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2023,43(5):1-6,26
, DOI: 10.13961/j.cnki.stbctb.2023.05.001
Abstract:
[Objective] The influence factors of artificial cyanobacterial crust on soil threshold wind velocity and wind erosion rate, and the effects of wind erosion prevention and control were analyzed, and the feasibility of using artificial cyanobacterial crust to prevent and control wind erosion on farmland soil was explored, in order to provide a new idea for farmland soil wind erosion prevention and control. [Methods] The effects of five inoculum amounts of cyanobacterial liquid, which were 400, 600, 800, 1 000, 1 200 ml/m2, on the formation of cyanobacterial crust on farmland soil were investigated. The effects and feasibility of using artificial cyanobacterial crust to reduce soil wind erosion were tested and estimated using wind tunnel tests. [Results] Cyanobacterial crusts of different coverages could be formed under outdoor conditions by inoculating the soil with cyanobacteria liquid having different inoculum amounts. When the cyanobacteria inoculum amount was 1 200 ml/m2, the coverage could reach 30% after 14 days of cultivation, and the coverage was greater than 60% after 50 days of cultivation. The biomass and thickness of the artificial cyanobacteria crust were 52 and 9 times of that of the control, respectively (p＜0.05). Artificial cyanobacterial crust significantly increased the threshold wind velocity for soil erosion and decreased the wind erosion rate. When the coverage of cyanobacterial crust was 30%, the threshold wind velocity (9 m/s) increased by 44% and the wind erosion rate decreased by more than 80%. [Conclusion] Inoculating farmland soil with cyanobacterial liquid can form a crust that can significantly change soil physical properties and enhance soil resistance to wind erosion. The formation of cyanobacterial crust on farmland soil by inoculation with cyanobacterial solution can be used as a rapid and effective method for prevention and control of soil erosion by wind.
[Objective] The influence factors of artificial cyanobacterial crust on soil threshold wind velocity and wind erosion rate, and the effects of wind erosion prevention and control were analyzed, and the feasibility of using artificial cyanobacterial crust to prevent and control wind erosion on farmland soil was explored, in order to provide a new idea for farmland soil wind erosion prevention and control. [Methods] The effects of five inoculum amounts of cyanobacterial liquid, which were 400, 600, 800, 1 000, 1 200 ml/m2, on the formation of cyanobacterial crust on farmland soil were investigated. The effects and feasibility of using artificial cyanobacterial crust to reduce soil wind erosion were tested and estimated using wind tunnel tests. [Results] Cyanobacterial crusts of different coverages could be formed under outdoor conditions by inoculating the soil with cyanobacteria liquid having different inoculum amounts. When the cyanobacteria inoculum amount was 1 200 ml/m2, the coverage could reach 30% after 14 days of cultivation, and the coverage was greater than 60% after 50 days of cultivation. The biomass and thickness of the artificial cyanobacteria crust were 52 and 9 times of that of the control, respectively (p＜0.05). Artificial cyanobacterial crust significantly increased the threshold wind velocity for soil erosion and decreased the wind erosion rate. When the coverage of cyanobacterial crust was 30%, the threshold wind velocity (9 m/s) increased by 44% and the wind erosion rate decreased by more than 80%. [Conclusion] Inoculating farmland soil with cyanobacterial liquid can form a crust that can significantly change soil physical properties and enhance soil resistance to wind erosion. The formation of cyanobacterial crust on farmland soil by inoculation with cyanobacterial solution can be used as a rapid and effective method for prevention and control of soil erosion by wind.
2023,43(5):7-17
, DOI: 10.13961/j.cnki.stbctb.2023.05.002
Abstract:
[Objective] The water-holding capacity of reclaimed grassland of different ages was studied in order to provide a scientific basis for water retention and soil and water conservation of reclaimed grassland in karst regions. [Methods] Reclaimed grassland of different ages (5, 10, 15, 20 yr) and cultivated land (CK) in a karst area in Anshui City, Guizhou Province was selected as the research objects, and the “space-time substitution method” was used to study litter storage, water-holding capacity, and water storage capacity. The change characteristics of soil profile bulk density, porosity, particle composition, water content, and water-holding capacity were determined for different ages of reclaimed grassland. [Results] ① The litter-layer storage capacity, maximum water-holding capacity, maximum storage capacity, and effective storage capacity followed the reclaimed grassland age order of 15 yr＞20 yr＞10 yr＞5 yr. The relationships of litter-layer water-holding capacity and water absorption rate with soaking time were characterized by a logarithmic function and a power function, respectively. ② The sand content and bulk density of the reclaimed grassland showed a trend of first decreasing and then increasing as age of reclaimed grassland increased. Changes in silt, clay, total porosity, capillary porosity, maximum water-holding capacity, and capillary water-holding capacity were opposite to the changes in soil bulk density. ③ The total water-holding capacity of the litter layer and the soil layer followed the order of 10 yr＞20 yr＞15 yr＞5 yr＞CK. The maximum water-holding contribution rate of the soil layer was more than 99%. [Conclusion] Reclaimed grassland of different ages not only increased the bioaccumulation, rainfall interception, and water-holding capacity of the litter layer, but also improved soil structure and pore status. The soil water-holding capacity gradually stabilized after 10 years. Therefore, it is recommended that planting deciduous trees after 10 years of farmland conversion to grassland.
[Objective] The water-holding capacity of reclaimed grassland of different ages was studied in order to provide a scientific basis for water retention and soil and water conservation of reclaimed grassland in karst regions. [Methods] Reclaimed grassland of different ages (5, 10, 15, 20 yr) and cultivated land (CK) in a karst area in Anshui City, Guizhou Province was selected as the research objects, and the “space-time substitution method” was used to study litter storage, water-holding capacity, and water storage capacity. The change characteristics of soil profile bulk density, porosity, particle composition, water content, and water-holding capacity were determined for different ages of reclaimed grassland. [Results] ① The litter-layer storage capacity, maximum water-holding capacity, maximum storage capacity, and effective storage capacity followed the reclaimed grassland age order of 15 yr＞20 yr＞10 yr＞5 yr. The relationships of litter-layer water-holding capacity and water absorption rate with soaking time were characterized by a logarithmic function and a power function, respectively. ② The sand content and bulk density of the reclaimed grassland showed a trend of first decreasing and then increasing as age of reclaimed grassland increased. Changes in silt, clay, total porosity, capillary porosity, maximum water-holding capacity, and capillary water-holding capacity were opposite to the changes in soil bulk density. ③ The total water-holding capacity of the litter layer and the soil layer followed the order of 10 yr＞20 yr＞15 yr＞5 yr＞CK. The maximum water-holding contribution rate of the soil layer was more than 99%. [Conclusion] Reclaimed grassland of different ages not only increased the bioaccumulation, rainfall interception, and water-holding capacity of the litter layer, but also improved soil structure and pore status. The soil water-holding capacity gradually stabilized after 10 years. Therefore, it is recommended that planting deciduous trees after 10 years of farmland conversion to grassland.
2023,43(5):18-26
, DOI: 10.13961/j.cnki.stbctb.2023.05.003
Abstract:
[Objective] The effects of Salix psammophila sand barrier decay on the composition and diversity of fungal communities were analyzed in order to provide a theoretical basis for further research on the ecological function of fungal communities in desert ecosystems. [Methods] S. psammophila sand barriers aged 1, 3, 5,and 7 years were observed, and newly laid sand barriers were used as the control. Field in-situ sampling, laboratory index determination, and Illumina MiSeq sequencing technology were used to determine the response relationships between fungal diversity and sand barrier components, soil properties, and enzyme activities during sand barrier decay. [Results] ① The relative abundance of Phialophora, Trichoderma, Knufia, Veronaea and Coniochaeta increased over time, while Didymella and Phaeococcomyces decreased over time. Fungal diversity and richness increased over time. ② Soil organic carbon, alkaline nitrogen, and dissolved organic carbon at seven years were 2.47, 1.83, and 1.71 times higher, respectively, than observed for the control. Activities of β-1,4-glucosidase and leucine aminopeptidase significantly increased by 139.36% and 35.16%, respectively. ③ Knufia, Parasola, Veronaea, and Coniochaeta were positively correlated with soil organic carbon, alkaline nitrogen, and dissolved orgainic carbon, but negatively correlated with cellulose and hemifiber (p＜0.05). The results of the redundancy analysis showed that cellulose and alkaline nitrogen were the main environmental factors that significantly affected the abundance of dominant fungal communities, and alkaline nitrogen and leucine aminopeptidase were the main factors that influenced the diversity index. [Conclusion] Both the dominant fungal genera and diversity were affected by a combination of factors during S. psammophila sand barrier decay. Alkaline nitrogen was the main influencing factor for both dominant fungal genera and diversity. Future studies should further explore the ecological functions of the dominant fungal groups in combination with the FUNGuild database.
[Objective] The effects of Salix psammophila sand barrier decay on the composition and diversity of fungal communities were analyzed in order to provide a theoretical basis for further research on the ecological function of fungal communities in desert ecosystems. [Methods] S. psammophila sand barriers aged 1, 3, 5,and 7 years were observed, and newly laid sand barriers were used as the control. Field in-situ sampling, laboratory index determination, and Illumina MiSeq sequencing technology were used to determine the response relationships between fungal diversity and sand barrier components, soil properties, and enzyme activities during sand barrier decay. [Results] ① The relative abundance of Phialophora, Trichoderma, Knufia, Veronaea and Coniochaeta increased over time, while Didymella and Phaeococcomyces decreased over time. Fungal diversity and richness increased over time. ② Soil organic carbon, alkaline nitrogen, and dissolved organic carbon at seven years were 2.47, 1.83, and 1.71 times higher, respectively, than observed for the control. Activities of β-1,4-glucosidase and leucine aminopeptidase significantly increased by 139.36% and 35.16%, respectively. ③ Knufia, Parasola, Veronaea, and Coniochaeta were positively correlated with soil organic carbon, alkaline nitrogen, and dissolved orgainic carbon, but negatively correlated with cellulose and hemifiber (p＜0.05). The results of the redundancy analysis showed that cellulose and alkaline nitrogen were the main environmental factors that significantly affected the abundance of dominant fungal communities, and alkaline nitrogen and leucine aminopeptidase were the main factors that influenced the diversity index. [Conclusion] Both the dominant fungal genera and diversity were affected by a combination of factors during S. psammophila sand barrier decay. Alkaline nitrogen was the main influencing factor for both dominant fungal genera and diversity. Future studies should further explore the ecological functions of the dominant fungal groups in combination with the FUNGuild database.
2023,43(5):27-34,44
, DOI: 10.13961/j.cnki.stbctb.2023.05.004
Abstract:
[Objective] The relationships between community characteristics, species diversity, and soil physical and chemical properties of Carex duriuscula in Hulunbeier steppe were analyzed in order to provide a scientific reference for the protection and restoration of grassland ecosystems. [Methods] Ninety-five sample plots typifying the Hulunbeier C. duriuscula steppe were studied. The relationships between community characteristics of four community types and species diversity and soil physical and chemical properties were studied. [Results] ① With regard to the community characteristics, aboveground biomass, species richness, and Shannon-Wiener index were significantly different among the four community types. The community of C. duriuscula-annual and biennial herbs was the highest. With regard to the soil physical and chemical properties, total nitrogen and total phosphorus were the highest in the community of C. duriuscula-rhizome herbs. ② Soil organic carbon, total nitrogen, and total phosphorus were significantly positively correlated with above-ground biomass and below-ground biomass in the C. duriuscula-clump herbs community and the C. duriuscula-forbs community. ③ Soil organic carbon, total nitrogen, and total phosphorus were significantly negatively correlated with the Shannon-Wiener index, Simpson index, and Pielou index in the C. duriuscula-rhizome herbs community and the C. duriuscula-annual and biennial herbs community. [Conclusion] There were differences in community characteristics among the four community types in the C. duriuscula steppe. Soil organic carbon, total nitrogen, and total phosphorus were the main factors affecting the differences in community characteristics and species diversity.
[Objective] The relationships between community characteristics, species diversity, and soil physical and chemical properties of Carex duriuscula in Hulunbeier steppe were analyzed in order to provide a scientific reference for the protection and restoration of grassland ecosystems. [Methods] Ninety-five sample plots typifying the Hulunbeier C. duriuscula steppe were studied. The relationships between community characteristics of four community types and species diversity and soil physical and chemical properties were studied. [Results] ① With regard to the community characteristics, aboveground biomass, species richness, and Shannon-Wiener index were significantly different among the four community types. The community of C. duriuscula-annual and biennial herbs was the highest. With regard to the soil physical and chemical properties, total nitrogen and total phosphorus were the highest in the community of C. duriuscula-rhizome herbs. ② Soil organic carbon, total nitrogen, and total phosphorus were significantly positively correlated with above-ground biomass and below-ground biomass in the C. duriuscula-clump herbs community and the C. duriuscula-forbs community. ③ Soil organic carbon, total nitrogen, and total phosphorus were significantly negatively correlated with the Shannon-Wiener index, Simpson index, and Pielou index in the C. duriuscula-rhizome herbs community and the C. duriuscula-annual and biennial herbs community. [Conclusion] There were differences in community characteristics among the four community types in the C. duriuscula steppe. Soil organic carbon, total nitrogen, and total phosphorus were the main factors affecting the differences in community characteristics and species diversity.
2023,43(5):35-44
, DOI: 10.13961/j.cnki.stbctb.2023.05.005
Abstract:
[Objective] The classification of sediment particles and the accompanying distribution characteristics of carbon, nitrogen and salt in the process of soil thawing layer by layer under snowmelt runoff scenario were analyzed in order to identify the mechanism of soil freeze-thaw erosion and the induced micro-environmental effects on eroding slopes. [Methods] Soil samples were obtained from an eroding slope in the mollisol region of Northeastern China. Air-dried soil was used to fill columns that were subjected to three treatments: non-freeze-thaw, full freeze-full thaw, and gradual progressive thawing after freezing. The soil columns were completely immersed in a water bath so that thawing occurred from outside to inside. All soil samples were then fractionated by settling velocity, and the electrical conductivity (EC), pH value, soil organic carbon (SOC), and total nitrogen (TN) of each particle size were determined and analyzed. [Results] ① The freeze-thaw process reduced the proportion of the soil particles ＞500 μm and ≤125 μm, but increased the proportion of soil particles between 125 μm and 500 μm. Larger particles had higher EC, but lower SOC and TN. ② Across gradual progressively thawed layers, the outer layer (thawed earlier) had fewer particles ≤63 μm, and the inner layer (thawed later) had more particles between 125 μm and 500 μm. More specifically, EC, SOC, and TN were higher in the larger fractions from the outer layer. ③ Compared with the original soil, 64.8% of the dissolved solids were lost from the soil that experienced gradual progressive thawing, but the loss rate of SOC and TN was only 4.08% and 2.72%, respectively. The loss of dissolved solids and organic matter was greater from the inner layer than from the outer layer. [Conclusion] After freezing and thawing, the degree of fragmentation of the outer layer of soil was large, and the soil particles on the slope tended to become homogenized. Organic matter content varied significantly between particle size classes, and its distribution was more stable in small-grained soils. Salts and organic matter migrated from the inner layer of the soil to the outer layer during the freeze-thaw process, resulting in loss.
[Objective] The classification of sediment particles and the accompanying distribution characteristics of carbon, nitrogen and salt in the process of soil thawing layer by layer under snowmelt runoff scenario were analyzed in order to identify the mechanism of soil freeze-thaw erosion and the induced micro-environmental effects on eroding slopes. [Methods] Soil samples were obtained from an eroding slope in the mollisol region of Northeastern China. Air-dried soil was used to fill columns that were subjected to three treatments: non-freeze-thaw, full freeze-full thaw, and gradual progressive thawing after freezing. The soil columns were completely immersed in a water bath so that thawing occurred from outside to inside. All soil samples were then fractionated by settling velocity, and the electrical conductivity (EC), pH value, soil organic carbon (SOC), and total nitrogen (TN) of each particle size were determined and analyzed. [Results] ① The freeze-thaw process reduced the proportion of the soil particles ＞500 μm and ≤125 μm, but increased the proportion of soil particles between 125 μm and 500 μm. Larger particles had higher EC, but lower SOC and TN. ② Across gradual progressively thawed layers, the outer layer (thawed earlier) had fewer particles ≤63 μm, and the inner layer (thawed later) had more particles between 125 μm and 500 μm. More specifically, EC, SOC, and TN were higher in the larger fractions from the outer layer. ③ Compared with the original soil, 64.8% of the dissolved solids were lost from the soil that experienced gradual progressive thawing, but the loss rate of SOC and TN was only 4.08% and 2.72%, respectively. The loss of dissolved solids and organic matter was greater from the inner layer than from the outer layer. [Conclusion] After freezing and thawing, the degree of fragmentation of the outer layer of soil was large, and the soil particles on the slope tended to become homogenized. Organic matter content varied significantly between particle size classes, and its distribution was more stable in small-grained soils. Salts and organic matter migrated from the inner layer of the soil to the outer layer during the freeze-thaw process, resulting in loss.
2023,43(5):45-52
, DOI: 10.13961/j.cnki.stbctb.2023.05.006
Abstract:
[Objective] The change trend and main limiting factors of the ecological stoichiometric characteristics of soil and leaves in different saline habitats were analyzed in order to provide basic research data for the study of nutrient limiting factors and adaptation mechanisms in the growth and development of halophytes in arid areas, and to provide references for ecological conservation and restoration of desert plants. [Methods] The euhalophyte Suaeda microphylla and the pseudohalophyte Apocynum pictum were selected from Ebinur Lake Wetland National Nature Reserve. Soil pH value, water content, salinity, available phosphorus, ammonium nitrogen, organic carbon, total nitrogen, total phosphorus, plant leaf organic carbon, total nitrogen, and total phosphorus were measured in the selected halophytes. The relationship between the ecological stoichiometry of the leaves of the two plants and the soil of their habitats was analyzed to investigate the soil limiting factors on the ecological stoichiometry of plant leaves. [Results] ① Soil phosphorus decreased with increasing salinity, organic carbon, nitrogen, and stoichiometric ratio showed an increasing trend. Salinization degree had a significant effect on soil nutrient content; ② Leaf nitrogen for the two plants was significantly affected by soil salt, and showed a decreasing trend with decreasing soil salt content, which was consistent with the change trend of soil nitrogen content. The mean value of leaf N/P was less than 14, indicating that both plants in the study area were limited by soil nitrogen content. [Conclusion] There were differences in the coupling relationship of soil-plant ecological stoichiometric characteristics among different types of halophytes. The euhalophyte S. microphylla was mainly affected by soil pH value and water content, while the pseudohalophyte A. pictum was mainly affected by soil phosphorus and ammonium nitrogen content.
[Objective] The change trend and main limiting factors of the ecological stoichiometric characteristics of soil and leaves in different saline habitats were analyzed in order to provide basic research data for the study of nutrient limiting factors and adaptation mechanisms in the growth and development of halophytes in arid areas, and to provide references for ecological conservation and restoration of desert plants. [Methods] The euhalophyte Suaeda microphylla and the pseudohalophyte Apocynum pictum were selected from Ebinur Lake Wetland National Nature Reserve. Soil pH value, water content, salinity, available phosphorus, ammonium nitrogen, organic carbon, total nitrogen, total phosphorus, plant leaf organic carbon, total nitrogen, and total phosphorus were measured in the selected halophytes. The relationship between the ecological stoichiometry of the leaves of the two plants and the soil of their habitats was analyzed to investigate the soil limiting factors on the ecological stoichiometry of plant leaves. [Results] ① Soil phosphorus decreased with increasing salinity, organic carbon, nitrogen, and stoichiometric ratio showed an increasing trend. Salinization degree had a significant effect on soil nutrient content; ② Leaf nitrogen for the two plants was significantly affected by soil salt, and showed a decreasing trend with decreasing soil salt content, which was consistent with the change trend of soil nitrogen content. The mean value of leaf N/P was less than 14, indicating that both plants in the study area were limited by soil nitrogen content. [Conclusion] There were differences in the coupling relationship of soil-plant ecological stoichiometric characteristics among different types of halophytes. The euhalophyte S. microphylla was mainly affected by soil pH value and water content, while the pseudohalophyte A. pictum was mainly affected by soil phosphorus and ammonium nitrogen content.
2023,43(5):53-61,68
, DOI: 10.13961/j.cnki.stbctb.2023.05.007
Abstract:
[Objective] Nitrogen and phosphorus loss characteristics and soil fertility changes on a gentle slope of cultivated land were analyzed under optimal fertilization and cross-slope tillage in order to provide a basis for reducing nitrogen and phosphorus losses, achieving non-point source prevention and treatment, protecting cultivated land resources, and maintaining soil fertility level. [Methods] The study was conducted on a gentle slope area of the mountain and hilly area in Yunnan Province under natural rainfall conditions. A surface runoff monitoring area was established with three treatments: down-slope tillage+conventional fertilization; cross-slope tillage+conventional fertilization; and cross-slope tillage+optimal fertilization. The characteristics of nitrogen and phosphorus loss under different tillage and fertilization methods were continuously monitored from January 2019 to December 2021, and soil fertility level was analyzed by the gray correlation method. [Results] There was a significant linear correlation between nitrogen and phosphorus losses and rainfall and runoff (p＜0.01). Compared with down-slope tillage, cross-slope tillage reduced surface runoff by 20.46%—40.74%, total nitrogen loss by 19.12%—33.71%, and total phosphorus loss by 33.33%—60.08%. Compared with conventional fertilization, optimized fertilization reduced total nitrogen loss by 1.20%—51.71%. All soil fertility factors showed different degrees of improvement except that the contents of nitrate nitrogen and organic matter decreased. The gray correlation degree of each treatment showed different degrees of improvement, and the gray correlation degree of the cross-slope tillage+optimized fertilization treatment increased significantly (p＜0.05), with an increase of 26.63%. [Conclusion] Cross-slope tillage stopped surface runoff and reduced the loss of nitrogen and phosphorus. The application of cross-slope tillage and optimal fertilization application had the greatest effect on improving soil fertility level and reducing nitrogen and phosphorus losses.
[Objective] Nitrogen and phosphorus loss characteristics and soil fertility changes on a gentle slope of cultivated land were analyzed under optimal fertilization and cross-slope tillage in order to provide a basis for reducing nitrogen and phosphorus losses, achieving non-point source prevention and treatment, protecting cultivated land resources, and maintaining soil fertility level. [Methods] The study was conducted on a gentle slope area of the mountain and hilly area in Yunnan Province under natural rainfall conditions. A surface runoff monitoring area was established with three treatments: down-slope tillage+conventional fertilization; cross-slope tillage+conventional fertilization; and cross-slope tillage+optimal fertilization. The characteristics of nitrogen and phosphorus loss under different tillage and fertilization methods were continuously monitored from January 2019 to December 2021, and soil fertility level was analyzed by the gray correlation method. [Results] There was a significant linear correlation between nitrogen and phosphorus losses and rainfall and runoff (p＜0.01). Compared with down-slope tillage, cross-slope tillage reduced surface runoff by 20.46%—40.74%, total nitrogen loss by 19.12%—33.71%, and total phosphorus loss by 33.33%—60.08%. Compared with conventional fertilization, optimized fertilization reduced total nitrogen loss by 1.20%—51.71%. All soil fertility factors showed different degrees of improvement except that the contents of nitrate nitrogen and organic matter decreased. The gray correlation degree of each treatment showed different degrees of improvement, and the gray correlation degree of the cross-slope tillage+optimized fertilization treatment increased significantly (p＜0.05), with an increase of 26.63%. [Conclusion] Cross-slope tillage stopped surface runoff and reduced the loss of nitrogen and phosphorus. The application of cross-slope tillage and optimal fertilization application had the greatest effect on improving soil fertility level and reducing nitrogen and phosphorus losses.
Zhou Xiaoqi, Chen Tingting, Li Yong, Yang Cuihong, Wu Zongmeng, Guo Hao, Yang Jiangyi, Wang Xu, Huang Zhigang
2023,43(5):62-68
, DOI: 10.13961/j.cnki.stbctb.20230327.001
Abstract:
[Objective] The influences of plants on reducing ditch erosion and C, N and P loss were studied in order to provide technical support for the prevention of ditch erosion and pollution control. [Methods] The study was conducted on ditches of the Nala River basin in the intensive sugarcane growing area of Southern Subtropical China. Vetiver (Vetiveria zizanioides, a herbaceous plant) was planted at different vegetation coverage amounts 〔bare ground. vegetation coverage of 0% (BG); somewhat covered, vegetation coverage of 1%—40% (SC); mostly covered, vegetation coverage of 41%—80% (MC); completely covered, vegetation coverage of 81%—100% (CC)〕 in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall events from April to October, and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified. [Results] ① From April to October, the width, erosion amount, and nutrient loss of ditches with different vegetation coverage gradually increased over time. Values for all three parameters followed the same order of BG＞SC＞MC＞CC; ② Compared with BG, the erosion amounts for 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; ③ Correlation analysis showed that the erosion amount for ditches was significantly negatively correlated with vetiver grass coverage and plant root density (p＜0.01), accounting for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] As vegetation coverage increased, ditch erosion and nutrient loss gradually decreased. There were no significant differences in ditch erosion and nutrient loss when vegetation coverage was between MC and CC. These results provide guidance for ameliorating ditch erosion and reducing pollutants in other water source areas.
[Objective] The influences of plants on reducing ditch erosion and C, N and P loss were studied in order to provide technical support for the prevention of ditch erosion and pollution control. [Methods] The study was conducted on ditches of the Nala River basin in the intensive sugarcane growing area of Southern Subtropical China. Vetiver (Vetiveria zizanioides, a herbaceous plant) was planted at different vegetation coverage amounts 〔bare ground. vegetation coverage of 0% (BG); somewhat covered, vegetation coverage of 1%—40% (SC); mostly covered, vegetation coverage of 41%—80% (MC); completely covered, vegetation coverage of 81%—100% (CC)〕 in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall events from April to October, and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified. [Results] ① From April to October, the width, erosion amount, and nutrient loss of ditches with different vegetation coverage gradually increased over time. Values for all three parameters followed the same order of BG＞SC＞MC＞CC; ② Compared with BG, the erosion amounts for 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; ③ Correlation analysis showed that the erosion amount for ditches was significantly negatively correlated with vetiver grass coverage and plant root density (p＜0.01), accounting for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] As vegetation coverage increased, ditch erosion and nutrient loss gradually decreased. There were no significant differences in ditch erosion and nutrient loss when vegetation coverage was between MC and CC. These results provide guidance for ameliorating ditch erosion and reducing pollutants in other water source areas.
Yang Cuihong, Li Yong, Wang Xu, Chen Tingting, Guo Hao, Yang Jiangyi, Wu Zongmeng, Zhou Xiaoqi, Huang Zhigang
2023,43(5):69-78
, DOI: 10.13961/j.cnki.stbctb.20230327.002
Abstract:
[Objective] The suitable configuration ratios for contour planting and replanted sugarcane on slopes were determined in order to provide technical support for reducing slope ditch erosion and nutrient loss, improving cultivated land quality and rational sugarcane planting in sugarcane planting area. [Methods] Three configuration ratios (high, medium, and low) for contour planting and replanted sugarcane were evaluated. Slope-gully erosion and nutrient losses were determined by field measurements and laboratory experiments at the growth stages of establishment growth (EG), vegetative growth (VG), grand growth (GG), and ripening growth (RG), and the factors influencing erosion and nutrient loss were determined. [Results] ① During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on slopes planted to sugarcane in the Nala River basin 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 the Nala River basin, accounting for 47.7%—57.7% of the total erosion and nutrient losses. ③ During TG, gully erosion and associated nutrient losses for higher contour ratios (HC) were 33.03%—35.42% lower than for lower contour ratios (LC) (p＜0.05), but the losses for medium contour ratios (MC) were not significant compared with those of HC and LC. Gully erosion and nutrient losses of lower replanted ratios (LRp) were 27.41%—32.98% lower than those of higher replanted ratios (HRp), and 21.02%25.86% lower than those of medium replanted ratios (MRp) (p＜0.05). Litter cover and root density were the important factors affecting gully erosion and nutrient losses. ④ During TG, TN and TP losses on slopes accounted for 24.1%—39.5% and 107.0%—156.7% of the annual N and P application, respectively. [Conclusion] Planting sugarcane on slopes with a contour planting ratio of greater than 60% and a replanted ratio of less than 30% can effectively reduce soil and nutrient losses on slopes.
[Objective] The suitable configuration ratios for contour planting and replanted sugarcane on slopes were determined in order to provide technical support for reducing slope ditch erosion and nutrient loss, improving cultivated land quality and rational sugarcane planting in sugarcane planting area. [Methods] Three configuration ratios (high, medium, and low) for contour planting and replanted sugarcane were evaluated. Slope-gully erosion and nutrient losses were determined by field measurements and laboratory experiments at the growth stages of establishment growth (EG), vegetative growth (VG), grand growth (GG), and ripening growth (RG), and the factors influencing erosion and nutrient loss were determined. [Results] ① During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on slopes planted to sugarcane in the Nala River basin 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 the Nala River basin, accounting for 47.7%—57.7% of the total erosion and nutrient losses. ③ During TG, gully erosion and associated nutrient losses for higher contour ratios (HC) were 33.03%—35.42% lower than for lower contour ratios (LC) (p＜0.05), but the losses for medium contour ratios (MC) were not significant compared with those of HC and LC. Gully erosion and nutrient losses of lower replanted ratios (LRp) were 27.41%—32.98% lower than those of higher replanted ratios (HRp), and 21.02%25.86% lower than those of medium replanted ratios (MRp) (p＜0.05). Litter cover and root density were the important factors affecting gully erosion and nutrient losses. ④ During TG, TN and TP losses on slopes accounted for 24.1%—39.5% and 107.0%—156.7% of the annual N and P application, respectively. [Conclusion] Planting sugarcane on slopes with a contour planting ratio of greater than 60% and a replanted ratio of less than 30% can effectively reduce soil and nutrient losses on slopes.
2023,43(5):79-86
, DOI: 10.13961/j.cnki.stbctb.2023.05.010
Abstract:
[Objective] Mangroves are part of a wetland ecosystem found along tropical and sub-tropical coastlines. The soil active organic carbon composition, soil enzyme activity, and the interaction between them, under different plant community conditions was analyzed in order to predict the ecological structure and functional development trend of the mangrove area in Dongzhai Port, and provide a scientific basis for ecological restoration and protection of the mangrove wetland in Dongzhai Port. [Methods] Soil enzyme activity, active organic carbon content in the soil, and physicochemical properties of nine mangrove communities 〔Rhizophora stylosa (Type 1), Avicennia marina (Type 2), Ceriops tagal (Type 3), Bruguiera sexangula + C. tagal (Type 4), Aegiceras corniculatum + B. sexangula + Kandelia obovata (Type 5), B. sexangula + Lumnitzera racemose + A. corniculatum (Type 6), K. obovate + B. sexangula + L. racemose (Type 7), B. sexangula + Sonneratia apetala + A. corniculatum + K. obovata (Type 8), B. sexangula + S. apetala (Type 9)〕 were analyzed by field sampling. [Results] Soil organic carbon ranged from 6.57 g/kg to 74.87 g/kg in Dongzhai Port, with Type 7 and Type 1 communities having the highest and lowest soil organic carbon contents, respectively. Enzyme activity of wetland soil in each mangrove community followed the order of urease ＞ phosphatase ＞ catalase ＞ sucrase. Type 8 community had the highest urease activity, significantly higher than Type 1 to Type 6 communities. Moreover, Type 8 community also reported the highest phosphatase activity, which was significantly higher than phosphatase activity for Type 1 to Type 3 communities. On the other hand, catalase activity was highest in Type 5 community, and significantly higher than in the other communities, except Type 6 and Type 7. Type 9 community recorded the highest sucrase activity, which was significantly higher than Type 2, Type 5, and Type 8 communities. Furthermore, it was found that urease, phosphatase, and catalase activities had significant positive correlations with soil organic carbon content. Urease and phosphatase activities were significantly negatively correlated with soil pH value, and significantly positively correlated with total nitrogen (TN) and total phosphorus (TP). Catalase and sucrase activities also had significant positive correlations with TN and TP. The redundancy analysis results indicated that light fraction carbon, total organic carbon, particulate organic carbon, and microbial biomass carbon (MBC) were the main factors affecting soil enzyme activity of mangrove communities in Dongzhai Port. [Conclusion] There was a strong positive correlation between soil enzyme activity and the carbon content of active organic matter. Therefore, soil enzyme activity can be used to characterize the soil carbon pool activity in the mangrove area of Dongzhai Port.
[Objective] Mangroves are part of a wetland ecosystem found along tropical and sub-tropical coastlines. The soil active organic carbon composition, soil enzyme activity, and the interaction between them, under different plant community conditions was analyzed in order to predict the ecological structure and functional development trend of the mangrove area in Dongzhai Port, and provide a scientific basis for ecological restoration and protection of the mangrove wetland in Dongzhai Port. [Methods] Soil enzyme activity, active organic carbon content in the soil, and physicochemical properties of nine mangrove communities 〔Rhizophora stylosa (Type 1), Avicennia marina (Type 2), Ceriops tagal (Type 3), Bruguiera sexangula + C. tagal (Type 4), Aegiceras corniculatum + B. sexangula + Kandelia obovata (Type 5), B. sexangula + Lumnitzera racemose + A. corniculatum (Type 6), K. obovate + B. sexangula + L. racemose (Type 7), B. sexangula + Sonneratia apetala + A. corniculatum + K. obovata (Type 8), B. sexangula + S. apetala (Type 9)〕 were analyzed by field sampling. [Results] Soil organic carbon ranged from 6.57 g/kg to 74.87 g/kg in Dongzhai Port, with Type 7 and Type 1 communities having the highest and lowest soil organic carbon contents, respectively. Enzyme activity of wetland soil in each mangrove community followed the order of urease ＞ phosphatase ＞ catalase ＞ sucrase. Type 8 community had the highest urease activity, significantly higher than Type 1 to Type 6 communities. Moreover, Type 8 community also reported the highest phosphatase activity, which was significantly higher than phosphatase activity for Type 1 to Type 3 communities. On the other hand, catalase activity was highest in Type 5 community, and significantly higher than in the other communities, except Type 6 and Type 7. Type 9 community recorded the highest sucrase activity, which was significantly higher than Type 2, Type 5, and Type 8 communities. Furthermore, it was found that urease, phosphatase, and catalase activities had significant positive correlations with soil organic carbon content. Urease and phosphatase activities were significantly negatively correlated with soil pH value, and significantly positively correlated with total nitrogen (TN) and total phosphorus (TP). Catalase and sucrase activities also had significant positive correlations with TN and TP. The redundancy analysis results indicated that light fraction carbon, total organic carbon, particulate organic carbon, and microbial biomass carbon (MBC) were the main factors affecting soil enzyme activity of mangrove communities in Dongzhai Port. [Conclusion] There was a strong positive correlation between soil enzyme activity and the carbon content of active organic matter. Therefore, soil enzyme activity can be used to characterize the soil carbon pool activity in the mangrove area of Dongzhai Port.
2023,43(5):87-94
, DOI: 10.13961/j.cnki.stbctb.2023.05.011
Abstract:
[Objective] The soil nutrient characteristics and influencing factors of surface soil gully erosion for low hilly terrain in the black soil area were studied in order to provide data and theoretical support for the rational use of land resources, accurate management of soil fertility, and restoration of degraded soil in the black soil area. [Methods] Surface soil gully erosion for different types of eroded ditches in Yanshou County, Heilongjiang Province was determined by measuring and analyzing soil samples from the 0—40 cm layer in each part of the erosion gully. [Results] ① The contents of soil organic matter, total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and alkali hydrolyzable nitrogen were significantly different (p＜0.05) for different erosion gully types compared with the check treatment. As an erosion gully developed, soil organic matter decreased in the 0—40 cm layer, and the contents of total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and alkali hydrolyzable nitrogen also decreased. These nutrient contents were significantly different (p＜0.05) in different soil layers. Soil nutrient contents decreased with increasing depth. Because of erosion deposition, the contents of soil organic matter, total nitrogen, total potassium, and alkali hydrolyzable nitrogen decreased dramatically at the head of the gully, and at the same time, the contents of soil organic matter, available phosphorus, and available potassium decreased slowly. ② The soil degradation index followed the order of CK＞A2＞A1＞A3 in the 0—40 cm layer as erosion gullies developed, and the soil was gradually degraded. [Conclusion] Soil nutrients had an overall significant negative correlation with bulk density, and soil nutrients were positively correlated with water stable aggregates and clay content. Soil profile differences were the fundamental reason for the variation in soil nutrients. Erosion gully development was the secondary reason for nutrient changes. The contents of soil organic matter, total nitrogen, and total potassium were also affected by positional differences.
[Objective] The soil nutrient characteristics and influencing factors of surface soil gully erosion for low hilly terrain in the black soil area were studied in order to provide data and theoretical support for the rational use of land resources, accurate management of soil fertility, and restoration of degraded soil in the black soil area. [Methods] Surface soil gully erosion for different types of eroded ditches in Yanshou County, Heilongjiang Province was determined by measuring and analyzing soil samples from the 0—40 cm layer in each part of the erosion gully. [Results] ① The contents of soil organic matter, total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and alkali hydrolyzable nitrogen were significantly different (p＜0.05) for different erosion gully types compared with the check treatment. As an erosion gully developed, soil organic matter decreased in the 0—40 cm layer, and the contents of total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and alkali hydrolyzable nitrogen also decreased. These nutrient contents were significantly different (p＜0.05) in different soil layers. Soil nutrient contents decreased with increasing depth. Because of erosion deposition, the contents of soil organic matter, total nitrogen, total potassium, and alkali hydrolyzable nitrogen decreased dramatically at the head of the gully, and at the same time, the contents of soil organic matter, available phosphorus, and available potassium decreased slowly. ② The soil degradation index followed the order of CK＞A2＞A1＞A3 in the 0—40 cm layer as erosion gullies developed, and the soil was gradually degraded. [Conclusion] Soil nutrients had an overall significant negative correlation with bulk density, and soil nutrients were positively correlated with water stable aggregates and clay content. Soil profile differences were the fundamental reason for the variation in soil nutrients. Erosion gully development was the secondary reason for nutrient changes. The contents of soil organic matter, total nitrogen, and total potassium were also affected by positional differences.
2023,43(5):95-103,110
, DOI: 10.13961/j.cnki.stbctb.20231016.001
Abstract:
[Objective] The Three-River-Source National Park (TRSNP) is considered to be the “water tower of China”, and is an important ecological security barrier in China. The soil erosion distribution law of TRSNP was studied to provide a basis for implementing ecological protection policy, soil and water conservation, and ecological civilization construction in TRSNP. [Methods] Based on the Chinese soil loss equation (CSLE), wind erosion model and freeze-thaw erosion intensity model, the soil erosion status and its distribution characteristics at different space and surface of TRSNP were analyzed by superposition analysis. [Results] In 2020, an area of 2.64×104 km2 suffered from soil erosion in TRSNP. Among the three sub-parks, the Yellow-River-Source Park exhibited the most extensive soil erosion, whereas the Yangtze-River-Source Park was subject to severe erosion comparatively. Soil erosion and its spatial distribution varied significantly at different elevations. Water erosion occurred mainly in the area with elevations above 4 900 m, which occupied 70% of the land area. However, 85% of the wind erosion occurred in zones with elevations less than 4 900 m. The wind erosion area with slopes between 0° and 5° accounted for 60%, which is the relatively concentrated distribution area of wind erosion. And three-quarters of water erosion areas were concentrated in regions where the slope ranged from 8° to 25°, all of which require urgent conservation measures. Grassland was the most important land cover in TRSNP, occupying about 80% of the area, with low and medium-low vegetation cover being responsible for significant soil losses. Additionally, sandy land and bare land were prone to high intensity soil erosion, which deserved special attention. [Conclusion] Two-thirds of water erosion areas were primarily located in zones where the elevation was above 4 900 m, slope gradients were between 8° and 35°, and grassland cover was below medium-low cover. Wind erosion was primarily located at elevations ranging from 4 200 m to 4 900 m, slopes were less than 5°, and grassland coverage was below medium-low cover.
[Objective] The Three-River-Source National Park (TRSNP) is considered to be the “water tower of China”, and is an important ecological security barrier in China. The soil erosion distribution law of TRSNP was studied to provide a basis for implementing ecological protection policy, soil and water conservation, and ecological civilization construction in TRSNP. [Methods] Based on the Chinese soil loss equation (CSLE), wind erosion model and freeze-thaw erosion intensity model, the soil erosion status and its distribution characteristics at different space and surface of TRSNP were analyzed by superposition analysis. [Results] In 2020, an area of 2.64×104 km2 suffered from soil erosion in TRSNP. Among the three sub-parks, the Yellow-River-Source Park exhibited the most extensive soil erosion, whereas the Yangtze-River-Source Park was subject to severe erosion comparatively. Soil erosion and its spatial distribution varied significantly at different elevations. Water erosion occurred mainly in the area with elevations above 4 900 m, which occupied 70% of the land area. However, 85% of the wind erosion occurred in zones with elevations less than 4 900 m. The wind erosion area with slopes between 0° and 5° accounted for 60%, which is the relatively concentrated distribution area of wind erosion. And three-quarters of water erosion areas were concentrated in regions where the slope ranged from 8° to 25°, all of which require urgent conservation measures. Grassland was the most important land cover in TRSNP, occupying about 80% of the area, with low and medium-low vegetation cover being responsible for significant soil losses. Additionally, sandy land and bare land were prone to high intensity soil erosion, which deserved special attention. [Conclusion] Two-thirds of water erosion areas were primarily located in zones where the elevation was above 4 900 m, slope gradients were between 8° and 35°, and grassland cover was below medium-low cover. Wind erosion was primarily located at elevations ranging from 4 200 m to 4 900 m, slopes were less than 5°, and grassland coverage was below medium-low cover.
2023,43(5):104-110
, DOI: 10.13961/j.cnki.stbctb.2023.05.013
Abstract:
[Objective] The cultivation of safflower with micro rainwater harvesting technology on the hillslopes of the temperate desert grassland in Yili Valley was evaluated in order to provide technical support for dryland cultivation of safflower and for preventing water erosion and desertification. [Methods] The study was conducted from April to September 2021 at the Tiechanggou observation field in Yining City, Xinjiang Wei Autonomous Region. Five runoff plot treatments were set up: control, pit, horizontal terrace, square ridge, and contour ridge. Natural rainfall was observed, as well as runoff, soil loss, and safflower growth for each treatment. The soil moisture content in the 0—10 cm layer was monitored by time-domain reflectometry, and the potential evapotranspiration of safflower was simulated by the FAO Penman-Monteith model. [Results] The total rainfall during the study was 53.1 mm, and the potential evapotranspiration of safflower initially increased and then decreased. Runoff for the control treatment was the highest of all of the treatments (6.50×10-2 mm), and safflower in this treatment did not emerge. Soil loss was greatest for the square ridge treatment (0.684 t/km2). The surface soil water content of the five treatments was the lowest in June, with a mean value of 1.50%. No runoff was observed for the pit treatment, and this treatment showed the highest plant survival number (16) and plant height at flowering (25. 3 cm). [Conclusion] Safflower growth at flowering for the five micro rainwater harvesting plots followed the order of pit＞horizontal terrace, square ridge, contour ridge＞control. Better conditions for safflower survival and growth were observed as total runoff declined.
[Objective] The cultivation of safflower with micro rainwater harvesting technology on the hillslopes of the temperate desert grassland in Yili Valley was evaluated in order to provide technical support for dryland cultivation of safflower and for preventing water erosion and desertification. [Methods] The study was conducted from April to September 2021 at the Tiechanggou observation field in Yining City, Xinjiang Wei Autonomous Region. Five runoff plot treatments were set up: control, pit, horizontal terrace, square ridge, and contour ridge. Natural rainfall was observed, as well as runoff, soil loss, and safflower growth for each treatment. The soil moisture content in the 0—10 cm layer was monitored by time-domain reflectometry, and the potential evapotranspiration of safflower was simulated by the FAO Penman-Monteith model. [Results] The total rainfall during the study was 53.1 mm, and the potential evapotranspiration of safflower initially increased and then decreased. Runoff for the control treatment was the highest of all of the treatments (6.50×10-2 mm), and safflower in this treatment did not emerge. Soil loss was greatest for the square ridge treatment (0.684 t/km2). The surface soil water content of the five treatments was the lowest in June, with a mean value of 1.50%. No runoff was observed for the pit treatment, and this treatment showed the highest plant survival number (16) and plant height at flowering (25. 3 cm). [Conclusion] Safflower growth at flowering for the five micro rainwater harvesting plots followed the order of pit＞horizontal terrace, square ridge, contour ridge＞control. Better conditions for safflower survival and growth were observed as total runoff declined.
2023,43(5):111-120,127
, DOI: 10.13961/j.cnki.stbctb.2023.05.014
Abstract:
[Objective] The water quality of the main stream and main tributary monitoring sections of the North River in 2020 was analyzed in order to provide a reference and basis for monitoring and protecting the water environment of the North River. [Methods] The single factor evaluation method and principal component analysis were used to determine the spatial and temporal trends and driving factors of water quality for the North River. [Results] In 2020, the overall water quality of the North River monitoring sections was good. Only the sections of Shuichetou, Manshui River estuary, Huanglongshui Bridge, and Longgui met the standards for water quality grades Ⅲ—Ⅳ, and the other sections were determined to be grade Ⅱ. Water temperature and dissolved oxygen in the North River were influenced by the seasons. The water body basically remained weakly alkaline throughout the year, and the pollution levels of nutrients and organic matter were higher downstream than at upstream and midstream locations. [Conclusion] Spatial analysis showed that downstream water quality was worse than upstream and midstream water quality. The main influencing factors were nutrients and dissolved oxygen. pH value alone did not have a significant impact on water quality. The seasonal pollution degree followed the order of summer ＞ autumn ＞ spring ＞ winter. The dominant factor on water quality for the entire river was dissolved oxygen, while the dominant factors for the downstream river section were nutrients and organic matter.
[Objective] The water quality of the main stream and main tributary monitoring sections of the North River in 2020 was analyzed in order to provide a reference and basis for monitoring and protecting the water environment of the North River. [Methods] The single factor evaluation method and principal component analysis were used to determine the spatial and temporal trends and driving factors of water quality for the North River. [Results] In 2020, the overall water quality of the North River monitoring sections was good. Only the sections of Shuichetou, Manshui River estuary, Huanglongshui Bridge, and Longgui met the standards for water quality grades Ⅲ—Ⅳ, and the other sections were determined to be grade Ⅱ. Water temperature and dissolved oxygen in the North River were influenced by the seasons. The water body basically remained weakly alkaline throughout the year, and the pollution levels of nutrients and organic matter were higher downstream than at upstream and midstream locations. [Conclusion] Spatial analysis showed that downstream water quality was worse than upstream and midstream water quality. The main influencing factors were nutrients and dissolved oxygen. pH value alone did not have a significant impact on water quality. The seasonal pollution degree followed the order of summer ＞ autumn ＞ spring ＞ winter. The dominant factor on water quality for the entire river was dissolved oxygen, while the dominant factors for the downstream river section were nutrients and organic matter.
2023,43(5):121-127
, DOI: 10.13961/j.cnki.stbctb.2023.05.015
Abstract:
[Objective] Remote sensing technology is used to monitor and evaluate the change of urban ecological environment quality timely, dynamically and objectively, in order to provide reference for urban ecological environment planning and management. [Methods] Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 were collected. The Google Earth Engine (GEE) platform was used to perform pixel-level cloud removal and chromatic aberration correction. The median value composite was used to calculate four remote sensing indicators including greenness, wetness, dryness, and heat. 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 environmental quality in Nanning City with the help of the parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning City, and its ecological environmental quality was observed to follow an overall fluctuating upward trend of “decreasing-increasing-stable”. The spatial heterogeneity of ecological environmental quality in Nanning City was obvious. The areas with better ecological environmental quality were mainly concentrated in the nature reserves, forest lands, grasslands and water areas, while the degraded areas of ecological environmental quality were mainly located in the cities, urban-rural transition zones and farming areas with frequent human activities and greater land use intensity. RSEI was positively correlated with greenness and wetness indicators, and negatively correlated with dryness and heat, and dryness index factor had the greatest influence on RSEI. [Conclusion] The ecological environmental quality of Nanning City was well characterized by RSEI, and the overall ecological environmental quality was at a good level from 2000 to 2020. The combination of GEE and RSEI could effectively improve the use of remote sensing images, and therefore could be used for long-term monitoring and assessing of ecological environmental quality in the urban region.
[Objective] Remote sensing technology is used to monitor and evaluate the change of urban ecological environment quality timely, dynamically and objectively, in order to provide reference for urban ecological environment planning and management. [Methods] Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 were collected. The Google Earth Engine (GEE) platform was used to perform pixel-level cloud removal and chromatic aberration correction. The median value composite was used to calculate four remote sensing indicators including greenness, wetness, dryness, and heat. 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 environmental quality in Nanning City with the help of the parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning City, and its ecological environmental quality was observed to follow an overall fluctuating upward trend of “decreasing-increasing-stable”. The spatial heterogeneity of ecological environmental quality in Nanning City was obvious. The areas with better ecological environmental quality were mainly concentrated in the nature reserves, forest lands, grasslands and water areas, while the degraded areas of ecological environmental quality were mainly located in the cities, urban-rural transition zones and farming areas with frequent human activities and greater land use intensity. RSEI was positively correlated with greenness and wetness indicators, and negatively correlated with dryness and heat, and dryness index factor had the greatest influence on RSEI. [Conclusion] The ecological environmental quality of Nanning City was well characterized by RSEI, and the overall ecological environmental quality was at a good level from 2000 to 2020. The combination of GEE and RSEI could effectively improve the use of remote sensing images, and therefore could be used for long-term monitoring and assessing of ecological environmental quality in the urban region.
2023,43(5):128-140,147
, DOI: 10.13961/j.cnki.stbctb.2023.05.016
Abstract:
[Objective] The spatiotemporal variation and distribution of cultivated land quality at Minhou County, Fujian Province over many years were analyzed in order to provide new ideas and new help for the study of spatiotemporal pattern evolution of cultivated land quality in complex geomorphic areas in the southeast hilly region. [Methods] The spatiotemporal statistical scanning method was introduced into multi-time series cultivated land quality monitoring, and combined with the traditional spatial analysis method to study the continuous change trend and spatial distribution of county scale cultivated land quality. Furthermore, the experimental results generated by the introduction of the spatiotemporal scanning model were compared with the results of a local autocorrelation model in the traditional spatial autocorrelation analysis method. [Results] ① The spatiotemporal scanning model was superior to the local autocorrelation model for mining high-value clustering features. ② The change amplitude and spatial distribution breadth of cultivated land quality grades at Minhou County from 2018 to 2019 were greater than in 2019—2020. ③ From 2018 to 2020, the overall cultivated land quality at Minhou County was stable from year by year, and showed an upward trend. ④ According to the variation of the spatial and temporal patterns of cultivated land quality at Minhou County, cultivated land was divided into five areas: high quality improvement area, low quality improvement area, primary key improvement area, secondary key improvement area, and moderate improvement area. [Conclusion] Replenishing nutrients, increasing water conservation, and balancing soil pH value are important practices to implement to prevent and reverse the deterioration of cultivated land quality and to maintain high quality and high yield of farmland. In addition, establishing cultivated land protection areas to prevent non-agricultural uses of cultivated land is also conducive to stabilizing and improving cultivated land quality.
[Objective] The spatiotemporal variation and distribution of cultivated land quality at Minhou County, Fujian Province over many years were analyzed in order to provide new ideas and new help for the study of spatiotemporal pattern evolution of cultivated land quality in complex geomorphic areas in the southeast hilly region. [Methods] The spatiotemporal statistical scanning method was introduced into multi-time series cultivated land quality monitoring, and combined with the traditional spatial analysis method to study the continuous change trend and spatial distribution of county scale cultivated land quality. Furthermore, the experimental results generated by the introduction of the spatiotemporal scanning model were compared with the results of a local autocorrelation model in the traditional spatial autocorrelation analysis method. [Results] ① The spatiotemporal scanning model was superior to the local autocorrelation model for mining high-value clustering features. ② The change amplitude and spatial distribution breadth of cultivated land quality grades at Minhou County from 2018 to 2019 were greater than in 2019—2020. ③ From 2018 to 2020, the overall cultivated land quality at Minhou County was stable from year by year, and showed an upward trend. ④ According to the variation of the spatial and temporal patterns of cultivated land quality at Minhou County, cultivated land was divided into five areas: high quality improvement area, low quality improvement area, primary key improvement area, secondary key improvement area, and moderate improvement area. [Conclusion] Replenishing nutrients, increasing water conservation, and balancing soil pH value are important practices to implement to prevent and reverse the deterioration of cultivated land quality and to maintain high quality and high yield of farmland. In addition, establishing cultivated land protection areas to prevent non-agricultural uses of cultivated land is also conducive to stabilizing and improving cultivated land quality.
2023,43(5):141-147
, DOI: 10.13961/j.cnki.stbctb.2023.05.017
Abstract:
[Objective] The stability evaluation of an open-pit mining area was carried out in order to provide technical support for landform remodeling, ecological environment restoration, and soil erosion monitoring in a mining area. [Methods] The ArcHydro hydrological model and watershed self-similarity principle were used in this study. The stability of geomorphic forms in an open-pit mining area and in the surrounding undisturbed area was evaluated using the geomorphic information entropy evaluation index. The risk of soil erosion and erosion intensity in the mine area were also determined. [Results] The geomorphic information entropy of the Hesigewula open-pit coal mine area in Inner Mongolia was affected by a series of processes such as stripping, mining, transportation, and disposal, and was mostly concentrated in the index value range of 0.105—0.145. The geomorphic system development of the watershed in the mining area was mostly in the juvenile stage or middle-aged to juvenile stage. The risk of watershed erosion was high. Most of the information entropy of the original landform and undisturbed area was greater than 0.40, where the watershed geomorphic system was stable and strong, with flat terrain and small soil erosion modulus. [Conclusion] The risk of soil erosion gradually increased from south to north at the Hesigewula open-pit mine due to the original landform of the mining area, the mining sequence, and the location of the dump site. The results of this study can be used as the basis for landform reconstruction and ecological environment restoration of similar open-pit coal mines.
[Objective] The stability evaluation of an open-pit mining area was carried out in order to provide technical support for landform remodeling, ecological environment restoration, and soil erosion monitoring in a mining area. [Methods] The ArcHydro hydrological model and watershed self-similarity principle were used in this study. The stability of geomorphic forms in an open-pit mining area and in the surrounding undisturbed area was evaluated using the geomorphic information entropy evaluation index. The risk of soil erosion and erosion intensity in the mine area were also determined. [Results] The geomorphic information entropy of the Hesigewula open-pit coal mine area in Inner Mongolia was affected by a series of processes such as stripping, mining, transportation, and disposal, and was mostly concentrated in the index value range of 0.105—0.145. The geomorphic system development of the watershed in the mining area was mostly in the juvenile stage or middle-aged to juvenile stage. The risk of watershed erosion was high. Most of the information entropy of the original landform and undisturbed area was greater than 0.40, where the watershed geomorphic system was stable and strong, with flat terrain and small soil erosion modulus. [Conclusion] The risk of soil erosion gradually increased from south to north at the Hesigewula open-pit mine due to the original landform of the mining area, the mining sequence, and the location of the dump site. The results of this study can be used as the basis for landform reconstruction and ecological environment restoration of similar open-pit coal mines.
2023,43(5):148-155
, DOI: 10.13961/j.cnki.stbctb.2023.05.018
Abstract:
[Objective] The relationship between soil column pore structure and soil erosion resistance for soil columns with Bahiagrass was analyzed in order to provide a scientific basis for the optimal arrangement of plants for soil and water conservation and to assess the benefits of planting Bahiagrass. [Methods] This study was conducted using long-term experiments of Bahiagrass grown in soil columns. Four pore indicators (pore length density, bulk density, surface area density, and pore number density) of Bahiagrass soil columns were quantified by CT scanning technology. Flushing tests using a flume with variable slopes were carried out to quantify soil erosion resistance at three slopes (10°, 20°, and 30°) and five runoff rates (0.8, 1.6, 2.4, 3.2, and 4.0 L/s). The relationships between pore structure characteristics and erosion resistance factors were then determined. [Results] Bahiagrass root system development increased during the growth period, but decreased with soil depth. The values of four pore structure indicators in 0—5 cm soil layer were much higher than those in 5—10 cm soil layer, and the average soil rill erodibility (0.026 s/m) and critical shear stress (7.0 Pa) in 0—5 cm surface layer were 0.33 and 1.54 times the values of those respective parameters in 5—10 cm lower soil layer. [Conclusion] The pore characteristics of plant root development indicated soil erosion resistance. The four pore structure indicators obtained by CT scanning were significantly related to factors such as rill erodibility. The pore surface area density was most closely related to the erosion resistance factors.
[Objective] The relationship between soil column pore structure and soil erosion resistance for soil columns with Bahiagrass was analyzed in order to provide a scientific basis for the optimal arrangement of plants for soil and water conservation and to assess the benefits of planting Bahiagrass. [Methods] This study was conducted using long-term experiments of Bahiagrass grown in soil columns. Four pore indicators (pore length density, bulk density, surface area density, and pore number density) of Bahiagrass soil columns were quantified by CT scanning technology. Flushing tests using a flume with variable slopes were carried out to quantify soil erosion resistance at three slopes (10°, 20°, and 30°) and five runoff rates (0.8, 1.6, 2.4, 3.2, and 4.0 L/s). The relationships between pore structure characteristics and erosion resistance factors were then determined. [Results] Bahiagrass root system development increased during the growth period, but decreased with soil depth. The values of four pore structure indicators in 0—5 cm soil layer were much higher than those in 5—10 cm soil layer, and the average soil rill erodibility (0.026 s/m) and critical shear stress (7.0 Pa) in 0—5 cm surface layer were 0.33 and 1.54 times the values of those respective parameters in 5—10 cm lower soil layer. [Conclusion] The pore characteristics of plant root development indicated soil erosion resistance. The four pore structure indicators obtained by CT scanning were significantly related to factors such as rill erodibility. The pore surface area density was most closely related to the erosion resistance factors.
2023,43(5):156-168
, DOI: 10.13961/j.cnki.stbctb.2023.05.019
Abstract:
[Objective] The dynamic characteristics of soil moisture under different land preparation measures were analyzed in order to provide a scientific basis for assessing the eco-hydrological benefits of slope land preparations and for promoting vegetation restoration in arid areas. [Methods] We used an in-situ controlled study of natural slopes, fish-scale pits, and reverse slopes of a Pinus tabulaeformis forest in a semi-arid loess area along with dynamic monitoring of soil moisture and rainfall events and HYDRUS-1D software simulations to quantify the effects of different land preparation measures on the vertical migration characteristics of soil moisture. [Results] ① The simulation accuracy of the one-dimensional unsaturated soil moisture transport numerical model for soil moisture in the 0—40 cm layer was greater than that of the 40—100 cm layer, which was suitable for the simulation of surface (0—40 cm) soil moisture. During the entire study period, under the same rainfall conditions, the soil moisture fluxes of the fish-scale pits and the reverse slope terraces were significantly higher than the soil moisture flux of the corresponding natural slope (p＜0.05). The soil moisture flux of the fish-scale pits was significantly higher than that of the reverse slope terraces (p＜0.05). ② Under individual rainfall conditions, the soil moisture fluxes of the fish-scale pits and the reverse slope terraces for the 0—40 cm layer were 9.07% and 4.02%, respectively, higher than that of corresponding natural slope plots. The average differences between the fish-scale pits, the reverse slope terraces, and the corresponding natural slope sample plots were the largest at 20 and 30 cm, which were 0.79% and 0.37%, respectively, exhibiting an overall trend of first increasing and then decreasing. When the rainfall was 5—10 mm, the maximum soil moisture fluxes of the fish-scale pits and the reverse slope terraces were 1.94% and 1.42%, respectively, at 30 cm and 40 cm. When the rainfall was more than 10 mm, the maximum soil moisture fluxes of the fish-scale pits and the reverse slope terraces were 0—20 cm, which gradually decreased with increasing rainfall. There was no significant differences in soil moisture fluxes between fish-scale pits and reverse slope terraces. ③ Under continuous rainfall, soil moisture fluxes of fish-scale pits and reverse slope terraces in 0—40 cm layer were 10.73% and 4.72% higher than the soil moisture flux of the control natural slope. The differences between fish-scale pits, reverse slope terraces and the corresponding control natural slope plots were the most significant within 0—20 cm layer (p＜0.05), and the average difference showed an overall decreasing trend. The differences between fish scale pits, reverse slope terraces, and corresponding control natural slope at each soil layer were the most significant when the rainfall was 10—20 mm (p＜0.05), and the maximum increment was at 10 cm, which was 1.35% and 0.53%, respectively. The average soil moisture flux in each layer of the fish-scale pits showed a decreasing trend, and the reverse slope terraces showed an increasing trend. Under different rainfall conditions, the depth of the maximum soil moisture flux of the fish-scale pits and the reverse slope terraces was different. When the rainfall was less than 20 mm, the fish-scale pits and the reverse slope terraces were at 10 and 20 cm, which were 1.58% and 0.72%, respectively. When rainfall was ＞20 mm, the values for both fish-scale pits and reverse slope terraces at 40 cm were 2.61% and 1.92%. There were significant differences in soil moisture flux between each layer of the fish-scale pits and the reverse slope terraces. When the rainfall was 5—10 mm, there were significant differences in soil moisture fluxes between each layer of the fish-scale pits (p＜0.05), and there were significant differences in soil moisture fluxes between 20—40 cm in the reverse slope terraces (p＜0.05). [Conclusion] The fish-scale pits and the reverse slope terraces had different effects on soil moisture. The fish-scale pits had better water retention under rainfall conditions.
[Objective] The dynamic characteristics of soil moisture under different land preparation measures were analyzed in order to provide a scientific basis for assessing the eco-hydrological benefits of slope land preparations and for promoting vegetation restoration in arid areas. [Methods] We used an in-situ controlled study of natural slopes, fish-scale pits, and reverse slopes of a Pinus tabulaeformis forest in a semi-arid loess area along with dynamic monitoring of soil moisture and rainfall events and HYDRUS-1D software simulations to quantify the effects of different land preparation measures on the vertical migration characteristics of soil moisture. [Results] ① The simulation accuracy of the one-dimensional unsaturated soil moisture transport numerical model for soil moisture in the 0—40 cm layer was greater than that of the 40—100 cm layer, which was suitable for the simulation of surface (0—40 cm) soil moisture. During the entire study period, under the same rainfall conditions, the soil moisture fluxes of the fish-scale pits and the reverse slope terraces were significantly higher than the soil moisture flux of the corresponding natural slope (p＜0.05). The soil moisture flux of the fish-scale pits was significantly higher than that of the reverse slope terraces (p＜0.05). ② Under individual rainfall conditions, the soil moisture fluxes of the fish-scale pits and the reverse slope terraces for the 0—40 cm layer were 9.07% and 4.02%, respectively, higher than that of corresponding natural slope plots. The average differences between the fish-scale pits, the reverse slope terraces, and the corresponding natural slope sample plots were the largest at 20 and 30 cm, which were 0.79% and 0.37%, respectively, exhibiting an overall trend of first increasing and then decreasing. When the rainfall was 5—10 mm, the maximum soil moisture fluxes of the fish-scale pits and the reverse slope terraces were 1.94% and 1.42%, respectively, at 30 cm and 40 cm. When the rainfall was more than 10 mm, the maximum soil moisture fluxes of the fish-scale pits and the reverse slope terraces were 0—20 cm, which gradually decreased with increasing rainfall. There was no significant differences in soil moisture fluxes between fish-scale pits and reverse slope terraces. ③ Under continuous rainfall, soil moisture fluxes of fish-scale pits and reverse slope terraces in 0—40 cm layer were 10.73% and 4.72% higher than the soil moisture flux of the control natural slope. The differences between fish-scale pits, reverse slope terraces and the corresponding control natural slope plots were the most significant within 0—20 cm layer (p＜0.05), and the average difference showed an overall decreasing trend. The differences between fish scale pits, reverse slope terraces, and corresponding control natural slope at each soil layer were the most significant when the rainfall was 10—20 mm (p＜0.05), and the maximum increment was at 10 cm, which was 1.35% and 0.53%, respectively. The average soil moisture flux in each layer of the fish-scale pits showed a decreasing trend, and the reverse slope terraces showed an increasing trend. Under different rainfall conditions, the depth of the maximum soil moisture flux of the fish-scale pits and the reverse slope terraces was different. When the rainfall was less than 20 mm, the fish-scale pits and the reverse slope terraces were at 10 and 20 cm, which were 1.58% and 0.72%, respectively. When rainfall was ＞20 mm, the values for both fish-scale pits and reverse slope terraces at 40 cm were 2.61% and 1.92%. There were significant differences in soil moisture flux between each layer of the fish-scale pits and the reverse slope terraces. When the rainfall was 5—10 mm, there were significant differences in soil moisture fluxes between each layer of the fish-scale pits (p＜0.05), and there were significant differences in soil moisture fluxes between 20—40 cm in the reverse slope terraces (p＜0.05). [Conclusion] The fish-scale pits and the reverse slope terraces had different effects on soil moisture. The fish-scale pits had better water retention under rainfall conditions.
2023,43(5):169-175
, DOI: 10.13961/j.cnki.stbctb.2023.05.020
Abstract:
[Objective] The soil and water conservation effects of production and construction projects implemented during the construction period were determined in order to provide data support for the follow-up supervision and management of soil and water conservation of hydropower stations, and to provide a reference for the evaluation of soil and water conservation effects of production and construction projects. [Methods] The study was conducted at the production and construction project of the Lawa hydropower station in the Xizang Autonomous Prefecture of Garze, Sichuan Province. The system framework consisted of the focal points and technical regulations of soil and water conservation monitoring of production and construction projects. The analytic hierarchy process (AHP) and fuzzy comprehensive evaluation were applied to establish a soil and water conservation effect evaluation system that included 14 indicators from five aspects (red line disturbance, soil and water loss control, greening restoration, implementation of soil and water conservation measures, and soil and water loss hazards) to comprehensively evaluate the water and soil conservation effect during the construction period of the Lawa hydropower station. [Results] The comprehensive evaluation indexes of the Lawa hydropower station during 2017—2021 were 0.840 (excellent), 0.727 (good), 0.571 (average), 0.786 (good), 0.792 (good), respectively, indicating a trend of decreasing first and then increasing. The overall result was good. [Conclusion] Soil and water conservation work performed during the construction of the Lawa hydropower station (including red line disturbance, soil and water loss control, greening restoration, implementation of soil and water conservation measures, and soil and water loss damage) performed well overall, and achieved good benefits.
[Objective] The soil and water conservation effects of production and construction projects implemented during the construction period were determined in order to provide data support for the follow-up supervision and management of soil and water conservation of hydropower stations, and to provide a reference for the evaluation of soil and water conservation effects of production and construction projects. [Methods] The study was conducted at the production and construction project of the Lawa hydropower station in the Xizang Autonomous Prefecture of Garze, Sichuan Province. The system framework consisted of the focal points and technical regulations of soil and water conservation monitoring of production and construction projects. The analytic hierarchy process (AHP) and fuzzy comprehensive evaluation were applied to establish a soil and water conservation effect evaluation system that included 14 indicators from five aspects (red line disturbance, soil and water loss control, greening restoration, implementation of soil and water conservation measures, and soil and water loss hazards) to comprehensively evaluate the water and soil conservation effect during the construction period of the Lawa hydropower station. [Results] The comprehensive evaluation indexes of the Lawa hydropower station during 2017—2021 were 0.840 (excellent), 0.727 (good), 0.571 (average), 0.786 (good), 0.792 (good), respectively, indicating a trend of decreasing first and then increasing. The overall result was good. [Conclusion] Soil and water conservation work performed during the construction of the Lawa hydropower station (including red line disturbance, soil and water loss control, greening restoration, implementation of soil and water conservation measures, and soil and water loss damage) performed well overall, and achieved good benefits.
2023,43(5):176-186
, DOI: 10.13961/j.cnki.stbctb.2023.05.021
Abstract:
[Objective] In view of problems such as unbalanced recharge, excessive ineffective evaporation, and limited water supply range in the current intermittent channel water transport exist in the lower reaches of the Tarim River, the spatial and temporal water transport modes during the growth and non-growth periods and the influence of improvements of water transport mode on the groundwater level were analyzed in order to further improve the ecological restoration system of rotary infiltration irrigation and to provide a theoretical basis for ecological restoration in the lower reaches of the Tarim River. [Methods] The study was conducted in Yingsu monitoring section of the lower reaches of the Tarim River. Groundwater depth was monitored during ten ecological water conveyances from 2012 to 2021. The Modflow model was used to numerically simulate two-dimensional flow movement of the groundwater profile in Yingsu section. The response data of ten intermittent ecological water deliveries in Yingsu section was fitted and analyzed. The process of groundwater level evolution and water quantity change during the growth period, the non-growth period, and in the artificial water channels in non-growth period were predicted and analyzed. [Results] ① Under the proposed schemes of water delivery during the growth period, non-growth period, and in the non-growth period with the artificial river channels, the groundwater levels on both sides of the artificial river channels were raised by 2.5, 0.7, and 3.2 m, respectively, compared with the current water delivery system. ② The area of groundwater depth less than 8 m in the study area was increased by 10.89%, 19.33%, and 26.17% under the three improvement schemes compared with the current water delivery system. ③ The groundwater storage capacity was increased by 10.97%, 11.88%, and 14.39% compared with the current water delivery system. [Conclusion] The artificial water channels in the non-growth period combined the advantages of both artificial water channels in the growth period and the non-growth periods, improved the utilization rate of downstream water discharge, solved the problem of difficult recovery of groundwater level under the current water delivery mode in the main river channel, and created conditions for the recovery of the inter-river ecological system and the establishment of a safe zone for downstream biodiversity.
[Objective] In view of problems such as unbalanced recharge, excessive ineffective evaporation, and limited water supply range in the current intermittent channel water transport exist in the lower reaches of the Tarim River, the spatial and temporal water transport modes during the growth and non-growth periods and the influence of improvements of water transport mode on the groundwater level were analyzed in order to further improve the ecological restoration system of rotary infiltration irrigation and to provide a theoretical basis for ecological restoration in the lower reaches of the Tarim River. [Methods] The study was conducted in Yingsu monitoring section of the lower reaches of the Tarim River. Groundwater depth was monitored during ten ecological water conveyances from 2012 to 2021. The Modflow model was used to numerically simulate two-dimensional flow movement of the groundwater profile in Yingsu section. The response data of ten intermittent ecological water deliveries in Yingsu section was fitted and analyzed. The process of groundwater level evolution and water quantity change during the growth period, the non-growth period, and in the artificial water channels in non-growth period were predicted and analyzed. [Results] ① Under the proposed schemes of water delivery during the growth period, non-growth period, and in the non-growth period with the artificial river channels, the groundwater levels on both sides of the artificial river channels were raised by 2.5, 0.7, and 3.2 m, respectively, compared with the current water delivery system. ② The area of groundwater depth less than 8 m in the study area was increased by 10.89%, 19.33%, and 26.17% under the three improvement schemes compared with the current water delivery system. ③ The groundwater storage capacity was increased by 10.97%, 11.88%, and 14.39% compared with the current water delivery system. [Conclusion] The artificial water channels in the non-growth period combined the advantages of both artificial water channels in the growth period and the non-growth periods, improved the utilization rate of downstream water discharge, solved the problem of difficult recovery of groundwater level under the current water delivery mode in the main river channel, and created conditions for the recovery of the inter-river ecological system and the establishment of a safe zone for downstream biodiversity.
Jiang Yunqing, Wang Guoyan, Huang Mengyue, Zhang Hongnan, Peng Peihao, Pei Xiangjun, Li Jingji, Tang Xiaolu, Yin Daqiu, Wang Shijun
2023,43(5):187-194
, DOI: 10.13961/j.cnki.stbctb.20230524.001
Abstract:
[Objective] The effects of environmental factors on the plant community of a slope during ecological restoration objective of Pai-Mo Highway in Qinghai-Xizang Plateau were analyzed in order to provide theoretical basis for ecological restoration plan of disturbed area in Southeast Xizang. [Methods] We studied an area of the newly constructed Pai-Mo Highway in Southeastern Xizang. 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 primary determinants of the regeneration of plant communities on slopes along the Pai-Mo Highway are elevation and restoration measures. 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 effects of environmental factors on the plant community of a slope during ecological restoration objective of Pai-Mo Highway in Qinghai-Xizang Plateau were analyzed in order to provide theoretical basis for ecological restoration plan of disturbed area in Southeast Xizang. [Methods] We studied an area of the newly constructed Pai-Mo Highway in Southeastern Xizang. 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 primary determinants of the regeneration of plant communities on slopes along the Pai-Mo Highway are elevation and restoration measures. 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.
2023,43(5):195-202
, DOI: 10.13961/j.cnki.stbctb.2023.05.023
Abstract:
[Objective] The urban land use in the future and corresponding waterlogging risk intensity was predicted, and the optimal control of the waterlogging risk and its implementation effects was explored in order to provide references for improving the prevention and control level of urban waterlogging and optimizing the layout of urban land use. [Methods] The study was conducted in Changsha City, Hunan Province. Urban land use layout and its waterlogging risk under a baseline scenario were predicted using the PLUS and SCS models. High-risk waterlogging areas were used as limiting conversion factors in the PLUS model to simulate the urban land layout and its waterlogging risk under a waterlogging control scenario by coupling the PLUS and SCS models. The implementation of the optimal management and control measures was verified by comparing the waterlogging risk differences under the two scenarios. [Results] The high-risk waterlogging area of construction land was predicted to be 96.47 km2 in 2035 under the baseline scenario, and the total waterlogging risk area of the urban construction land under the waterlogging control scenario would be reduced by 36.94 km2 compared with the baseline scenario without reducing construction land area. Furthermore, all high-risk areas in the new construction land would be avoided. [Conclusion] The waterlogging risk in urban land will increase significantly in the future. An optimization control method based on the PLUS-SCS model will help cities avoid waterlogging risk.
[Objective] The urban land use in the future and corresponding waterlogging risk intensity was predicted, and the optimal control of the waterlogging risk and its implementation effects was explored in order to provide references for improving the prevention and control level of urban waterlogging and optimizing the layout of urban land use. [Methods] The study was conducted in Changsha City, Hunan Province. Urban land use layout and its waterlogging risk under a baseline scenario were predicted using the PLUS and SCS models. High-risk waterlogging areas were used as limiting conversion factors in the PLUS model to simulate the urban land layout and its waterlogging risk under a waterlogging control scenario by coupling the PLUS and SCS models. The implementation of the optimal management and control measures was verified by comparing the waterlogging risk differences under the two scenarios. [Results] The high-risk waterlogging area of construction land was predicted to be 96.47 km2 in 2035 under the baseline scenario, and the total waterlogging risk area of the urban construction land under the waterlogging control scenario would be reduced by 36.94 km2 compared with the baseline scenario without reducing construction land area. Furthermore, all high-risk areas in the new construction land would be avoided. [Conclusion] The waterlogging risk in urban land will increase significantly in the future. An optimization control method based on the PLUS-SCS model will help cities avoid waterlogging risk.
2023,43(5):203-211,278
, DOI: 10.13961/j.cnki.stbctb.2023.05.024
Abstract:
[Objective] The spatial-temporal variation of terrestrial vegetation coverage in Lugu Lake Wetland Nature Reserve in Sichuan Province during 2000—2020 was analyzed in order to provide a reference for the construction and management of the reserve. [Methods] MODIS data from June to September of 2000—2020 for the Lugu Lake Wetland Nature Reserve in Sichuan Province was the data source. Correlation analysis methods such as pixel dichotomy and Theil-SenMedian trend analysis were combined to determine the spatial-temporal variation characteristics of vegetation coverage and their response to climate. [Results] ① The overall terrestrial vegetation coverage of Lugu Lake Wetland Nature Reserve in Sichuan Province slightly increased from 2000 to 2020, and increased at a rate of 0.09/10 yr. ② Vegetation coverage of the protected area was low in the lake area and the surrounding areas, and higher in the north and south areas. The spatial variation of vegetation coverage of the protected area increased overall but decreased locally. ③ The climate of the reserve (from June to September) tended to be “warmer and drier”, and fractional vegetation coverage was mainly positively correlated with temperature and precipitation. The influence of temperature was greater than that of precipitation. The specific influencing factors had spatial differences. [Conclusion] From 2000 to 2020, the vegetation coverage of the Lugu Lake Wetland Nature Reserve in Sichuan Province was good, and the vegetation coverage slightly increased over time. Temperature was the main climate factor affecting vegetation coverage. Topography and human activities, meanwhile, had some effects on the vegetation coverage of the reserve to a certain extent.
[Objective] The spatial-temporal variation of terrestrial vegetation coverage in Lugu Lake Wetland Nature Reserve in Sichuan Province during 2000—2020 was analyzed in order to provide a reference for the construction and management of the reserve. [Methods] MODIS data from June to September of 2000—2020 for the Lugu Lake Wetland Nature Reserve in Sichuan Province was the data source. Correlation analysis methods such as pixel dichotomy and Theil-SenMedian trend analysis were combined to determine the spatial-temporal variation characteristics of vegetation coverage and their response to climate. [Results] ① The overall terrestrial vegetation coverage of Lugu Lake Wetland Nature Reserve in Sichuan Province slightly increased from 2000 to 2020, and increased at a rate of 0.09/10 yr. ② Vegetation coverage of the protected area was low in the lake area and the surrounding areas, and higher in the north and south areas. The spatial variation of vegetation coverage of the protected area increased overall but decreased locally. ③ The climate of the reserve (from June to September) tended to be “warmer and drier”, and fractional vegetation coverage was mainly positively correlated with temperature and precipitation. The influence of temperature was greater than that of precipitation. The specific influencing factors had spatial differences. [Conclusion] From 2000 to 2020, the vegetation coverage of the Lugu Lake Wetland Nature Reserve in Sichuan Province was good, and the vegetation coverage slightly increased over time. Temperature was the main climate factor affecting vegetation coverage. Topography and human activities, meanwhile, had some effects on the vegetation coverage of the reserve to a certain extent.
2023,43(5):212-219
, DOI: 10.13961/j.cnki.stbctb.2023.05.025
Abstract:
[Objective] Plateau pika (Ochotona curzoniae) is a key species in the alpine meadow ecosystem of the Qinghai-Xizang Plateau. The coupling relationship between pika activity and meadow degradation was analyzed in order to further improve the observation system of plateau pika interference intensity and to provide more comprehensive and scientific investigation data of plateau pika activity. [Methods] An observation and grading system for alpine pika disturbance intensity (PDI) was constructed using observational data from an unmanned aerial vehicle (UAV) and deep learning methods. Spatial-temporal variation analysis was conducted using a landscape index and a coupling degree model to clarify the coupling relationship between pika and meadow degradation. [Results] ①The accuracy of the ResNet-101 model for extracting bald patches on pika mounds reached 92.7%. Slight and light pika disturbance areas accounted for 82.0% of the total area in 2019, and the moderate and high disturbance intensity areas accounted for 62.5% of the total area in 2021. The area with significantly increased PDI from 2019 to 2021 accounted for 43.0% of the total area. ②Alpine meadow vegetation was predominantly classified as moderately degraded in 2019 and 2021. From 2019 to 2021, 30.2% of the area shifted to moderately degraded to severely degraded, and 7.7% of the area experienced a significant decrease in vegetation cover. ③The landscape of the study area transformed to bald patches in a single direction, and the landscape type became more aggregated, regular, and homogenized. The dominance of bald patches in the landscape increased significantly. ④The coupling degree was increased in most regions increased from 2019 to 2021, and the interaction between plateau pika disturbance and alpine meadow degradation was enhanced from 2019 to 2021. [Conclusion] The intensity of plateau pika disturbance in the study area increased from 2019 to 2020, vegetation coverage decreased, and the landscape gradually transformed to bald patches. The alpine meadow degraded under plateau pika disturbance. The coupling effect between plateau pika disturbance and alpine meadow degradation has gradually increased, and it is therefore necessary to take more active prevention and restoration measures.
[Objective] Plateau pika (Ochotona curzoniae) is a key species in the alpine meadow ecosystem of the Qinghai-Xizang Plateau. The coupling relationship between pika activity and meadow degradation was analyzed in order to further improve the observation system of plateau pika interference intensity and to provide more comprehensive and scientific investigation data of plateau pika activity. [Methods] An observation and grading system for alpine pika disturbance intensity (PDI) was constructed using observational data from an unmanned aerial vehicle (UAV) and deep learning methods. Spatial-temporal variation analysis was conducted using a landscape index and a coupling degree model to clarify the coupling relationship between pika and meadow degradation. [Results] ①The accuracy of the ResNet-101 model for extracting bald patches on pika mounds reached 92.7%. Slight and light pika disturbance areas accounted for 82.0% of the total area in 2019, and the moderate and high disturbance intensity areas accounted for 62.5% of the total area in 2021. The area with significantly increased PDI from 2019 to 2021 accounted for 43.0% of the total area. ②Alpine meadow vegetation was predominantly classified as moderately degraded in 2019 and 2021. From 2019 to 2021, 30.2% of the area shifted to moderately degraded to severely degraded, and 7.7% of the area experienced a significant decrease in vegetation cover. ③The landscape of the study area transformed to bald patches in a single direction, and the landscape type became more aggregated, regular, and homogenized. The dominance of bald patches in the landscape increased significantly. ④The coupling degree was increased in most regions increased from 2019 to 2021, and the interaction between plateau pika disturbance and alpine meadow degradation was enhanced from 2019 to 2021. [Conclusion] The intensity of plateau pika disturbance in the study area increased from 2019 to 2020, vegetation coverage decreased, and the landscape gradually transformed to bald patches. The alpine meadow degraded under plateau pika disturbance. The coupling effect between plateau pika disturbance and alpine meadow degradation has gradually increased, and it is therefore necessary to take more active prevention and restoration measures.
2023,43(5):220-226
, DOI: 10.13961/j.cnki.stbctb.2023.05.026
Abstract:
[Objective] The ecological changes in Zhalong Nature Reserve since 2010 were studied accurately in order to provide data support and theoretical references for improving the ability to assess the value of wetland ecosystem services. [Methods] Based on remote sensing, meteorology, and ground-based observation data, the impacts of climate change on land cover, vegetation ecological quality, and net ecological productivity in Zhalong Nature Reserve were analyzed using the Carnegie-Ames-Stanford Approach (CASA) model, the Geostatistical Model of Soil Respiration (GSMSR) model, regression analysis, and other statistical methods. [Results] ① The main land cover type in Zhalong Nature Reserve was a water-bearing meadow, which accounted for 37.24% of the total area of the reserve, and was mainly located in the core area. This land cover type showed a downward trend over time in the area. ② Vegetation coverage showed a fluctuating growth pattern, with annual maximum vegetation coverage of 74.26%. ③ The vegetation ecological quality index showed an increasing trend and was characterized as being in the good level in 2019 and 2020. The average net ecological productivity (NEP) was 253.59 g/(m2·yr) (calculated in C), and showed a spatial distribution pattern of higher in the east and lower in the west. ④ The average carbon fixation during the growing season was 5.694×105 tons/yr, and the oxygen release was 1.517×106 tons/yr, both of which showed upward trends. ⑤ The impacts of air temperature on ecological monitoring indicators were greater than the impacts of precipitation. [Conclusion] Zhalong Nature Reserve is the most ecologically fragile area in Nenjiang River basin, and its vegetation productivity is greatly affected by climate. Therefore, it is necessary to strengthen ecological protection and restoration.
[Objective] The ecological changes in Zhalong Nature Reserve since 2010 were studied accurately in order to provide data support and theoretical references for improving the ability to assess the value of wetland ecosystem services. [Methods] Based on remote sensing, meteorology, and ground-based observation data, the impacts of climate change on land cover, vegetation ecological quality, and net ecological productivity in Zhalong Nature Reserve were analyzed using the Carnegie-Ames-Stanford Approach (CASA) model, the Geostatistical Model of Soil Respiration (GSMSR) model, regression analysis, and other statistical methods. [Results] ① The main land cover type in Zhalong Nature Reserve was a water-bearing meadow, which accounted for 37.24% of the total area of the reserve, and was mainly located in the core area. This land cover type showed a downward trend over time in the area. ② Vegetation coverage showed a fluctuating growth pattern, with annual maximum vegetation coverage of 74.26%. ③ The vegetation ecological quality index showed an increasing trend and was characterized as being in the good level in 2019 and 2020. The average net ecological productivity (NEP) was 253.59 g/(m2·yr) (calculated in C), and showed a spatial distribution pattern of higher in the east and lower in the west. ④ The average carbon fixation during the growing season was 5.694×105 tons/yr, and the oxygen release was 1.517×106 tons/yr, both of which showed upward trends. ⑤ The impacts of air temperature on ecological monitoring indicators were greater than the impacts of precipitation. [Conclusion] Zhalong Nature Reserve is the most ecologically fragile area in Nenjiang River basin, and its vegetation productivity is greatly affected by climate. Therefore, it is necessary to strengthen ecological protection and restoration.
2023,43(5):227-234
, DOI: 10.13961/j.cnki.stbctb.2023.05.027
Abstract:
[Objective] The spatiotemporal characteristics of soil erosion were analyzed in order to provide a reference for soil erosion control and evaluation of soil and water conservation benefits. [Methods] Based on the RUSLE soil erosion equation, the spatial-temporal evolution of soil erosion in the typical black soil region of Binxian County, Heilongjiang Province from 2000 to 2020 was analyzed with the support of RS and GIS. The effects of topographic factors and land use on soil erosion were also investigated. [Results] ① The average modulus of soil erosion in 2000, 2010, and 2020 was 893.02 t/(km2·yr), 499.84 t/(km2·yr), and 1 561.02 t/(km2·yr), respectively. The soil erosion intensity was mainly classified as slight and mild. ② The low intensity erosion was distributed across the entire region, and the high intensity erosion was mainly located in the southern mountainous area. ③ Erosion mainly occurred at elevations of 100 to 200 m. Soil erosion area was inversely proportional to slope. 0°—5° slope was the main erosion gradient zone. Soil erosion area in the direction of the north slope was larger than in the direction of the south slope; ④ The soil erosion modulus and the area of sloping farmland in the study area were larger. This area is the key area for soil erosion control in Binxian County, Heilongjiang Province. [Conclusion] From 2000 to 2020, the average soil erosion modulus initially increased and then decreased, showing a significant spatiotemporal differentiation. Topographic factors and land use change had significant driving effects on soil erosion in the study area. It can be used as a reference for soil erosion control and soil and water conservation benefit evaluation in black soil region.
[Objective] The spatiotemporal characteristics of soil erosion were analyzed in order to provide a reference for soil erosion control and evaluation of soil and water conservation benefits. [Methods] Based on the RUSLE soil erosion equation, the spatial-temporal evolution of soil erosion in the typical black soil region of Binxian County, Heilongjiang Province from 2000 to 2020 was analyzed with the support of RS and GIS. The effects of topographic factors and land use on soil erosion were also investigated. [Results] ① The average modulus of soil erosion in 2000, 2010, and 2020 was 893.02 t/(km2·yr), 499.84 t/(km2·yr), and 1 561.02 t/(km2·yr), respectively. The soil erosion intensity was mainly classified as slight and mild. ② The low intensity erosion was distributed across the entire region, and the high intensity erosion was mainly located in the southern mountainous area. ③ Erosion mainly occurred at elevations of 100 to 200 m. Soil erosion area was inversely proportional to slope. 0°—5° slope was the main erosion gradient zone. Soil erosion area in the direction of the north slope was larger than in the direction of the south slope; ④ The soil erosion modulus and the area of sloping farmland in the study area were larger. This area is the key area for soil erosion control in Binxian County, Heilongjiang Province. [Conclusion] From 2000 to 2020, the average soil erosion modulus initially increased and then decreased, showing a significant spatiotemporal differentiation. Topographic factors and land use change had significant driving effects on soil erosion in the study area. It can be used as a reference for soil erosion control and soil and water conservation benefit evaluation in black soil region.
2023,43(5):235-243
, DOI: 10.13961/j.cnki.stbctb.2023.05.028
Abstract:
[Objective] The spatial and temporal evolution characteristics and driving factors of sand-dust weather in Inner Mongolia Autonomous Region from 1960 to 2020 were analyzed in order to scientifically understand the changes in regional sand-dust weather under the background of climate change and to provide a theoretical basis for ecological governance. [Methods] Daily data for floating dust, blowing sand, and sandstorms from 119 meteorological stations within the Inner Mongolia during 1960—2020 were analyzed to determine the spatial-temporal variation characteristics of sand-dust weather for this region using trend analysis, the M—K test, wavelet analysis, etc. [Results] ① The number and intensity of sand-dust storm days at each level exhibited a very significant (p＜0.01) downward trend in the Inner Mongolia Autonomous Region from 1960 to 2020. There was an abrupt decreasing point around 1990 for both the number of floating dust days and blowing sand days. There was no obvious change point in either the number of sand-dust storm days or the sand dust intensity index. ② The frequency and intensity of sand-dust weather was high in the western part of the region, and the high-value center was at the junction of the central and western parts of Alxa League and Wuhai City. The influence of sand-dust weather quickly weakened to the east, and regional differences were great. The weakening degree of sand-dust weather was significantly greater in the western region than in the eastern region. ③ The reduction in number of sand-dust days for the Inner Mongolia Autonomous Region resulted from (a) the decreasing number of windy days (10.1 d/10 yr，p＜0.01) and the increasing amount of precipitation in winter and spring (10.1 d/10 yr，p＜0.01) caused by significant warming, and from (b) increasing NDVI (0.036/10 yr，p＜0.01) and a better ecological environment owing to the government’s large-scale ecological governance. [Conclusion] Desertified land control is an effective way to suppress the frequency and intensity of sand-dust weather. It will be necessary to continuously promote the construction of the ecological environment and to minimize the sources of sand and dust. Moreover, we increase efforts to effectively develop and utilize water resources under the background of climate change, thereby promoting a virtuous cycle of ecological environment and reducing the harm caused by sand-dust weather.
[Objective] The spatial and temporal evolution characteristics and driving factors of sand-dust weather in Inner Mongolia Autonomous Region from 1960 to 2020 were analyzed in order to scientifically understand the changes in regional sand-dust weather under the background of climate change and to provide a theoretical basis for ecological governance. [Methods] Daily data for floating dust, blowing sand, and sandstorms from 119 meteorological stations within the Inner Mongolia during 1960—2020 were analyzed to determine the spatial-temporal variation characteristics of sand-dust weather for this region using trend analysis, the M—K test, wavelet analysis, etc. [Results] ① The number and intensity of sand-dust storm days at each level exhibited a very significant (p＜0.01) downward trend in the Inner Mongolia Autonomous Region from 1960 to 2020. There was an abrupt decreasing point around 1990 for both the number of floating dust days and blowing sand days. There was no obvious change point in either the number of sand-dust storm days or the sand dust intensity index. ② The frequency and intensity of sand-dust weather was high in the western part of the region, and the high-value center was at the junction of the central and western parts of Alxa League and Wuhai City. The influence of sand-dust weather quickly weakened to the east, and regional differences were great. The weakening degree of sand-dust weather was significantly greater in the western region than in the eastern region. ③ The reduction in number of sand-dust days for the Inner Mongolia Autonomous Region resulted from (a) the decreasing number of windy days (10.1 d/10 yr，p＜0.01) and the increasing amount of precipitation in winter and spring (10.1 d/10 yr，p＜0.01) caused by significant warming, and from (b) increasing NDVI (0.036/10 yr，p＜0.01) and a better ecological environment owing to the government’s large-scale ecological governance. [Conclusion] Desertified land control is an effective way to suppress the frequency and intensity of sand-dust weather. It will be necessary to continuously promote the construction of the ecological environment and to minimize the sources of sand and dust. Moreover, we increase efforts to effectively develop and utilize water resources under the background of climate change, thereby promoting a virtuous cycle of ecological environment and reducing the harm caused by sand-dust weather.
2023,43(5):244-251
, DOI: 10.13961/j.cnki.stbctb.2023.05.029
Abstract:
[Objective] The effect of growth and management of a Larix principis-rupprechtii plantation was analyzed in order to provide a reference for the scientific and rational management of L. principis-rupprechtii plantations by giving full attention to ecological functions and cost-effectiveness. [Methods] The methods used in this study included consulting archives, conducting interviews, and field investigations regarding the input costs and growth of stands of the main L. principis-rupprechtii under traditional forest management and under near-natural forest management in Yuanzhou District, Guyuan City, Ningxia Hui Autonomous Region located in the upper reaches of the Jinghe River basin. Measured parameters included input costs, average diameter at breast height, average tree height, stock volume per hectare, and aboveground biomass of per hectare. The fuzzy mathematics subordination function value method was used to quantitatively compare and evaluate the growth of trees. [Results] The growth of trees under different forest management models was significantly dissimilar. The average height, diameter at breast height, stock volume per hectare, and aboveground biomass per hectare at Huangjiagou and Diediegou under near-natural forest management were greater than under traditional forest management. The comprehensive evaluation of the growth effect of the many plantations of L. principis-rupprechtii under different management models in Yuanzhou District of Guyuan City was extremely obvious (p＜0.05). The stand growth effect followed the order (ranging from strong to weak) of Huangjiagou (0.995 8)＞Diediegou (0.628 8)＞Qingshixia(0.224 6)＞Hongzhuangliang (0.222 7)＞Madong Mountain (0.159 8)＞Chenger Mountain (0.048 6)＞Longdegou (0.000 0). [Conclusion] Tree growth under the traditional forest management model was poor. Therefore, implementation of multi-functional and near-natural target tree management measures is conducive to cultivating large diameter timber to accelerate the growth of forests.
[Objective] The effect of growth and management of a Larix principis-rupprechtii plantation was analyzed in order to provide a reference for the scientific and rational management of L. principis-rupprechtii plantations by giving full attention to ecological functions and cost-effectiveness. [Methods] The methods used in this study included consulting archives, conducting interviews, and field investigations regarding the input costs and growth of stands of the main L. principis-rupprechtii under traditional forest management and under near-natural forest management in Yuanzhou District, Guyuan City, Ningxia Hui Autonomous Region located in the upper reaches of the Jinghe River basin. Measured parameters included input costs, average diameter at breast height, average tree height, stock volume per hectare, and aboveground biomass of per hectare. The fuzzy mathematics subordination function value method was used to quantitatively compare and evaluate the growth of trees. [Results] The growth of trees under different forest management models was significantly dissimilar. The average height, diameter at breast height, stock volume per hectare, and aboveground biomass per hectare at Huangjiagou and Diediegou under near-natural forest management were greater than under traditional forest management. The comprehensive evaluation of the growth effect of the many plantations of L. principis-rupprechtii under different management models in Yuanzhou District of Guyuan City was extremely obvious (p＜0.05). The stand growth effect followed the order (ranging from strong to weak) of Huangjiagou (0.995 8)＞Diediegou (0.628 8)＞Qingshixia(0.224 6)＞Hongzhuangliang (0.222 7)＞Madong Mountain (0.159 8)＞Chenger Mountain (0.048 6)＞Longdegou (0.000 0). [Conclusion] Tree growth under the traditional forest management model was poor. Therefore, implementation of multi-functional and near-natural target tree management measures is conducive to cultivating large diameter timber to accelerate the growth of forests.
2023,43(5):252-261
, DOI: 10.13961/j.cnki.stbctb.2023.05.030
Abstract:
[Objective] Investigating the coupling relationship between the risk of soil erosion and the natural suitability of human settlements in Guyuan City, Ningxia Hui Autonomous Region provides theoretical support for the prevention and control of soil erosion in small watersheds, and thereby contributes more to the improvement of human settlements. [Methods] The PSR model and the human settlement index model were used to calculate the risk of soil erosion in a small watershed as well as the natural suitability for human settlement. The correlation and the coupling degree of the two factors were calculated to analyze their coupling coordination degree and the coupling coordination type. [Results] ① The small watersheds with moderate and high risk of soil erosion accounted for 28% of the area, and were located in the southwest and southeast. Small watersheds that were rated as unsuitable for human settlement accounted for 12% of the area, located in the southern of Xiji County and Northeastern Longde County. ② The correlation coefficient between soil erosion risk and natural suitability of human settlements was 0.61. 74% of small watersheds were found to have high coupling degree and benign resonance coupling areas, and 67% of small watersheds were found to be coordinated development and highly coordinated development areas. ③ There were 75, 36, 79, and 114 watersheds classified as coordination and synchronization type small watersheds, imbalance and co-loss type small watersheds, soil erosion lag type small watersheds, and human settlement lag type small watersheds, respectively. [Conclusion] ① Soil erosion and human settlement in Guyuan City had high correlation, high coupling degree, and significant mutual promotion effects. ② There were 79 small watersheds with lagging risk of soil erosion that needed to be controlled, and 36 dysfunctional co-loss type small watersheds should be treated and reconstructed according to the local conditions.
[Objective] Investigating the coupling relationship between the risk of soil erosion and the natural suitability of human settlements in Guyuan City, Ningxia Hui Autonomous Region provides theoretical support for the prevention and control of soil erosion in small watersheds, and thereby contributes more to the improvement of human settlements. [Methods] The PSR model and the human settlement index model were used to calculate the risk of soil erosion in a small watershed as well as the natural suitability for human settlement. The correlation and the coupling degree of the two factors were calculated to analyze their coupling coordination degree and the coupling coordination type. [Results] ① The small watersheds with moderate and high risk of soil erosion accounted for 28% of the area, and were located in the southwest and southeast. Small watersheds that were rated as unsuitable for human settlement accounted for 12% of the area, located in the southern of Xiji County and Northeastern Longde County. ② The correlation coefficient between soil erosion risk and natural suitability of human settlements was 0.61. 74% of small watersheds were found to have high coupling degree and benign resonance coupling areas, and 67% of small watersheds were found to be coordinated development and highly coordinated development areas. ③ There were 75, 36, 79, and 114 watersheds classified as coordination and synchronization type small watersheds, imbalance and co-loss type small watersheds, soil erosion lag type small watersheds, and human settlement lag type small watersheds, respectively. [Conclusion] ① Soil erosion and human settlement in Guyuan City had high correlation, high coupling degree, and significant mutual promotion effects. ② There were 79 small watersheds with lagging risk of soil erosion that needed to be controlled, and 36 dysfunctional co-loss type small watersheds should be treated and reconstructed according to the local conditions.
2023,43(5):262-269
, DOI: 10.13961/j.cnki.stbctb.2023.05.031
Abstract:
[Objective] The characteristics of sand-driving wind and sand-transporting potential are the key indexes for evaluating the regional wind energy environment. The change characteristics of the wind regime and transport potential of sand-driving wind in the Northeast Bayan Wendur Desert were analyzed, the dynamic wind characteristics and the intensity of the wind energy activity near the ground were revealed, and the regional wind energy environment was evaluated, in order to provide a theoretical basis for the study of sand movement and scientific options for sand movement prevention and control. [Methods] Wind data were acquired from a meteorological station on the northeast edge of the Bayan Wendur Desert from 2017 to 2021, and the characteristics of the sand-driving wind and sediment transport potential in the region were analyzed. [Results] ① The annual average frequency of sand-driving wind was 43.70%, and the average sand-driving wind speed was 7.57 m/s, both of which were the highest in spring. The sand-driving winds in different seasons and the annual average were mainly westerly (W, WSW, SW) and southerly (S, SSE, SE). ② The annual average sediment transport potential (DP) was 68.36 VU. The composite sediment transport potential (RDP) was 29.39 VU. The wind direction variability index (RDP/DP) was 0.43. The composite sediment transport potential direction (RDD) was 91.33°. The DP and RDP in spring were significantly greater than in other seasons. ③ The influence of the average wind speed on the sediment transport potential in the study area was greater than the frequency of the wind speed. The intensity of sand movement was mainly determined by wind speed. [Conclusion] The northeast edge of the Bayan Wendur Desert generally belongs to a low wind energy environment. The surface sand material is transported eastward throughout the year. Spring is the most important period of wind and sand activity. June is the key period for the construction of artificial protective forests and aerial-seeding afforestation for sand control. We recommend that the direction of planting protective forest shelterbelts and for aerial seeding of forest seeds be perpendicular to the direction of sand transport potential so as to block the continuous eastward movement of sand.
[Objective] The characteristics of sand-driving wind and sand-transporting potential are the key indexes for evaluating the regional wind energy environment. The change characteristics of the wind regime and transport potential of sand-driving wind in the Northeast Bayan Wendur Desert were analyzed, the dynamic wind characteristics and the intensity of the wind energy activity near the ground were revealed, and the regional wind energy environment was evaluated, in order to provide a theoretical basis for the study of sand movement and scientific options for sand movement prevention and control. [Methods] Wind data were acquired from a meteorological station on the northeast edge of the Bayan Wendur Desert from 2017 to 2021, and the characteristics of the sand-driving wind and sediment transport potential in the region were analyzed. [Results] ① The annual average frequency of sand-driving wind was 43.70%, and the average sand-driving wind speed was 7.57 m/s, both of which were the highest in spring. The sand-driving winds in different seasons and the annual average were mainly westerly (W, WSW, SW) and southerly (S, SSE, SE). ② The annual average sediment transport potential (DP) was 68.36 VU. The composite sediment transport potential (RDP) was 29.39 VU. The wind direction variability index (RDP/DP) was 0.43. The composite sediment transport potential direction (RDD) was 91.33°. The DP and RDP in spring were significantly greater than in other seasons. ③ The influence of the average wind speed on the sediment transport potential in the study area was greater than the frequency of the wind speed. The intensity of sand movement was mainly determined by wind speed. [Conclusion] The northeast edge of the Bayan Wendur Desert generally belongs to a low wind energy environment. The surface sand material is transported eastward throughout the year. Spring is the most important period of wind and sand activity. June is the key period for the construction of artificial protective forests and aerial-seeding afforestation for sand control. We recommend that the direction of planting protective forest shelterbelts and for aerial seeding of forest seeds be perpendicular to the direction of sand transport potential so as to block the continuous eastward movement of sand.
2023,43(5):270-278
, DOI: 10.13961/j.cnki.stbctb.2023.05.032
Abstract:
[Objective] The relationship between water adaptation and the distribution pattern of desert shrubs at the regional scale was studied and the process and mechanism of plant population response to environment in arid and semi-arid areas was analyzed in order to provide a basis for further understanding the co-evolution relationship between plants and environments. [Methods] The spatial distribution pattern and water use strategy of Reaumuria songarica populations were analyzed by using point pattern analysis and hydrogen and oxygen stable isotope tracing techniques. [Results] ① Under the complete spatial randomness model, the R. songarica population was uniformly distributed at ＜3 m scale, and aggregated at ＞32 m scale. The intra-population ecological relationship changed from competition to promotion. After habitat heterogeneity was eliminated, the population showed random distribution at ＞ 30 m scale, and the intra-population ecological relationship showed a weakening trend, indicating that habitat heterogeneity played an important role in the formation of the spatial distribution pattern of the R. songarica population. This result indicated that habitat heterogeneity played an important role in the formation of the spatial distribution pattern of R. songarica populations at large scales. ② As the multi-year average precipitation decreased, the water use depth of the R. songarica population deepened from 0—20 cm to 60—100 cm. The density of the R. songarica population showed a highly significant negative correlation with multi-year precipitation (p＜0.01). The change in vegetation cover at the sample site was mainly influenced by the herbaceous cover, and the change in R. songarica vegetation cover was not significant. [Conclusion] As multi-year average precipitation decreased, the distribution pattern of R. songarica populations was affected by environmental heterogeneity, and R. songarica adapted to environmental stress by increasing plant density and using deeper soil moisture.
[Objective] The relationship between water adaptation and the distribution pattern of desert shrubs at the regional scale was studied and the process and mechanism of plant population response to environment in arid and semi-arid areas was analyzed in order to provide a basis for further understanding the co-evolution relationship between plants and environments. [Methods] The spatial distribution pattern and water use strategy of Reaumuria songarica populations were analyzed by using point pattern analysis and hydrogen and oxygen stable isotope tracing techniques. [Results] ① Under the complete spatial randomness model, the R. songarica population was uniformly distributed at ＜3 m scale, and aggregated at ＞32 m scale. The intra-population ecological relationship changed from competition to promotion. After habitat heterogeneity was eliminated, the population showed random distribution at ＞ 30 m scale, and the intra-population ecological relationship showed a weakening trend, indicating that habitat heterogeneity played an important role in the formation of the spatial distribution pattern of the R. songarica population. This result indicated that habitat heterogeneity played an important role in the formation of the spatial distribution pattern of R. songarica populations at large scales. ② As the multi-year average precipitation decreased, the water use depth of the R. songarica population deepened from 0—20 cm to 60—100 cm. The density of the R. songarica population showed a highly significant negative correlation with multi-year precipitation (p＜0.01). The change in vegetation cover at the sample site was mainly influenced by the herbaceous cover, and the change in R. songarica vegetation cover was not significant. [Conclusion] As multi-year average precipitation decreased, the distribution pattern of R. songarica populations was affected by environmental heterogeneity, and R. songarica adapted to environmental stress by increasing plant density and using deeper soil moisture.
2023,43(5):279-287,296
, DOI: 10.13961/j.cnki.stbctb.2023.05.033
Abstract:
[Objective] Under total carbon emission control, an equitable and scientific allocation of carbon emission quota among provinces of China is a key approach for achieving the “dual carbon” goal, as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction was analyzed under different scenarios with regard to the results of carbon emission quota allocation in order to determine the optimal carbon emission quota budget scheme at the lowest cost, thereby providing a theoretical basis for subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] An ecological index was introduced based on the carbon quota budget index established in previous studies. Four scenarios (including equity, efficiency, ecology, and balanced equity-efficiency-ecology) were evaluated. The slacks-based measure (SBM) dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal budget scheme was determined based on these results. [Results] Under the scenarios of equity, efficiency, ecology and balanced, the average marginal costs of carbon emission reduction were 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. When the ecological index was introduced, the emission reduction cost of the scheme was significantly lower, and it can be inferred that the carbon sink offsets a portion of the carbon emissions that are more difficult and costly to reduce. The cost of emission reduction under the balanced scenario was significantly higher than under the equity and ecology scenarios, indicating that improvement in carbon emission efficiency will lead to an increase in marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under the ecology scenario was the best scheme for achieving the “dual carbon” goal with the lowest marginal carbon emission reduction cost. Attention should be paid to the formulation of regional carbon emission schemes and carbon trading mechanisms.
[Objective] Under total carbon emission control, an equitable and scientific allocation of carbon emission quota among provinces of China is a key approach for achieving the “dual carbon” goal, as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction was analyzed under different scenarios with regard to the results of carbon emission quota allocation in order to determine the optimal carbon emission quota budget scheme at the lowest cost, thereby providing a theoretical basis for subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] An ecological index was introduced based on the carbon quota budget index established in previous studies. Four scenarios (including equity, efficiency, ecology, and balanced equity-efficiency-ecology) were evaluated. The slacks-based measure (SBM) dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal budget scheme was determined based on these results. [Results] Under the scenarios of equity, efficiency, ecology and balanced, the average marginal costs of carbon emission reduction were 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. When the ecological index was introduced, the emission reduction cost of the scheme was significantly lower, and it can be inferred that the carbon sink offsets a portion of the carbon emissions that are more difficult and costly to reduce. The cost of emission reduction under the balanced scenario was significantly higher than under the equity and ecology scenarios, indicating that improvement in carbon emission efficiency will lead to an increase in marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under the ecology scenario was the best scheme for achieving the “dual carbon” goal with the lowest marginal carbon emission reduction cost. Attention should be paid to the formulation of regional carbon emission schemes and carbon trading mechanisms.
2023,43(5):288-296
, DOI: 10.13961/j.cnki.stbctb.2023.05.034
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 “higher in the west and south, lower 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 “higher in the west and south, lower 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.
2023,43(5):297-303,311
, DOI: 10.13961/j.cnki.stbctb.2023.05.035
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 from 2005 to 2020. 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 “higher in the central region and lower 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 in Yunnan Province. [Conclusion] In Yunnan Province, 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 from 2005 to 2020. 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 “higher in the central region and lower 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 in Yunnan Province. [Conclusion] In Yunnan Province, 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.
2023,43(5):304-311
, DOI: 10.13961/j.cnki.stbctb.20231011.001
Abstract:
[Objective] The carbon sinks of soil and vegetation were monitored and evaluated in order to provide technology and methodology for implementing dynamic monitoring and evaluation of carbon sinks for soil and water conservation projects, and to provide theoretical and methodological support for soil and water conservation projects to participate in carbon emissions trading, and to research and formulate relevant rules. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in Luodihe small watershed at Changting County, Fujian Province during 2001—2022 was calculated through field sampling analysis and LiDAR collection of relevant parameters. Carbon sink capacity of various soil and water conservation management measures in the small watershed was evaluated. [Results] ① After 21 years of comprehensive management, various soil and water conservation measures in the study area have significantly improved the role and capacity of carbon sinks. The carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/yr. ② The carbon storage of soil and vegetation carbon pools increased by 73.73% and 346.41%, respectively, during 2001—2022. The carbon sink of the small watershed reached 3.05×104 t, of which 1.66×104 t was attributed to the soil carbon sink and 1.39×104 t was attributed to the vegetation carbon sink. ③ There were differences in the ability of various measures to increase the carbon sinks. Chestnut forest land and fertilized Pinus massoniana forest land increased carbon sink the most obviously, followed by coniferous and broad-leaved mixed forest, nursery and managed P. massoniana, horizontal grade land preparation of P. massoniana forest, and finally close management and bayberry forest land. [Conclusion] Various soil and water conservation measures had obvious effects on carbon retention, carbon sequestration, and carbon sink increase. The carbon sink capacity of forest land such as chestnut forest and fertilized P. massoniana forest land with land preparation, afforestation, and fertilization and breeding measures was even more significant. These practices provide an effective means for improving the efficiency of soil and water retention and for increasing carbon sink.
[Objective] The carbon sinks of soil and vegetation were monitored and evaluated in order to provide technology and methodology for implementing dynamic monitoring and evaluation of carbon sinks for soil and water conservation projects, and to provide theoretical and methodological support for soil and water conservation projects to participate in carbon emissions trading, and to research and formulate relevant rules. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in Luodihe small watershed at Changting County, Fujian Province during 2001—2022 was calculated through field sampling analysis and LiDAR collection of relevant parameters. Carbon sink capacity of various soil and water conservation management measures in the small watershed was evaluated. [Results] ① After 21 years of comprehensive management, various soil and water conservation measures in the study area have significantly improved the role and capacity of carbon sinks. The carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/yr. ② The carbon storage of soil and vegetation carbon pools increased by 73.73% and 346.41%, respectively, during 2001—2022. The carbon sink of the small watershed reached 3.05×104 t, of which 1.66×104 t was attributed to the soil carbon sink and 1.39×104 t was attributed to the vegetation carbon sink. ③ There were differences in the ability of various measures to increase the carbon sinks. Chestnut forest land and fertilized Pinus massoniana forest land increased carbon sink the most obviously, followed by coniferous and broad-leaved mixed forest, nursery and managed P. massoniana, horizontal grade land preparation of P. massoniana forest, and finally close management and bayberry forest land. [Conclusion] Various soil and water conservation measures had obvious effects on carbon retention, carbon sequestration, and carbon sink increase. The carbon sink capacity of forest land such as chestnut forest and fertilized P. massoniana forest land with land preparation, afforestation, and fertilization and breeding measures was even more significant. These practices provide an effective means for improving the efficiency of soil and water retention and for increasing carbon sink.
2023,43(5):312-319
, DOI: 10.13961/j.cnki.stbctb.2023.05.037
Abstract:
[Objective] Land use change is one of the important driving forces for increasing carbon emissions and the 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 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 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 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, 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 and the 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 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 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 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, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
2023,43(5):320-329,342
, DOI: 10.13961/j.cnki.stbctb.2023.05.038
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 that time period, with the fastest growth rate being 83.4% for construction land. ② Carbon storage for Hainan Island was generally characterized as “higher in the middle and lower 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 7 439 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 that time period, with the fastest growth rate being 83.4% for construction land. ② Carbon storage for Hainan Island was generally characterized as “higher in the middle and lower 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 7 439 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.
2023,43(5):330-342
, DOI: 10.13961/j.cnki.stbctb.2023.05.039
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, Liaoning Province. [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 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, Liaoning Province. [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 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.
2023,43(5):343-354
, DOI: 10.13961/j.cnki.stbctb.2023.05.040
Abstract:
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential were 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 of counties in Hunan Province. [Results] The overall agricultural carbon emissions of counties in Hunan Province exhibited a structural form of “higher value areas in the center, and gradually decreased outwards”. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of “higher in the southwest, lower in the northeast” and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of “higher in the east, central, and north regions, lower 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 higher carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were lower, thous 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 higher agricultural carbon compensation capacity. The future work should focus 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.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential were 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 of counties in Hunan Province. [Results] The overall agricultural carbon emissions of counties in Hunan Province exhibited a structural form of “higher value areas in the center, and gradually decreased outwards”. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of “higher in the southwest, lower in the northeast” and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of “higher in the east, central, and north regions, lower 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 higher carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were lower, thous 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 higher agricultural carbon compensation capacity. The future work should focus 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.
2023,43(5):355-364,394
, DOI: 10.13961/j.cnki.stbctb.2023.05.041
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 (＞3 000 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 (＞3 000 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.
2023,43(5):365-373
, DOI: 10.13961/j.cnki.stbctb.2023.05.042
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, Jiangxi Province. [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 City 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. Overall, 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] It is suggested to optimize land use structure, implement ecological protection and cultivate land protection policies, limit excessive expansion of construction land, and strengthen the regulation of key areas, so as to achieve the goal of carbon peak and carbon neutrality of Nanchang City 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, Jiangxi Province. [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 City 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. Overall, 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] It is suggested to optimize land use structure, implement ecological protection and cultivate land protection policies, limit excessive expansion of construction land, and strengthen the regulation of key areas, so as to achieve the goal of carbon peak and carbon neutrality of Nanchang City as soon as possible.
2023,43(5):374-384
, DOI: 10.13961/j.cnki.stbctb.2023.05.043
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, Henan Province 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 1 004.98 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 6.59×107 t and 5.67×107 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 “higher in the west, lower in the east, medium in the north and south, and lower 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. In future land use planning of Zhengzhou City, people 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, Henan Province 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 1 004.98 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 6.59×107 t and 5.67×107 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 “higher in the west, lower in the east, medium in the north and south, and lower 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. In future land use planning of Zhengzhou City, people should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
Xia Quansheng, Hong Xin, Gui Xiang, Shen Gaoping, Deng Liang, Yao Zhenhai, Peng Peng, Chu Yunzhi, Xu Sheng, Xu Wei
2023,43(5):385-394
, DOI: 10.13961/j.cnki.stbctb.20230526.001
Abstract:
[Objective] The spatial and temporal distribution pattern of carbon storage at Wuhu City, Anhui Province from 2011 to 2021 were analyzed, and the influence of ecological environmental factors, topographic factors, meteorological factors, and land use degree on carbon sequestration capacity were determined in order to provide a reference for land resource management and green agricultural development at Wuhu City. [Methods] The carbon storage module of the InVEST model was used to quantitatively determine the spatial distribution of carbon storage, to explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and to calculate the hot spots of carbon storage based on correlation analysis superposition using land use data from 2011, 2015, and 2021 at Wuhu City. [Results] ① Carbon storage at Wuhu City has declined by 4.15×105 t in recent years due to land use changes, with an annually decreasing trend. The carbon sequestration capacity of grassland was lower than that of cultivated land. The carbon storage capacity of cultivated land was 7.41×106 t, while that of forest land was 5 489.01 t/km2. ② Land use type, elevation, slope, and land use degree were the most important natural factors determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope. The overall distribution of carbon stocks was “lower in the north and higher in the south.” ③ Carbon storage and soil conservation were significantly and positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there was a trade-off with soil erosion. ④ Carbon storage in the south showed a pattern of “high-high accumulation”, accounting for 18.77% of the total carbon accumulation, whereas carbon storage in the north showed a pattern of low-low accumulation, accounting for just 2.73% of the total carbon accumulation. The hotspots of carbon storage declined over time as a result of the effect of resource development and usage, with 11.95% of the area classified as excellent concentrated in the southern mountain forest. Certain areas were found to be vulnerable and will need to be conserved and optimized. [Conclusion] From 2011 to 2021, the total amount of carbon sequestration at Wuhu City decreased year by year, and the carbon sequestration rate showed a trend of weakening over time, while carbon sequestration capacity was relatively stable. Carbon sequestration capacity in the northern part of Wuhu City was relatively weak, and could be increased through land management optimization.
[Objective] The spatial and temporal distribution pattern of carbon storage at Wuhu City, Anhui Province from 2011 to 2021 were analyzed, and the influence of ecological environmental factors, topographic factors, meteorological factors, and land use degree on carbon sequestration capacity were determined in order to provide a reference for land resource management and green agricultural development at Wuhu City. [Methods] The carbon storage module of the InVEST model was used to quantitatively determine the spatial distribution of carbon storage, to explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and to calculate the hot spots of carbon storage based on correlation analysis superposition using land use data from 2011, 2015, and 2021 at Wuhu City. [Results] ① Carbon storage at Wuhu City has declined by 4.15×105 t in recent years due to land use changes, with an annually decreasing trend. The carbon sequestration capacity of grassland was lower than that of cultivated land. The carbon storage capacity of cultivated land was 7.41×106 t, while that of forest land was 5 489.01 t/km2. ② Land use type, elevation, slope, and land use degree were the most important natural factors determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope. The overall distribution of carbon stocks was “lower in the north and higher in the south.” ③ Carbon storage and soil conservation were significantly and positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there was a trade-off with soil erosion. ④ Carbon storage in the south showed a pattern of “high-high accumulation”, accounting for 18.77% of the total carbon accumulation, whereas carbon storage in the north showed a pattern of low-low accumulation, accounting for just 2.73% of the total carbon accumulation. The hotspots of carbon storage declined over time as a result of the effect of resource development and usage, with 11.95% of the area classified as excellent concentrated in the southern mountain forest. Certain areas were found to be vulnerable and will need to be conserved and optimized. [Conclusion] From 2011 to 2021, the total amount of carbon sequestration at Wuhu City decreased year by year, and the carbon sequestration rate showed a trend of weakening over time, while carbon sequestration capacity was relatively stable. Carbon sequestration capacity in the northern part of Wuhu City was relatively weak, and could be increased through land management optimization.
2023,43(5):395-403
, DOI: 10.13961/j.cnki.stbctb.20230526.004
Abstract:
[Objective] The spatial-temporal characteristics and decoupling effects of agricultural carbon emissions at Xuzhou City, Jiangsu Province were analyzed in order to provide a theoretical basis and data reference for green, high-quality sustainable development of agriculture and the benign growth of the agricultural economy in Xuzhou City, and its surrounding resource-based cities in the future. [Methods] The total amount, intensity, and structure of agricultural carbon emissions at Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and their decoupling relationship with agricultural economic development was determine based on the Tapio decoupling model. [Results] ① The overall trend of agricultural carbon emissions at Xuzhou City could be described as M-shaped (rapid rise-fluctuating rise-rapid decline) from 1.61×106 t in 2000 to 1.69×106 t in 2020. The contributions of factors affecting agricultural carbon emissions followed 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; ② Agricultural carbon emission at Xuzhou City varied significantly among districts (counties and cities) and had undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of “higher in the middle and lower in the surrounding areas”, with Pizhou City being the most prominent; ③ Xuzhou City’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 has mainly manifested as strong decoupling since the 13th Five-Year Plan. [Conclusion] Xuzhou City’s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen. Agricultural economic development has also achieved clear and convincing effects.
[Objective] The spatial-temporal characteristics and decoupling effects of agricultural carbon emissions at Xuzhou City, Jiangsu Province were analyzed in order to provide a theoretical basis and data reference for green, high-quality sustainable development of agriculture and the benign growth of the agricultural economy in Xuzhou City, and its surrounding resource-based cities in the future. [Methods] The total amount, intensity, and structure of agricultural carbon emissions at Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and their decoupling relationship with agricultural economic development was determine based on the Tapio decoupling model. [Results] ① The overall trend of agricultural carbon emissions at Xuzhou City could be described as M-shaped (rapid rise-fluctuating rise-rapid decline) from 1.61×106 t in 2000 to 1.69×106 t in 2020. The contributions of factors affecting agricultural carbon emissions followed 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; ② Agricultural carbon emission at Xuzhou City varied significantly among districts (counties and cities) and had undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of “higher in the middle and lower in the surrounding areas”, with Pizhou City being the most prominent; ③ Xuzhou City’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 has mainly manifested as strong decoupling since the 13th Five-Year Plan. [Conclusion] Xuzhou City’s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen. Agricultural economic development has also achieved clear and convincing effects.
2023,43(5):404-410
, DOI: 10.13961/j.cnki.stbctb.20230831.001
Abstract:
[Objective] The effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution were analyzed in order to provide a scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes at Xiangjiaba Hydropower Station. [Methods] Four different ecological restoration slopes at 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 determined by the wet sieve method for two natural restoration slopes: natural forest (NF) and abandoned land (AS, used as the control). [Results] ① The soil for each slope was dominated by large aggregates ＞0.25 mm. The macroaggregate content in natural forest was the highest (81.83%). The vegetation concrete and thick base material slope had the second highest macroaggregate contents, and the macroaggregate content of waste residue land was the lowest (55.19%). The MWD and GMD values of the four artificial ecological restoration slopes were lower than the values of the natural forest, and higher than the values of the waste residue land. The values of the thick substrate slope were the highest (2.96 mm and 1.47 mm), respectively. The fractal dimension (D) of the soil spray seeding and slag field was significantly higher (p＜0.05) than observed for the other four slopes. ② The organic carbon contents of macro aggregates with particle size ＞0.25 mm were the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests had the largest contribution rate of ＞2 mm soil aggregates. ③ Correlation analysis showed that SOC was significantly positively correlated with MWD, GMD, and R0.25 (p＜0.01). Aggregates of size ＞5 mm and 5—2 mm were 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, thick substrate spraying technology and vegetation concrete ecological restoration technology improved soil structure and organic carbon pool similarly to natural forest. The improvement effect of external soil spraying technology was poor.
[Objective] The effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution were analyzed in order to provide a scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes at Xiangjiaba Hydropower Station. [Methods] Four different ecological restoration slopes at 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 determined by the wet sieve method for two natural restoration slopes: natural forest (NF) and abandoned land (AS, used as the control). [Results] ① The soil for each slope was dominated by large aggregates ＞0.25 mm. The macroaggregate content in natural forest was the highest (81.83%). The vegetation concrete and thick base material slope had the second highest macroaggregate contents, and the macroaggregate content of waste residue land was the lowest (55.19%). The MWD and GMD values of the four artificial ecological restoration slopes were lower than the values of the natural forest, and higher than the values of the waste residue land. The values of the thick substrate slope were the highest (2.96 mm and 1.47 mm), respectively. The fractal dimension (D) of the soil spray seeding and slag field was significantly higher (p＜0.05) than observed for the other four slopes. ② The organic carbon contents of macro aggregates with particle size ＞0.25 mm were the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests had the largest contribution rate of ＞2 mm soil aggregates. ③ Correlation analysis showed that SOC was significantly positively correlated with MWD, GMD, and R0.25 (p＜0.01). Aggregates of size ＞5 mm and 5—2 mm were 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, thick substrate spraying technology and vegetation concrete ecological restoration technology improved soil structure and organic carbon pool similarly to natural forest. The improvement effect of external soil spraying technology was poor.
2023,43(5):411-418
, DOI: 10.13961/j.cnki.stbctb.20231013.001
Abstract:
[Objective] The response of soil labile organic carbon components and enzyme activities to natural forest conversion was analyzed in order to provide a scientific basis for predicting regional soil health evolution and environmental change. [Methods] A native evergreen broad-leaved forest and a converted conifer plantation, an orchard, a sloping tillage area, and a paddy with similar geographical background and clear land use history were studied. The responses of labile organic carbon fractions and enzyme activities in topsoil to native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to an orchard, a sloping tillage area, and a paddy significantly reduced the soil organic carbon content, labile carbon fraction contents, and enzyme activities by 42%—67%, 47%—88%, and 36%—89%, respectively. Notably, the readily oxidizable organic carbon, microbial biomass carbon, and invertase activity experienced the greatest reduction compared with the native forest conversion, sensitively indicating the reduction in soil organic carbon content and its lability. Readily oxidizable organic carbon was, therefore, considered to be a practical index. Reductions in soil labile organic carbon fractions and enzyme activities were lower for the conversion of native forest conversion to plantation than for the native forest conversion to orchard and sloping tillage area, showing the preservation capacity of soil labile carbon in the plantation. The ratio of labile organic carbon to total organic carbon in soil was significantly reduced after the native forest conversion to plantation, sensitively reflecting the reduction in soil carbon quality. [Conclusion] Native forest conversion led to substantial reductions in labile organic carbon quantity, carbon quality, and related enzyme activities in soil, suggesting a degradation of soil biological health and a decline in soil quality.
[Objective] The response of soil labile organic carbon components and enzyme activities to natural forest conversion was analyzed in order to provide a scientific basis for predicting regional soil health evolution and environmental change. [Methods] A native evergreen broad-leaved forest and a converted conifer plantation, an orchard, a sloping tillage area, and a paddy with similar geographical background and clear land use history were studied. The responses of labile organic carbon fractions and enzyme activities in topsoil to native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to an orchard, a sloping tillage area, and a paddy significantly reduced the soil organic carbon content, labile carbon fraction contents, and enzyme activities by 42%—67%, 47%—88%, and 36%—89%, respectively. Notably, the readily oxidizable organic carbon, microbial biomass carbon, and invertase activity experienced the greatest reduction compared with the native forest conversion, sensitively indicating the reduction in soil organic carbon content and its lability. Readily oxidizable organic carbon was, therefore, considered to be a practical index. Reductions in soil labile organic carbon fractions and enzyme activities were lower for the conversion of native forest conversion to plantation than for the native forest conversion to orchard and sloping tillage area, showing the preservation capacity of soil labile carbon in the plantation. The ratio of labile organic carbon to total organic carbon in soil was significantly reduced after the native forest conversion to plantation, sensitively reflecting the reduction in soil carbon quality. [Conclusion] Native forest conversion led to substantial reductions in labile organic carbon quantity, carbon quality, and related enzyme activities in soil, suggesting a degradation of soil biological health and a decline in soil quality.
2023,43(5):419-425
, DOI: 10.13961/j.cnki.stbctb.2023.05.048
Abstract:
[Objective] The spatial differences and dynamic evolution of carbon ecological security level were analyzed to optimize the overall plan of carbon ecological security in the Yellow River basin (an important “energy basin” in China) in order to objectively reflect the current status and evolution trend of carbon ecological security, and to provide a reference for optimizing the carbon ecological security pattern. [Methods] An evaluation index system for carbon ecological security in the Yellow River basin was constructed under the framework of driving-pressure-state-impact-response (DPSIR) analysis. The technique for order preference by similarity to ideal solution (TOPSIS) model was used to evaluate the level of carbon ecological security, and the spatial-temporal evolution characteristics were analyzed by the kernel density estimation method. [Results] ① Carbon sinks and carbon emissions increased from 2012 to 2021 in the Yellow River basin, and the growth rate of carbon emissions was faster than that of carbon sinks. Carbon sinks were spatially characterized as “higher in the west and lower in the east”, while carbon emissions were “lower in the west and higher in the east”. ② The carbon ecological security level in the Yellow River basin increased over time, from 0.356 in 2012 to 0.639 in 2021. In terms of spatial distribution, the carbon ecological security level in the upstream region was higher than in the middle and downstream regions, and was characterized as “upstream leading, midstream catching up, and downstream surpassing”. In addition, the level of carbon ecological security tended to be good. ③ Based on the kernel density estimation results, the differences in carbon security levels among different regions in the Yellow River basin were gradually narrowing, and were decreasing in the upstream region faster than in the middle and downstream regions. [Conclusion] Based on the current status of carbon ecological security in the Yellow River basin, carbon sink capacity in the upstream region is expected to increase over time, while clean energy industries and technology-intensive industries with high added value should be developed to promote green GDP growth in the middle and downstream regions. In addition, a carbon ecological compensation mechanism should be established to coordinate and resolve cross-regional security issues, and to improve the carbon ecological security level of the entire basin.
[Objective] The spatial differences and dynamic evolution of carbon ecological security level were analyzed to optimize the overall plan of carbon ecological security in the Yellow River basin (an important “energy basin” in China) in order to objectively reflect the current status and evolution trend of carbon ecological security, and to provide a reference for optimizing the carbon ecological security pattern. [Methods] An evaluation index system for carbon ecological security in the Yellow River basin was constructed under the framework of driving-pressure-state-impact-response (DPSIR) analysis. The technique for order preference by similarity to ideal solution (TOPSIS) model was used to evaluate the level of carbon ecological security, and the spatial-temporal evolution characteristics were analyzed by the kernel density estimation method. [Results] ① Carbon sinks and carbon emissions increased from 2012 to 2021 in the Yellow River basin, and the growth rate of carbon emissions was faster than that of carbon sinks. Carbon sinks were spatially characterized as “higher in the west and lower in the east”, while carbon emissions were “lower in the west and higher in the east”. ② The carbon ecological security level in the Yellow River basin increased over time, from 0.356 in 2012 to 0.639 in 2021. In terms of spatial distribution, the carbon ecological security level in the upstream region was higher than in the middle and downstream regions, and was characterized as “upstream leading, midstream catching up, and downstream surpassing”. In addition, the level of carbon ecological security tended to be good. ③ Based on the kernel density estimation results, the differences in carbon security levels among different regions in the Yellow River basin were gradually narrowing, and were decreasing in the upstream region faster than in the middle and downstream regions. [Conclusion] Based on the current status of carbon ecological security in the Yellow River basin, carbon sink capacity in the upstream region is expected to increase over time, while clean energy industries and technology-intensive industries with high added value should be developed to promote green GDP growth in the middle and downstream regions. In addition, a carbon ecological compensation mechanism should be established to coordinate and resolve cross-regional security issues, and to improve the carbon ecological security level of the entire basin.
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Abstract:
[Objective] Exploring the spatial functional evolution and ecological effects of the "production-living-ecological" space in scenic areas is of great significance for environmental protection, resource utilization and management, and sustainable development of scenic spots. [Methods]Taking scenic areas in Guizhou Province as an example, based on the land use status data of 2009 and 2021, constructing the "production-living- ecological" space , using the spatial function evolution and ecological effects of the "production-living- ecological" space from 2009 to 2021 were analyzed by combining the "production-living- ecological" space spatial transfer matrix, ecological environment quality index, and ecological contribution rate methods. [Results] The results indicate that:(1) From 2009 to 2021, scenic areas in Guizhou Province were mainly characterized by ecological space, with an increase in living and ecological space and a decrease in production space; (2) During the research period, the overall ecological environment quality of scenic areas in Guizhou Province increased from 0.59 to 0.61, showing a spatial pattern of "high in the east and low in the west", with a significant increase in high-quality and higher quality areas, This is mainly related to a series of ecological protection and restoration engineering implemented in Guizhou Province in recent years, as well as carrying out work such as resource protection and forestry reform; (3) The ecological environment quality of scenic areas in Guizhou Province has significantly improved from 2009 to 2021, mainly due to the shift of agricultural production land and grassland ecological land to forest ecological land. [Conclusion] By studying the spatial function evolution and ecological effects of the "production-living-ecological" space in scenic areas in Guizhou Province, reference and decision-making basis can be provided for optimizing the spatial function of the "production-living- ecological" space and protecting the ecological environment in scenic areas in Guizhou Province.
[Objective] Exploring the spatial functional evolution and ecological effects of the "production-living-ecological" space in scenic areas is of great significance for environmental protection, resource utilization and management, and sustainable development of scenic spots. [Methods]Taking scenic areas in Guizhou Province as an example, based on the land use status data of 2009 and 2021, constructing the "production-living- ecological" space , using the spatial function evolution and ecological effects of the "production-living- ecological" space from 2009 to 2021 were analyzed by combining the "production-living- ecological" space spatial transfer matrix, ecological environment quality index, and ecological contribution rate methods. [Results] The results indicate that:(1) From 2009 to 2021, scenic areas in Guizhou Province were mainly characterized by ecological space, with an increase in living and ecological space and a decrease in production space; (2) During the research period, the overall ecological environment quality of scenic areas in Guizhou Province increased from 0.59 to 0.61, showing a spatial pattern of "high in the east and low in the west", with a significant increase in high-quality and higher quality areas, This is mainly related to a series of ecological protection and restoration engineering implemented in Guizhou Province in recent years, as well as carrying out work such as resource protection and forestry reform; (3) The ecological environment quality of scenic areas in Guizhou Province has significantly improved from 2009 to 2021, mainly due to the shift of agricultural production land and grassland ecological land to forest ecological land. [Conclusion] By studying the spatial function evolution and ecological effects of the "production-living-ecological" space in scenic areas in Guizhou Province, reference and decision-making basis can be provided for optimizing the spatial function of the "production-living- ecological" space and protecting the ecological environment in scenic areas in Guizhou Province.
Abstract:
[Objective] To analyze the spatiotemporal evolution characteristics and driving factors of land use in Lvliang City, and provide reference for land management and sustainable development. [Methods] Based on land use data from 2000 to 2020 in Lvliang City, the spatiotemporal evolution characteristics of land use were analyzed using land use transfer matrix, dynamic degree, stability degree, and standard deviation ellipse. The PLUS model was used to explore the natural and social driving factors of land use change. [Results] ① The land use in Lvliang City is mainly cropland, forest, and grassland. From 2000 to 2020, the cropland decreased by 396.1 km2, the construction land expanded by 540.6 km2, and the water area increased. The transfer between cropland - grassland, and cropland - construction land dominates. Cropland is concentrated and reduced in the southeastern plain, with scattered changes in forest. Construction land is expanding in clusters along valleys and roads. ② The period from 2010 to 2020 was a period of intense land use changes. The reduction of cropland, forest and grassland, expansion of construction land, rapid change rate, and poor stability. The overall rate of land use change has significantly accelerated over time. ③ Elevation has the highest contribution to land use change, followed by slope. Factors such as temperature, precipitation, population density, GDP, and distance from roads affect land use transfer. [Conclusion] From 2000 to 2020, the expansion of construction land in Lvliang City was significant, with a decrease in cropland. There was heterogeneity in the spatial distribution of land use, and the rate of change gradually accelerated. Controlling the encroachment of construction land on cropland and strengthening the protection of forest resources in mountainous areas is beneficial for regional sustainable development.
[Objective] To analyze the spatiotemporal evolution characteristics and driving factors of land use in Lvliang City, and provide reference for land management and sustainable development. [Methods] Based on land use data from 2000 to 2020 in Lvliang City, the spatiotemporal evolution characteristics of land use were analyzed using land use transfer matrix, dynamic degree, stability degree, and standard deviation ellipse. The PLUS model was used to explore the natural and social driving factors of land use change. [Results] ① The land use in Lvliang City is mainly cropland, forest, and grassland. From 2000 to 2020, the cropland decreased by 396.1 km2, the construction land expanded by 540.6 km2, and the water area increased. The transfer between cropland - grassland, and cropland - construction land dominates. Cropland is concentrated and reduced in the southeastern plain, with scattered changes in forest. Construction land is expanding in clusters along valleys and roads. ② The period from 2010 to 2020 was a period of intense land use changes. The reduction of cropland, forest and grassland, expansion of construction land, rapid change rate, and poor stability. The overall rate of land use change has significantly accelerated over time. ③ Elevation has the highest contribution to land use change, followed by slope. Factors such as temperature, precipitation, population density, GDP, and distance from roads affect land use transfer. [Conclusion] From 2000 to 2020, the expansion of construction land in Lvliang City was significant, with a decrease in cropland. There was heterogeneity in the spatial distribution of land use, and the rate of change gradually accelerated. Controlling the encroachment of construction land on cropland and strengthening the protection of forest resources in mountainous areas is beneficial for regional sustainable development.
Abstract:
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
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Abstract: [Objective] The level of grassland carrying capacity affects the sustainability of grassland utilization and the security of grassland ecosystems. As an important ecological barrier in the north, an in-depth study of the carrying capacity of grassland resources in Xilingol League can provide a scientific basis for the regional ecological security and sustainable use of grassland and the construction of ecological civilization. [Methods] This study analyzed and evaluated the status of grassland resource carrying capacity, ecological deficit (ED)/ remainder (ER) and ecological pressure index of Xilingol League of Inner Mongolia based on three-dimensional ecological footprint model, by using land use and other relevant data in 2013, 2015, 2018 and 2020. [Results] (1) The ecological footprint continued to be higher than the ecological carrying capacity, and the total ecological footprint and total ecological carrying capacity showed a trend of first increasing and then decreasing, decreasing by 2.76% and 7.35% respectively within 7 years. The change rates of per capita ecological footprint and per capita carrying capacity in 7 years were -9.62% and -13.19%, respectively. The ecological footprint decreased from east to west, and the ecological carrying capacity in the east and north was higher than that in the west and south . (2) The ecological footprint depth first increased and then decreased, with an overall increase of 4.95%, which was greater than 1. The grassland ecosystem remained in an ecological deficit for many years, indicating the grassland was unsustainable and unhealthy. (3) The results of ecological profit and loss and ecological pressure index reflecting the ecological security of grassland showed that ER/ED was less than 0 and the ecological pressure index was greater than 1 in the four periods of the study area. The ecological carrying state of grassland was continuously overloaded for many years, and the ecological security and stability continued to decrease. [Conclusion] The arid and semi-arid geographic location of Xilingol League and its resource endowment, superimposed on high-intensity human economic and social activities, have led to a reduction in the ecological carrying capacity of the grasslands of the League, and the ecology is in an extremely insecure state.
Abstract: [Objective] The level of grassland carrying capacity affects the sustainability of grassland utilization and the security of grassland ecosystems. As an important ecological barrier in the north, an in-depth study of the carrying capacity of grassland resources in Xilingol League can provide a scientific basis for the regional ecological security and sustainable use of grassland and the construction of ecological civilization. [Methods] This study analyzed and evaluated the status of grassland resource carrying capacity, ecological deficit (ED)/ remainder (ER) and ecological pressure index of Xilingol League of Inner Mongolia based on three-dimensional ecological footprint model, by using land use and other relevant data in 2013, 2015, 2018 and 2020. [Results] (1) The ecological footprint continued to be higher than the ecological carrying capacity, and the total ecological footprint and total ecological carrying capacity showed a trend of first increasing and then decreasing, decreasing by 2.76% and 7.35% respectively within 7 years. The change rates of per capita ecological footprint and per capita carrying capacity in 7 years were -9.62% and -13.19%, respectively. The ecological footprint decreased from east to west, and the ecological carrying capacity in the east and north was higher than that in the west and south . (2) The ecological footprint depth first increased and then decreased, with an overall increase of 4.95%, which was greater than 1. The grassland ecosystem remained in an ecological deficit for many years, indicating the grassland was unsustainable and unhealthy. (3) The results of ecological profit and loss and ecological pressure index reflecting the ecological security of grassland showed that ER/ED was less than 0 and the ecological pressure index was greater than 1 in the four periods of the study area. The ecological carrying state of grassland was continuously overloaded for many years, and the ecological security and stability continued to decrease. [Conclusion] The arid and semi-arid geographic location of Xilingol League and its resource endowment, superimposed on high-intensity human economic and social activities, have led to a reduction in the ecological carrying capacity of the grasslands of the League, and the ecology is in an extremely insecure state.
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[Objective] Taking Meizhou Island, a “cultural”, “pilgrimage” and “tourism” island, as the research object, this paper analyzed the spatio-temporal changes of ecosystem service value (ESV) during the development and construction of the island in the past 20 years, and provided scientific reference for the formulation of land use planning and ecological construction of the tourism area of Meizhou Island.[Methods] The global 30 m fine land cover dynamic monitoring data covering Meizhou Island from 1985 to 2020 was used as the data source, and the ArcGIS technology was used to extract the land use data of 2000, 2005, 2010, 2015 and 2020 in the study area. The land use change on Meizhou Island in recent 20 years was revealed through land use dynamic , land use transfer matrix and ecological contribution rate, and the value equivalent method was used to estimate ESV of Meizhou Island.[Results] ① From 2000-2020, the land use types in Meizhou island were mainly construction land and cultivated land; The area change was mainly manifested as the construction land and wetland increased, cultivated land and forest land decreased. The land use transfer was reflected in the mutual flow among forest-cultivated land-construction land-water area and the encroachment of construction land on cultivated land and forest land; ② During the study period, the ESV of Meizhou Island decreased by 12.5269 million yuan, of which forest land and cultivated land were the main contributing factors of ESV of Meizhou Island, and the increase of wetland and water area were the main influencing factor of the increase of ESV; ③ The values of each individual ecosystem service function were as follows: regulating service>supporting service>supplying service>cultural service; ④The spatial distribution of ESV showed the characteristics of “low in the middle and high around”, and the distribution of high value areas overlapped highly with that of forest land, low value areas of ecosystem service value were concentrated in the construction land. [Conclusion] Forest and cultivated land were the main contribution factors of ESV on Meizhou Island, the regulation service contributed the most to the ESV . Therefore, in the process of development and construction, we should improve the utilization efficiency of construction land and strengthen the protection of forest and cultivated land.
[Objective] Taking Meizhou Island, a “cultural”, “pilgrimage” and “tourism” island, as the research object, this paper analyzed the spatio-temporal changes of ecosystem service value (ESV) during the development and construction of the island in the past 20 years, and provided scientific reference for the formulation of land use planning and ecological construction of the tourism area of Meizhou Island.[Methods] The global 30 m fine land cover dynamic monitoring data covering Meizhou Island from 1985 to 2020 was used as the data source, and the ArcGIS technology was used to extract the land use data of 2000, 2005, 2010, 2015 and 2020 in the study area. The land use change on Meizhou Island in recent 20 years was revealed through land use dynamic , land use transfer matrix and ecological contribution rate, and the value equivalent method was used to estimate ESV of Meizhou Island.[Results] ① From 2000-2020, the land use types in Meizhou island were mainly construction land and cultivated land; The area change was mainly manifested as the construction land and wetland increased, cultivated land and forest land decreased. The land use transfer was reflected in the mutual flow among forest-cultivated land-construction land-water area and the encroachment of construction land on cultivated land and forest land; ② During the study period, the ESV of Meizhou Island decreased by 12.5269 million yuan, of which forest land and cultivated land were the main contributing factors of ESV of Meizhou Island, and the increase of wetland and water area were the main influencing factor of the increase of ESV; ③ The values of each individual ecosystem service function were as follows: regulating service>supporting service>supplying service>cultural service; ④The spatial distribution of ESV showed the characteristics of “low in the middle and high around”, and the distribution of high value areas overlapped highly with that of forest land, low value areas of ecosystem service value were concentrated in the construction land. [Conclusion] Forest and cultivated land were the main contribution factors of ESV on Meizhou Island, the regulation service contributed the most to the ESV . Therefore, in the process of development and construction, we should improve the utilization efficiency of construction land and strengthen the protection of forest and cultivated land.
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[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
Abstract:
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
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[Objective] Total phosphorus content is one of the important indicators for assessing water quality health. However, traditional methods for detecting water pollutants are complex to operate and are easily influenced by other factors, making it difficult to reflect water quality health intuitively. In order to accurately and efficiently predict the concentration of total phosphorus in water bodies in real-time, this study proposes a water body total phosphorus prediction model that combines spectral dimensionality reduction, an improved particle swarm optimization algorithm, and support vector regression. [Methods] This study uses water quality samples collected in 2021 from the Wuhan-Anhui region in the middle and lower reaches of the Yangtze River as the research object. Firstly, the collected spectral data of the Yangtze River is preprocessed by both maximum-minimum normalization and mean centering to unify the range and mean point of the data. Kernel principal component analysis is then used to perform dimensionality reduction on the preprocessed spectral data. Six feature vectors are selected based on a variance explanation rate of 99.6% for training the subsequent prediction model. Next, an improved particle swarm optimization algorithm is proposed by introducing an adaptive inertia weight updating formula and a genetic-simulated annealing mutation concept to enhance the optimization ability of the algorithm. The improved particle swarm optimization algorithm is used to optimize the hyperparameter combinations in the support vector regression model. The support vector regression model is trained using the output results for predicting the total phosphorus concentration. Finally, the test set data is used to predict the total phosphorus concentration. [Results] By comparing the accuracy with several well-performing machine learning models, this experimental model achieves an R2 of 0.973920, an RMSE of 0.003012, and an MAE of 0.002105 when predicting the total phosphorus concentration in the Yangtze River water. The accuracy and fitting effect of this model are better. [Conclusion] This study discusses the feasibility and effectiveness of using spectral data combined with dimensionality reduction techniques, partricle swarm optimization algorithms, and machine learning models, providing new perspectives and ideas for the field of water quality detection.
[Objective] Total phosphorus content is one of the important indicators for assessing water quality health. However, traditional methods for detecting water pollutants are complex to operate and are easily influenced by other factors, making it difficult to reflect water quality health intuitively. In order to accurately and efficiently predict the concentration of total phosphorus in water bodies in real-time, this study proposes a water body total phosphorus prediction model that combines spectral dimensionality reduction, an improved particle swarm optimization algorithm, and support vector regression. [Methods] This study uses water quality samples collected in 2021 from the Wuhan-Anhui region in the middle and lower reaches of the Yangtze River as the research object. Firstly, the collected spectral data of the Yangtze River is preprocessed by both maximum-minimum normalization and mean centering to unify the range and mean point of the data. Kernel principal component analysis is then used to perform dimensionality reduction on the preprocessed spectral data. Six feature vectors are selected based on a variance explanation rate of 99.6% for training the subsequent prediction model. Next, an improved particle swarm optimization algorithm is proposed by introducing an adaptive inertia weight updating formula and a genetic-simulated annealing mutation concept to enhance the optimization ability of the algorithm. The improved particle swarm optimization algorithm is used to optimize the hyperparameter combinations in the support vector regression model. The support vector regression model is trained using the output results for predicting the total phosphorus concentration. Finally, the test set data is used to predict the total phosphorus concentration. [Results] By comparing the accuracy with several well-performing machine learning models, this experimental model achieves an R2 of 0.973920, an RMSE of 0.003012, and an MAE of 0.002105 when predicting the total phosphorus concentration in the Yangtze River water. The accuracy and fitting effect of this model are better. [Conclusion] This study discusses the feasibility and effectiveness of using spectral data combined with dimensionality reduction techniques, partricle swarm optimization algorithms, and machine learning models, providing new perspectives and ideas for the field of water quality detection.
WANG Jingzheng, ZHAO Chuanchuan, WANG Yuqin, XIE Linghua, WANG Yuqin, WANG Jiayi, ZHANG Sha, JIA Dongjin
Abstract:
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott's second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott's second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
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Abstract: 【Objective】In order to understand the freeze-thaw adaptability of frost-resistant artificial soil and its application effects in slope vegetation restoration, indoor and outdoor tests of various physical and chemical indexes were carried out, aiming to provide scientific support and basis for the application of slope vegetation restoration in alpine region.【Methods】The physical and chemical properties of two kinds of soil after freeze-thaw cycles were measured by indoor tests, and four representative indexes were selected by principal component analysis for outdoor tests. The practical application effect of two kinds of soil in Tibet was monitored by outdoor sampling. Natural soil was used as a control sample during both indoor and outdoor tests.【Results】The results of indoor tests showed that the relative dynamic elastic modulus, >0.25 mm water stable large aggregate content, average weight diameter, aggregation degree, organic matter, ammonium nitrogen, nitrate nitrogen, available phosphorus and available potassium content in frost-resistant artificial soil were significantly higher than those in the natural soil before and after freeze-thaw (P<0.05), and the mass loss rate and structural failure rate in frost-resistant artificial soil were significantly decreased. The principal component analysis showed that the relative dynamic elastic modulus, structural failure rate, pH value and organic matter content in indoor tests were highly correlated with principal component factors. Therefore, these four indicators were selected for outdoor sampling and monitoring of vegetation restoration in the field. The monitoring results showed that the structure failure rate, relative dynamic elastic modulus, and organic matter content of frost-resistant artificial soil were higher than natural soil at different time periods each year. In terms of vegetation restoration effect, the vegetation coverage, species diversity, aboveground biomass and underground biomass of frost-resistant artificial soil are higher than that of natural soil.【Conclusions】According to the results of tests, the aggregate stability and fertility of frost-resistant artificial soil are better than those of natural soil after freeze-thaw cycles, and its vegetation restoration effect is also better when applied in alpine region, so it is more suitable for the application of slope vegetation restoration.
Abstract: 【Objective】In order to understand the freeze-thaw adaptability of frost-resistant artificial soil and its application effects in slope vegetation restoration, indoor and outdoor tests of various physical and chemical indexes were carried out, aiming to provide scientific support and basis for the application of slope vegetation restoration in alpine region.【Methods】The physical and chemical properties of two kinds of soil after freeze-thaw cycles were measured by indoor tests, and four representative indexes were selected by principal component analysis for outdoor tests. The practical application effect of two kinds of soil in Tibet was monitored by outdoor sampling. Natural soil was used as a control sample during both indoor and outdoor tests.【Results】The results of indoor tests showed that the relative dynamic elastic modulus, >0.25 mm water stable large aggregate content, average weight diameter, aggregation degree, organic matter, ammonium nitrogen, nitrate nitrogen, available phosphorus and available potassium content in frost-resistant artificial soil were significantly higher than those in the natural soil before and after freeze-thaw (P<0.05), and the mass loss rate and structural failure rate in frost-resistant artificial soil were significantly decreased. The principal component analysis showed that the relative dynamic elastic modulus, structural failure rate, pH value and organic matter content in indoor tests were highly correlated with principal component factors. Therefore, these four indicators were selected for outdoor sampling and monitoring of vegetation restoration in the field. The monitoring results showed that the structure failure rate, relative dynamic elastic modulus, and organic matter content of frost-resistant artificial soil were higher than natural soil at different time periods each year. In terms of vegetation restoration effect, the vegetation coverage, species diversity, aboveground biomass and underground biomass of frost-resistant artificial soil are higher than that of natural soil.【Conclusions】According to the results of tests, the aggregate stability and fertility of frost-resistant artificial soil are better than those of natural soil after freeze-thaw cycles, and its vegetation restoration effect is also better when applied in alpine region, so it is more suitable for the application of slope vegetation restoration.
Abstract:
Abstract: [Objective] Taking Kongtong District of Gansu Province as an example, through the analysis of the causes of the current spatial pattern of cultivated land protection and its spatial correlation, the scientific zoning of cultivated land renovation planning was divided to provide reference for further optimizing the layout of cultivated land, improving the quality of cultivated land, and scientific utilization and protection of cultivated land. [Methods] Landscape pattern index method,multi-objective decision-making method, Spreaman rank correlation method and clusteranalysis method were used to analyze the synergistic or tradeoff relationship between the current situation of cultivated land landscape pattern and its spatial existence by selecting cultivated land slope, cultivated land protection policy and urbanization impact, and to construct the correlation analysis and evaluation index system of cultivated land protection pattern. [Results] （1）（As a whole, the cultivated land landscape pattern index of the study area increased by 3.55% from 2010 to 2022, and the degree of cultivated land agglomeration showed a downward trend in most regions, but it fluctuated during the whole process. The regional land use degree showed an upward trend on the whole, and the characteristics of cultivated land layout and land use degree of each township were significantly different.（2）The cultivated land protection index in 2022 increased by 315.30% compared with 2010, the cultivated land in 2-6° increased by 120.96%, the cultivated land in 15-25° decreased by 32.64%, and the cultivated land in > 25° decreased by 100%, which was highly coordinated with the cultivated land landscape pattern in space. The urbanization impact index showed an upward trend, which increased by 25.17% from 2010 to 2022. The urbanization impact on cultivated land distribution increased, and there was a significant spatial balance between urbanization and cultivated land landscape pattern.（3）Divided into cultivated land quality improvement key area, cultivated land quality improvement general area, cultivated land new development potential area, cultivated land coordination protection area, four units of cultivated land renovation planning, classified renovation planning countermeasures and suggestions.
Abstract: [Objective] Taking Kongtong District of Gansu Province as an example, through the analysis of the causes of the current spatial pattern of cultivated land protection and its spatial correlation, the scientific zoning of cultivated land renovation planning was divided to provide reference for further optimizing the layout of cultivated land, improving the quality of cultivated land, and scientific utilization and protection of cultivated land. [Methods] Landscape pattern index method,multi-objective decision-making method, Spreaman rank correlation method and clusteranalysis method were used to analyze the synergistic or tradeoff relationship between the current situation of cultivated land landscape pattern and its spatial existence by selecting cultivated land slope, cultivated land protection policy and urbanization impact, and to construct the correlation analysis and evaluation index system of cultivated land protection pattern. [Results] （1）（As a whole, the cultivated land landscape pattern index of the study area increased by 3.55% from 2010 to 2022, and the degree of cultivated land agglomeration showed a downward trend in most regions, but it fluctuated during the whole process. The regional land use degree showed an upward trend on the whole, and the characteristics of cultivated land layout and land use degree of each township were significantly different.（2）The cultivated land protection index in 2022 increased by 315.30% compared with 2010, the cultivated land in 2-6° increased by 120.96%, the cultivated land in 15-25° decreased by 32.64%, and the cultivated land in > 25° decreased by 100%, which was highly coordinated with the cultivated land landscape pattern in space. The urbanization impact index showed an upward trend, which increased by 25.17% from 2010 to 2022. The urbanization impact on cultivated land distribution increased, and there was a significant spatial balance between urbanization and cultivated land landscape pattern.（3）Divided into cultivated land quality improvement key area, cultivated land quality improvement general area, cultivated land new development potential area, cultivated land coordination protection area, four units of cultivated land renovation planning, classified renovation planning countermeasures and suggestions.
Abstract:
[Objective]Scientific identification of ecosystem types in Taihang Mountain area of Hebei province is the basis for understanding the spatial and temporal distribution pattern of ecosystem in Taihang Mountain area of Hebei Province and supporting ecosystem classification management. [Methods]Based on the classification principle of Realms-Biomes-Ecosystem functional groups(RBE),a classification system including 3 primary classes,8 secondary classes and 24 tertiary classes was constructed,and multi-source data was integrated to carry out the classification mapping of the ecosystem in the Taihang mountain area of Hebei Province in 2000 and 2020. Based on RUSLE model,InVEST model and hot spot analysis,this paper analyzed the spatio-temporal evolution of ecosystem services. [Results] (1) The construction land ecosystem in Taihang Mountain area of Hebei province increased the most in the past 20 years, mainly from farmland ecosystem. The farmland ecosystem had shrunk by 61,105.95 ha and was dominated by rain-fed farmland. Under the influence of human activities, the area of river and constructed wetland increased by 5584.32 ha and 2535.66 ha respectively, while the ecosystem of forest and grassland decreased by 0.96% and 8.18% respectively. The unused ecosystem was reduced by 5800.68 ha due to the ecological protection measures in the study area. (2) Affected by the distribution of ecosystem types, the overall distribution pattern of ecosystem service value was high in the west and low in the east, except that the FS value was low in the west and high in the east, mainly because farmland was mainly distributed in the eastern region. (3) The spatial distribution of cold hot spots overlaps on the whole, but there were still differences. [Conclusion]The classification system proposed in this study is feasible, with a classification accuracy of more than 80%, which is in line with the trend of ecosystem type change in the study area, and can provide scientific support for the identification of mountain ecosystem classification and ecosystem protection and restoration policies, so as to promote the realization of mountain ecological development goals and sustainable development.
[Objective]Scientific identification of ecosystem types in Taihang Mountain area of Hebei province is the basis for understanding the spatial and temporal distribution pattern of ecosystem in Taihang Mountain area of Hebei Province and supporting ecosystem classification management. [Methods]Based on the classification principle of Realms-Biomes-Ecosystem functional groups(RBE),a classification system including 3 primary classes,8 secondary classes and 24 tertiary classes was constructed,and multi-source data was integrated to carry out the classification mapping of the ecosystem in the Taihang mountain area of Hebei Province in 2000 and 2020. Based on RUSLE model,InVEST model and hot spot analysis,this paper analyzed the spatio-temporal evolution of ecosystem services. [Results] (1) The construction land ecosystem in Taihang Mountain area of Hebei province increased the most in the past 20 years, mainly from farmland ecosystem. The farmland ecosystem had shrunk by 61,105.95 ha and was dominated by rain-fed farmland. Under the influence of human activities, the area of river and constructed wetland increased by 5584.32 ha and 2535.66 ha respectively, while the ecosystem of forest and grassland decreased by 0.96% and 8.18% respectively. The unused ecosystem was reduced by 5800.68 ha due to the ecological protection measures in the study area. (2) Affected by the distribution of ecosystem types, the overall distribution pattern of ecosystem service value was high in the west and low in the east, except that the FS value was low in the west and high in the east, mainly because farmland was mainly distributed in the eastern region. (3) The spatial distribution of cold hot spots overlaps on the whole, but there were still differences. [Conclusion]The classification system proposed in this study is feasible, with a classification accuracy of more than 80%, which is in line with the trend of ecosystem type change in the study area, and can provide scientific support for the identification of mountain ecosystem classification and ecosystem protection and restoration policies, so as to promote the realization of mountain ecological development goals and sustainable development.
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Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
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[Objective]Scientific identification of the suitability of ecological product value realization in different regions, and then proposing the path of ecological product value realization in each suitable region, is the key to promote the value transformation of ecological products and promote common prosperity. [Method]Taking Ordos City in Inner Mongolia as an example, with the help of ArcGIS platform, analytic hierarchy process and multi-factor space superposition method are used to evaluate the suitability of ecological product value realization from two perspectives of development potential and environmental protection importance on the basis of accounting for ecological product value, and then configure the value realization path. [Result]1) In 2020, the total value of ecological products in Ordos will reach 147.272 billion yuan, with a high value in the northeast-to-southwest direction and a low value in the northeast-to-southeast direction. 2) The high value areas of ecological product development potential are concentrated in the northeast with better ecological background conditions; The importance of environmental protection is generally high in the east and low in the west, and the high value area is obviously clustered in the southeast. 3)The proportion of suitable area, basic suitable area, basic unsuitable area and unsuitable area of ecological product value in Ordos is 9.7%, 25.5%, 37.4% and 27.3%, respectively. In terms of spatial distribution, the suitability of the northeastern and southwestern Jungar Banner, EjinHoro Banner and the western Otog Banner were significantly higher. 4) In the path selection, the suitable area is dominated by industrial ecology, the basic suitable area is dominated by ecological industrialization, the basic unsuitable area is dominated by ecological restoration, and the unsuitable area is dominated by ecological compensation. [Conclusion]The suitability evaluation of ecological product value realization in Ordos City is generally low. In the future, the value realization path should pay attention to the protection of ecological environment, increase ecological restoration efforts, and optimize the regional development layout according to local conditions.
[Objective]Scientific identification of the suitability of ecological product value realization in different regions, and then proposing the path of ecological product value realization in each suitable region, is the key to promote the value transformation of ecological products and promote common prosperity. [Method]Taking Ordos City in Inner Mongolia as an example, with the help of ArcGIS platform, analytic hierarchy process and multi-factor space superposition method are used to evaluate the suitability of ecological product value realization from two perspectives of development potential and environmental protection importance on the basis of accounting for ecological product value, and then configure the value realization path. [Result]1) In 2020, the total value of ecological products in Ordos will reach 147.272 billion yuan, with a high value in the northeast-to-southwest direction and a low value in the northeast-to-southeast direction. 2) The high value areas of ecological product development potential are concentrated in the northeast with better ecological background conditions; The importance of environmental protection is generally high in the east and low in the west, and the high value area is obviously clustered in the southeast. 3)The proportion of suitable area, basic suitable area, basic unsuitable area and unsuitable area of ecological product value in Ordos is 9.7%, 25.5%, 37.4% and 27.3%, respectively. In terms of spatial distribution, the suitability of the northeastern and southwestern Jungar Banner, EjinHoro Banner and the western Otog Banner were significantly higher. 4) In the path selection, the suitable area is dominated by industrial ecology, the basic suitable area is dominated by ecological industrialization, the basic unsuitable area is dominated by ecological restoration, and the unsuitable area is dominated by ecological compensation. [Conclusion]The suitability evaluation of ecological product value realization in Ordos City is generally low. In the future, the value realization path should pay attention to the protection of ecological environment, increase ecological restoration efforts, and optimize the regional development layout according to local conditions.
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Abstract: [Purpose] This study explores the impact of different gravel contents on soil erosion of engineered deposit slopes in the sandy soil region of northern Shaanxi. It aims to provide data support and theoretical references for soil erosion control in production and construction projects. [Methods] Indoor rainfall experiments were conducted to study the hydrodynamic, runoff and sediment characteristics of engineered deposit slopes with varying gravel contents (0%, 10%, 20%, 30%, 40%). [Results] (1) Under the same rainfall intensity, the initial runoff time on the engineered deposit slopes showed a decreasing trend with the increase of gravel content, ranging from 27.22~64.62%、35.09~71.70%、47.37~78.77%、51.75~82.31%. The runoff coefficient during subsequent rainfall events exhibited a "rapid increase-stable fluctuation" trend, and the average runoff coefficient increased significantly with the increase of gravel content and rainfall duration. However, the peak value of runoff decreased with the increase of gravel content, and the occurrence time of it was gradually advanced. (2) The Reynolds index for all experiments was less than 500, indicating the flow types were laminar flow, while the Froude number ranged from 2.14 to 3.71indicating they were rapid flow. The shear force, flow power and unit flow power increase with the increase of rainfall times. (3) The erosion modulus on the engineered deposit slopes were in the range of 0.45 to 6.73, 0.13 to 4.09, 0.25 to 1.26, 0.14 to 0.96, and 0.13 to 0.88 g/(m2·min), respectively. The sediment reduction for each gravel content were 36.06%, 49.05%, 55.23%, and 56.62%, respectively. The highest gravel coverage (40%) resulting in lower soil erosion intensity in the sandy soil region of the engineered deposit slopes. [Conclusion] Gravel coverage on engineered deposit slopes significantly reduces soil loss.
Abstract: [Purpose] This study explores the impact of different gravel contents on soil erosion of engineered deposit slopes in the sandy soil region of northern Shaanxi. It aims to provide data support and theoretical references for soil erosion control in production and construction projects. [Methods] Indoor rainfall experiments were conducted to study the hydrodynamic, runoff and sediment characteristics of engineered deposit slopes with varying gravel contents (0%, 10%, 20%, 30%, 40%). [Results] (1) Under the same rainfall intensity, the initial runoff time on the engineered deposit slopes showed a decreasing trend with the increase of gravel content, ranging from 27.22~64.62%、35.09~71.70%、47.37~78.77%、51.75~82.31%. The runoff coefficient during subsequent rainfall events exhibited a "rapid increase-stable fluctuation" trend, and the average runoff coefficient increased significantly with the increase of gravel content and rainfall duration. However, the peak value of runoff decreased with the increase of gravel content, and the occurrence time of it was gradually advanced. (2) The Reynolds index for all experiments was less than 500, indicating the flow types were laminar flow, while the Froude number ranged from 2.14 to 3.71indicating they were rapid flow. The shear force, flow power and unit flow power increase with the increase of rainfall times. (3) The erosion modulus on the engineered deposit slopes were in the range of 0.45 to 6.73, 0.13 to 4.09, 0.25 to 1.26, 0.14 to 0.96, and 0.13 to 0.88 g/(m2·min), respectively. The sediment reduction for each gravel content were 36.06%, 49.05%, 55.23%, and 56.62%, respectively. The highest gravel coverage (40%) resulting in lower soil erosion intensity in the sandy soil region of the engineered deposit slopes. [Conclusion] Gravel coverage on engineered deposit slopes significantly reduces soil loss.
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Abstract: [Objective] To investigate the influence of soil texture types and parameters of banded sand ditch structures on soil infiltration processes; [Methods] Based on the HYDRUS-2D/3D software, a mathematical model for soil water movement in a strip gully mode was established, and the reliability of simulating the soil infiltration process in a strip gully mode was verified using laboratory experiments. On this basis, the cumulative infiltration and movement of the wetting front under different influencing factors in the strip gully mode were simulated and analyzed. [Results] The simulated results were consistent with the measured data. They showed no significant differences, indicating that the established model and its solution method can effectively obtain the numerical values of soil cumulative infiltration and wetting front movement at different times in the banded sand ditches mode. There was a significant increase in infiltration in homogeneous soil filled with banded sand ditches. The original soil texture, sand trench spacing, sand trench width, and sand trench depth all significantly impact the infiltration rate. The infiltration rate decreases with an increase in the original soil-saturated hydraulic conductivity and sand trench spacing but increases with an increase in sand trench width and depth. The soil-wetting front profile forms a U-shaped pattern with a lower front and a higher back. With time, the U-shaped side wetting front gradually approaches the intersection of the sand trench, and the top plateau gradually disappears. The original soil texture significantly impacts the migration distance of the wetting front, which increases with an increase in the original soil-saturated hydraulic conductivity. Sand trench depth significantly impacts the shape and distribution of the wetting front. With an increase in sand trench depth, the U-shaped pattern stretches vertically, and the wetting depth on the left side increases significantly, while the change in wetting depth on the right side is minimal. Sand soil texture, sand trench spacing, and sand trench width have a relatively minor influence on the migration distance of the wetting front.[Conclusion] The soil body configuration in strip gullies can significantly improve soil infiltration capacity. The relevant research results can provide the scientific basis for the design, operation, and management of sand ditch rainwater collection projects in the Loess Plateau region.
Abstract: [Objective] To investigate the influence of soil texture types and parameters of banded sand ditch structures on soil infiltration processes; [Methods] Based on the HYDRUS-2D/3D software, a mathematical model for soil water movement in a strip gully mode was established, and the reliability of simulating the soil infiltration process in a strip gully mode was verified using laboratory experiments. On this basis, the cumulative infiltration and movement of the wetting front under different influencing factors in the strip gully mode were simulated and analyzed. [Results] The simulated results were consistent with the measured data. They showed no significant differences, indicating that the established model and its solution method can effectively obtain the numerical values of soil cumulative infiltration and wetting front movement at different times in the banded sand ditches mode. There was a significant increase in infiltration in homogeneous soil filled with banded sand ditches. The original soil texture, sand trench spacing, sand trench width, and sand trench depth all significantly impact the infiltration rate. The infiltration rate decreases with an increase in the original soil-saturated hydraulic conductivity and sand trench spacing but increases with an increase in sand trench width and depth. The soil-wetting front profile forms a U-shaped pattern with a lower front and a higher back. With time, the U-shaped side wetting front gradually approaches the intersection of the sand trench, and the top plateau gradually disappears. The original soil texture significantly impacts the migration distance of the wetting front, which increases with an increase in the original soil-saturated hydraulic conductivity. Sand trench depth significantly impacts the shape and distribution of the wetting front. With an increase in sand trench depth, the U-shaped pattern stretches vertically, and the wetting depth on the left side increases significantly, while the change in wetting depth on the right side is minimal. Sand soil texture, sand trench spacing, and sand trench width have a relatively minor influence on the migration distance of the wetting front.[Conclusion] The soil body configuration in strip gullies can significantly improve soil infiltration capacity. The relevant research results can provide the scientific basis for the design, operation, and management of sand ditch rainwater collection projects in the Loess Plateau region.
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Abstract: [Objective] Taking Qilian Mountain area as the study area, to explore the spatial and temporal change characteristics of soil conservation services and spatial heterogeneity attribution, and to provide reference for ecological protection and sustainable development in the study area. [Methods] Based on the land use data of 4 periods from 2005 to 2020, combined with topographic, soil and meteorological data, the InVEST model and geodector method were used to simulate the soil conservation service, explore the spatial and temporal characteristics of soil conservation and its value, and attribute its spatial heterogeneity. [Results] ①The variation interval of soil conservation in Qilian Mountain area from 2005 to 2020 was 5.02~7.89×109t, with a decreasing trend; the spatial distribution of soil conservation was high in the southeast and low in the northwest, and the high value areas were all concentrated in the east side of Qinghai Lake and Qilian Mountain area in the study area. ②Among the different land use types, the total amount of grassland soil retention is the largest, and the soil retention intensity of forest land is the largest; the soil retention intensity with the increase in elevation shows a single peak curve that increases and then decreases; the soil retention intensity with the increase in slope shows a linear increase. ③The average annual value of soil conservation services in the study area is 3.912×1013 yuan, dominated by the value of maintaining soil fertility, E1.Geodetection results showed that slope and soil type had the highest explanatory power for the spatial heterogeneity of soil conservation, and the overall highest explanatory power was explained by the interaction of vegetation cover and soil type. [Conclusion] Slope and soil type act together on vegetation cover, and vegetation cover is the dominant factor influencing the spatial heterogeneity of soil conservation services. Part of the cultivated land should be converted to grassland or forest land, and ecological protection should be increased to improve vegetation cover, reduce soil erosion, and increase the soil conservation capacity, so as to improve the ecological environment.”
Abstract: [Objective] Taking Qilian Mountain area as the study area, to explore the spatial and temporal change characteristics of soil conservation services and spatial heterogeneity attribution, and to provide reference for ecological protection and sustainable development in the study area. [Methods] Based on the land use data of 4 periods from 2005 to 2020, combined with topographic, soil and meteorological data, the InVEST model and geodector method were used to simulate the soil conservation service, explore the spatial and temporal characteristics of soil conservation and its value, and attribute its spatial heterogeneity. [Results] ①The variation interval of soil conservation in Qilian Mountain area from 2005 to 2020 was 5.02~7.89×109t, with a decreasing trend; the spatial distribution of soil conservation was high in the southeast and low in the northwest, and the high value areas were all concentrated in the east side of Qinghai Lake and Qilian Mountain area in the study area. ②Among the different land use types, the total amount of grassland soil retention is the largest, and the soil retention intensity of forest land is the largest; the soil retention intensity with the increase in elevation shows a single peak curve that increases and then decreases; the soil retention intensity with the increase in slope shows a linear increase. ③The average annual value of soil conservation services in the study area is 3.912×1013 yuan, dominated by the value of maintaining soil fertility, E1.Geodetection results showed that slope and soil type had the highest explanatory power for the spatial heterogeneity of soil conservation, and the overall highest explanatory power was explained by the interaction of vegetation cover and soil type. [Conclusion] Slope and soil type act together on vegetation cover, and vegetation cover is the dominant factor influencing the spatial heterogeneity of soil conservation services. Part of the cultivated land should be converted to grassland or forest land, and ecological protection should be increased to improve vegetation cover, reduce soil erosion, and increase the soil conservation capacity, so as to improve the ecological environment.”
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[Objective]The determination of the target value of soil and water conservation rate is of great significance to the goal and task of soil and water conservation, the accurate evaluation of the effect of soil and water conservation, and the scientific promotion of the comprehensive prevention and control of soil and water loss in Shaanxi province.[Methods]Based on the comprehensive consideration of the social and economic conditions and the natural conditions of Shaanxi province, the change of soil and water loss area and the change of soil and water conservation rate were analyzed, based on the assessment results of annual water conservancy yearbooks and national soil and water conservation planning, the paper presents the spatial data of soil erosion classification, land use, elevation, topography and vegetation cover data, the situation of soil and water loss control in Shaanxi province is studied, the long-term target value of soil and water conservation rate in 2050, and the stage target value in 2025,2030 and 2035 were determined.And combined with the target responsibility system assessment, the way to achieve the rate of soil and water conservation is put forward.[Results](1)The results show that since 2011, the area of soil and water loss in the whole province has decreased from 72686.00 km2 to 62637.02 km2. (2)by2050，Soil and water loss control measures after all the implementation，the area of soil and water loss is expected to be reduced by 21,607.05 km2 and the?Long-term target value of soil and water conservation rate is 79.02%.(3)The phased targets for 2025,2030 and 2035 are 71.42% , 73.97% and 75.62% respectively.[Conclusion]Scientific and reasonable determination of the target value of soil and water conservation rate in Shaanxi province can meet the needs of carrying out the assessment of ecological civilization construction target and the assessment of responsibility for soil and water conservation target in Shaanxi province.
[Objective]The determination of the target value of soil and water conservation rate is of great significance to the goal and task of soil and water conservation, the accurate evaluation of the effect of soil and water conservation, and the scientific promotion of the comprehensive prevention and control of soil and water loss in Shaanxi province.[Methods]Based on the comprehensive consideration of the social and economic conditions and the natural conditions of Shaanxi province, the change of soil and water loss area and the change of soil and water conservation rate were analyzed, based on the assessment results of annual water conservancy yearbooks and national soil and water conservation planning, the paper presents the spatial data of soil erosion classification, land use, elevation, topography and vegetation cover data, the situation of soil and water loss control in Shaanxi province is studied, the long-term target value of soil and water conservation rate in 2050, and the stage target value in 2025,2030 and 2035 were determined.And combined with the target responsibility system assessment, the way to achieve the rate of soil and water conservation is put forward.[Results](1)The results show that since 2011, the area of soil and water loss in the whole province has decreased from 72686.00 km2 to 62637.02 km2. (2)by2050，Soil and water loss control measures after all the implementation，the area of soil and water loss is expected to be reduced by 21,607.05 km2 and the?Long-term target value of soil and water conservation rate is 79.02%.(3)The phased targets for 2025,2030 and 2035 are 71.42% , 73.97% and 75.62% respectively.[Conclusion]Scientific and reasonable determination of the target value of soil and water conservation rate in Shaanxi province can meet the needs of carrying out the assessment of ecological civilization construction target and the assessment of responsibility for soil and water conservation target in Shaanxi province.
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[Objective] To explore the mechanism of human activities affecting vegetation cover change in the " the Yarlung Zangbo River,the Lasa River and the Nyang Qu River " area of Tibet, and to provide important theoretical basis and scientific guidance for the implementation of integrated protection and restoration projects of mountain, water, forest, farmland, lake, grass, sand and ice in the area. [Methods] Based on normalized vegetation index, land use data, ecological engineering data and meteorological data from 2000 to 2020, this paper used GIS technology, residual analysis, slope trend analysis and M-K test to study the influence mechanism of human activities on temporal and spatial changes of vegetation cover in the " the Yarlung Zangbo River,the Lasa River and the Nyang Qu River " area. [Results] (1) From 2000 to 2020, NDVI of vegetation in the study area showed an overall increase trend, but showed a significant spatial difference, and the increase area of NDVI was mainly concentrated on both sides of the river valley. (2) From 2000 to 2020, the positive impact of human activities on NDVI was mainly concentrated in the valley areas of Yarlung Zangbo River and Lhasa River, while the negative impact was mainly distributed in Lhasa and its surrounding areas. Positive influences dominate. (3) Different land use types had different degrees of influence on vegetation cover change. Grassland and scrub contributed the most to NDVI change, reaching 92.8% in total. The area of urban and forest increased sharply, and the increase area of urban ecosystem was mainly transferred from farmland and grassland ecosystems, while forest and scrub ecosystems were mainly transferred from grassland and desert ecosystems. (4) The ecological engineering forest is one of the main reasons for the increase of NDVI in the study area. The area change of ecological engineering forest is positively correlated with the rate of change of NDVI and the rate of change of residual, and the ecological engineering forest can explain the residual change well. [Conclusion] Human activity is an important contributing factor to vegetation cover change, and appropriate ecological engineering plays an important role in vegetation restoration.
[Objective] To explore the mechanism of human activities affecting vegetation cover change in the " the Yarlung Zangbo River,the Lasa River and the Nyang Qu River " area of Tibet, and to provide important theoretical basis and scientific guidance for the implementation of integrated protection and restoration projects of mountain, water, forest, farmland, lake, grass, sand and ice in the area. [Methods] Based on normalized vegetation index, land use data, ecological engineering data and meteorological data from 2000 to 2020, this paper used GIS technology, residual analysis, slope trend analysis and M-K test to study the influence mechanism of human activities on temporal and spatial changes of vegetation cover in the " the Yarlung Zangbo River,the Lasa River and the Nyang Qu River " area. [Results] (1) From 2000 to 2020, NDVI of vegetation in the study area showed an overall increase trend, but showed a significant spatial difference, and the increase area of NDVI was mainly concentrated on both sides of the river valley. (2) From 2000 to 2020, the positive impact of human activities on NDVI was mainly concentrated in the valley areas of Yarlung Zangbo River and Lhasa River, while the negative impact was mainly distributed in Lhasa and its surrounding areas. Positive influences dominate. (3) Different land use types had different degrees of influence on vegetation cover change. Grassland and scrub contributed the most to NDVI change, reaching 92.8% in total. The area of urban and forest increased sharply, and the increase area of urban ecosystem was mainly transferred from farmland and grassland ecosystems, while forest and scrub ecosystems were mainly transferred from grassland and desert ecosystems. (4) The ecological engineering forest is one of the main reasons for the increase of NDVI in the study area. The area change of ecological engineering forest is positively correlated with the rate of change of NDVI and the rate of change of residual, and the ecological engineering forest can explain the residual change well. [Conclusion] Human activity is an important contributing factor to vegetation cover change, and appropriate ecological engineering plays an important role in vegetation restoration.
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[Objective] Understand the health status and ecological functions of forest ecosystems in karst areas through remote sensing monitoring of forest stock. [Methods] In this study, typical karst mountainous areas were selected as the research objects. Based on Sentinel-2A images and sample plot survey data, three machine learning models, including Random Forest (RF), K-Nearest Neighbor (KNN), and Back Propagation (BP), were combined to conduct a study on the inversion of forest accumulation under the constraint of mountain slope conditions. [Results] ① The performance of single-band reflectance, vegetation index, and texture features varied under different topographic constraints, and the optimal subsets of models established were different. There were differences in the establishment of accumulation estimation models under different site conditions. ②In the estimation of forest accumulation in the karst mountainous area, RF had the strongest robustness and adaptability compared with KNN and BP models. Under the conditions of gentle slope, inclined slope, and steep slope, the accuracy of RF model reached 80.1%, 79.0%, and 80.5%, respectively. [Conclusion] The spatial heterogeneity of karst mountainous areas is strong, and the modeling independent variables involved in the remote sensing estimation of accumulation are not the same under different slope site conditions. The division of slope can refine the remote sensing estimation model of complex scenes and improve the accuracy of remote sensing estimation of accumulation, providing a theoretical basis for carbon sink monitoring and assessment in mountainous areas with complex terrain and forest management and decision-making.
[Objective] Understand the health status and ecological functions of forest ecosystems in karst areas through remote sensing monitoring of forest stock. [Methods] In this study, typical karst mountainous areas were selected as the research objects. Based on Sentinel-2A images and sample plot survey data, three machine learning models, including Random Forest (RF), K-Nearest Neighbor (KNN), and Back Propagation (BP), were combined to conduct a study on the inversion of forest accumulation under the constraint of mountain slope conditions. [Results] ① The performance of single-band reflectance, vegetation index, and texture features varied under different topographic constraints, and the optimal subsets of models established were different. There were differences in the establishment of accumulation estimation models under different site conditions. ②In the estimation of forest accumulation in the karst mountainous area, RF had the strongest robustness and adaptability compared with KNN and BP models. Under the conditions of gentle slope, inclined slope, and steep slope, the accuracy of RF model reached 80.1%, 79.0%, and 80.5%, respectively. [Conclusion] The spatial heterogeneity of karst mountainous areas is strong, and the modeling independent variables involved in the remote sensing estimation of accumulation are not the same under different slope site conditions. The division of slope can refine the remote sensing estimation model of complex scenes and improve the accuracy of remote sensing estimation of accumulation, providing a theoretical basis for carbon sink monitoring and assessment in mountainous areas with complex terrain and forest management and decision-making.
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[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
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[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
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[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
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[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
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[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
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[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
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[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
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[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
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[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
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[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
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[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
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[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
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[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
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[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
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Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
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[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
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Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
Abstract:
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
Abstract:
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
Abstract:
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
Abstract:
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
Abstract:
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
Abstract:
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
Abstract:
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
Abstract:
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
Abstract:
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
Abstract:
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
YANG Cuihong, LI Yong, WANG Xu, CHEN Tingting, GUO Hao, YANG Yijiang, WU Zongmeng, ZHOU Xiaoqi, HUANG Zhigang
Abstract:
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
Abstract:
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
Abstract:
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
Display Method:
2023,43(4):238-247, DOI: 10.13961/j.cnki.stbctb.20230508.007
Abstract:
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
2023,43(4):154-161,210, DOI: 10.13961/j.cnki.stbctb.2023.04.019
Abstract:
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
2012(5):8-12, DOI: 10.13961/j.cnki.stbctb.2012.05.011
Abstract:
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
2022,42(2):264-274, DOI: 10.13961/j.cnki.stbctb.2022.02.036
Abstract:
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
2023,43(4):220-228,326, DOI: 10.13961/j.cnki.stbctb.2023.04.027
Abstract:
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
2006(3):1-5, DOI: 10.13961/j.cnki.stbctb.2006.03.002
Abstract:
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
2009(1):62-65, DOI: 10.13961/j.cnki.stbctb.2009.01.027
Abstract:
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
2022,42(2):210-218, DOI: 10.13961/j.cnki.stbctb.20220124.001
Abstract:
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
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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