station shows a decreasing characteristic, the average wind speed between the arrays and along the back edge of the electric panel increases with height, and the average wind speed along the front edge of the electric panel shows a decreasing and then increasing trend with height. (2) 1. Grass square observation section, the wind speed at the wind outlet in front of the electric panel increases significantly, and the wind speed along the wind inlet behind the electric panel and below 100 cm of the center line between arrays decreases; 2. Wind erosion pit observation section, the wind speed of PV panels below 150 cm decreases, and wind speed pulsation between arrays varies significantly; 3. Gravel observation section, the relative rate of change of the wind speed and the pattern of the wind flow field are stable, and the wind speed along the back edge of the electric panel above 150 cm increases. The wind speed increases in the section above 150 cm behind the electric plate. Average wind protection effect: gravel > grass square. (3) Sand transport is shown as follows: front edge of the electric plate>back edge of the electric plate>midline between the arrays; the reference point of the flowing dune (upwind) is saturated with λ (the characteristic value of the wind-sand flow structure) at the front edge of the electric plate, and unsaturated at the back edge of the electric plate and λ between the arrays. [Conclusion] Compared with the flowing dune, the photovoltaic array perturbed the wind velocity flow field pattern, the wind velocity pulsation and turbulence degree changed, the sand transport decreased significantly, and the sand fixation benefit was obvious.
Abstract: [Objective] The construction of photovoltaic (PV) arrays in desert areas interferes with surface erosion and accretion processes, to better understand the structural characteristics of the near-surface airflow field and wind-sand flow under the disturbance of PV arrays. [Methods] In this study, the vertical distribution of wind speed, wind velocity flow field and wind-sand flow structure of PV arrays (front edge of electric panels, back edge of electric panels and midline between arrays) and control points were observed in the field by using the gradient wind speed observation equipment, and the airflow field and sand transport characteristics of different locations inside and outside the power plant were compared and analyzed. [Results] (1) The overall wind speed inside the power station shows a decreasing characteristic, the average wind speed between the arrays and along the back edge of the electric panel increases with height, and the average wind speed along the front edge of the electric panel shows a decreasing and then increasing trend with height. (2) 1. Grass square observation section, the wind speed at the wind outlet in front of the electric panel increases significantly, and the wind speed along the wind inlet behind the electric panel and below 100 cm of the center line between arrays decreases; 2. Wind erosion pit observation section, the wind speed of PV panels below 150 cm decreases, and wind speed pulsation between arrays varies significantly; 3. Gravel observation section, the relative rate of change of the wind speed and the pattern of the wind flow field are stable, and the wind speed along the back edge of the electric panel above 150 cm increases. The wind speed increases in the section above 150 cm behind the electric plate. Average wind protection effect: gravel > grass square. (3) Sand transport is shown as follows: front edge of the electric plate>back edge of the electric plate>midline between the arrays; the reference point of the flowing dune (upwind) is saturated with λ (the characteristic value of the wind-sand flow structure) at the front edge of the electric plate, and unsaturated at the back edge of the electric plate and λ between the arrays. [Conclusion] Compared with the flowing dune, the photovoltaic array perturbed the wind velocity flow field pattern, the wind velocity pulsation and turbulence degree changed, the sand transport decreased significantly, and the sand fixation benefit was obvious.
Abstract:
[Objective] This study explored the carbon storage effect resulting from the transformation of the production-living-ecological space in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area，and also analyzed the driving factors involved in this process to provide scientific reference for the high-quality development of the Xiamen-Zhangzhou-Quanzhou Metropolitan Area under new circumstances. [Methods] Spatial analysis，InVEST，and GeoDetector were comprehensively utilized to reveal the transformation characteristics of production-living-ecological space，carbon storage effect，and the main influencing factors in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area. [Results] ① From 2000 to 2020，the living space in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area continued to expand，while the production space and ecological space continued to shrink. The transformation of the production-living-ecological space was primarily manifested in the shift from agricultural production space，woodland ecological space，and grassland ecological space to industrial production space and urban living space. ② Over the past 20 years，carbon storage in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area decreased by 1.57×107 t. The shift of forest ecological space to industrial production space (34.75%) and grassland ecological space (16.73%)，as well as the shift of agricultural production space to industrial production space (12.92%) and urban living space (7.63%)，were significant reasons for the decrease in carbon storage. The spatial distribution of carbon storage exhibited a decreasing trend from the hilly mountains in the west to the coastal plains in the east. ③ The natural environment and social economy emerged as the primary factors influencing regional carbon storage，with location conditions exerting minimal influence. Notably，the gross output value of the secondary and tertiary industries，along with slope consistently played significant roles in carbon storage in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area. Moreover，the interaction among all factors significantly amplified their impact on carbon storage. [Conclusion] Future efforts should prioritize the protection of ecological space and promote the region's role as a leading economic growth pole to achieve the coordinated progress of carbon emission reduction and economic development in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area.
[Objective] This study explored the carbon storage effect resulting from the transformation of the production-living-ecological space in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area，and also analyzed the driving factors involved in this process to provide scientific reference for the high-quality development of the Xiamen-Zhangzhou-Quanzhou Metropolitan Area under new circumstances. [Methods] Spatial analysis，InVEST，and GeoDetector were comprehensively utilized to reveal the transformation characteristics of production-living-ecological space，carbon storage effect，and the main influencing factors in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area. [Results] ① From 2000 to 2020，the living space in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area continued to expand，while the production space and ecological space continued to shrink. The transformation of the production-living-ecological space was primarily manifested in the shift from agricultural production space，woodland ecological space，and grassland ecological space to industrial production space and urban living space. ② Over the past 20 years，carbon storage in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area decreased by 1.57×107 t. The shift of forest ecological space to industrial production space (34.75%) and grassland ecological space (16.73%)，as well as the shift of agricultural production space to industrial production space (12.92%) and urban living space (7.63%)，were significant reasons for the decrease in carbon storage. The spatial distribution of carbon storage exhibited a decreasing trend from the hilly mountains in the west to the coastal plains in the east. ③ The natural environment and social economy emerged as the primary factors influencing regional carbon storage，with location conditions exerting minimal influence. Notably，the gross output value of the secondary and tertiary industries，along with slope consistently played significant roles in carbon storage in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area. Moreover，the interaction among all factors significantly amplified their impact on carbon storage. [Conclusion] Future efforts should prioritize the protection of ecological space and promote the region's role as a leading economic growth pole to achieve the coordinated progress of carbon emission reduction and economic development in the Xiamen-Zhangzhou-Quanzhou Metropolitan Area.
Abstract:
[Objective] Exploring the characteristics and influencing factors of cultivated land changes in the Yellow River alluvial area of southwestern Shandong, providing a basis for regional cultivated land protection. [Methods] Based on 2m high score remote sensing images, combined with “Heze Statistical Yearbook”, remote sensing interpretation, center of gravity model, cold and hot spot analysis, geographical detector and other methods were used to analyze the land change characteristics and influencing factors of the cultivated land in the Yellow River alluvial area of southwest Shandong from 2019 to 2022. [Results] ① In 2019-2022, there was cultivated land loss in the Yellow River alluvial area of southwest Shandong every year, and the lost area showed a decreasing trend year by year, Yuncheng county had the largest reduction in cultivated land, followed by Cao county, Juancheng county, Shan county, and Mudan district, Dongming county had the smallest reduction in cultivated land, and the center of cultivated land migrated to the northeast. ② The outflow area of cultivated land was higher than the inflow area, and the main outflow direction and inflow direction are both construction land and forest land. The area with the most concentrated cultivated land changes was mainly distributed in the south of Cao county. ③ The single factors affecting the change of cultivated land were mainly rural employees (X5), the number of rural labor resources (X4), the gross product of primary industry (X9); the two-factor interactive combination was mainly the intersection of the number of rural labor resources (X4) and the per capita income of urban residents (X6). [Conclusion] The loss of cultivated land in the Yellow River alluvial area of southwest Shandong from 2019 to 2022 was the result of the comprehensive effect of multiple factors based on economic and social factors.
[Objective] Exploring the characteristics and influencing factors of cultivated land changes in the Yellow River alluvial area of southwestern Shandong, providing a basis for regional cultivated land protection. [Methods] Based on 2m high score remote sensing images, combined with “Heze Statistical Yearbook”, remote sensing interpretation, center of gravity model, cold and hot spot analysis, geographical detector and other methods were used to analyze the land change characteristics and influencing factors of the cultivated land in the Yellow River alluvial area of southwest Shandong from 2019 to 2022. [Results] ① In 2019-2022, there was cultivated land loss in the Yellow River alluvial area of southwest Shandong every year, and the lost area showed a decreasing trend year by year, Yuncheng county had the largest reduction in cultivated land, followed by Cao county, Juancheng county, Shan county, and Mudan district, Dongming county had the smallest reduction in cultivated land, and the center of cultivated land migrated to the northeast. ② The outflow area of cultivated land was higher than the inflow area, and the main outflow direction and inflow direction are both construction land and forest land. The area with the most concentrated cultivated land changes was mainly distributed in the south of Cao county. ③ The single factors affecting the change of cultivated land were mainly rural employees (X5), the number of rural labor resources (X4), the gross product of primary industry (X9); the two-factor interactive combination was mainly the intersection of the number of rural labor resources (X4) and the per capita income of urban residents (X6). [Conclusion] The loss of cultivated land in the Yellow River alluvial area of southwest Shandong from 2019 to 2022 was the result of the comprehensive effect of multiple factors based on economic and social factors.
LIU Yabin, PANG Jinghao, LIANG Shen, YU Dongmei, SHI Xingping, LI Guorong, MIAO Xiaoxing, WANG Yanxiu, ZHU Haili, HU Xiasong
Abstract:
[Objective] To clarify the characteristics of runoff and sediment production on the slopes of alpine metal mine dumps with different recovery years, and to provide a scientific foundation for the efficient and rational execution of artificial vegetation restoration, as well as soil and water conservation efforts, on these alpine metal mine dumps. [Methods] In this study, a total of seven dumps of the Delni Copper Mine in Machin County, Guoluo Tibetan Autonomous Prefecture, Qinghai Province, with recovery periods ranging from 2-15 years, were selected as the research objects. The characteristics of runoff, sediment, and runoff hydrodynamics on the slopes of dumps with different recovery periods were obtained via simulated rainfall tests, and their influencing factors were further analyzed. [Results] The process of runoff and sediment yield on the slope of the dump in the study area was relatively complex and random. There were great differences in the variation of runoff and sediment yield per unit area with rainfall duration in different recovery years. There was no significant relationship between the cumulative runoff per unit area of the dump slope and the recovery period. The cumulative sediment per unit area and average volume diameter of eroded sediment decreased with increasing recovery period. There was a significant power function relationship between the average volume diameter of eroded sediment and the recovery period (P < 0.05). The runoff generation time initially decreased with recovery period and then increased, and there was a significant quadratic function relationship between them (P < 0.05). The runoff flow pattern of the dump slope in each year was mainly laminar flow, and all belonged to tranquil flow. The Reynolds number and flow shear stress of runoff showed a significant exponential decrease and a linear decrease with the increase of the recovery period, respectively (P < 0.05). There was no significant relationship between the velocity and Froude number of the runoff and the recovery period. As the recovery period increased, the erosion and sediment carrying capacity of runoff on the slope of the dump decreased accordingly. There were significant positive correlations (P < 0.05) between the slope gradient and the cumulative sediment per unit area, runoff velocity, and Reynolds number on the slope of the dump. [Conclusion] The anti-erosion ability of artificial vegetation restoration of dump slopes in alpine mine showed a positive trend with the increase of recovery years. Due to the influence of alpine climate, the regreening and emergence of vegetation in the dump were delayed, and the effect of soil and water conservation by vegetation in the early rainy season was relatively weak.
[Objective] To clarify the characteristics of runoff and sediment production on the slopes of alpine metal mine dumps with different recovery years, and to provide a scientific foundation for the efficient and rational execution of artificial vegetation restoration, as well as soil and water conservation efforts, on these alpine metal mine dumps. [Methods] In this study, a total of seven dumps of the Delni Copper Mine in Machin County, Guoluo Tibetan Autonomous Prefecture, Qinghai Province, with recovery periods ranging from 2-15 years, were selected as the research objects. The characteristics of runoff, sediment, and runoff hydrodynamics on the slopes of dumps with different recovery periods were obtained via simulated rainfall tests, and their influencing factors were further analyzed. [Results] The process of runoff and sediment yield on the slope of the dump in the study area was relatively complex and random. There were great differences in the variation of runoff and sediment yield per unit area with rainfall duration in different recovery years. There was no significant relationship between the cumulative runoff per unit area of the dump slope and the recovery period. The cumulative sediment per unit area and average volume diameter of eroded sediment decreased with increasing recovery period. There was a significant power function relationship between the average volume diameter of eroded sediment and the recovery period (P < 0.05). The runoff generation time initially decreased with recovery period and then increased, and there was a significant quadratic function relationship between them (P < 0.05). The runoff flow pattern of the dump slope in each year was mainly laminar flow, and all belonged to tranquil flow. The Reynolds number and flow shear stress of runoff showed a significant exponential decrease and a linear decrease with the increase of the recovery period, respectively (P < 0.05). There was no significant relationship between the velocity and Froude number of the runoff and the recovery period. As the recovery period increased, the erosion and sediment carrying capacity of runoff on the slope of the dump decreased accordingly. There were significant positive correlations (P < 0.05) between the slope gradient and the cumulative sediment per unit area, runoff velocity, and Reynolds number on the slope of the dump. [Conclusion] The anti-erosion ability of artificial vegetation restoration of dump slopes in alpine mine showed a positive trend with the increase of recovery years. Due to the influence of alpine climate, the regreening and emergence of vegetation in the dump were delayed, and the effect of soil and water conservation by vegetation in the early rainy season was relatively weak.
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] 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.
SHI Xiaopeng, GOU Heran, LIU Baiting, RAN Lanfang, YANG Qilin, ZHA Xilamu, CHEN Yuxin, LUO Ziteng, HE Shuqin
Abstract:
[Objective] This paper aims to study the anti-erosion and anti-scouring characteristics and influencing factors of road green spaces and campus green spaces in Wenjiang District, Chengdu City, which could provide functional guidance for urban green space soil and water conservation and ecologically sustainable development. [Methods] Characterisation of soil anti-erosion and anti-scouring of arbor + grass, arbor + bush, bush, bush + grass, and grass in road and campus green spaces were obtained by the method of field sampling and laboratory test. [Results] The >5 mm soil water-stable aggregates content showed maximum in both road (79.72%) and campus green space (39.23%).Soil total porosity, soil water content and silt content showed that campus green space > road green space (P<0.05). MWD, GMD, soil anti-erosion, water stability aggregates index and anti-scouring all showed that road green space>campus green space (P<0.05), in which the anti-erosion and anti-scouring of arbor + bush and bush + grass structure was better than other vegetation structures, and the soil anti-scouring coefficient decreased with the increase of slope.The soil anti-erosion and anti-scouring were positively correlated with >5 mm soil water-stable aggregates, Organic matter content and soil clay particles, and negatively correlated with PAD, ELT, <0.25 mm and 0.25~2 mm water-stable aggregates (P<0.01).[Conclusion] Arbor + bush and bush + grasse have the best soil anti-erosion and anti-scouring in road greens, and campus greens can reduce the risk of soil erosion by adjusting the vegetation structure to enhance resilience and ornamental properties.
[Objective] This paper aims to study the anti-erosion and anti-scouring characteristics and influencing factors of road green spaces and campus green spaces in Wenjiang District, Chengdu City, which could provide functional guidance for urban green space soil and water conservation and ecologically sustainable development. [Methods] Characterisation of soil anti-erosion and anti-scouring of arbor + grass, arbor + bush, bush, bush + grass, and grass in road and campus green spaces were obtained by the method of field sampling and laboratory test. [Results] The >5 mm soil water-stable aggregates content showed maximum in both road (79.72%) and campus green space (39.23%).Soil total porosity, soil water content and silt content showed that campus green space > road green space (P<0.05). MWD, GMD, soil anti-erosion, water stability aggregates index and anti-scouring all showed that road green space>campus green space (P<0.05), in which the anti-erosion and anti-scouring of arbor + bush and bush + grass structure was better than other vegetation structures, and the soil anti-scouring coefficient decreased with the increase of slope.The soil anti-erosion and anti-scouring were positively correlated with >5 mm soil water-stable aggregates, Organic matter content and soil clay particles, and negatively correlated with PAD, ELT, <0.25 mm and 0.25~2 mm water-stable aggregates (P<0.01).[Conclusion] Arbor + bush and bush + grasse have the best soil anti-erosion and anti-scouring in road greens, and campus greens can reduce the risk of soil erosion by adjusting the vegetation structure to enhance resilience and ornamental properties.
Abstract:
[Objective] Land survey is the foundation of effective management of land resources, but the current national land survey has the problem of asymmetry of capital input, that is, the mismatch of input-output ratio, so it is necessary to identify the key and non-key areas of the land survey in order to realize the economic efficiency of the future land survey and to avoid unnecessary waste of resources. [Methods] Based on the land use data of Guizhou Province from 2000 to 2020, the spatial and temporal distribution characteristics of the land use change frequency in Guizhou Province were analyzed by using land use change frequency statistics, kernel density analysis and spatial autocorrelation, and the influencing factors were studied with the help of geographic probes.[Results] (1) The area of land changed in the 2000-2020 land use change frequency in Guizhou Province is only 2%, but the inputs of capital and manpower are relatively high, so the relationship between the two inputs and discordance. (2) The land that has changed in the 2000-2020 land use change frequency in Guizhou Province has significant spatial heterogeneity in spatial distribution. (3) The kernel density of changed land in Guizhou Province from 2000 to 2020 shows the distribution characteristic of "high in the west and low in the east", with the distribution density of one land change being the largest, and the distribution density of three land changes being the smallest. (4) In 2000-2020, both changed and unchanged land in Guizhou Province showed significant spatial agglomeration characteristics, with changed hotspots in cities such as Weining, Hezhang and Dafang, and unchanged hotspots in cities such as Weining and Congjiang. (5) The results of the interaction detection of the driving factors of land use change frequency in Guizhou Province from 2000 to 2020 show that the interaction of slope and slope direction has the strongest explanatory power for the spatial variation of land use change frequency in Guizhou Province.[Conclusion] There is obvious spatial heterogeneity in the distribution of land-use change frequency in Guizhou Province, and a mechanism to regulate the frequency of land-use change in Guizhou Province should be established to realize the effective use of social resources and reduce the financial burden of society.
[Objective] Land survey is the foundation of effective management of land resources, but the current national land survey has the problem of asymmetry of capital input, that is, the mismatch of input-output ratio, so it is necessary to identify the key and non-key areas of the land survey in order to realize the economic efficiency of the future land survey and to avoid unnecessary waste of resources. [Methods] Based on the land use data of Guizhou Province from 2000 to 2020, the spatial and temporal distribution characteristics of the land use change frequency in Guizhou Province were analyzed by using land use change frequency statistics, kernel density analysis and spatial autocorrelation, and the influencing factors were studied with the help of geographic probes.[Results] (1) The area of land changed in the 2000-2020 land use change frequency in Guizhou Province is only 2%, but the inputs of capital and manpower are relatively high, so the relationship between the two inputs and discordance. (2) The land that has changed in the 2000-2020 land use change frequency in Guizhou Province has significant spatial heterogeneity in spatial distribution. (3) The kernel density of changed land in Guizhou Province from 2000 to 2020 shows the distribution characteristic of "high in the west and low in the east", with the distribution density of one land change being the largest, and the distribution density of three land changes being the smallest. (4) In 2000-2020, both changed and unchanged land in Guizhou Province showed significant spatial agglomeration characteristics, with changed hotspots in cities such as Weining, Hezhang and Dafang, and unchanged hotspots in cities such as Weining and Congjiang. (5) The results of the interaction detection of the driving factors of land use change frequency in Guizhou Province from 2000 to 2020 show that the interaction of slope and slope direction has the strongest explanatory power for the spatial variation of land use change frequency in Guizhou Province.[Conclusion] There is obvious spatial heterogeneity in the distribution of land-use change frequency in Guizhou Province, and a mechanism to regulate the frequency of land-use change in Guizhou Province should be established to realize the effective use of social resources and reduce the financial burden of society.
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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.
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[Objective] The Beijing-Tianjin-Hebei region confronts critical challenges, including water resource scarcity and ecological degradation. Advancing the sophisticated development of the water resources system is pivotal for regional progress and aligns with national strategic objectives. [Methods] This study utilized the JRC global surface water dataset to identify surface water variations in Beijing, Tianjin, and Hebei from 2000 to 2021. We examined the spatial-temporal trends of surface water and the morphological evolution within Baiyangdian and Qilihai wetlands using the Morphological Spatial Pattern Analysis (MSPA). Correlation analyses, incorporating climate and anthropogenic factors, elucidated the drivers behind these spatial-temporal changes. [Results] Temporally, the region’s permanent water bodies diminished, whereas seasonal water bodies expanded over the past 22 years. Spatially, urban centers like Beijing, Tianjin, and Langfang saw a decline in surface water, in contrast to cities along the South-to-North Water Transfer project, which experienced growth. Baiyangdian's core wetland area fluctuated, decreasing initially then rising post-2005, while its periphery steadily increased. Qilihai wetlands saw a decline until 2010, followed by recovery. A positive correlation exists between maximum water area and precipitation in the south, and a negative one in eastern coastal cities, highlighting the natural replenishment and human activity imbalance. Significant correlations between water usage and surface water area in Beijing, Chengde, and Tangshan indicate the positive impact of water transfers and ecological replenishment, whereas negative correlations in Qinhuangdao and Tianjin suggest adverse effects of groundwater over-extraction. [Conclusion] This analysis uncovers the two-decade dynamics of surface water in the Beijing-Tianjin-Hebei region, offering insights for sustainable water resource management.
[Objective] The Beijing-Tianjin-Hebei region confronts critical challenges, including water resource scarcity and ecological degradation. Advancing the sophisticated development of the water resources system is pivotal for regional progress and aligns with national strategic objectives. [Methods] This study utilized the JRC global surface water dataset to identify surface water variations in Beijing, Tianjin, and Hebei from 2000 to 2021. We examined the spatial-temporal trends of surface water and the morphological evolution within Baiyangdian and Qilihai wetlands using the Morphological Spatial Pattern Analysis (MSPA). Correlation analyses, incorporating climate and anthropogenic factors, elucidated the drivers behind these spatial-temporal changes. [Results] Temporally, the region’s permanent water bodies diminished, whereas seasonal water bodies expanded over the past 22 years. Spatially, urban centers like Beijing, Tianjin, and Langfang saw a decline in surface water, in contrast to cities along the South-to-North Water Transfer project, which experienced growth. Baiyangdian's core wetland area fluctuated, decreasing initially then rising post-2005, while its periphery steadily increased. Qilihai wetlands saw a decline until 2010, followed by recovery. A positive correlation exists between maximum water area and precipitation in the south, and a negative one in eastern coastal cities, highlighting the natural replenishment and human activity imbalance. Significant correlations between water usage and surface water area in Beijing, Chengde, and Tangshan indicate the positive impact of water transfers and ecological replenishment, whereas negative correlations in Qinhuangdao and Tianjin suggest adverse effects of groundwater over-extraction. [Conclusion] This analysis uncovers the two-decade dynamics of surface water in the Beijing-Tianjin-Hebei region, offering insights for sustainable water resource management.
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[Objective] Objective of this study was to study the effects of different biochar additions on the physical and chemical properties and tobacco growth, yield and output value in the yellow loam soil of mountain Chongqing region. [Methods] Flue-cured tobacco K326 was used as the experimental material. In 2022-2023, a completely random design was adopted in the tobacco field, and 7 biochar addition treatments were set up based on conventional film ridge cultivating and fertilization methods. The 7 biochar addition treatments were: zero biochar addition (CK), 750 kg/hm2 (T50), 1500 kg/hm2 (T100), 3000 kg/hm2 (T200), 4500 kg/hm2 (T300), 6000 kg/hm2 (T400) and 7500 kg/hm2 (T500). During the studied periods, soil physical and chemical properties and tobacco agronomic traits, ground and above ground dry matters, yield and output value were measured. [Results] The results showed that:(1)the application of biochar reduced soil bulk density and increase soil porosity and capillary water capacity. The differences in soil porosities and capillary water capacities under T400 and T500 treatments and CK treatment were significant, while the rest treatments did not significantly change soil physical properties compared to CK treatments in the second year; (2) compared with CK treatment, biochar addition significantly increased the content of available nitrogen, available phosphorus and available potassium in the 0-20 cm soil profile, and T300, T400 and T500 treatments significantly increased organic matter content and pH value in the 0-20 cm soil profile, which could effectively alleviate soil acidification; (3) compared with CK treatment, T300, T400 and T500 treatments significantly promoted the growth and biomass accumulation of tobacco and significantly increased the yield and output value of tobacco leaves. Considered the input-output ratio, T400 treatment was optimal biochar addition methods for improving soil physical and chemical properties and tobacco yield and output value. [Conclusion]Therefore, adding suitable biochar to tobacco fieldsoil can improve soil physical and chemical properties, increase soil cultivability, promote the growth, development and dry matter accumulation of tobacco plants, and finally increase the yield and output value of tobacco leaves.
[Objective] Objective of this study was to study the effects of different biochar additions on the physical and chemical properties and tobacco growth, yield and output value in the yellow loam soil of mountain Chongqing region. [Methods] Flue-cured tobacco K326 was used as the experimental material. In 2022-2023, a completely random design was adopted in the tobacco field, and 7 biochar addition treatments were set up based on conventional film ridge cultivating and fertilization methods. The 7 biochar addition treatments were: zero biochar addition (CK), 750 kg/hm2 (T50), 1500 kg/hm2 (T100), 3000 kg/hm2 (T200), 4500 kg/hm2 (T300), 6000 kg/hm2 (T400) and 7500 kg/hm2 (T500). During the studied periods, soil physical and chemical properties and tobacco agronomic traits, ground and above ground dry matters, yield and output value were measured. [Results] The results showed that:(1)the application of biochar reduced soil bulk density and increase soil porosity and capillary water capacity. The differences in soil porosities and capillary water capacities under T400 and T500 treatments and CK treatment were significant, while the rest treatments did not significantly change soil physical properties compared to CK treatments in the second year; (2) compared with CK treatment, biochar addition significantly increased the content of available nitrogen, available phosphorus and available potassium in the 0-20 cm soil profile, and T300, T400 and T500 treatments significantly increased organic matter content and pH value in the 0-20 cm soil profile, which could effectively alleviate soil acidification; (3) compared with CK treatment, T300, T400 and T500 treatments significantly promoted the growth and biomass accumulation of tobacco and significantly increased the yield and output value of tobacco leaves. Considered the input-output ratio, T400 treatment was optimal biochar addition methods for improving soil physical and chemical properties and tobacco yield and output value. [Conclusion]Therefore, adding suitable biochar to tobacco fieldsoil can improve soil physical and chemical properties, increase soil cultivability, promote the growth, development and dry matter accumulation of tobacco plants, and finally increase the yield and output value of tobacco leaves.
Abstract:
[Objective] The species composition and diversity characteristics of different types of vegetation communities in the Zhangye desert-oasis transition zone in Gansu were analyzed and studied, as well as the correlation between plant community characteristics and soil moisture content,, it provides a scientific basis for the evaluation of water and soil conservation benefits in the region. [Methods] Choose different types of desert vegetation, investigate and determine the diversity of different types of vegetation community plants and 0 to 120 cm of soil moisture content. [Results] The results showed that:①There are 6 vegetation types in this area, the vegetation structure is very simple, and the species composition is dominated by drought-tolerant and super-drought-tolerant small shrubs, semi-shrubs and herbs such as Reaumuria songarica, Sympegma regelii, Caroxylon passerinum, Aristida adscensionis, Grubovia dasyphylla that suitable for arid desert habitats, and the plant community is a type of shrub and grass community, with a relatively small species diversity index. ② The change of soil moisture in the vertical direction presents a "double peak", and the soil humidity gradually increases from the surface layer to the deep, it rises to the "first peak" at 20-40 cm, drops to a lower level at 40-60 cm, and gradually rises at 60-120 cm, until to the "second peak" at 120 cm.③ The vegetation height, vegetation density and vegetation cover of each plant community increased with the increase of soil moisture content. The vegetation height was significantly positively correlated with the soil moisture in the soil layer of 40-120 cm, and the density and vegetation cover of herbaceous plants and shrubs were significantly positively correlated with the soil moisture content in the layer where their root systems were mainly distributed. [Conclusion] In the desert oasis transition zone where the moisture content of the surface soil (0-20 cm) deep soil (40-80 cm) is less than 2 per cent, it is appropriate to plant arid shrubs such as Reaumuria songarica, Sympegma regelii, Nitraria tangutorum and other herbaceous plants such as Aristida adscensionis, Salsola tragus, Grubovia dasyphylla, Eragrostis pilosa and Artemisia scoparia, etc.; and in the desert zones where the moisture content of the surface soil and the deep soil is more than 2 per cent, it is appropriate to plant arid shrubs such as Reaumuria songarica, Caroxylon passerinum, etc., and herbaceous plants such as Artemisia frigida, Artemisia xerophytica and Carex duriuscula, etc., which are capable of effectively promoting ecological recovery and reconstruction.
[Objective] The species composition and diversity characteristics of different types of vegetation communities in the Zhangye desert-oasis transition zone in Gansu were analyzed and studied, as well as the correlation between plant community characteristics and soil moisture content,, it provides a scientific basis for the evaluation of water and soil conservation benefits in the region. [Methods] Choose different types of desert vegetation, investigate and determine the diversity of different types of vegetation community plants and 0 to 120 cm of soil moisture content. [Results] The results showed that:①There are 6 vegetation types in this area, the vegetation structure is very simple, and the species composition is dominated by drought-tolerant and super-drought-tolerant small shrubs, semi-shrubs and herbs such as Reaumuria songarica, Sympegma regelii, Caroxylon passerinum, Aristida adscensionis, Grubovia dasyphylla that suitable for arid desert habitats, and the plant community is a type of shrub and grass community, with a relatively small species diversity index. ② The change of soil moisture in the vertical direction presents a "double peak", and the soil humidity gradually increases from the surface layer to the deep, it rises to the "first peak" at 20-40 cm, drops to a lower level at 40-60 cm, and gradually rises at 60-120 cm, until to the "second peak" at 120 cm.③ The vegetation height, vegetation density and vegetation cover of each plant community increased with the increase of soil moisture content. The vegetation height was significantly positively correlated with the soil moisture in the soil layer of 40-120 cm, and the density and vegetation cover of herbaceous plants and shrubs were significantly positively correlated with the soil moisture content in the layer where their root systems were mainly distributed. [Conclusion] In the desert oasis transition zone where the moisture content of the surface soil (0-20 cm) deep soil (40-80 cm) is less than 2 per cent, it is appropriate to plant arid shrubs such as Reaumuria songarica, Sympegma regelii, Nitraria tangutorum and other herbaceous plants such as Aristida adscensionis, Salsola tragus, Grubovia dasyphylla, Eragrostis pilosa and Artemisia scoparia, etc.; and in the desert zones where the moisture content of the surface soil and the deep soil is more than 2 per cent, it is appropriate to plant arid shrubs such as Reaumuria songarica, Caroxylon passerinum, etc., and herbaceous plants such as Artemisia frigida, Artemisia xerophytica and Carex duriuscula, etc., which are capable of effectively promoting ecological recovery and reconstruction.
Abstract:
Abstract: [Objective] In order to provide a reference basis for the assessment of meteorological disaster risk and the prevention of soil erosion, the spatial and temporal distribution characteristics of rainfall erosivity under different levels of rainfall in Jilin Province were analyzed. [Methods] Based on the daily rainfall data of 51 meteorological stations in Jilin Province from 1980 to 2022, they were divided into different magnitudes of rainfall according to rainfall grades. The daily rainfall erosivity calculation model proposed by Xie was adopted to calculating the rainfall erosivity, M-K mutation test, coefficient of variation, and climate tendency rate were used to analyze the spatial and temporal distribution of different grades of rainfall erosivity. [Results] (1) The average annual erosive rainfall and rainfall erosivity in Jilin Province during 1980-2022 were 420.04 mm and 1967.12 MJ·mm/(hm2·h), respectively, and the coefficients of variation were 0.27 and 0.2, which were both moderate variations. (2) Different grades of rainfall erosivity showed an upward trend during the past 5 decades. The torrential rain erosivity increased by 57.7 MJ·mm/(hm2·h·10a) the largest, while the moderate rainfall erosivity increased by 5.8 MJ·mm/(hm2·h·10a) the smallest. The contribution of heavy rain erosivity to average annual rainfall erosivity was the largest, which was 36.68%. (3) The distribution of different grades of rainfall erosivity was uneven throughout the year. Moderate rainfall erosivity occurring throughout the year, and heavy rainfall erosivity only occurred from June to September. From October to May of the next year, the moderate rainfall erosivity played a dominant role in the annual rainfall erosivity. From June to September, the heavy and torrential rain erosivity gradually replaced moderate rainfall erosivity, and played a dominant role in the annual rainfall erosivity. (4) The spatial distribution of average annual erosive rainfall, average annual rainfall erosivity and different grades of rainfall erosivity showed a pattern of high in the Central and South, and low in the East and West. [Conclusion] The regional characteristics of different grades of rainfall erosivity in Jilin Province were obvious, and the time and areas with high probability of soil erosion caused by different grades of rainfall were identified, providing a reference basis for formulating meteorological disaster prevention and the measures of water and soil conservation according to local conditions.
Abstract: [Objective] In order to provide a reference basis for the assessment of meteorological disaster risk and the prevention of soil erosion, the spatial and temporal distribution characteristics of rainfall erosivity under different levels of rainfall in Jilin Province were analyzed. [Methods] Based on the daily rainfall data of 51 meteorological stations in Jilin Province from 1980 to 2022, they were divided into different magnitudes of rainfall according to rainfall grades. The daily rainfall erosivity calculation model proposed by Xie was adopted to calculating the rainfall erosivity, M-K mutation test, coefficient of variation, and climate tendency rate were used to analyze the spatial and temporal distribution of different grades of rainfall erosivity. [Results] (1) The average annual erosive rainfall and rainfall erosivity in Jilin Province during 1980-2022 were 420.04 mm and 1967.12 MJ·mm/(hm2·h), respectively, and the coefficients of variation were 0.27 and 0.2, which were both moderate variations. (2) Different grades of rainfall erosivity showed an upward trend during the past 5 decades. The torrential rain erosivity increased by 57.7 MJ·mm/(hm2·h·10a) the largest, while the moderate rainfall erosivity increased by 5.8 MJ·mm/(hm2·h·10a) the smallest. The contribution of heavy rain erosivity to average annual rainfall erosivity was the largest, which was 36.68%. (3) The distribution of different grades of rainfall erosivity was uneven throughout the year. Moderate rainfall erosivity occurring throughout the year, and heavy rainfall erosivity only occurred from June to September. From October to May of the next year, the moderate rainfall erosivity played a dominant role in the annual rainfall erosivity. From June to September, the heavy and torrential rain erosivity gradually replaced moderate rainfall erosivity, and played a dominant role in the annual rainfall erosivity. (4) The spatial distribution of average annual erosive rainfall, average annual rainfall erosivity and different grades of rainfall erosivity showed a pattern of high in the Central and South, and low in the East and West. [Conclusion] The regional characteristics of different grades of rainfall erosivity in Jilin Province were obvious, and the time and areas with high probability of soil erosion caused by different grades of rainfall were identified, providing a reference basis for formulating meteorological disaster prevention and the measures of water and soil conservation according to local conditions.
Abstract:
[Objective] To clarify the process of runoff and sediment production on the upper and lower slopes of construction access roads under vegetation recovery conditions, and to reveal the impact of vegetation recovery after the disturbance caused by the construction of access roads on soil and water loss at the slope scale in the ecologically fragile subalpine forest and shrub area of southeastern Tibet. [Methods] Typical slopes under different vegetation recovery conditions after the disturbance on the upper and lower slopes of the construction access roads were selected for indoor simulated rainfall experiments. The study investigated the process of runoff and sediment production under four types of vegetation coverage (0%, 30%, 60%, 90%), three slopes (15°, 30°, 45°), and two rainfall intensities (30 mm/h, 60 mm/h) after engineering disturbance, to clarify the impact of vegetation recovery of construction access roads on soil and water loss. [Results] (1) After the engineering disturbance of the construction access roads, vegetation recovery on the bare slopes of the upper and lower slopes effectively delayed the initial runoff time, and this effect became more pronounced with increasing vegetation coverage, especially on the upper slopes. (2) Within the range of 0% to 60% vegetation coverage, the stable runoff rate on both upper and lower slopes significantly decreased with the increase of vegetation coverage, with the stable runoff rate of 60% and 90% vegetation coverage being close. Compared to bare slopes, the runoff reduction benefits of 60% and 90% vegetation coverage were 59%–75% and 58%–77% respectively, indicating that the critical vegetation coverage for runoff reduction is 60%. (3) The sediment reduction benefits at 30% and 60% vegetation coverage reached 29%–82% and 86%–96% respectively. Below 60% vegetation coverage, the sediment reduction effect significantly increased with the increase in coverage; beyond this critical threshold, even with increased coverage, the sediment reduction benefits showed little change. (4) Under the same vegetation coverage, slope, and rainfall intensity conditions, the total runoff volume from the upper slopes formed by excavation was always higher than that from the lower slopes formed by filling, while the total sediment yield from the lower slopes was always higher than that from the upper slopes, reflecting significant differences in soil erosion on the slope surface after the disturbance of the construction access roads between excavation and filling slopes. [Conclusion] In the prevention and control of soil and water loss in the disturbed areas of construction access roads in southeastern Tibet, a 60% vegetation recovery rate offers both good control benefits and economic feasibility. In the layout of soil and water conservation measures, more emphasis should be placed on "controlling water" for excavation slopes and on "blocking sediment" for filling slopes. Only by fully considering these differences can better soil and water conservation effects be achieved in disturbed areas of construction access roads.
[Objective] To clarify the process of runoff and sediment production on the upper and lower slopes of construction access roads under vegetation recovery conditions, and to reveal the impact of vegetation recovery after the disturbance caused by the construction of access roads on soil and water loss at the slope scale in the ecologically fragile subalpine forest and shrub area of southeastern Tibet. [Methods] Typical slopes under different vegetation recovery conditions after the disturbance on the upper and lower slopes of the construction access roads were selected for indoor simulated rainfall experiments. The study investigated the process of runoff and sediment production under four types of vegetation coverage (0%, 30%, 60%, 90%), three slopes (15°, 30°, 45°), and two rainfall intensities (30 mm/h, 60 mm/h) after engineering disturbance, to clarify the impact of vegetation recovery of construction access roads on soil and water loss. [Results] (1) After the engineering disturbance of the construction access roads, vegetation recovery on the bare slopes of the upper and lower slopes effectively delayed the initial runoff time, and this effect became more pronounced with increasing vegetation coverage, especially on the upper slopes. (2) Within the range of 0% to 60% vegetation coverage, the stable runoff rate on both upper and lower slopes significantly decreased with the increase of vegetation coverage, with the stable runoff rate of 60% and 90% vegetation coverage being close. Compared to bare slopes, the runoff reduction benefits of 60% and 90% vegetation coverage were 59%–75% and 58%–77% respectively, indicating that the critical vegetation coverage for runoff reduction is 60%. (3) The sediment reduction benefits at 30% and 60% vegetation coverage reached 29%–82% and 86%–96% respectively. Below 60% vegetation coverage, the sediment reduction effect significantly increased with the increase in coverage; beyond this critical threshold, even with increased coverage, the sediment reduction benefits showed little change. (4) Under the same vegetation coverage, slope, and rainfall intensity conditions, the total runoff volume from the upper slopes formed by excavation was always higher than that from the lower slopes formed by filling, while the total sediment yield from the lower slopes was always higher than that from the upper slopes, reflecting significant differences in soil erosion on the slope surface after the disturbance of the construction access roads between excavation and filling slopes. [Conclusion] In the prevention and control of soil and water loss in the disturbed areas of construction access roads in southeastern Tibet, a 60% vegetation recovery rate offers both good control benefits and economic feasibility. In the layout of soil and water conservation measures, more emphasis should be placed on "controlling water" for excavation slopes and on "blocking sediment" for filling slopes. Only by fully considering these differences can better soil and water conservation effects be achieved in disturbed areas of construction access roads.
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[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:
[目的]分析茅尾海土地利用变化与碳储量演化特征，为增碳汇提高生态价值提供科学依据。[方法]使用监督分类的方法对茅尾海2009年、2015年和2021年的遥感影像数据进行解译提取，基于ArcGIS软件和InVEST模型对茅尾海土地利用变化与碳储量演化进行研究分析。[结果]①茅尾海土地类型主要呈现“大聚居，小杂局”的分布特点，2009-2021年土地利用类型存在较大变化，耕地、浅海水域和渔业养殖区面积减少，红树林湿地、建筑用地、林草地、淤泥质滩涂面积增加；②茅尾海碳储量呈先下降后上升趋势，2009-2015年、2015-2021年、2009-2021年区域碳储量变化量分别为-11.05万t、3.77万t、-7.29万t；碳固定净现值分别为-1.37亿元、0.47亿元、-0.90亿元；③2009-2021年，茅尾海主要为渔业养殖区、林草地等高固碳土地利用类型向建筑用地等低固碳类型的转变，转为建筑用地造成的碳储量损失最大，达28.51万t；转为渔业养殖区增加的碳储量达18.08万t。[结论]加快推动茅尾海养殖方式转型升级，加强红树林在宜林区域的增殖及加快森林城市建设，有利于研究区域固碳与可持续发展。
[目的]分析茅尾海土地利用变化与碳储量演化特征，为增碳汇提高生态价值提供科学依据。[方法]使用监督分类的方法对茅尾海2009年、2015年和2021年的遥感影像数据进行解译提取，基于ArcGIS软件和InVEST模型对茅尾海土地利用变化与碳储量演化进行研究分析。[结果]①茅尾海土地类型主要呈现“大聚居，小杂局”的分布特点，2009-2021年土地利用类型存在较大变化，耕地、浅海水域和渔业养殖区面积减少，红树林湿地、建筑用地、林草地、淤泥质滩涂面积增加；②茅尾海碳储量呈先下降后上升趋势，2009-2015年、2015-2021年、2009-2021年区域碳储量变化量分别为-11.05万t、3.77万t、-7.29万t；碳固定净现值分别为-1.37亿元、0.47亿元、-0.90亿元；③2009-2021年，茅尾海主要为渔业养殖区、林草地等高固碳土地利用类型向建筑用地等低固碳类型的转变，转为建筑用地造成的碳储量损失最大，达28.51万t；转为渔业养殖区增加的碳储量达18.08万t。[结论]加快推动茅尾海养殖方式转型升级，加强红树林在宜林区域的增殖及加快森林城市建设，有利于研究区域固碳与可持续发展。
Abstract:
【目的】“双碳”背景下,探究华北地区市域粮食生产碳排放效率并量化其空间分异及动态演进规律,分析华北地区粮食生产碳排放效率现状,有利于促进华北地区粮食绿色低碳生产。【方法】采用碳排放系数法测算2011-2020年华北地区市域粮食生产碳排放,在此基础上,运用三阶段超效率SBM模型进一步测度华北地区粮食生产碳排放效率,最后借助泰尔指数和核密度估计分别探究了粮食生产碳排放效率的地区差异及动态演进。【结果】①研究期内,华北地区市域粮食生产碳排放呈“M”型波动下降趋势,但下降缓慢。②华北地区市域粮食生产碳排放效率呈先降后升的演变趋势,第一阶段效率均值为0.59,剔除环境变量和随机误差对效率值的影响,第三阶段效率均值为0.48,明显低于第一阶段效率。其中,滁州、驻马店、德州等地效率值较高,而三门峡、黄山、济源等地效率值较低。③粮食生产碳排放效率空间差异呈上升趋势,区域内差异是影响总体差异的主要因素,其中安徽省各地市差异最为显著。④核密度估计结果显示,研究期内,波峰呈波动上升的趋势,主峰向右移动的幅度较小且主要以单峰出现,侧峰隆起幅度较小,各地级市的粮食生产碳排放效率主要集中于0.4-0.6之间,华北地区各市粮食生产碳排放效率水平整体较低。【结论】华北地区粮食生产碳排放效率整体水平较低,且地区差异明显,应减少化肥等物资投入冗余,加强地区交流与合作。
【目的】“双碳”背景下,探究华北地区市域粮食生产碳排放效率并量化其空间分异及动态演进规律,分析华北地区粮食生产碳排放效率现状,有利于促进华北地区粮食绿色低碳生产。【方法】采用碳排放系数法测算2011-2020年华北地区市域粮食生产碳排放,在此基础上,运用三阶段超效率SBM模型进一步测度华北地区粮食生产碳排放效率,最后借助泰尔指数和核密度估计分别探究了粮食生产碳排放效率的地区差异及动态演进。【结果】①研究期内,华北地区市域粮食生产碳排放呈“M”型波动下降趋势,但下降缓慢。②华北地区市域粮食生产碳排放效率呈先降后升的演变趋势,第一阶段效率均值为0.59,剔除环境变量和随机误差对效率值的影响,第三阶段效率均值为0.48,明显低于第一阶段效率。其中,滁州、驻马店、德州等地效率值较高,而三门峡、黄山、济源等地效率值较低。③粮食生产碳排放效率空间差异呈上升趋势,区域内差异是影响总体差异的主要因素,其中安徽省各地市差异最为显著。④核密度估计结果显示,研究期内,波峰呈波动上升的趋势,主峰向右移动的幅度较小且主要以单峰出现,侧峰隆起幅度较小,各地级市的粮食生产碳排放效率主要集中于0.4-0.6之间,华北地区各市粮食生产碳排放效率水平整体较低。【结论】华北地区粮食生产碳排放效率整体水平较低,且地区差异明显,应减少化肥等物资投入冗余,加强地区交流与合作。
Abstract:
[目的]探究黄河流域内蒙古段土地利用变化格局对碳汇空间分布的影响，并找出背后的主要驱动因素，为研究区生态空间发展方向和增汇政策提供依据。[方法]以黄河流域内蒙古段为例，基于2000、2010与2020年土地利用数据，使用InVEST-FLUS模型分析各期碳汇能力变化情况，并模拟2040年自然发展、生态保护及农业优先3种不同情景下碳储量变化格局，借助地理探测器找出造成碳汇空间分布差异背后的主要驱动因素。[结果]①2000-2020年间，黄河流域内蒙古段碳储量呈先上升后下降态势，碳储量总体增加8.63×106t，其中，地下生物碳储量增加3.91×106t，土壤碳储量增加2.28×106t。②未来自然发展情景下碳储量继续减少3.92×106t，而在生态保护情景下增长22.1×106t，高于农业优先情景下4.99×106t的碳储增量，其中，土壤碳库是造成增量差异的关键。③年平均降雨量、年平均温度的不平衡分布是造成黄河流域内蒙古段各类碳库差异的主要因素。[结论]合理的生态保护政策更符合未来城镇集约化和生态高质量发展要求，未来应重视荒漠化防治工作，推进林草建设，为提升区域生态安全格局和增汇政策提供保障。
[目的]探究黄河流域内蒙古段土地利用变化格局对碳汇空间分布的影响，并找出背后的主要驱动因素，为研究区生态空间发展方向和增汇政策提供依据。[方法]以黄河流域内蒙古段为例，基于2000、2010与2020年土地利用数据，使用InVEST-FLUS模型分析各期碳汇能力变化情况，并模拟2040年自然发展、生态保护及农业优先3种不同情景下碳储量变化格局，借助地理探测器找出造成碳汇空间分布差异背后的主要驱动因素。[结果]①2000-2020年间，黄河流域内蒙古段碳储量呈先上升后下降态势，碳储量总体增加8.63×106t，其中，地下生物碳储量增加3.91×106t，土壤碳储量增加2.28×106t。②未来自然发展情景下碳储量继续减少3.92×106t，而在生态保护情景下增长22.1×106t，高于农业优先情景下4.99×106t的碳储增量，其中，土壤碳库是造成增量差异的关键。③年平均降雨量、年平均温度的不平衡分布是造成黄河流域内蒙古段各类碳库差异的主要因素。[结论]合理的生态保护政策更符合未来城镇集约化和生态高质量发展要求，未来应重视荒漠化防治工作，推进林草建设，为提升区域生态安全格局和增汇政策提供保障。
Abstract:
[目的] 探究辽宁省“三生”功能时空演变及其碳排放效应，为“双碳”目标下的国土空间规划提供依据。[方法] 基于土地利用多功能性分类识别辽宁省国土“三生”功能、结合直接和间接排放因子法核算碳排放量，探索“三生”功能与碳排放量空间关系及其时空分异性，揭示“三生”功能时空演变的碳排放效应。[结果] ① 2005-2020年辽宁省“三生”功能空间分布格局总体变化不大，大部分地区以生产和生态功能为主，生活功能区扩张明显，各地级市中心与周边区域空间差异明显；② 2005-2013年，辽宁省各县域碳排放量增长迅速，2013-2020年增速缓慢，但空间差异愈发显著，碳排放高值明显集中在沈阳市和大连市；③ 辽宁省“三生”功能与碳排放量空间布局及数量变化的相关性总体较强，但空间差异明显且影响因素复杂。[结论]辽宁省各县域需要在自然地理条件约束和经济社会发展需求引导下，在明确各自土地主导功能定位的基础上，依托自身区域优势与资源禀赋，加强区域协作，以实现全域碳减排。
[目的] 探究辽宁省“三生”功能时空演变及其碳排放效应，为“双碳”目标下的国土空间规划提供依据。[方法] 基于土地利用多功能性分类识别辽宁省国土“三生”功能、结合直接和间接排放因子法核算碳排放量，探索“三生”功能与碳排放量空间关系及其时空分异性，揭示“三生”功能时空演变的碳排放效应。[结果] ① 2005-2020年辽宁省“三生”功能空间分布格局总体变化不大，大部分地区以生产和生态功能为主，生活功能区扩张明显，各地级市中心与周边区域空间差异明显；② 2005-2013年，辽宁省各县域碳排放量增长迅速，2013-2020年增速缓慢，但空间差异愈发显著，碳排放高值明显集中在沈阳市和大连市；③ 辽宁省“三生”功能与碳排放量空间布局及数量变化的相关性总体较强，但空间差异明显且影响因素复杂。[结论]辽宁省各县域需要在自然地理条件约束和经济社会发展需求引导下，在明确各自土地主导功能定位的基础上，依托自身区域优势与资源禀赋，加强区域协作，以实现全域碳减排。
Abstract:
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
Abstract:
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract:
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
Abstract:
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
Abstract:
[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.
Abstract:
[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.
Abstract:
[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.
Abstract:
[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.
Abstract:
[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.
Abstract:
[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
Abstract:
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
Abstract:
[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.
Abstract:
[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.
Abstract:
[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.
Abstract:
[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
Abstract:
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
Abstract:
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
Abstract:
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
Abstract:
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
Abstract:
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
Abstract:
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
Abstract:
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
Abstract:
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
Abstract:
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
Abstract:
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
Abstract:
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
Abstract:
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
Abstract:
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
YANG Cuihong, LI Yong, WANG Xu, CHEN Tingting, GUO Hao, YANG Yijiang, WU Zongmeng, ZHOU Xiaoqi, HUANG Zhigang
Abstract:
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
Abstract:
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
Abstract:
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
Display Method:
2023,43(4):238-247, DOI: 10.13961/j.cnki.stbctb.20230508.007
Abstract:
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
2023,43(4):154-161,210, DOI: 10.13961/j.cnki.stbctb.2023.04.019
Abstract:
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
2012(5):8-12, DOI: 10.13961/j.cnki.stbctb.2012.05.011
Abstract:
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
2023,43(4):220-228,326, DOI: 10.13961/j.cnki.stbctb.2023.04.027
Abstract:
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
2022,42(2):264-274, DOI: 10.13961/j.cnki.stbctb.2022.02.036
Abstract:
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
2006(3):1-5, DOI: 10.13961/j.cnki.stbctb.2006.03.002
Abstract:
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
2009(1):62-65, DOI: 10.13961/j.cnki.stbctb.2009.01.027
Abstract:
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
2022,42(2):210-218, DOI: 10.13961/j.cnki.stbctb.20220124.001
Abstract:
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
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(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
2002(3):58-58, DOI: 10.13961/j.cnki.stbctb.2002.03.017
Abstract:
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
2023,43(2):43-49,59, DOI: 10.13961/j.cnki.stbctb.20230423.001
Abstract:
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
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。
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.
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.
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。
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Journal Information
- Founded in 1981, bimonthly
- CN：
61-1094/X
- ISSN：
1000-288X
- Administrted by：
Chinese Academy of Sciences
- Sponsored by：
Institute of Soil and Water Conservation, CAS & MWR;
Monitoring Center of Soil and Water Conservation, Ministry of Water Resources - Published by：
Science Press
- Editor-in-Chief：
Prof. FENG Hao
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