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2024,43(5):1-9,57
, DOI: 10.13961/j.cnki.stbctb.2024.05.001
Abstract:
[Objective] The relationship between laterite disintegration characteristics and the occurrence of slumping erosion was investigated in order to provide a theoretical basis for slope management. [Methods] The basic parameters of slumping slopes such as slope gradient and angle of repose were measured; the characteristics of laterite agglomerates and the disintegration process under alternating wet and dry conditions were experimentally determined; and the conditions of the slope, stability of laterite water-stable agglomerates, and changes of the disintegration characteristics of the slumping erosion area were analyzed. [Results] ① Slope gradient and angle of repose were two factors that influenced the occurrence of slumping erosion. Sloughing was unusual in loess plateau areas with slope gradients of 40° or less and was considerably weakened by gradients greater than 80°. The natural angle of repose between red soil and slumping slopes varied from 25° to 36°. ② Most of the laterite agglomerates easily disintegrated when exposed to water because they were non-hydrostable and had weak stability, resulting in sloughing and erosion. The average mass diameter (MWD) and geometric mean diameter (GMD) of the laterite agglomerates were 2.16 mm and 1.37 mm for dry sieve and 0.51 mm and 0.25 mm for wet sieve, respectively. The percentage of agglomerate destruction (PAD) was 57.66%, with a fractal size D of 2.96. aggregate stability index (ASI) is a metric that represents the overall stability of agglomeration in the transfer matrix method, and the red clay ASI in this study was 1.75. ③ Dry-wet alternation reduced the rate of slumping erosion by reducing laterite disintegration. The highest disintegration index was 81.79%, and the average disintegration rate was 51.03 g/min. The disintegration degree of the laterite was lowered under the dry-wet alternation condition compared to under the natural state. The maximum disintegration index of the laterite varied between different dry-wet alternation circumstances but the difference was not statistically significant. ④ Laterite disintegration rates were favorably linked with the angle of repose, slope gradient, and ASI (p＜0.01) of the slumping erosion. [Conclusion] Laterite disintegration properties are directly related to slumping erosion, and dry-wet alternation reduces the rate of slumping erosion by reducing laterite disintegration.
[Objective] The relationship between laterite disintegration characteristics and the occurrence of slumping erosion was investigated in order to provide a theoretical basis for slope management. [Methods] The basic parameters of slumping slopes such as slope gradient and angle of repose were measured; the characteristics of laterite agglomerates and the disintegration process under alternating wet and dry conditions were experimentally determined; and the conditions of the slope, stability of laterite water-stable agglomerates, and changes of the disintegration characteristics of the slumping erosion area were analyzed. [Results] ① Slope gradient and angle of repose were two factors that influenced the occurrence of slumping erosion. Sloughing was unusual in loess plateau areas with slope gradients of 40° or less and was considerably weakened by gradients greater than 80°. The natural angle of repose between red soil and slumping slopes varied from 25° to 36°. ② Most of the laterite agglomerates easily disintegrated when exposed to water because they were non-hydrostable and had weak stability, resulting in sloughing and erosion. The average mass diameter (MWD) and geometric mean diameter (GMD) of the laterite agglomerates were 2.16 mm and 1.37 mm for dry sieve and 0.51 mm and 0.25 mm for wet sieve, respectively. The percentage of agglomerate destruction (PAD) was 57.66%, with a fractal size D of 2.96. aggregate stability index (ASI) is a metric that represents the overall stability of agglomeration in the transfer matrix method, and the red clay ASI in this study was 1.75. ③ Dry-wet alternation reduced the rate of slumping erosion by reducing laterite disintegration. The highest disintegration index was 81.79%, and the average disintegration rate was 51.03 g/min. The disintegration degree of the laterite was lowered under the dry-wet alternation condition compared to under the natural state. The maximum disintegration index of the laterite varied between different dry-wet alternation circumstances but the difference was not statistically significant. ④ Laterite disintegration rates were favorably linked with the angle of repose, slope gradient, and ASI (p＜0.01) of the slumping erosion. [Conclusion] Laterite disintegration properties are directly related to slumping erosion, and dry-wet alternation reduces the rate of slumping erosion by reducing laterite disintegration.
2024,43(5):10-18,27
, DOI: 10.13961/j.cnki.stbctb.2024.05.002
Abstract:
[Objective] The effect of simulated acid rain on the shear strength characteristics of red clay was investigated and the influence strength mechanism and microstructure of red clay after acid rain corrosion was analyzed in order to provide theoretical and engineering guidance for the construction of infrastructure in acid rain area, especially the protection of roadbed slope and safe operation of infrastructure. [Methods] The red clay of a roadbed slope in Kunming City, Yunnan Province was used as the research object. The study adopted the static soaking test and used pure water and acid liquor with different concentrations to soak and erode the red clay for 7, 14, and 28 days. Thereafter, the shear strength of the red clay was measured using the direct shear tests, and the microstructures of the eroded soil samples were analyzed via electron microscope scanning and energy spectrum analysis to analyze the influence mechanism of strength. [Results] ① The effect of acid liquor on the stress-strain characteristics of red clay is significant, especially under high concentration acid. The stress-strain curve was unstable and increased like a step, with strain hardening characteristics. ② With the increase in soaking time and acid concentration, the shear strength of red clay and its index of cohesion and internal friction angle gradually decreased, and the acid concentration had a more significant effect on the strength and its index. ③ Acid liquor decreased the sequioxide and the interparticle adhesion and bonding force and simultaneously increased the internal pores, loosened the structure, and increased the soil moisture content, thereby resulting in a decrease in shear strength and cohesion; however, the overall decrease in particle size caused by acid was the main reason for the decrease in the internal friction angle. [Conclusion] Acid rain has a significant effect on the strength of red clay from roadbed slope, and the intensity of acid rain has a more significant effect on the strength than the duration of rainfall. Attention should be paid to the prediction and prevention of roadbed slope stability and the safe operation of highway infrastructure.
[Objective] The effect of simulated acid rain on the shear strength characteristics of red clay was investigated and the influence strength mechanism and microstructure of red clay after acid rain corrosion was analyzed in order to provide theoretical and engineering guidance for the construction of infrastructure in acid rain area, especially the protection of roadbed slope and safe operation of infrastructure. [Methods] The red clay of a roadbed slope in Kunming City, Yunnan Province was used as the research object. The study adopted the static soaking test and used pure water and acid liquor with different concentrations to soak and erode the red clay for 7, 14, and 28 days. Thereafter, the shear strength of the red clay was measured using the direct shear tests, and the microstructures of the eroded soil samples were analyzed via electron microscope scanning and energy spectrum analysis to analyze the influence mechanism of strength. [Results] ① The effect of acid liquor on the stress-strain characteristics of red clay is significant, especially under high concentration acid. The stress-strain curve was unstable and increased like a step, with strain hardening characteristics. ② With the increase in soaking time and acid concentration, the shear strength of red clay and its index of cohesion and internal friction angle gradually decreased, and the acid concentration had a more significant effect on the strength and its index. ③ Acid liquor decreased the sequioxide and the interparticle adhesion and bonding force and simultaneously increased the internal pores, loosened the structure, and increased the soil moisture content, thereby resulting in a decrease in shear strength and cohesion; however, the overall decrease in particle size caused by acid was the main reason for the decrease in the internal friction angle. [Conclusion] Acid rain has a significant effect on the strength of red clay from roadbed slope, and the intensity of acid rain has a more significant effect on the strength than the duration of rainfall. Attention should be paid to the prediction and prevention of roadbed slope stability and the safe operation of highway infrastructure.
2024,43(5):19-27
, DOI: 10.13961/j.cnki.stbctb.2024.05.003
Abstract:
[Objective] The infiltration process and characteristics of the slump body in the alpine grassland blanket layer in the source region of the Yellow River were analyzed to provide data and theoretical basis for the slump body deformation and damage prevention and soil and water conservation. [Methods] This study used the alpine grass felt layer slump body in the source area of the Yellow River as the research object. The relationship curve between infiltration rate and time and the permeability coefficient of the slope grass felt layer slump body in the Eling Lake area of the Yellow River source were obtained through the double loop permeability test, and the suitable permeability model was determined. [Results] The infiltration rate of the grass felt layer slump body in the study area generally decreased sharply and then gradually flattened with the increase of infiltration time. The average permeability coefficients of the three test points were (5.81±2.18)×10-3, (4.53±0.82)×10-3, and (4.42±0.51)×10-3 cm/s, respectively, and there was no significant difference between each other. Compared to the Kostiakov model and the general empirical model, the Horton model had a higher applicability in simulating the water infiltration process of the grass felt layer slump body in the study area. [Conclusion] The Horton model is more suitable for simulating the water infiltration process of the grass felt layer slump body.
[Objective] The infiltration process and characteristics of the slump body in the alpine grassland blanket layer in the source region of the Yellow River were analyzed to provide data and theoretical basis for the slump body deformation and damage prevention and soil and water conservation. [Methods] This study used the alpine grass felt layer slump body in the source area of the Yellow River as the research object. The relationship curve between infiltration rate and time and the permeability coefficient of the slope grass felt layer slump body in the Eling Lake area of the Yellow River source were obtained through the double loop permeability test, and the suitable permeability model was determined. [Results] The infiltration rate of the grass felt layer slump body in the study area generally decreased sharply and then gradually flattened with the increase of infiltration time. The average permeability coefficients of the three test points were (5.81±2.18)×10-3, (4.53±0.82)×10-3, and (4.42±0.51)×10-3 cm/s, respectively, and there was no significant difference between each other. Compared to the Kostiakov model and the general empirical model, the Horton model had a higher applicability in simulating the water infiltration process of the grass felt layer slump body in the study area. [Conclusion] The Horton model is more suitable for simulating the water infiltration process of the grass felt layer slump body.
2024,43(5):28-37,47
, DOI: 10.13961/j.cnki.stbctb.2024.05.004
Abstract:
[Objective] The water sources of alfalfa and seabuckthorn under different vegetation allocation patterns in drought and rainy seasons were studied to provide a theoretical basis for vegetation restoration in mining areas. [Methods] The platform of the dumping site of Manlailiang coal mine in Ordos City, Inner Monglia Autonomous Region was taken as the research area. The stable isotope technique was used to collect plant xylem samples, soil samples, and precipitation samples under three vegetation configuration modes in the study area, and the hydrogen and oxygen stable isotope compositions were analyzed. [Results] ① With the advent of the rainy season, the soil moisture content of all plots showed an increasing trend. The pure seabuckthorn land increased from 6.56% in the dry season to 9.88%, the pure alfalfa land increased from 7.94% to 9.15%, and the mixed land increased from 9.4% to 15.45%. ② Alfalfa and seabuckthorn mainly used 80—100 cm soil water as their water source under different vegetation configuration modes in the dry season. In the rainy season, with the supplement of rainfall to soil water, the soil moisture content increased, and the water absorption depth of various types of vegetation moved up, mainly concentrated at 20—60 cm. [Conclusion] The water sources of alfalfa and seabuckthorn were very different in the dry and rainy seasons under different vegetation configuration modes. In the dry season it was mainly concentrated in deep soil, and the water absorption depth moved up and the water absorption range increased in the rainy season. To avoid resource competition, seabuckthorn will choose deep soil water as its main water source under the mixed condition in the rainy season.
[Objective] The water sources of alfalfa and seabuckthorn under different vegetation allocation patterns in drought and rainy seasons were studied to provide a theoretical basis for vegetation restoration in mining areas. [Methods] The platform of the dumping site of Manlailiang coal mine in Ordos City, Inner Monglia Autonomous Region was taken as the research area. The stable isotope technique was used to collect plant xylem samples, soil samples, and precipitation samples under three vegetation configuration modes in the study area, and the hydrogen and oxygen stable isotope compositions were analyzed. [Results] ① With the advent of the rainy season, the soil moisture content of all plots showed an increasing trend. The pure seabuckthorn land increased from 6.56% in the dry season to 9.88%, the pure alfalfa land increased from 7.94% to 9.15%, and the mixed land increased from 9.4% to 15.45%. ② Alfalfa and seabuckthorn mainly used 80—100 cm soil water as their water source under different vegetation configuration modes in the dry season. In the rainy season, with the supplement of rainfall to soil water, the soil moisture content increased, and the water absorption depth of various types of vegetation moved up, mainly concentrated at 20—60 cm. [Conclusion] The water sources of alfalfa and seabuckthorn were very different in the dry and rainy seasons under different vegetation configuration modes. In the dry season it was mainly concentrated in deep soil, and the water absorption depth moved up and the water absorption range increased in the rainy season. To avoid resource competition, seabuckthorn will choose deep soil water as its main water source under the mixed condition in the rainy season.
2024,43(5):38-47
, DOI: 10.13961/j.cnki.stbctb.20240729.002
Abstract:
[Objective] The dynamic pattern of soil enzyme activities and its relationship with soil chemical properties in a subtropical Pinus armandii forest was investigated to provide reference for the study of nitrogen deposition in subtropical regions. [Methods] Four nitrogen gradient treatments for the control (CK) and low (LN), medium (MN), and high nitrogen (HN) at 0, 10, 20 and 25 g/(m2·a), respectively, were set up in the subtropical Pinus armandii forest of Central Yunnan to analyse the response of soil enzymes to nitrogen deposition and its correlation with soil chemical properties. [Results] ① Nitrogen deposition promoted the activities of invertase (16.94%—34.00%) and acid phosphatase (23.42%—40.09%) and inhibited the activities of urease (8.70%—27.18%) and catalase (9.26%—23.36%), with temporal variation (p<0.05). Invertase and urease activities were highest at 25th and 27th month after nitrogen deposition (August and October, 2021), whereas acid phosphatase and catalase activities were highest at 33th month after nitrogen deposition (June, 2022). ② Soil pH value, organic carbon, and total phosphorus content decreased with increasing nitrogen deposition; in contrary, soil nitrate and ammonia nitrogen content increased in MN and decreased in HN. ③ Soil chemical properties and enzyme activities were characterized by a vertical soil layer distribution of 0—5 cm >5—10 cm >10—20 cm. The synergism between different soil enzyme activities under nitrogen deposition was high (p<0.05), among the environmental factors affecting soil enzyme activities, soil total nitrogen was the most sensitive factor affecting invertase activity; soil organic carbon, total phosphorus, and ammoniacal nitrogen were the most sensitive factors affecting urease and catalase activities. [Conclusion] With continuously increase in nitrogen deposition, the synergism among soil enzymes was enhanced, the environmental factors affecting forest soil were changed, the soil enzyme activity was promoted or inhibited, and then the soil nutrient cycling was changed too.
[Objective] The dynamic pattern of soil enzyme activities and its relationship with soil chemical properties in a subtropical Pinus armandii forest was investigated to provide reference for the study of nitrogen deposition in subtropical regions. [Methods] Four nitrogen gradient treatments for the control (CK) and low (LN), medium (MN), and high nitrogen (HN) at 0, 10, 20 and 25 g/(m2·a), respectively, were set up in the subtropical Pinus armandii forest of Central Yunnan to analyse the response of soil enzymes to nitrogen deposition and its correlation with soil chemical properties. [Results] ① Nitrogen deposition promoted the activities of invertase (16.94%—34.00%) and acid phosphatase (23.42%—40.09%) and inhibited the activities of urease (8.70%—27.18%) and catalase (9.26%—23.36%), with temporal variation (p<0.05). Invertase and urease activities were highest at 25th and 27th month after nitrogen deposition (August and October, 2021), whereas acid phosphatase and catalase activities were highest at 33th month after nitrogen deposition (June, 2022). ② Soil pH value, organic carbon, and total phosphorus content decreased with increasing nitrogen deposition; in contrary, soil nitrate and ammonia nitrogen content increased in MN and decreased in HN. ③ Soil chemical properties and enzyme activities were characterized by a vertical soil layer distribution of 0—5 cm >5—10 cm >10—20 cm. The synergism between different soil enzyme activities under nitrogen deposition was high (p<0.05), among the environmental factors affecting soil enzyme activities, soil total nitrogen was the most sensitive factor affecting invertase activity; soil organic carbon, total phosphorus, and ammoniacal nitrogen were the most sensitive factors affecting urease and catalase activities. [Conclusion] With continuously increase in nitrogen deposition, the synergism among soil enzymes was enhanced, the environmental factors affecting forest soil were changed, the soil enzyme activity was promoted or inhibited, and then the soil nutrient cycling was changed too.
2024,43(5):48-57
, DOI: 10.13961/j.cnki.stbctb.2024.05.006
Abstract:
[Objective] The change of wind erosion characteristics of physical crust under freeze-thaw conditions was studied to provide theoretical reference for the study of freeze-thaw wind erosion. [Methods] The study examined sandy loess of the Liudaogou sub-watershed in Shenmu City, Shaanxi Province, situated within the wind and water erosion crisscross region of the northern Loess Plateau. The synergistic approaches of indoor freeze-thaw simulation and wind tunnel testing were used to assess the impact of freeze-thaw cycles on wind erosion intensity, sand transport rate, and kinetic parameters such as friction wind speed and aerodynamic roughness across varying soil physical crust coverage levels (0%, 20%, 40%, 60%, 80% and 100%). [Results] ① Wind erosion intensity was found to increase significantly with increasing wind speed (p＜0.05) and decrease with increasing incrust coverage (p＜0.05), and the maximum reduction in erosion rate was up to 96.07%. Compared to that under pre-freeze-thaw condition, there was a significant rise in the wind erosion intensity of physical crusts under post-freeze-thaw condition, and the increase ranged from 0.02 to 1.27 times. ② Physical crust coverage significantly reduced the near-surface sand transport, which decreased with increasing crust coverage and increased with increasing wind speeds. After freeze-thaw cycles, the near-surface sand transport rates increased by 0.7 to 4.3 times, and the transport height increased by 2 to 10 cm. ③ Changes in friction wind speed and aerodynamic roughness in response to variations in crust coverage were not statistically significant. The friction wind speed before freeze-thaw was between 0.84 and 1.35 m/s, and post-freeze-thaw varied from 0.80 to 1.51 m/s. Although the friction wind speed was slightly reduced after freeze-thaw, the aerodynamic roughness exhibited minimal variation. [Conclusion] In the northern part of the Loess Plateau, the protective effects of physical crusts against wind erosion reduced and soil wind erosion was intensified by freeze-thaw processes. With increased crust coverage, there was a more noticeable increase in wind erosion intensity and near-surface sand transport following freeze-thaw cycles. The influence of crust coverage and freeze-thaw processes on aerodynamic roughness is negligible.
[Objective] The change of wind erosion characteristics of physical crust under freeze-thaw conditions was studied to provide theoretical reference for the study of freeze-thaw wind erosion. [Methods] The study examined sandy loess of the Liudaogou sub-watershed in Shenmu City, Shaanxi Province, situated within the wind and water erosion crisscross region of the northern Loess Plateau. The synergistic approaches of indoor freeze-thaw simulation and wind tunnel testing were used to assess the impact of freeze-thaw cycles on wind erosion intensity, sand transport rate, and kinetic parameters such as friction wind speed and aerodynamic roughness across varying soil physical crust coverage levels (0%, 20%, 40%, 60%, 80% and 100%). [Results] ① Wind erosion intensity was found to increase significantly with increasing wind speed (p＜0.05) and decrease with increasing incrust coverage (p＜0.05), and the maximum reduction in erosion rate was up to 96.07%. Compared to that under pre-freeze-thaw condition, there was a significant rise in the wind erosion intensity of physical crusts under post-freeze-thaw condition, and the increase ranged from 0.02 to 1.27 times. ② Physical crust coverage significantly reduced the near-surface sand transport, which decreased with increasing crust coverage and increased with increasing wind speeds. After freeze-thaw cycles, the near-surface sand transport rates increased by 0.7 to 4.3 times, and the transport height increased by 2 to 10 cm. ③ Changes in friction wind speed and aerodynamic roughness in response to variations in crust coverage were not statistically significant. The friction wind speed before freeze-thaw was between 0.84 and 1.35 m/s, and post-freeze-thaw varied from 0.80 to 1.51 m/s. Although the friction wind speed was slightly reduced after freeze-thaw, the aerodynamic roughness exhibited minimal variation. [Conclusion] In the northern part of the Loess Plateau, the protective effects of physical crusts against wind erosion reduced and soil wind erosion was intensified by freeze-thaw processes. With increased crust coverage, there was a more noticeable increase in wind erosion intensity and near-surface sand transport following freeze-thaw cycles. The influence of crust coverage and freeze-thaw processes on aerodynamic roughness is negligible.
2024,43(5):58-67
, DOI: 10.13961/j.cnki.stbctb.2024.05.007
Abstract:
[Objective] The tensile and shear resistance characteristics of the riparian alpine meadow rooted soil and the influencing factors along the riverbanks of the Yellow River source area were analyzed to provide data support for research on riverbank protection and the mechanical mechanisms of riverbank failure in the source area. [Methods] Taking the meandering river Lanmucuoqu in Henan County, Qinghai Province, as the study area and the rooted soil of alpine meadows with varying degrees of degradation along riverbanks as the research object. The effects of water content, root content, root system composition, and the number of freeze-thaw cycles on the tensile and shear strength of root-bearing soil were analyzed. The relationship between the tensile and shear strengths of the root-bearing soil was also explored. [Results] The tensile and shear strengths of the rooted soil gradually decreased as the water content increased from 30% to 55%, and the shear strength was approximately five times than that of the tensile strength. The addition of plant roots effectively improved the tensile and shear strength of the soil. As the root content increased from 0% to 0.25%, the tensile and shear strengths increased by 45% and 107%, reaching maximum values of 4.38 and 19.98 kPa, respectively, when the proportion of gramineous plants was 100%. After multiple freeze-thaw cycles, the fitting curve of the root-bearing soil showed a bimodal pattern, with the original network structure of the soil first being destroyed and then reaching a new equilibrium as the number of freeze-thaw cycles increased. A linear correlation was observed between the tensile and shear strengths of root-bearing soil. [Conclusion] The degradation of alpine meadows in the Yellow River source area has led to significant changes in root quantity and root system morphology, resulting in a gradual decrease in the tensile and shear strengths of the rooted soil. Therefore, it is necessary to minimize overgrazing and human interference to protect the native alpine meadow vegetation along riverbanks and maintain the stability of riverbanks in the source area.
[Objective] The tensile and shear resistance characteristics of the riparian alpine meadow rooted soil and the influencing factors along the riverbanks of the Yellow River source area were analyzed to provide data support for research on riverbank protection and the mechanical mechanisms of riverbank failure in the source area. [Methods] Taking the meandering river Lanmucuoqu in Henan County, Qinghai Province, as the study area and the rooted soil of alpine meadows with varying degrees of degradation along riverbanks as the research object. The effects of water content, root content, root system composition, and the number of freeze-thaw cycles on the tensile and shear strength of root-bearing soil were analyzed. The relationship between the tensile and shear strengths of the root-bearing soil was also explored. [Results] The tensile and shear strengths of the rooted soil gradually decreased as the water content increased from 30% to 55%, and the shear strength was approximately five times than that of the tensile strength. The addition of plant roots effectively improved the tensile and shear strength of the soil. As the root content increased from 0% to 0.25%, the tensile and shear strengths increased by 45% and 107%, reaching maximum values of 4.38 and 19.98 kPa, respectively, when the proportion of gramineous plants was 100%. After multiple freeze-thaw cycles, the fitting curve of the root-bearing soil showed a bimodal pattern, with the original network structure of the soil first being destroyed and then reaching a new equilibrium as the number of freeze-thaw cycles increased. A linear correlation was observed between the tensile and shear strengths of root-bearing soil. [Conclusion] The degradation of alpine meadows in the Yellow River source area has led to significant changes in root quantity and root system morphology, resulting in a gradual decrease in the tensile and shear strengths of the rooted soil. Therefore, it is necessary to minimize overgrazing and human interference to protect the native alpine meadow vegetation along riverbanks and maintain the stability of riverbanks in the source area.
2024,43(5):68-74
, DOI: 10.13961/j.cnki.stbctb.2024.05.008
Abstract:
[Objective] The effects of rainfall levels, planting patterns and their interactions on slope sediment yield and loss in metamorphic rock areas were studied to provide references for soil and water conservation, land management strategies and vegetation allocation in Dabie Mountains area. [Methods] Experimental investigations on soil erosion in runoff plots with three distinct planting patterns (monoculture of Camellia oleifera, monoculture of Camellia sinensis, and mixed planting of C. oleifera and C. sinensis at intervals) were carried out in Panxin Town, Luoshan County, Dabie Mountains. Instruments such as soil erosion monitors and tipping bucket rain gauges were used to monitor real-time runoff and rainfall in the year 2023. Variance analysis and correlation analysis were conducted to investigate the impact of rainfall variables and planting configurations on runoff and sediment yield. [Results] The monoculture of C. sinensis plot exhibited the highest runoff, and the mixed planting plot demonstrated significantly lower runoff compared to the monoculture plots, but no significant variance in sediment yield among the plots (p＞0.05) without considering rainfall levels. Under light and moderate rainfall, there was no significant distinction in runoff among the plots; however, the sediment yield in the mixed planting plot was notably lower than that in the other plots, particularly under moderate rainfall conditions. During periods of intense and prolonged rainfall, the runoff in the mixed planting plot exhibited a statistically significant decrease compared to the monoculture plots (p＜0.05). However, there was no significant variance in sediment yield among the plots. Both runoff and sediment yield showed a significant correlation with total rainfall and hourly rainfall, but runoff was additionally influenced by the maximum 60-minute rainfall intensity. [Conclusion] Compared to the monoculture practices of C. oleifera or C. sinensis, the mixed planting pattern demonstrated a notable decrease in runoff on slopes within the metamorphic rock regions of the Dabie Mountains. Furthermore, sediment yield under light to moderate rainfall conditions was effectively mitigated. Attention should be paid to soil and water conservation, land management strategy formulation, and vegetation allocation in Dabie Mountains area in the future.
[Objective] The effects of rainfall levels, planting patterns and their interactions on slope sediment yield and loss in metamorphic rock areas were studied to provide references for soil and water conservation, land management strategies and vegetation allocation in Dabie Mountains area. [Methods] Experimental investigations on soil erosion in runoff plots with three distinct planting patterns (monoculture of Camellia oleifera, monoculture of Camellia sinensis, and mixed planting of C. oleifera and C. sinensis at intervals) were carried out in Panxin Town, Luoshan County, Dabie Mountains. Instruments such as soil erosion monitors and tipping bucket rain gauges were used to monitor real-time runoff and rainfall in the year 2023. Variance analysis and correlation analysis were conducted to investigate the impact of rainfall variables and planting configurations on runoff and sediment yield. [Results] The monoculture of C. sinensis plot exhibited the highest runoff, and the mixed planting plot demonstrated significantly lower runoff compared to the monoculture plots, but no significant variance in sediment yield among the plots (p＞0.05) without considering rainfall levels. Under light and moderate rainfall, there was no significant distinction in runoff among the plots; however, the sediment yield in the mixed planting plot was notably lower than that in the other plots, particularly under moderate rainfall conditions. During periods of intense and prolonged rainfall, the runoff in the mixed planting plot exhibited a statistically significant decrease compared to the monoculture plots (p＜0.05). However, there was no significant variance in sediment yield among the plots. Both runoff and sediment yield showed a significant correlation with total rainfall and hourly rainfall, but runoff was additionally influenced by the maximum 60-minute rainfall intensity. [Conclusion] Compared to the monoculture practices of C. oleifera or C. sinensis, the mixed planting pattern demonstrated a notable decrease in runoff on slopes within the metamorphic rock regions of the Dabie Mountains. Furthermore, sediment yield under light to moderate rainfall conditions was effectively mitigated. Attention should be paid to soil and water conservation, land management strategy formulation, and vegetation allocation in Dabie Mountains area in the future.
2024,43(5):75-82
, DOI: 10.13961/j.cnki.stbctb.2024.05.009
Abstract:
[Objective] The soil and water conservation benefits of vegetation measures were analyzed under different land use types for the small catchment from the mountainous areas in the Central Yunnan Plateau to provide scientific basis and theoretical guidance for rational planting and improvement of land use status in the area. [Methods] The Jianshan River small catchment from Yuxi City of Yunnan Province was selected as the study area, and the rainfall data were collected from 2012 to 2022. The runoff and sediment yield characteristics and their influencing factors under different land use types (secondary forest, artificial forest, shrub land, cultivated land, economic fruit forest) were analyzed based on the runoff and sediment data from the runoff plots. [Results] ① The order of runoff from different land uses was in the order of cultivated land ＞economic fruit forest ＞shrub land ＞secondary forest ＞artificial forest, and the order for sediment yield was cultivated land ＞artificial forest ＞economic fruit forest secondary forest＞shrub land. The erosion resistance of cultivated land was worse than that of other land use types under the same rainfall conditions. ② A significant positive correlation was determined between sediment yield and runoff (p＜0.01). The sediment delivery lagged behind the runoff generation. Only when the runoff was ≥0.02 mm for the secondary forest, ≥0.46 mm for shrubland, ≥0.4 mm for artificial forest, ≥0.62 mm for economic fruit forest, and ≥0.09 mm for cultivated land could they carry sediment. ③ Runoff and sediment yield were significantly correlated with vegetation coverage, rainfall, soil capillary water-holding capacity, soil capillary porosity, and total soil porosity (p＜0.05). [Conclusion] This study has an important practical significance for scientifically setting up the layout of vegetation types, reasonably allocating the land planting pattern, and laying out the farmland consolidation.
[Objective] The soil and water conservation benefits of vegetation measures were analyzed under different land use types for the small catchment from the mountainous areas in the Central Yunnan Plateau to provide scientific basis and theoretical guidance for rational planting and improvement of land use status in the area. [Methods] The Jianshan River small catchment from Yuxi City of Yunnan Province was selected as the study area, and the rainfall data were collected from 2012 to 2022. The runoff and sediment yield characteristics and their influencing factors under different land use types (secondary forest, artificial forest, shrub land, cultivated land, economic fruit forest) were analyzed based on the runoff and sediment data from the runoff plots. [Results] ① The order of runoff from different land uses was in the order of cultivated land ＞economic fruit forest ＞shrub land ＞secondary forest ＞artificial forest, and the order for sediment yield was cultivated land ＞artificial forest ＞economic fruit forest secondary forest＞shrub land. The erosion resistance of cultivated land was worse than that of other land use types under the same rainfall conditions. ② A significant positive correlation was determined between sediment yield and runoff (p＜0.01). The sediment delivery lagged behind the runoff generation. Only when the runoff was ≥0.02 mm for the secondary forest, ≥0.46 mm for shrubland, ≥0.4 mm for artificial forest, ≥0.62 mm for economic fruit forest, and ≥0.09 mm for cultivated land could they carry sediment. ③ Runoff and sediment yield were significantly correlated with vegetation coverage, rainfall, soil capillary water-holding capacity, soil capillary porosity, and total soil porosity (p＜0.05). [Conclusion] This study has an important practical significance for scientifically setting up the layout of vegetation types, reasonably allocating the land planting pattern, and laying out the farmland consolidation.
2024,43(5):83-91,99
, DOI: 10.13961/j.cnki.stbctb.2024.05.010
Abstract:
[Objective] The pedo-transfer functions was established through the simple and easily measurable soil properties, and the soil saturated hydraulic conductivity was obtained indirectly, in order to provide data support for soil water transport and simulation of typical agricultural small watershed of the Three Gorges reservoir area. [Methods] Using the Shipanqiu watershed of the Three Gorges reservoir area as the research object, the soil saturated hydraulic conductivity (Ks) and other basic physical and chemical properties of typical land use types (cultivated land, garden land, and grassland) were measured. In addition to correlation and principal component analysis, multiple linear regression (MLR), BP neural network (BP-ANN), and support vector machine (SVM) methods were used to construct pedo-transfer functions for the saturated hydraulic conductivity of the surface soil in the study area. Furthermore, four common pedo-transfer functions were selected to verify their applicability in this study area. [Results] The average soil Ks values were in the order of grassland>garden>cultivated land, with significant differences among different land use types. The saturated hydraulic conductivity of the soil was significantly correlated with bulk density, organic matter content, saturated water content, and soil texture. Compared with the Ks pedo-transfer functions established through multiple linear regression, BP neural network, and support vector machine, the previously used soil transfer functions model have poor prediction performance for soil saturated hydraulic conductivity in this study area. The forecast accuracy of the transfer function created using the three methods was in the order of SVM>BP-ANN>MLR, and the forecast accuracy created using principal component P1 and P2 as input variables was better than others. [Conclusion] The Ks values under different land use types have strong spatial variability. The pedo-transfer functions built through BP-ANN and SVM can meet the prediction requirements of Ks in this study area, and the prediction accuracy of SVM is better than that of BP-ANN.
[Objective] The pedo-transfer functions was established through the simple and easily measurable soil properties, and the soil saturated hydraulic conductivity was obtained indirectly, in order to provide data support for soil water transport and simulation of typical agricultural small watershed of the Three Gorges reservoir area. [Methods] Using the Shipanqiu watershed of the Three Gorges reservoir area as the research object, the soil saturated hydraulic conductivity (Ks) and other basic physical and chemical properties of typical land use types (cultivated land, garden land, and grassland) were measured. In addition to correlation and principal component analysis, multiple linear regression (MLR), BP neural network (BP-ANN), and support vector machine (SVM) methods were used to construct pedo-transfer functions for the saturated hydraulic conductivity of the surface soil in the study area. Furthermore, four common pedo-transfer functions were selected to verify their applicability in this study area. [Results] The average soil Ks values were in the order of grassland>garden>cultivated land, with significant differences among different land use types. The saturated hydraulic conductivity of the soil was significantly correlated with bulk density, organic matter content, saturated water content, and soil texture. Compared with the Ks pedo-transfer functions established through multiple linear regression, BP neural network, and support vector machine, the previously used soil transfer functions model have poor prediction performance for soil saturated hydraulic conductivity in this study area. The forecast accuracy of the transfer function created using the three methods was in the order of SVM>BP-ANN>MLR, and the forecast accuracy created using principal component P1 and P2 as input variables was better than others. [Conclusion] The Ks values under different land use types have strong spatial variability. The pedo-transfer functions built through BP-ANN and SVM can meet the prediction requirements of Ks in this study area, and the prediction accuracy of SVM is better than that of BP-ANN.
2024,43(5):92-99
, DOI: 10.13961/j.cnki.stbctb.2024.05.011
Abstract:
[Objective] This study assessed of soil and water loss and evaluation of the benefits of measures caused by rainstorms. Soil erosion caused by rainstorms was analyzed, and the benefits of terrace measures were evaluated to provide an effective supplement for the dynamic monitoring of soil and water loss. [Methods] The Qingcheng County and Qiugou small watershed of the rainstorm (2022·7·15) center in Gansu Province were used as the research areas based on daily rainfall data and the results of the national dynamic monitoring of soil and water loss projects. An improved Chinese soil loss equation(CSLE) model was used to calculate the soil erosion modulus based on the rainfall erosivity of rainstorms. The relationship between rainfall erosivity of the rainstorm and annual rainfall erosivity under the condition of multiannual average rainfall was analyzed. The spatial distribution of the soil erosion intensity grades of different land-use types under rainstorm conditions was further analyzed, and the influence of terraces on regional soil erosion was discussed. [Results] The rainfall erosivity generated by this rainstorm in Qingcheng County reached 1.85 times the annual rainfall erosivity under the condition of multiyear average rainfall, and the rainfall erosivity of the rainstorm center reached 4.88 times the annual rainfall erosivity under the condition of multiyear average rainfall. The area of soil erosion above the strong level caused by rainstorms was 3.46 times, and the rainstorm center was 6.93 times that of the soil erosion above the strong level in 2021. Strong soil erosion caused by heavy rainstorms was primarily distributed in dry lands, grasslands, and shrubs. The current terrace area of Qingcheng County is 325 km2. The amount of soil erosion in the county decreased by 72.87% compared to the situation without terrace measures. [Conclusion] Strengthening soil and water conservation work, such as returning farmland to forest and grassland, comprehensively improving sloped farmland, and constructing dry terraces, is an effective means of preventing and controlling soil and water loss disasters under heavy rainstorm conditions.
[Objective] This study assessed of soil and water loss and evaluation of the benefits of measures caused by rainstorms. Soil erosion caused by rainstorms was analyzed, and the benefits of terrace measures were evaluated to provide an effective supplement for the dynamic monitoring of soil and water loss. [Methods] The Qingcheng County and Qiugou small watershed of the rainstorm (2022·7·15) center in Gansu Province were used as the research areas based on daily rainfall data and the results of the national dynamic monitoring of soil and water loss projects. An improved Chinese soil loss equation(CSLE) model was used to calculate the soil erosion modulus based on the rainfall erosivity of rainstorms. The relationship between rainfall erosivity of the rainstorm and annual rainfall erosivity under the condition of multiannual average rainfall was analyzed. The spatial distribution of the soil erosion intensity grades of different land-use types under rainstorm conditions was further analyzed, and the influence of terraces on regional soil erosion was discussed. [Results] The rainfall erosivity generated by this rainstorm in Qingcheng County reached 1.85 times the annual rainfall erosivity under the condition of multiyear average rainfall, and the rainfall erosivity of the rainstorm center reached 4.88 times the annual rainfall erosivity under the condition of multiyear average rainfall. The area of soil erosion above the strong level caused by rainstorms was 3.46 times, and the rainstorm center was 6.93 times that of the soil erosion above the strong level in 2021. Strong soil erosion caused by heavy rainstorms was primarily distributed in dry lands, grasslands, and shrubs. The current terrace area of Qingcheng County is 325 km2. The amount of soil erosion in the county decreased by 72.87% compared to the situation without terrace measures. [Conclusion] Strengthening soil and water conservation work, such as returning farmland to forest and grassland, comprehensively improving sloped farmland, and constructing dry terraces, is an effective means of preventing and controlling soil and water loss disasters under heavy rainstorm conditions.
2024,43(5):100-112
, DOI: 10.13961/j.cnki.stbctb.2024.05.012
Abstract:
[Objective] The patterns and mechanisms of farmland conversion to non-agricultural were explored in the hilly regions of Northeast Guangdong Province (NGP) to provide theoretical guidance for preventing Farmland Conversion to Non-agricultural. [Methods] Using NGP as an example, information on farmland conversion was extracted land-use images for the years 1990, 2000, 2010, and 2020. Spatial autocorrelation analysis and optimal parameter geographic detector methods were employed to investigate the spatiotemporal distribution characteristics and factors influencing farmland conversion. [Results] ① From 1990 to 2020, farmland conversion to non-agricultural in NGP exhibited a trend of “steady development followed by a sharp decline”, with a cumulative non-agriculturalized area spanning 2.29×105 hm2 at a rate of 25.31%. Forestland and constructed land were identified as the primary types of non-agricultural land. ② Vertically, croplands above 1 000 m in elevation and with a slope of 25°—35° were more prone to non-agriculturalization; horizontally, croplands within 50 m of construction land and 1 000—1 500 m from rivers were more likely to undergo non-agriculturalization. ③ Cropland non-agriculturalization in NGP exhibited significant positive clustering, with Global Molan’s I gradually decreasing from 0.371 to 0.255. The changes in “high-high” and “low-low” clustering dominated the evolution of the spatial autocorrelation pattern of cropland non-agriculturalization rates. ④ Agricultural population and cropland fragmentation consistently had strong explanatory power for the spatial distribution of cropland non-agriculturalization. In contrast, the explanatory power of socioeconomic factors for non-agriculturalization has weakened over the past decade. The interaction of multiple factors, especially agricultural and socioeconomic factors, can further enhance the explanatory power of cropland non-agriculturalization. [Conclusion] From 1990 to 2020, the area and spatial clustering of farmland conversion to non-agricultural in NGP decreased. However, the impact of the agricultural population and farmland fragmentation on farmland conversion to non-agricultural has intensified. It is suggested to reasonably control the speed of urban expansion, consolidate fragmented farmland, introduce small-scale agricultural machinery to improve farming conditions, and encourage farmers to cultivate by promoting rural e-commerce to address the issue of farmland conversion to non-agricultural.
[Objective] The patterns and mechanisms of farmland conversion to non-agricultural were explored in the hilly regions of Northeast Guangdong Province (NGP) to provide theoretical guidance for preventing Farmland Conversion to Non-agricultural. [Methods] Using NGP as an example, information on farmland conversion was extracted land-use images for the years 1990, 2000, 2010, and 2020. Spatial autocorrelation analysis and optimal parameter geographic detector methods were employed to investigate the spatiotemporal distribution characteristics and factors influencing farmland conversion. [Results] ① From 1990 to 2020, farmland conversion to non-agricultural in NGP exhibited a trend of “steady development followed by a sharp decline”, with a cumulative non-agriculturalized area spanning 2.29×105 hm2 at a rate of 25.31%. Forestland and constructed land were identified as the primary types of non-agricultural land. ② Vertically, croplands above 1 000 m in elevation and with a slope of 25°—35° were more prone to non-agriculturalization; horizontally, croplands within 50 m of construction land and 1 000—1 500 m from rivers were more likely to undergo non-agriculturalization. ③ Cropland non-agriculturalization in NGP exhibited significant positive clustering, with Global Molan’s I gradually decreasing from 0.371 to 0.255. The changes in “high-high” and “low-low” clustering dominated the evolution of the spatial autocorrelation pattern of cropland non-agriculturalization rates. ④ Agricultural population and cropland fragmentation consistently had strong explanatory power for the spatial distribution of cropland non-agriculturalization. In contrast, the explanatory power of socioeconomic factors for non-agriculturalization has weakened over the past decade. The interaction of multiple factors, especially agricultural and socioeconomic factors, can further enhance the explanatory power of cropland non-agriculturalization. [Conclusion] From 1990 to 2020, the area and spatial clustering of farmland conversion to non-agricultural in NGP decreased. However, the impact of the agricultural population and farmland fragmentation on farmland conversion to non-agricultural has intensified. It is suggested to reasonably control the speed of urban expansion, consolidate fragmented farmland, introduce small-scale agricultural machinery to improve farming conditions, and encourage farmers to cultivate by promoting rural e-commerce to address the issue of farmland conversion to non-agricultural.
2024,43(5):113-121
, DOI: 10.13961/j.cnki.stbctb.2024.05.013
Abstract:
[Objective] The distribution characteristics of water pollution risk in inland river basins were analyzed. A regional assessment was conducted to provide theoretical support and reference for the study of water pollution risks and incidents in inland river basins. [Methods] Geographic information system (GIS) spatial analysis was used to refine and visualize the degree and distribution of water pollution risk based on environmental statistical data, digital elevation model(DEM) data, water quality monitoring section data, and basic geographic data of the Heihe River basin in 2021, and a 1 km×1 km grid as the basic unit. The environmental risk field was used to assess the water pollution risk in the Heihe River basin and to analyze the distribution characteristics of water pollution risk zoning. [Results] Only a few areas in the Heihe River basin were at high-risk levels. Severly polluted water systems were mainly concentrated in the middle and lower reaches of the river, including Hongshui River, Taolai River system, and many rivers such as the Heidaban River from Shandan Ciyaokou to the Gaotai, main stream of Heihe River, and Liyuan River, Nineteen high-risk “hot spots” in the Heihe River basin have been accurately identified. Severe pollution was mainly distributed in the risk sources around the water system and in the overlapping areas of roads along the river, bridges across the river, and companion sections of the water system. The risk of water pollution in the entire Heihe River basin was low and within a manageable range. [Conclusion] This evaluation index system can characterize the main problems of water pollution risk in inland river basins from multi-dimensional and multi-spatial perspectives to improve the evaluation index system of water pollution risk in these basins and the level of risk management in the entire river basin.
[Objective] The distribution characteristics of water pollution risk in inland river basins were analyzed. A regional assessment was conducted to provide theoretical support and reference for the study of water pollution risks and incidents in inland river basins. [Methods] Geographic information system (GIS) spatial analysis was used to refine and visualize the degree and distribution of water pollution risk based on environmental statistical data, digital elevation model(DEM) data, water quality monitoring section data, and basic geographic data of the Heihe River basin in 2021, and a 1 km×1 km grid as the basic unit. The environmental risk field was used to assess the water pollution risk in the Heihe River basin and to analyze the distribution characteristics of water pollution risk zoning. [Results] Only a few areas in the Heihe River basin were at high-risk levels. Severly polluted water systems were mainly concentrated in the middle and lower reaches of the river, including Hongshui River, Taolai River system, and many rivers such as the Heidaban River from Shandan Ciyaokou to the Gaotai, main stream of Heihe River, and Liyuan River, Nineteen high-risk “hot spots” in the Heihe River basin have been accurately identified. Severe pollution was mainly distributed in the risk sources around the water system and in the overlapping areas of roads along the river, bridges across the river, and companion sections of the water system. The risk of water pollution in the entire Heihe River basin was low and within a manageable range. [Conclusion] This evaluation index system can characterize the main problems of water pollution risk in inland river basins from multi-dimensional and multi-spatial perspectives to improve the evaluation index system of water pollution risk in these basins and the level of risk management in the entire river basin.
2024,43(5):122-133,143
, DOI: 10.13961/j.cnki.stbctb.20240729.003
Abstract:
[Objective] The impact of groundwater dynamics on the evolution of soil salinization and its mechanism were systematically investigated to provide a theoretical reference for the comprehensive treatment of saline-alkaline land. [Methods] Based on VOSviewer and Citespace visualization software, the relevant literature in the Web of Science core database (WoS) and China National Knowledge Infrastructure (CNKI) was used to analyse the number of articles issued and their countries and institution form. A quantitative and multivariate dynamic visualization analysis of domestic and international research in this field from 2000—2022 was carried out, starting from the amount, country institution and author of publications, and keyword clustering, and their changes over time. [Results] The research on the impact of groundwater dynamics on soil water salinity at home and abroad followed a fluctuating upward trend with China and the United States as the core, and the cooperation between China and the United States, Germany, Australia, and other countries was more closely linked. The core authors and institutions focused on the comprehensive utilization of saline-alkaline land and groundwater regulation, which has contributed greatly to the effective improvement of the quality of arable land. The English literature mainly covered the disciplines of water resources (26.18%) and environmental science and ecology (23.22%); the disciplines that accounted for the largest proportion of the Chinese literature were basic agricultural science (30.05%) and agronomy (27.76%). The focus has been gradually improved from single to diversified research and has been transformed from the basic theory of salinity to the comprehensive utilization of saline-alkaline land to improve quality and increase the efficiency of land use. Studies have actively responded to national strategic needs and have clarified the comprehensive utilization of saline-alkaline land to improve the quality of arable land. [Conclusion] This field is a hotspot for future research. Future research should focus on the following aspects: optimal allocation of water resources, establishment of a sound water resources development and management system, construction of a national cloud platform for comprehensive utilization of saline and alkaline land, strengthen the in-depth integration of information technology and water conservancy, and in-depth investigation of the mechanism of influence of groundwater regulation on the water and salt transport in the soil-air pocket. This research could provide new ideas and methods for the comprehensive utilization of saline land.
[Objective] The impact of groundwater dynamics on the evolution of soil salinization and its mechanism were systematically investigated to provide a theoretical reference for the comprehensive treatment of saline-alkaline land. [Methods] Based on VOSviewer and Citespace visualization software, the relevant literature in the Web of Science core database (WoS) and China National Knowledge Infrastructure (CNKI) was used to analyse the number of articles issued and their countries and institution form. A quantitative and multivariate dynamic visualization analysis of domestic and international research in this field from 2000—2022 was carried out, starting from the amount, country institution and author of publications, and keyword clustering, and their changes over time. [Results] The research on the impact of groundwater dynamics on soil water salinity at home and abroad followed a fluctuating upward trend with China and the United States as the core, and the cooperation between China and the United States, Germany, Australia, and other countries was more closely linked. The core authors and institutions focused on the comprehensive utilization of saline-alkaline land and groundwater regulation, which has contributed greatly to the effective improvement of the quality of arable land. The English literature mainly covered the disciplines of water resources (26.18%) and environmental science and ecology (23.22%); the disciplines that accounted for the largest proportion of the Chinese literature were basic agricultural science (30.05%) and agronomy (27.76%). The focus has been gradually improved from single to diversified research and has been transformed from the basic theory of salinity to the comprehensive utilization of saline-alkaline land to improve quality and increase the efficiency of land use. Studies have actively responded to national strategic needs and have clarified the comprehensive utilization of saline-alkaline land to improve the quality of arable land. [Conclusion] This field is a hotspot for future research. Future research should focus on the following aspects: optimal allocation of water resources, establishment of a sound water resources development and management system, construction of a national cloud platform for comprehensive utilization of saline and alkaline land, strengthen the in-depth integration of information technology and water conservancy, and in-depth investigation of the mechanism of influence of groundwater regulation on the water and salt transport in the soil-air pocket. This research could provide new ideas and methods for the comprehensive utilization of saline land.
2024,43(5):134-143
, DOI: 10.13961/j.cnki.stbctb.2024.05.015
Abstract:
[Objective] The present study was performed to develop a geological disaster susceptibility evaluation model for predicting frequent geological disasters in the Taishan area. The aim was to use the results of this susceptibility evaluation as reference for preventing and managing geological disasters in this area. [Methods] Our analyses focused on the Taishan area, employing a method in which the certainty factor (CF) model was coupled with a random forest (RF) model optimized using the particle swarm optimization (PSO) algorithm to evaluate the geological disaster susceptibility in the research area. This method uses the CF model to calculate the sensitivity values of the factors influencing geological disasters, which are then used as attribute values for model training. The PSO algorithm was introduced to optimize the parameters of the RF model, thereby improving the accuracy and precision of the model in predicting geological disasters. Eleven influencing factors, including slope, distance to roads, land-use type, and vegetation index, were selected. The Pearson correlation coefficient method and a multicollinearity check were used to screen and optimize these influencing factors. The precision of the trained model was evaluated using ROC and PR curves. [Results] Compared with those of the single SVR, single RF, and CF-PSO-SVR models, the CF-PSO-RF coupled model significantly improved the proportion of extremely-high-susceptibility areas by 10.55%, 10.04%, and 5.08%, respectively, increased the AUC values by 14%, 5.1%, and 1.7%, respectively, and enhanced the average precision (AP)accuracy by 11.7%, 4.4%, and 1.2%, respectively. The prediction results revealed that the regions with high and extremely high susceptibility to geological disasters were mainly located in the Taishan scenic area, Northern Daiyue District, and other regions with significant topographic relief and steep slopes, covering 28.05% of the area and encompassing 60.1% of the geological disaster points. In contrast, regions with low and very low susceptibility were primarily distributed in flat areas, such as construction and farm lands, accounting for 59.26% of the total area. [Conclusion] The accuracy of the CF-PSO-RF coupled model for disaster susceptibility evaluation was notably higher than that of the single models; further, its precision was superior to that of the CF-PSO-SVR model. These evaluation results are consistent with actual conditions.
[Objective] The present study was performed to develop a geological disaster susceptibility evaluation model for predicting frequent geological disasters in the Taishan area. The aim was to use the results of this susceptibility evaluation as reference for preventing and managing geological disasters in this area. [Methods] Our analyses focused on the Taishan area, employing a method in which the certainty factor (CF) model was coupled with a random forest (RF) model optimized using the particle swarm optimization (PSO) algorithm to evaluate the geological disaster susceptibility in the research area. This method uses the CF model to calculate the sensitivity values of the factors influencing geological disasters, which are then used as attribute values for model training. The PSO algorithm was introduced to optimize the parameters of the RF model, thereby improving the accuracy and precision of the model in predicting geological disasters. Eleven influencing factors, including slope, distance to roads, land-use type, and vegetation index, were selected. The Pearson correlation coefficient method and a multicollinearity check were used to screen and optimize these influencing factors. The precision of the trained model was evaluated using ROC and PR curves. [Results] Compared with those of the single SVR, single RF, and CF-PSO-SVR models, the CF-PSO-RF coupled model significantly improved the proportion of extremely-high-susceptibility areas by 10.55%, 10.04%, and 5.08%, respectively, increased the AUC values by 14%, 5.1%, and 1.7%, respectively, and enhanced the average precision (AP)accuracy by 11.7%, 4.4%, and 1.2%, respectively. The prediction results revealed that the regions with high and extremely high susceptibility to geological disasters were mainly located in the Taishan scenic area, Northern Daiyue District, and other regions with significant topographic relief and steep slopes, covering 28.05% of the area and encompassing 60.1% of the geological disaster points. In contrast, regions with low and very low susceptibility were primarily distributed in flat areas, such as construction and farm lands, accounting for 59.26% of the total area. [Conclusion] The accuracy of the CF-PSO-RF coupled model for disaster susceptibility evaluation was notably higher than that of the single models; further, its precision was superior to that of the CF-PSO-SVR model. These evaluation results are consistent with actual conditions.
2024,43(5):144-151
, DOI: 10.13961/j.cnki.stbctb.2024.05.016
Abstract:
[Objective] The spatial autocorrelation patterns and influencing factors of soil and water loss and socio-economic development in Jilin Province were analyzed to provide a scientific basis for soil and water conservation and the green coordinated development in Jilin Province. [Methods] The analysis was based on the area of soil and water loss in various counties and cities in Jilin Province, combined with the social and economic statistics in the corresponding period. Tools including geographic information system (GIS), GeoDa, and ordinary least squares (OLS)linear regression models were used to analyze the spatial autocorrelation patterns of soil and water loss and socio-economic development and to identify the key influencing factors in Jilin Province from 2017 to 2021. [Results] ① The index of Moran’s I of soil and water loss in Jilin Province was positive with a minimum value of 0.254 6. Soil and water loss had an agglomeration effect in certain areas. The high-high agglomeration areas were primarily concentrated in the northwest of Jilin Province, and the low-low agglomeration areas were primarily concentrated in the southern region. ② The values of Moran’s I of urbanization rate, proportion of construction land, vegetation coverage area, and agricultural economic growth rate from the socio-economic indicators system of Jilin Province were relatively higher, and there were certain agglomeration characteristics in spatial. ③ The spatial autocorrelation analysis of soil and water loss and socio-economic reflected that Moran’s I values of “urbanization rate” and “forest area” were relatively large, and the spatial distribution of social type data was more concentrated compared to population and economic type data. ④ A high correlation was observed between the agricultural GDP, agricultural land use ratio, vegetation coverage ratio, and soil and water loss. The five-year average results of the correlation were 0.038, 0.003, and 0.154, respectively. [Conclusion] The soil and water loss, socio-economic development, and the double variables of soil and water loss and socio-economic development in Jilin Province have strong autocorrelation in space, respectively. Urbanization rate and vegetation coverage area were determined to have the most significant impact on soil and water loss among all the influencing factors.
[Objective] The spatial autocorrelation patterns and influencing factors of soil and water loss and socio-economic development in Jilin Province were analyzed to provide a scientific basis for soil and water conservation and the green coordinated development in Jilin Province. [Methods] The analysis was based on the area of soil and water loss in various counties and cities in Jilin Province, combined with the social and economic statistics in the corresponding period. Tools including geographic information system (GIS), GeoDa, and ordinary least squares (OLS)linear regression models were used to analyze the spatial autocorrelation patterns of soil and water loss and socio-economic development and to identify the key influencing factors in Jilin Province from 2017 to 2021. [Results] ① The index of Moran’s I of soil and water loss in Jilin Province was positive with a minimum value of 0.254 6. Soil and water loss had an agglomeration effect in certain areas. The high-high agglomeration areas were primarily concentrated in the northwest of Jilin Province, and the low-low agglomeration areas were primarily concentrated in the southern region. ② The values of Moran’s I of urbanization rate, proportion of construction land, vegetation coverage area, and agricultural economic growth rate from the socio-economic indicators system of Jilin Province were relatively higher, and there were certain agglomeration characteristics in spatial. ③ The spatial autocorrelation analysis of soil and water loss and socio-economic reflected that Moran’s I values of “urbanization rate” and “forest area” were relatively large, and the spatial distribution of social type data was more concentrated compared to population and economic type data. ④ A high correlation was observed between the agricultural GDP, agricultural land use ratio, vegetation coverage ratio, and soil and water loss. The five-year average results of the correlation were 0.038, 0.003, and 0.154, respectively. [Conclusion] The soil and water loss, socio-economic development, and the double variables of soil and water loss and socio-economic development in Jilin Province have strong autocorrelation in space, respectively. Urbanization rate and vegetation coverage area were determined to have the most significant impact on soil and water loss among all the influencing factors.
2024,43(5):152-161,233
, DOI: 10.13961/j.cnki.stbctb.2024.05.017
Abstract:
[Objective] The evaluation of carrying capacity of territorial space resources and environment in watersheds were studied based on multi scale fusion in order to provide scientific basis and reference for the sustainable development of the basin, and promote the coordinated development of resources and environment. [Methods] Using the Minjiang River basin as an example and considering the multifunctional characteristics and connotations of territorial spatial resources, we established a multi-scale evaluation system for territorial spatial resources and environmental carrying capacity. By applying an improved multiscale integration model, this study conducted a detailed micro-analysis of the evaluation results for research cross-sections from the years 2000, 2010, and 2020. [Results] ① Over the long term, the overall ecological carrying capacity (CCE) of the basin has mostly been at a medium level. The living carrying capacity (CCL) has generally been at a medium level or below, while the production carrying capacity (CCP) has predominantly been at a very low level. Consequently, the comprehensive carrying capacity (CCC) has mainly been at a low level, with no instances of a very high level. ② During the study period, the regions with low levels of all carrying capacities expanded. The expansion of CCE mostly occurred in the middle and southeast of the basin; the expansion of CCL occurred in the upper, middle, and lower reaches of the basin; the expansion of CCP mostly occurred in the western and southern parts of Shuangliu and Renshou; and the expansion of CCC mostly occurred in Wenchuan, Pujiang, and Jingyan. ③ The high CCE and low CCL and CCP in the upper reaches of the Minjiang River can be attributed to the combined effects of topographical conditions and socioeconomic levels. In contrast, Chengdu’s central urban area has achieved outstanding levels of CCL, CCP, and CCC, driven by high-quality socioeconomic development, and has maintained these levels over the long term. [Conclusion] The Minjiang River Basin exhibits significant regional differences in natural conditions and socioeconomic levels, resulting in varying levels of carrying capacity across different areas and hindering coordinated and balanced regional development. Persistently promoting high-quality development and leveraging the spillover and radiative effects of Chengdu City, the provincial capital, will help enhance the carrying capacity levels, reduce regional disparities, and drive overall coordinated development across the basin.
[Objective] The evaluation of carrying capacity of territorial space resources and environment in watersheds were studied based on multi scale fusion in order to provide scientific basis and reference for the sustainable development of the basin, and promote the coordinated development of resources and environment. [Methods] Using the Minjiang River basin as an example and considering the multifunctional characteristics and connotations of territorial spatial resources, we established a multi-scale evaluation system for territorial spatial resources and environmental carrying capacity. By applying an improved multiscale integration model, this study conducted a detailed micro-analysis of the evaluation results for research cross-sections from the years 2000, 2010, and 2020. [Results] ① Over the long term, the overall ecological carrying capacity (CCE) of the basin has mostly been at a medium level. The living carrying capacity (CCL) has generally been at a medium level or below, while the production carrying capacity (CCP) has predominantly been at a very low level. Consequently, the comprehensive carrying capacity (CCC) has mainly been at a low level, with no instances of a very high level. ② During the study period, the regions with low levels of all carrying capacities expanded. The expansion of CCE mostly occurred in the middle and southeast of the basin; the expansion of CCL occurred in the upper, middle, and lower reaches of the basin; the expansion of CCP mostly occurred in the western and southern parts of Shuangliu and Renshou; and the expansion of CCC mostly occurred in Wenchuan, Pujiang, and Jingyan. ③ The high CCE and low CCL and CCP in the upper reaches of the Minjiang River can be attributed to the combined effects of topographical conditions and socioeconomic levels. In contrast, Chengdu’s central urban area has achieved outstanding levels of CCL, CCP, and CCC, driven by high-quality socioeconomic development, and has maintained these levels over the long term. [Conclusion] The Minjiang River Basin exhibits significant regional differences in natural conditions and socioeconomic levels, resulting in varying levels of carrying capacity across different areas and hindering coordinated and balanced regional development. Persistently promoting high-quality development and leveraging the spillover and radiative effects of Chengdu City, the provincial capital, will help enhance the carrying capacity levels, reduce regional disparities, and drive overall coordinated development across the basin.
Zhang Jianhai, Jiang Xintong, Ma Guoqing, Shu Rui, Liang Zhewei, Ma Xiaolin, Li Zhaoying, Ma Ling, Song Tianjian, Tong Rongxin, Ding Tianzi, Liang Xun, Guan Qingfeng
2024,43(5):162-172
, DOI: 10.13961/j.cnki.stbctb.2024.05.018
Abstract:
[Objective] The impact of the expansion of Lycium barbarum planting land was predict scientifically in Zhongning County, Ningxia Hui Autonomous Region, in order to provide scientific and reliable suggestions for the future agricultural spatial layout and planting development of characteristic industries in the area. [Methods] Based on land survey data from 2005 to 2021 and considering the policy of “balancing in and out” of arable land, Zhongning County was taken as the research object and two constraint scenarios-one with and the other without the protection of permanent basic farmland-were set up. These were then used to simulate the future land use change of Zhongning County in 2025 and 2035 using the patch-generating land use simulation model (PLUS). Specifically, this model helped investigate the occupation of permanent basic farmland for L. barbarum cultivation in the future. [Results] According to the model, by 2035, under the with and without permanent basic farmland constraints scenarios, the area of land used for L. barbarum will grow by 59.81% and 98.48%, respectively. Most of the newly added L. chincnse will be around the original L. barbarum land, and the main townships with increased area will be concentrated in Mingsha Town and Dazhanchang Town. Moreover, the study showed that, under the scenario without permanent basic farmland constraints, the areas of permanent basic farmland in 2025 and 2035 will be encroached by 1,100.00 hm2 and 2,386.67 hm2, respectively, in which the risk of permanent basic farmland in the north-central region being encroached by L. barbarum land will be the highest. [Conclusion] It is therefore necessary to strengthen the regulation of the development of L. barbarum cultivation in high-risk townships and rationally plan existing and future land for “non-food” cultivation in order to coordinate the economic development of the area better with the protection of permanent basic farmland and promote the development of sustainable agriculture in the region.
[Objective] The impact of the expansion of Lycium barbarum planting land was predict scientifically in Zhongning County, Ningxia Hui Autonomous Region, in order to provide scientific and reliable suggestions for the future agricultural spatial layout and planting development of characteristic industries in the area. [Methods] Based on land survey data from 2005 to 2021 and considering the policy of “balancing in and out” of arable land, Zhongning County was taken as the research object and two constraint scenarios-one with and the other without the protection of permanent basic farmland-were set up. These were then used to simulate the future land use change of Zhongning County in 2025 and 2035 using the patch-generating land use simulation model (PLUS). Specifically, this model helped investigate the occupation of permanent basic farmland for L. barbarum cultivation in the future. [Results] According to the model, by 2035, under the with and without permanent basic farmland constraints scenarios, the area of land used for L. barbarum will grow by 59.81% and 98.48%, respectively. Most of the newly added L. chincnse will be around the original L. barbarum land, and the main townships with increased area will be concentrated in Mingsha Town and Dazhanchang Town. Moreover, the study showed that, under the scenario without permanent basic farmland constraints, the areas of permanent basic farmland in 2025 and 2035 will be encroached by 1,100.00 hm2 and 2,386.67 hm2, respectively, in which the risk of permanent basic farmland in the north-central region being encroached by L. barbarum land will be the highest. [Conclusion] It is therefore necessary to strengthen the regulation of the development of L. barbarum cultivation in high-risk townships and rationally plan existing and future land for “non-food” cultivation in order to coordinate the economic development of the area better with the protection of permanent basic farmland and promote the development of sustainable agriculture in the region.
2024,43(5):173-182,222
, DOI: 10.13961/j.cnki.stbctb.2024.05.019
Abstract:
[Objective] The characteristics of soil and water loss and the effects of different soil and water conservation measures in Xi’an urban production and construction projects were investigated to provide scientific basis for improving the soil and water loss environment in Xi’an City and formulating more accurate and effective policies and measures. [Methods] Eighty-four production and construction projects in Xi’an City in 2022 were used as case studies, and a soil erosion evaluation system, which included three indicators such as water loss ratio, soil erosion ratio, and green space ratio, was constructed. The TOPSIS method was used to assess the water and soil loss risks associated with each project. [Results] ① The surface changes mainly shifted from rural homesteads, grasslands, idle land, and cultivated land to construction land. Among these changes, the conversion of rural homesteads constituted the primary form, accounting for approximately 70% of the total transfer area. ② Green space ratio increased in 83% of urban production and construction projects. Among the production and construction projects, there was a decreasing trend in the runoff losses observed in 61% of the cases in the order as follows: new real estate ＜ commercial services ＜ education and medical care ＜ municipal facilities ＜ urban village renovation projects. Approximately 54% of the production and construction projects successfully reduced soil erosion risks, with significant reductions observed in new real estate projects on cultivated land, grasslands, and idle land. But urban village renovation projects can increase regional soil erosion levels. The average reduction in water loss in all the projects was 3.58×104 m3, and the average annual soil erosion decreased by 169.05 tons. ③ The risk of soil erosion in production and construction projects in Xi’an City were classified into four levels: high, medium, low, and very low. The projects classified as low and very low levels accounted for 69% of the total, with a particular focus on urban village renovation projects. All the projects involved in the occupation of grassland were classified as high risk. [Conclusion] Production and construction projects in Xi’an City have shown significant effectiveness in preventing soil and water erosion; however, they need to be improved further. In the future, it will be necessary to further strengthen the management of soil and water erosion risks in these projects.
[Objective] The characteristics of soil and water loss and the effects of different soil and water conservation measures in Xi’an urban production and construction projects were investigated to provide scientific basis for improving the soil and water loss environment in Xi’an City and formulating more accurate and effective policies and measures. [Methods] Eighty-four production and construction projects in Xi’an City in 2022 were used as case studies, and a soil erosion evaluation system, which included three indicators such as water loss ratio, soil erosion ratio, and green space ratio, was constructed. The TOPSIS method was used to assess the water and soil loss risks associated with each project. [Results] ① The surface changes mainly shifted from rural homesteads, grasslands, idle land, and cultivated land to construction land. Among these changes, the conversion of rural homesteads constituted the primary form, accounting for approximately 70% of the total transfer area. ② Green space ratio increased in 83% of urban production and construction projects. Among the production and construction projects, there was a decreasing trend in the runoff losses observed in 61% of the cases in the order as follows: new real estate ＜ commercial services ＜ education and medical care ＜ municipal facilities ＜ urban village renovation projects. Approximately 54% of the production and construction projects successfully reduced soil erosion risks, with significant reductions observed in new real estate projects on cultivated land, grasslands, and idle land. But urban village renovation projects can increase regional soil erosion levels. The average reduction in water loss in all the projects was 3.58×104 m3, and the average annual soil erosion decreased by 169.05 tons. ③ The risk of soil erosion in production and construction projects in Xi’an City were classified into four levels: high, medium, low, and very low. The projects classified as low and very low levels accounted for 69% of the total, with a particular focus on urban village renovation projects. All the projects involved in the occupation of grassland were classified as high risk. [Conclusion] Production and construction projects in Xi’an City have shown significant effectiveness in preventing soil and water erosion; however, they need to be improved further. In the future, it will be necessary to further strengthen the management of soil and water erosion risks in these projects.
2024,43(5):183-192,213
, DOI: 10.13961/j.cnki.stbctb.2024.05.020
Abstract:
[Objective] The spatial and temporal properties of vegetation cover in the Hengduan Mountains and the variables that influence them was investigated in order to provide the scientific basis to understand this topic. [Methods] The Theil-Sen trend analysis and Mann-Kendall test were used to analyse the inter-monthly and inter-annual variability of the normalized difference vegetation index (NDVI) in the Hengduan mountains from 2002 to 2022, as well as spatially overall. Using partial correlation analysis, the effects of temperature and precipitation on vegetation cover were examined. Finally, the impact of human activities on vegetation cover was explored combining with land cover data. [Results] ① The NDVI in the Hengduan mountains area showed an increasing fluctuating trend over 21 years, at its lowest in March and highest in September. ② The spatial vegetation cover increased by 83.78%, primarily in the southeastern, southwestern, and northern regions, and decreased by 15.87%, primarily in the central, southern, northwestern, and northeastern regions, with a good trend of increasing vegetation cover throughout the study area. ③ The NDVI showed a strong positive correlation with both temperature and precipitation on the monthly scale, while on the annual scale, it showed a weak negative correlation with precipitation and a positive correlation with temperature. ④ During the 21-year period, there was a significant decrease in the area of agricultural land, a large increase in the area of forestland, a slight decrease in the area of grassland, and little change in the areas of urban and built-up land and water. One of the reasons for the increase in the NDVI throughout the 21-year period in the Hengduan Mountains region is the large increase in forested land area. [Conclusion] There were significant temporal and spatial variations in vegetation cover in the Hengduan Mountains. Temperature and precipitation influenced both vegetation cover and land use as driving factors of vegetation cover change.
[Objective] The spatial and temporal properties of vegetation cover in the Hengduan Mountains and the variables that influence them was investigated in order to provide the scientific basis to understand this topic. [Methods] The Theil-Sen trend analysis and Mann-Kendall test were used to analyse the inter-monthly and inter-annual variability of the normalized difference vegetation index (NDVI) in the Hengduan mountains from 2002 to 2022, as well as spatially overall. Using partial correlation analysis, the effects of temperature and precipitation on vegetation cover were examined. Finally, the impact of human activities on vegetation cover was explored combining with land cover data. [Results] ① The NDVI in the Hengduan mountains area showed an increasing fluctuating trend over 21 years, at its lowest in March and highest in September. ② The spatial vegetation cover increased by 83.78%, primarily in the southeastern, southwestern, and northern regions, and decreased by 15.87%, primarily in the central, southern, northwestern, and northeastern regions, with a good trend of increasing vegetation cover throughout the study area. ③ The NDVI showed a strong positive correlation with both temperature and precipitation on the monthly scale, while on the annual scale, it showed a weak negative correlation with precipitation and a positive correlation with temperature. ④ During the 21-year period, there was a significant decrease in the area of agricultural land, a large increase in the area of forestland, a slight decrease in the area of grassland, and little change in the areas of urban and built-up land and water. One of the reasons for the increase in the NDVI throughout the 21-year period in the Hengduan Mountains region is the large increase in forested land area. [Conclusion] There were significant temporal and spatial variations in vegetation cover in the Hengduan Mountains. Temperature and precipitation influenced both vegetation cover and land use as driving factors of vegetation cover change.
2024,43(5):193-203
, DOI: 10.13961/j.cnki.stbctb.2024.05.021
Abstract:
[Objective] The value of ecological products was calculated scientifically and the transformation path of “Two Mountains” (lucid waters and lush mountains are invaluable assets) was explored in order to provide theoretical support for the practical effect of the “Two Mountains” theory and promote the construction of an ecological civilization. [Methods] Based on the theory of “Two Mountains,” and taking Guizhou Province as the research object, this paper constructed an index system of ecological product value accounting, measured the ecological product value using the gross ecosystem production (GEP) accounting method, and assessed the effect of the “Two Mountains” transformation. [Results] ① From 2017 to 2021, the GEP of Guizhou province showed an upward trend, which was 2.08~2.54 times the GDP of the same year, but the growth rate of the GEP was lower than that of the GDP. The GEP per unit area was 1.96×107 yuan/m2 to 2.32×107 yuan/m2, and the per capita GEP was 90 500 yuan/m2 to 1.06×106 yuan/m2. The results showed that the transformation of environmental resource protection, sustainable utilization, and the economic growth mode has achieved certain results. ② The value of ecological material supply products presented an upward trend with a range of 18.66%; the value of agricultural products was the highest and the value of fishery products was the lowest. The results showed that Guizhou is still a province with agriculture as its main focus, and planting is the main aspect of the agricultural industry. ③ The total value of ecological regulation service products showed an increasing trend, with an increasing range of 8.34%, accounting for 60.30%—66.35% of the GEP. The value of climate regulation was the highest, and the value of water quality purification was the lowest. This shows that a superior ecological environment and high forest coverage are important climate regulators and ecological barriers. ④ The value of eco-cultural service products (ECVs) showed an increasing trend, with an increasing range of 45.71%, accounting for 20.56%—27.65% of the GEP. ⑤ The transformation value of “Two mountains” showed an increasing trend of dynamic change, with an increasing range of 39.37%, accounting for 82.40%—92.40% of the GDP. This shows that the “Two Mountains” transformation has achieved certain results, and the contribution of ECVs has been high. However, Guizhou Province needs to further enhance the effectiveness and contribution of eco-material product value and eco-cultural product value in the process of the “Two Mountains” transformation. Based on the research results, this paper refines the path to promoting the “Two Mountains” transformation. [Conclusion] The protection effect of natural resources and ecological environment in Guizhou Province is increasing, the ecosystem has strong ecological regulation function, and climate regulation is the main type of ecological regulation; The value of non-physical products is dominant, and the value of physical products is relatively small. The transformation effect of “Two Mountains” is increasing year by year, however, it is necessary to further improve the contribution of the value of ecological material products and ecological culture products to the transformation of “Two mountains”.
[Objective] The value of ecological products was calculated scientifically and the transformation path of “Two Mountains” (lucid waters and lush mountains are invaluable assets) was explored in order to provide theoretical support for the practical effect of the “Two Mountains” theory and promote the construction of an ecological civilization. [Methods] Based on the theory of “Two Mountains,” and taking Guizhou Province as the research object, this paper constructed an index system of ecological product value accounting, measured the ecological product value using the gross ecosystem production (GEP) accounting method, and assessed the effect of the “Two Mountains” transformation. [Results] ① From 2017 to 2021, the GEP of Guizhou province showed an upward trend, which was 2.08~2.54 times the GDP of the same year, but the growth rate of the GEP was lower than that of the GDP. The GEP per unit area was 1.96×107 yuan/m2 to 2.32×107 yuan/m2, and the per capita GEP was 90 500 yuan/m2 to 1.06×106 yuan/m2. The results showed that the transformation of environmental resource protection, sustainable utilization, and the economic growth mode has achieved certain results. ② The value of ecological material supply products presented an upward trend with a range of 18.66%; the value of agricultural products was the highest and the value of fishery products was the lowest. The results showed that Guizhou is still a province with agriculture as its main focus, and planting is the main aspect of the agricultural industry. ③ The total value of ecological regulation service products showed an increasing trend, with an increasing range of 8.34%, accounting for 60.30%—66.35% of the GEP. The value of climate regulation was the highest, and the value of water quality purification was the lowest. This shows that a superior ecological environment and high forest coverage are important climate regulators and ecological barriers. ④ The value of eco-cultural service products (ECVs) showed an increasing trend, with an increasing range of 45.71%, accounting for 20.56%—27.65% of the GEP. ⑤ The transformation value of “Two mountains” showed an increasing trend of dynamic change, with an increasing range of 39.37%, accounting for 82.40%—92.40% of the GDP. This shows that the “Two Mountains” transformation has achieved certain results, and the contribution of ECVs has been high. However, Guizhou Province needs to further enhance the effectiveness and contribution of eco-material product value and eco-cultural product value in the process of the “Two Mountains” transformation. Based on the research results, this paper refines the path to promoting the “Two Mountains” transformation. [Conclusion] The protection effect of natural resources and ecological environment in Guizhou Province is increasing, the ecosystem has strong ecological regulation function, and climate regulation is the main type of ecological regulation; The value of non-physical products is dominant, and the value of physical products is relatively small. The transformation effect of “Two Mountains” is increasing year by year, however, it is necessary to further improve the contribution of the value of ecological material products and ecological culture products to the transformation of “Two mountains”.
2024,43(5):204-213
, DOI: 10.13961/j.cnki.stbctb.2024.05.022
Abstract:
[Objective] The water poverty in China’s provinces (cities) was measured and social network analysis was conducted in order to provide a decision-making basis for alleviating China’s water poverty dilemma. [Methods] The entropy weight method and social network analysis were employed to measure and analyze the spatial correlation effects of water poverty in various Chinese provinces (cities) from 2010 to 2021. [Results] ① The water poverty index of Chinese provinces has shown an overall upward trend during the inspection period, and the degree of water poverty has gradually decreased. However, the spatial non-equilibrium characteristics remain quite evident. ② The provincial water poverty network exhibits significant spatial correlation and complex structural forms as a whole, with all regions interconnected; however, the degree of closeness of this correlation is not high. ③ According to the block model analysis results, 5 provinces (cities) including Beijing and Tianjin are classified as the “net beneficiary” group, 13 provinces (cities) including Hunan and Hainan as the “net spillover” group, 4 provinces (cities) including Guangdong and Chongqing as the “two-way spillover” group, and 9 provinces (cities) including Inner Mongolia and Heilongjiang as the “broker” group. In addition, the relationships within the plates are sparse, whereas the connections between the plates are strong. ④ Analysis of the core-edge density shows that the number of core areas fluctuates frequently, while the number of edge areas initially increases and then decreases. [Conclusion] The State should develop a comprehensive understanding of the spatial correlation and network structure characteristics of the Water Poverty Index, formulate and implement regionally differentiated policies and strategies, promote coordinated development, give full play to the roles of the government and market, effectively address the challenges of water poverty, and enhance water security.
[Objective] The water poverty in China’s provinces (cities) was measured and social network analysis was conducted in order to provide a decision-making basis for alleviating China’s water poverty dilemma. [Methods] The entropy weight method and social network analysis were employed to measure and analyze the spatial correlation effects of water poverty in various Chinese provinces (cities) from 2010 to 2021. [Results] ① The water poverty index of Chinese provinces has shown an overall upward trend during the inspection period, and the degree of water poverty has gradually decreased. However, the spatial non-equilibrium characteristics remain quite evident. ② The provincial water poverty network exhibits significant spatial correlation and complex structural forms as a whole, with all regions interconnected; however, the degree of closeness of this correlation is not high. ③ According to the block model analysis results, 5 provinces (cities) including Beijing and Tianjin are classified as the “net beneficiary” group, 13 provinces (cities) including Hunan and Hainan as the “net spillover” group, 4 provinces (cities) including Guangdong and Chongqing as the “two-way spillover” group, and 9 provinces (cities) including Inner Mongolia and Heilongjiang as the “broker” group. In addition, the relationships within the plates are sparse, whereas the connections between the plates are strong. ④ Analysis of the core-edge density shows that the number of core areas fluctuates frequently, while the number of edge areas initially increases and then decreases. [Conclusion] The State should develop a comprehensive understanding of the spatial correlation and network structure characteristics of the Water Poverty Index, formulate and implement regionally differentiated policies and strategies, promote coordinated development, give full play to the roles of the government and market, effectively address the challenges of water poverty, and enhance water security.
2024,43(5):214-222
, DOI: 10.13961/j.cnki.stbctb.2024.05.023
Abstract:
[Objective] The vulnerability and obstacle factors of water resources in Wuhan City were explored to further clarify the characteristics and influencing mechanism of water resources system, therefore to provide a basis for regional water resources management and efficient utilization. [Methods] Combined with the current situation of water resources in Wuhan City, 12 indicators were selected to construct a water resource vulnerability assessment system based on a pressure-state-response model. The entropy weight method was used to calculate the indicator weight, and the set pair analysis method was used to assess water resource vulnerability. On this basis, an obstacle degree model was applied to identify obstacles of water resource vulnerability in Wuhan City. [Results] The overall vulnerability of water resources in Wuhan City showed a gradually decreasing trend from 2013 to 2022, and the vulnerability level decreased from middle to micro vulnerability. From the perspective of each subsystem, the vulnerability of water resources in the pressure subsystem gradually decreased, whereas the state and response system vulnerability levels showed a fluctuating decrease. The main obstacles affecting the vulnerability of water resources are water consumption per 10 000 yuan of GDP, water consumption per 10 000 yuan of industrial added value, compliance rate of river water quality, development and utilization rate of water resources, and the centralized treatment rate of sewage. The order of obstacle degree was pressure > state > response. [Conclusion] Although water resources are greatly influenced by human activities, they can provide important support for economic and social development in Wuhan City. The vulnerability of regional water resources could be effectively reduced and the supply-demand contradiction of water resources alleviated by continuously optimizing the allocation of water resources, accelerating the upgrading of industrial structures, improving the level of sewage treatment, and applying technological innovation.
[Objective] The vulnerability and obstacle factors of water resources in Wuhan City were explored to further clarify the characteristics and influencing mechanism of water resources system, therefore to provide a basis for regional water resources management and efficient utilization. [Methods] Combined with the current situation of water resources in Wuhan City, 12 indicators were selected to construct a water resource vulnerability assessment system based on a pressure-state-response model. The entropy weight method was used to calculate the indicator weight, and the set pair analysis method was used to assess water resource vulnerability. On this basis, an obstacle degree model was applied to identify obstacles of water resource vulnerability in Wuhan City. [Results] The overall vulnerability of water resources in Wuhan City showed a gradually decreasing trend from 2013 to 2022, and the vulnerability level decreased from middle to micro vulnerability. From the perspective of each subsystem, the vulnerability of water resources in the pressure subsystem gradually decreased, whereas the state and response system vulnerability levels showed a fluctuating decrease. The main obstacles affecting the vulnerability of water resources are water consumption per 10 000 yuan of GDP, water consumption per 10 000 yuan of industrial added value, compliance rate of river water quality, development and utilization rate of water resources, and the centralized treatment rate of sewage. The order of obstacle degree was pressure > state > response. [Conclusion] Although water resources are greatly influenced by human activities, they can provide important support for economic and social development in Wuhan City. The vulnerability of regional water resources could be effectively reduced and the supply-demand contradiction of water resources alleviated by continuously optimizing the allocation of water resources, accelerating the upgrading of industrial structures, improving the level of sewage treatment, and applying technological innovation.
2024,43(5):223-233
, DOI: 10.13961/j.cnki.stbctb.2024.05.024
Abstract:
[Objective] The coupling and coordination status of agricultural ecological security and food security was explored in order to provide decision-making reference for improving both, individually, and their coordinated development in the Yangtze River economic belt. [Methods] Taking 11 provinces (cities) in the Yangtze River economic belt as the research areas, the entropy weight method, comprehensive index model, coupling degree model, coupling coordination degree model, grey correlation degree model, grey prediction model, and exponential smoothing model were used to quantitatively analyze the coupling coordination level, coupling coordination development level, influencing factors, and future trends of agricultural ecological security and food security. [Results] ① From 2002 to 2022, the comprehensive index of agricultural ecological security and food security in most provinces of the Yangtze River economic belt showed a significant fluctuation trend. The gap in the level of comprehensive index of agricultural ecological security and food security between provinces first narrowed and then expanded, and the overall gap between samples was not significant. ② From a temporal perspective, the coupling coordination degree of various provinces in the Yangtze River economic belt fluctuated significantly from 2002 to 2022, showing an overall upward trend, with most coupling coordination levels rising to a more optimal level. Regarding spatial dimension, the overall distribution characteristics show relatively low upstream, low midstream, and high downstream trends, as well as significant regional differences. ③ Agricultural ecological security and food security are a coupled and interactive system, and both the subsystems of them influence the degree of coupling coordination. The impact of the provincial grain security subsystem in the Yangtze River economic belt on the coupling coordination degree is higher. ④ Using the exponential smoothing method to predict the coupling coordination degree of provinces in the Yangtze River economic belt for the next five years, different provinces show different trends, with both upward and slightly downward trends. [Conclusion] Provinces in the Yangtze River economic belt should adapt to local conditions, further enhance the synergy and linkage of internal and external factors on the basis of filling in the shortcomings and weaknesses of the subsystems, and ultimately achieve the benign coordinated development of the two.
[Objective] The coupling and coordination status of agricultural ecological security and food security was explored in order to provide decision-making reference for improving both, individually, and their coordinated development in the Yangtze River economic belt. [Methods] Taking 11 provinces (cities) in the Yangtze River economic belt as the research areas, the entropy weight method, comprehensive index model, coupling degree model, coupling coordination degree model, grey correlation degree model, grey prediction model, and exponential smoothing model were used to quantitatively analyze the coupling coordination level, coupling coordination development level, influencing factors, and future trends of agricultural ecological security and food security. [Results] ① From 2002 to 2022, the comprehensive index of agricultural ecological security and food security in most provinces of the Yangtze River economic belt showed a significant fluctuation trend. The gap in the level of comprehensive index of agricultural ecological security and food security between provinces first narrowed and then expanded, and the overall gap between samples was not significant. ② From a temporal perspective, the coupling coordination degree of various provinces in the Yangtze River economic belt fluctuated significantly from 2002 to 2022, showing an overall upward trend, with most coupling coordination levels rising to a more optimal level. Regarding spatial dimension, the overall distribution characteristics show relatively low upstream, low midstream, and high downstream trends, as well as significant regional differences. ③ Agricultural ecological security and food security are a coupled and interactive system, and both the subsystems of them influence the degree of coupling coordination. The impact of the provincial grain security subsystem in the Yangtze River economic belt on the coupling coordination degree is higher. ④ Using the exponential smoothing method to predict the coupling coordination degree of provinces in the Yangtze River economic belt for the next five years, different provinces show different trends, with both upward and slightly downward trends. [Conclusion] Provinces in the Yangtze River economic belt should adapt to local conditions, further enhance the synergy and linkage of internal and external factors on the basis of filling in the shortcomings and weaknesses of the subsystems, and ultimately achieve the benign coordinated development of the two.
2024,43(5):234-242,314
, DOI: 10.13961/j.cnki.stbctb.2024.05.025
Abstract:
[Objective] The impact of comprehensive flood control projects on the improvement of river happiness was analyzed in order to improve the construction level of happy rivers, and provide a theoretical basis for the evaluation and construction of happy rivers in Shandong Province. [Methods] Taking Xiaoqing River basin as the research object, a multi-level happy river evaluation index system, based on the “goal layer-criteria layer-index layer” was established, including 20 indices from 5 criteria layers: water safety, water resources, water environment, water ecology, and water culture. It also evaluated the state of well-being and identified the main obstacles that hindered the construction of happy rivers. A combination weighting method based on the analytic hierarchy process and reverse entropy weight method was applied to determine the indices weights at urban and rural sections and identify the main obstacles affecting the construction of happy rivers through the obstacle degree. [Results] ① Watershed area retention had the highest weight in the urban section, and the percentage of levee flood defense standard compliance had the highest weight in the rural section. ② Before the construction of the flood control project, the happiness levels of the urban and rural sections were generally lower. After construction, the happiness levels in both sections improved; happiness was maintained in the urban section and improved to a generally higher level in the rural section. ③ In the criteria layer, the main obstacle affecting the construction of happy rivers in the urban section focused on the water resource layer, and the main obstacle affecting the rural section focused on the water safety, water resources, and water culture layers. [Conclusion] To improve the happiness level of rivers, it is necessary to enhance the water supply capacity through reservoir storage and water diversion projects, maintain a smooth flow in flood channels, and stabilize river courses to ensure flood control safety.
[Objective] The impact of comprehensive flood control projects on the improvement of river happiness was analyzed in order to improve the construction level of happy rivers, and provide a theoretical basis for the evaluation and construction of happy rivers in Shandong Province. [Methods] Taking Xiaoqing River basin as the research object, a multi-level happy river evaluation index system, based on the “goal layer-criteria layer-index layer” was established, including 20 indices from 5 criteria layers: water safety, water resources, water environment, water ecology, and water culture. It also evaluated the state of well-being and identified the main obstacles that hindered the construction of happy rivers. A combination weighting method based on the analytic hierarchy process and reverse entropy weight method was applied to determine the indices weights at urban and rural sections and identify the main obstacles affecting the construction of happy rivers through the obstacle degree. [Results] ① Watershed area retention had the highest weight in the urban section, and the percentage of levee flood defense standard compliance had the highest weight in the rural section. ② Before the construction of the flood control project, the happiness levels of the urban and rural sections were generally lower. After construction, the happiness levels in both sections improved; happiness was maintained in the urban section and improved to a generally higher level in the rural section. ③ In the criteria layer, the main obstacle affecting the construction of happy rivers in the urban section focused on the water resource layer, and the main obstacle affecting the rural section focused on the water safety, water resources, and water culture layers. [Conclusion] To improve the happiness level of rivers, it is necessary to enhance the water supply capacity through reservoir storage and water diversion projects, maintain a smooth flow in flood channels, and stabilize river courses to ensure flood control safety.
2024,43(5):243-250,261
, DOI: 10.13961/j.cnki.stbctb.2024.05.026
Abstract:
[Objective] The response characteristics and demand changes of soil and microbial nutrients to shrub encroachment in Loess Plateau were investigated to provide reference for grassland resource management in the Loess Plateau. [Methods] The no-shrub encroachment grassland, subshrub (Artemisia sacrorum) encroachment grassland, and shrub (Caragana brachypoda) encroachment grassland in the Yunwu Mountain National Nature Reserve and measured the physicochemical properties of soil and activities of five enzymes involved in soil carbon, nitrogen, and phosphorus cycles. Afterward, we analyzed the effects of subshrub and shrub encroachment on soil nutrient content, enzyme activities, and stoichiometric ratios. [Results] Subshrub and shrub encroachment increased the content of soil water and nutrients and the activities of carbon, nitrogen, and phosphorus cycling enzymes. Soil microbial nutrient demands were not consistent across soil layers: in the 0—15 cm soil layer, soil microorganisms in the subshrub and shrub encroachment grassland had a higher demand for phosphorus element, whereas in the 15—30 cm soil layer, soil microorganisms had a higher demand for carbon element. Redundancy analysis showed that soil available nutrients were the key factors affecting soil enzyme activity and stoichiometric ratio. [Conclusion] Subshrub and shrub encroachment had positive effects on soil nutrient content and enzyme activity of enclosed grassland in Loess Plateau, and soil microorganisms under the subshrub and shrub encroachment grassland met their nutrient demands by changing the relative input of carbon, nitrogen, and phosphorus cycling enzymes; therefore, the trend of subshrub and shrub expansion in the region need to be further strengthened in the future. To maintain the stability of grassland ecosystem in Loess Plateau, corresponding regulatory measures need to be explored urgently.
[Objective] The response characteristics and demand changes of soil and microbial nutrients to shrub encroachment in Loess Plateau were investigated to provide reference for grassland resource management in the Loess Plateau. [Methods] The no-shrub encroachment grassland, subshrub (Artemisia sacrorum) encroachment grassland, and shrub (Caragana brachypoda) encroachment grassland in the Yunwu Mountain National Nature Reserve and measured the physicochemical properties of soil and activities of five enzymes involved in soil carbon, nitrogen, and phosphorus cycles. Afterward, we analyzed the effects of subshrub and shrub encroachment on soil nutrient content, enzyme activities, and stoichiometric ratios. [Results] Subshrub and shrub encroachment increased the content of soil water and nutrients and the activities of carbon, nitrogen, and phosphorus cycling enzymes. Soil microbial nutrient demands were not consistent across soil layers: in the 0—15 cm soil layer, soil microorganisms in the subshrub and shrub encroachment grassland had a higher demand for phosphorus element, whereas in the 15—30 cm soil layer, soil microorganisms had a higher demand for carbon element. Redundancy analysis showed that soil available nutrients were the key factors affecting soil enzyme activity and stoichiometric ratio. [Conclusion] Subshrub and shrub encroachment had positive effects on soil nutrient content and enzyme activity of enclosed grassland in Loess Plateau, and soil microorganisms under the subshrub and shrub encroachment grassland met their nutrient demands by changing the relative input of carbon, nitrogen, and phosphorus cycling enzymes; therefore, the trend of subshrub and shrub expansion in the region need to be further strengthened in the future. To maintain the stability of grassland ecosystem in Loess Plateau, corresponding regulatory measures need to be explored urgently.
2024,43(5):251-261
, DOI: 10.13961/j.cnki.stbctb.2024.05.027
Abstract:
[Objective] The impact of reed-based exogenous carbon on soil properties and organic carbon stability was investigated to provide theoretical insights into the application of reed resource materials for soil improvement. [Methods] A 60-day soil culture test was conducted for the application of various exogenous carbon materials, including reed aerobic compost (compost T1 conditioned with biochar and compost T2 conditioned with sediment and biochar), straw (RS), and biochar (RB). The effects of different exogenous carbon sources and amounts (5%, 10%, and 15%) were analyzed on the physicochemical properties, enzyme activities, and organic carbon mineralization of the soil. [Results] The application of exogenous carbon influenced the soil nutrient content, with the soil organic carbon content in the experimental group increasing significantly by 28.0%—64.2% compared to that in the control group (p<0.05) at the beginning of the culture. Compared with the initial stage, the organic carbon content of the soil supplemented with biochar and compost at final stage was significantly reduced by 15.5%—23.5%, whereas the total nitrogen content of the soil at final stage decreased by 20.0%—69.1%. The concentrations of β-glucosidase and dehydrogenase increased following the addition of exogenous carbon, with the most significant effect observed for biochar and compost. The β-glucosidase and dehydrogenase contents in the soil presented highly significant positive correlations with the soil bulk density, carbon source content, and total nitrogen (p＜0.01). The cumulative mineralization of organic carbon in the soil following the addition of exogenous carbon during the culture experiment exhibited first-order kinetics, while the soil organic carbon mineralization in the straw and biochar treatment groups was 652.9—758.2 mg/kg, which was significantly higher than that in the control group (532.8 mg/kg) and T2 composting (598.3—623.7 mg/kg) treatments. The amount of exogenous carbon added significantly influenced the soil organic carbon mineralization. [Conclusion] The addition of reed-based exogenous carbon improved soil physical and chemical properties and significantly enhanced enzyme activities. The excitation effect of reed straw on soil organic carbon mineralization was significantly greater than that of biochar and compost.
[Objective] The impact of reed-based exogenous carbon on soil properties and organic carbon stability was investigated to provide theoretical insights into the application of reed resource materials for soil improvement. [Methods] A 60-day soil culture test was conducted for the application of various exogenous carbon materials, including reed aerobic compost (compost T1 conditioned with biochar and compost T2 conditioned with sediment and biochar), straw (RS), and biochar (RB). The effects of different exogenous carbon sources and amounts (5%, 10%, and 15%) were analyzed on the physicochemical properties, enzyme activities, and organic carbon mineralization of the soil. [Results] The application of exogenous carbon influenced the soil nutrient content, with the soil organic carbon content in the experimental group increasing significantly by 28.0%—64.2% compared to that in the control group (p<0.05) at the beginning of the culture. Compared with the initial stage, the organic carbon content of the soil supplemented with biochar and compost at final stage was significantly reduced by 15.5%—23.5%, whereas the total nitrogen content of the soil at final stage decreased by 20.0%—69.1%. The concentrations of β-glucosidase and dehydrogenase increased following the addition of exogenous carbon, with the most significant effect observed for biochar and compost. The β-glucosidase and dehydrogenase contents in the soil presented highly significant positive correlations with the soil bulk density, carbon source content, and total nitrogen (p＜0.01). The cumulative mineralization of organic carbon in the soil following the addition of exogenous carbon during the culture experiment exhibited first-order kinetics, while the soil organic carbon mineralization in the straw and biochar treatment groups was 652.9—758.2 mg/kg, which was significantly higher than that in the control group (532.8 mg/kg) and T2 composting (598.3—623.7 mg/kg) treatments. The amount of exogenous carbon added significantly influenced the soil organic carbon mineralization. [Conclusion] The addition of reed-based exogenous carbon improved soil physical and chemical properties and significantly enhanced enzyme activities. The excitation effect of reed straw on soil organic carbon mineralization was significantly greater than that of biochar and compost.
2024,43(5):262-270
, DOI: 10.13961/j.cnki.stbctb.2024.05.028
Abstract:
[Objective] Soil CO2 production potential of different vegetation types in response to temperature change was analyzed in order to provide the basis for accurate estimation of CO2 production and greenhouse gas emissions. [Methods] A simulated culture experiment was conducted for 120 days for three different types of wetland soil (Nelumbo nucifera, Phragmites australis and open water), and the treatment was set at 15, 25, and 35 ℃ to observe the difference in the CO2 production potential of the wetland soil of different vegetation types and evaluate their response to temperature change. [Results] The fastest soil CO2 production rate among the different vegetation types in East Taihu Lake was recorded in the 35 ℃ culture treatment. Under the culture temperature of 35 ℃, the CO2 production rate of P. australis and open water surface increased with an increase in dissolved organic carbon (DOC) but that of the rest were negatively correlated. The maximum CO2 production potential of N. nucifera and P. australis soil was in the order as follows: 35 ℃ ＞ 15 ℃ ＞ 25 ℃ and that of open water surface was 15 ℃ ＞ 25 ℃ ＞ 35 ℃. The CO2 production potential of N. nucifera and P. australis wetlands was positively correlated with culture temperature, whereas that of the open water surface was significantly negatively correlated. Comparising all of the temperature sensitivity coefficient Q10 values, it was found that only N. nucifera soil temperature rise Q10＞ temperature drop Q10. [Conclusion] High temperature can accelerate CO2 production rate and increase DOC change in different vegetation types. Regarding the CO2 production potential of soil with the same temperature and different vegetation, it was found that P. australis and open water surface were more sensitive to cooling. The greenhouse gas production of wetland plants and the soil was greatly affected by external temperature; therefore, more attention should be paid to future urban water ecological management.
[Objective] Soil CO2 production potential of different vegetation types in response to temperature change was analyzed in order to provide the basis for accurate estimation of CO2 production and greenhouse gas emissions. [Methods] A simulated culture experiment was conducted for 120 days for three different types of wetland soil (Nelumbo nucifera, Phragmites australis and open water), and the treatment was set at 15, 25, and 35 ℃ to observe the difference in the CO2 production potential of the wetland soil of different vegetation types and evaluate their response to temperature change. [Results] The fastest soil CO2 production rate among the different vegetation types in East Taihu Lake was recorded in the 35 ℃ culture treatment. Under the culture temperature of 35 ℃, the CO2 production rate of P. australis and open water surface increased with an increase in dissolved organic carbon (DOC) but that of the rest were negatively correlated. The maximum CO2 production potential of N. nucifera and P. australis soil was in the order as follows: 35 ℃ ＞ 15 ℃ ＞ 25 ℃ and that of open water surface was 15 ℃ ＞ 25 ℃ ＞ 35 ℃. The CO2 production potential of N. nucifera and P. australis wetlands was positively correlated with culture temperature, whereas that of the open water surface was significantly negatively correlated. Comparising all of the temperature sensitivity coefficient Q10 values, it was found that only N. nucifera soil temperature rise Q10＞ temperature drop Q10. [Conclusion] High temperature can accelerate CO2 production rate and increase DOC change in different vegetation types. Regarding the CO2 production potential of soil with the same temperature and different vegetation, it was found that P. australis and open water surface were more sensitive to cooling. The greenhouse gas production of wetland plants and the soil was greatly affected by external temperature; therefore, more attention should be paid to future urban water ecological management.
2024,43(5):271-279
, DOI: 10.13961/j.cnki.stbctb.2024.05.029
Abstract:
[Objective] The relative enzyme activity and kinetic parameters of typical forest soil in loess hilly region were analyzed and the driving factors of soil enzyme activity characteristics were revealed in order to provide theoretical basis for the construction and improvement of regional artificial forests. [Methods] Coniferous forest (Pinus tabulaeformis), broad-leaved forest (Quercus acutissima), and mixed forest (P. tabulaeformis Q. acutissima mixed forest) in loess hilly region were selected as the research objects. Through field soil sampling and laboratory incubation analysis, soil physical and chemical properties and specific soil carbon, nitrogen, phosphorus transformation-linked enzyme activities 〔β-1,4-Glucosidase (BG), N-acety-β-glucosaminidase (NAG)〕, L-leucine aminopeptidase (LAP), and alkaline phosphatase (ALP) and their kinetic parameters 〔maximum reaction rate (Vmax), Michaelis constant (Km), and catalytic efficiency (Kcat)〕 were measured. [Results] ① The soil bulk density (BD), pH value, and enzyme activities of BG, LAP, and ALP per unit of organic carbon all increased with soil depth; however, the soil water content (SWC) and soil organic carbon (SOC) content decreased with soil depth. The highest pH value was in the coniferous forest, and the ammonium nitrogen (NH4+-N) and total phosphorus (TP) contents were in the order of broad-leaved forest＞mixed forest＞coniferous forest. ② The average (comprehensive) soil enzyme activities and Kcat value were in the order of mixed forest＞coniferous forest＞broad-leaved forest. The Km value were in the order of mixed forest＞coniferous forest＞broad-leaved forest. ③ The specific activities of the four enzymes related to carbon, nitrogen, and phosphorus transformation were significantly negatively correlated with NH4+-N, nitrate nitrogen (NO3--N), available phosphorus (AP), and SOC content, whereas the specific activities of BG, NAG, and ALP per unit of organic carbon were significantly positively correlated with pH value. Redundancy analysis showed that SOC content had significant influence on enzymatic reaction parameters in both coniferous forest and broad-leaved forest (p＜0.01). The main factors affecting the specific enzyme activities and kinetic parameters in mixed forest were SOC (p＜0.01) and TP (p＜0.05) content. [Conclusion] The soil enzyme activities per unit of organic carbon and Kcat of mixed forest were higher than those of coniferous forest and broad-leaved forest in loess hill region, indicating that the enzyme catalytic ability in mixed forest was higher than those in coniferous forest and broad-leaved forest. Therefore, mixed forest should be given priority consideration in artificial afforestation to improve soil quality.
[Objective] The relative enzyme activity and kinetic parameters of typical forest soil in loess hilly region were analyzed and the driving factors of soil enzyme activity characteristics were revealed in order to provide theoretical basis for the construction and improvement of regional artificial forests. [Methods] Coniferous forest (Pinus tabulaeformis), broad-leaved forest (Quercus acutissima), and mixed forest (P. tabulaeformis Q. acutissima mixed forest) in loess hilly region were selected as the research objects. Through field soil sampling and laboratory incubation analysis, soil physical and chemical properties and specific soil carbon, nitrogen, phosphorus transformation-linked enzyme activities 〔β-1,4-Glucosidase (BG), N-acety-β-glucosaminidase (NAG)〕, L-leucine aminopeptidase (LAP), and alkaline phosphatase (ALP) and their kinetic parameters 〔maximum reaction rate (Vmax), Michaelis constant (Km), and catalytic efficiency (Kcat)〕 were measured. [Results] ① The soil bulk density (BD), pH value, and enzyme activities of BG, LAP, and ALP per unit of organic carbon all increased with soil depth; however, the soil water content (SWC) and soil organic carbon (SOC) content decreased with soil depth. The highest pH value was in the coniferous forest, and the ammonium nitrogen (NH4+-N) and total phosphorus (TP) contents were in the order of broad-leaved forest＞mixed forest＞coniferous forest. ② The average (comprehensive) soil enzyme activities and Kcat value were in the order of mixed forest＞coniferous forest＞broad-leaved forest. The Km value were in the order of mixed forest＞coniferous forest＞broad-leaved forest. ③ The specific activities of the four enzymes related to carbon, nitrogen, and phosphorus transformation were significantly negatively correlated with NH4+-N, nitrate nitrogen (NO3--N), available phosphorus (AP), and SOC content, whereas the specific activities of BG, NAG, and ALP per unit of organic carbon were significantly positively correlated with pH value. Redundancy analysis showed that SOC content had significant influence on enzymatic reaction parameters in both coniferous forest and broad-leaved forest (p＜0.01). The main factors affecting the specific enzyme activities and kinetic parameters in mixed forest were SOC (p＜0.01) and TP (p＜0.05) content. [Conclusion] The soil enzyme activities per unit of organic carbon and Kcat of mixed forest were higher than those of coniferous forest and broad-leaved forest in loess hill region, indicating that the enzyme catalytic ability in mixed forest was higher than those in coniferous forest and broad-leaved forest. Therefore, mixed forest should be given priority consideration in artificial afforestation to improve soil quality.
He Shurui, Zhao Runying, Wang Xiaodong, Zhang Ping, Pei Xiangjun, Lai Zhanghong, Song Fang, Tang Xiaolu
2024,43(5):280-286,293
, DOI: 10.13961/j.cnki.stbctb.2024.05.030
Abstract:
[Objective] The impact of tunnel construction on soil organic carbon content and enzyme activity in the Qinghai-Xizang Plateau was researched in order to provide a theoretical reference for elucidating the impact of tunnel construction on the ecological environment. [Methods] Based on the construction of a tunnel project on the Qinghai-Xizang Plateau, fixed monitoring plots with a radius of 10 m were set up in the impact area and control area of tunnel construction to study the short-term effects of tunnel construction on surface soil organic carbon content and enzyme activity. [Results] After one year of tunnel construction, the soil organic carbon content, easily oxidizable organic carbon content, and soluble organic carbon content in the tunnel-impact area were determined to be 76.84, 25.90, and 3.15 g/kg, respectively, while that of the control area was 52.91, 15.60, and 3.18 g/kg, respectively, whereas that after three years of tunnel construction was 92.63, 28.65, and 3.41 g/kg in the impact area respectively, and 94.81, 23.11, and 3.34 g/kg in the control area, respectively. The differences were not significant (p＞0.05), indicating that tunnel construction has no impact on soil organic carbon and component content in the short term. The activities of β-glucosidase and catalase in the soil of the tunnel-affected area demonstrated no significant differences compared to the control area after one year and three years of construction (p＞0.05), while the activity of polyphenol oxidase in the tunnel-impact area decreased significantly after one year of construction (p=0.02). However, after three years of construction, there was no significant difference in polyphenol oxidase activity between the tunnel-impact area and the control area (p＞0.05), indicating that tunnel construction had no significant effect on soil enzyme activity. [Conclusion] Tunnel construction has no significant impact on soil organic carbon and its component content, as well as enzyme activity in the short term. This is primarily because the tunnel construction process has no significant impact on soil microbial processes, soil nutrients, and input and output of soil organic carbon, while the long-term impact needs further research.
[Objective] The impact of tunnel construction on soil organic carbon content and enzyme activity in the Qinghai-Xizang Plateau was researched in order to provide a theoretical reference for elucidating the impact of tunnel construction on the ecological environment. [Methods] Based on the construction of a tunnel project on the Qinghai-Xizang Plateau, fixed monitoring plots with a radius of 10 m were set up in the impact area and control area of tunnel construction to study the short-term effects of tunnel construction on surface soil organic carbon content and enzyme activity. [Results] After one year of tunnel construction, the soil organic carbon content, easily oxidizable organic carbon content, and soluble organic carbon content in the tunnel-impact area were determined to be 76.84, 25.90, and 3.15 g/kg, respectively, while that of the control area was 52.91, 15.60, and 3.18 g/kg, respectively, whereas that after three years of tunnel construction was 92.63, 28.65, and 3.41 g/kg in the impact area respectively, and 94.81, 23.11, and 3.34 g/kg in the control area, respectively. The differences were not significant (p＞0.05), indicating that tunnel construction has no impact on soil organic carbon and component content in the short term. The activities of β-glucosidase and catalase in the soil of the tunnel-affected area demonstrated no significant differences compared to the control area after one year and three years of construction (p＞0.05), while the activity of polyphenol oxidase in the tunnel-impact area decreased significantly after one year of construction (p=0.02). However, after three years of construction, there was no significant difference in polyphenol oxidase activity between the tunnel-impact area and the control area (p＞0.05), indicating that tunnel construction had no significant effect on soil enzyme activity. [Conclusion] Tunnel construction has no significant impact on soil organic carbon and its component content, as well as enzyme activity in the short term. This is primarily because the tunnel construction process has no significant impact on soil microbial processes, soil nutrients, and input and output of soil organic carbon, while the long-term impact needs further research.
2024,43(5):287-293
, DOI: 10.13961/j.cnki.stbctb.2024.05.031
Abstract:
[Objective] The carbon sink function of terraces and their characteristics were analyzed and discussed to provide a scientific reference for clarifying the carbon sink function, consolidating and enhancing the carbon sink capacity of ecosystems, and researching and compiling a carbon sink methodology for terraces. [Methods] Terraces with the operational ages of 1—7 a (T5), 8—12 a (T10), 13—17 a (T15), 18—22 a (T20), and 23—27 a (T25) were selected at Wuqi County, Shaanxi Province in the loess hilly and gully region. Slope croplands without soil and water conservation measures were selected for baseline comparison to study the capabilities of terraces in terms of carbon preservation, emission reduction, and carbon sequestration across different years. [Results] ① After the transformation of sloped croplands into terraces, an increase was observed in carbon preservation, emission reduction, and carbon sequestration. Annual carbon preservation, emission reduction, and carbon sequestration (0—100 cm) were 0.26, 0.05 and 1.36 t/hm2 respectively. ② Each soil layer of the terraces contributed certain benefits; the carbon sequestration benefits of the surface (0—40 cm) and deep (40—100 cm) soil layers accounted for 61.50% and 38.50% of the entire soil layer, respectively. ③ The benefits of the terrace surface soil significantly increased with the increase in the operation year of the terrace, while the benefits of deep soil were slightly improved but remained stable on the whole. The rate of carbon sequestration in the surface soil increased from 16.30% at T5 to 51.34% at T25 and that in the deep soil increased from 14.00% at T5 to 23.66% at T25. [Conclusion] The terraces in the loess hilly and gully regions exhibited significant carbon sink functions, including carbon preservation, emission reduction, and carbon sequestration. The proportion of carbon sequestration capacity was the largest within 27 years of terrace operation, and the increase in the surface soil was more significant. The proportion of carbon preservation in the carbon sink capacity of terraces gradually increases with an increase in terrace operation years.
[Objective] The carbon sink function of terraces and their characteristics were analyzed and discussed to provide a scientific reference for clarifying the carbon sink function, consolidating and enhancing the carbon sink capacity of ecosystems, and researching and compiling a carbon sink methodology for terraces. [Methods] Terraces with the operational ages of 1—7 a (T5), 8—12 a (T10), 13—17 a (T15), 18—22 a (T20), and 23—27 a (T25) were selected at Wuqi County, Shaanxi Province in the loess hilly and gully region. Slope croplands without soil and water conservation measures were selected for baseline comparison to study the capabilities of terraces in terms of carbon preservation, emission reduction, and carbon sequestration across different years. [Results] ① After the transformation of sloped croplands into terraces, an increase was observed in carbon preservation, emission reduction, and carbon sequestration. Annual carbon preservation, emission reduction, and carbon sequestration (0—100 cm) were 0.26, 0.05 and 1.36 t/hm2 respectively. ② Each soil layer of the terraces contributed certain benefits; the carbon sequestration benefits of the surface (0—40 cm) and deep (40—100 cm) soil layers accounted for 61.50% and 38.50% of the entire soil layer, respectively. ③ The benefits of the terrace surface soil significantly increased with the increase in the operation year of the terrace, while the benefits of deep soil were slightly improved but remained stable on the whole. The rate of carbon sequestration in the surface soil increased from 16.30% at T5 to 51.34% at T25 and that in the deep soil increased from 14.00% at T5 to 23.66% at T25. [Conclusion] The terraces in the loess hilly and gully regions exhibited significant carbon sink functions, including carbon preservation, emission reduction, and carbon sequestration. The proportion of carbon sequestration capacity was the largest within 27 years of terrace operation, and the increase in the surface soil was more significant. The proportion of carbon preservation in the carbon sink capacity of terraces gradually increases with an increase in terrace operation years.
2024,43(5):294-304
, DOI: 10.13961/j.cnki.stbctb.2024.05.032
Abstract:
[Objective] The effects of different management intensities on soil physicochemical properties and soil quality were analyzed to provide a scientific basis for the scientific management and nutrient management of Phyllostachys praecox forests. [Methods] Based on the analysis of soil physicochemical properties in P. praecox plantations under various management intensities in Huangshan District, Anhui Province, a minimum dataset was established through principal component analysis, and the soil quality in P. praecox plantations under different management intensities was analyzed. [Results] Significant differences were observed in the soil physicochemical properties under different management intensities. The bulk density was significantly lower in mid-intensity management than in high-intensity and extensive management in the 0—10 cm soil layer. The soil water contents in mid- and high-intensity management were significantly lower than those in extensive management. In the 0—10 cm soil layer, the value of soil pH value was ranked in the order of high-intensity management (4.12) ＞extensive management (4.01) ＞mid-intensity management (3.97). The soil organic carbon (24.82 g/kg) and total nitrogen (1.67 g/kg) in mid-intensity management were significantly higher than those in extensive management (18.64, 1.35 g/kg) and high-intensity management (17.39, 1.25 g/kg). The soil total phosphorus (0.53, 0.49 g/kg) was significantly higher in mid- and high-intensity management than in extensive management (0.27 g/kg). The ranges of C/P (30.99—53.40) and N/P (2.77—3.60) in mid-and high-intensity were lower than those in extensive management 〔(64.82—78.96) and (5.20—5.56)〕, and the average value of soil C/N in three different management intensities ranged from 10.95 to 14.68. In the 0—10 cm soil layer, the soil quality indices in the different management intensities were ranked in the order of extensive management (0.42) ＞mid-intensity management (0.36) ＞high-intensity management (0.31), where the soil quality index decreased with the deepening of the soil layer. [Conclusion] A strong acidic soil environment was determined not to be conducive to the growth of bamboo. Soil water holding capacity and water conservation capacity of mid-intensity management were determined to be better. Soil fertility was observed to be lower with the strengthening of management intensity, which is not conducive to the maintenance of soil quality.
[Objective] The effects of different management intensities on soil physicochemical properties and soil quality were analyzed to provide a scientific basis for the scientific management and nutrient management of Phyllostachys praecox forests. [Methods] Based on the analysis of soil physicochemical properties in P. praecox plantations under various management intensities in Huangshan District, Anhui Province, a minimum dataset was established through principal component analysis, and the soil quality in P. praecox plantations under different management intensities was analyzed. [Results] Significant differences were observed in the soil physicochemical properties under different management intensities. The bulk density was significantly lower in mid-intensity management than in high-intensity and extensive management in the 0—10 cm soil layer. The soil water contents in mid- and high-intensity management were significantly lower than those in extensive management. In the 0—10 cm soil layer, the value of soil pH value was ranked in the order of high-intensity management (4.12) ＞extensive management (4.01) ＞mid-intensity management (3.97). The soil organic carbon (24.82 g/kg) and total nitrogen (1.67 g/kg) in mid-intensity management were significantly higher than those in extensive management (18.64, 1.35 g/kg) and high-intensity management (17.39, 1.25 g/kg). The soil total phosphorus (0.53, 0.49 g/kg) was significantly higher in mid- and high-intensity management than in extensive management (0.27 g/kg). The ranges of C/P (30.99—53.40) and N/P (2.77—3.60) in mid-and high-intensity were lower than those in extensive management 〔(64.82—78.96) and (5.20—5.56)〕, and the average value of soil C/N in three different management intensities ranged from 10.95 to 14.68. In the 0—10 cm soil layer, the soil quality indices in the different management intensities were ranked in the order of extensive management (0.42) ＞mid-intensity management (0.36) ＞high-intensity management (0.31), where the soil quality index decreased with the deepening of the soil layer. [Conclusion] A strong acidic soil environment was determined not to be conducive to the growth of bamboo. Soil water holding capacity and water conservation capacity of mid-intensity management were determined to be better. Soil fertility was observed to be lower with the strengthening of management intensity, which is not conducive to the maintenance of soil quality.
2024,43(5):305-314
, DOI: 10.13961/j.cnki.stbctb.2024.05.033
Abstract:
[Objective] The changes of land use and carbon storage under different scenarios were analyzed to provide the scientific bases were provided for optimizing of land use pattern and formulating protection policies in Hainan Tropical Rainforest National Park. [Methods] Based on the land use data of Hainan Tropical Rainforest National Park in 2001, 2011 and 2021, and the PLUS and InVEST models, the changes of land use and carbon storage in 2001—2021 and 2030 under different scenarios were analyzed and predicted, respectively. [Results] ① From 2001 to 2021, the cultivated lands, grassland and water decreased continually, while the forest land and construction land gradually expanded in Hainan Tropical Rainforest National Park. And the forest land increased by 561.19 km2 in 20 years. The predicting results of land use changes under natural development scenario and farmland protection scenario in 2030 were similar but were much different with the results of ecological protection scenario. ② In 2001, 2011, and 2021, the carbon storage of Hainan Tropical Rainforest National Park was 8.72×107 t，9.22×107 t，and 9.13×107 t, respectively. In 2030, the carbon storage of Hainan Tropical Rainforest National Park would be 9.04×107 t under natural development scenario, 9.12×107 t under farmland protection scenario, 9.13×107 t under ecological protection scenario. These results indicating that the ecological protection measures could improve the ability of carbon storage in Hainan Tropical Rainforest National Park. [Conclusion] The change of carbon storage was highly consistent with the change of land use, and land use change could affect the pattern of carbon storage in Hainan Tropical Rainforest National Park.
[Objective] The changes of land use and carbon storage under different scenarios were analyzed to provide the scientific bases were provided for optimizing of land use pattern and formulating protection policies in Hainan Tropical Rainforest National Park. [Methods] Based on the land use data of Hainan Tropical Rainforest National Park in 2001, 2011 and 2021, and the PLUS and InVEST models, the changes of land use and carbon storage in 2001—2021 and 2030 under different scenarios were analyzed and predicted, respectively. [Results] ① From 2001 to 2021, the cultivated lands, grassland and water decreased continually, while the forest land and construction land gradually expanded in Hainan Tropical Rainforest National Park. And the forest land increased by 561.19 km2 in 20 years. The predicting results of land use changes under natural development scenario and farmland protection scenario in 2030 were similar but were much different with the results of ecological protection scenario. ② In 2001, 2011, and 2021, the carbon storage of Hainan Tropical Rainforest National Park was 8.72×107 t，9.22×107 t，and 9.13×107 t, respectively. In 2030, the carbon storage of Hainan Tropical Rainforest National Park would be 9.04×107 t under natural development scenario, 9.12×107 t under farmland protection scenario, 9.13×107 t under ecological protection scenario. These results indicating that the ecological protection measures could improve the ability of carbon storage in Hainan Tropical Rainforest National Park. [Conclusion] The change of carbon storage was highly consistent with the change of land use, and land use change could affect the pattern of carbon storage in Hainan Tropical Rainforest National Park.
2024,43(5):315-326,336
, DOI: 10.13961/j.cnki.stbctb.2024.05.034
Abstract:
[Objective] Spatial network characteristics and driving forces of net carbon sequestration in the Yangtze River economic belt (YREB) were analyzed to provide a scientific reference for promoting coordinated carbon emission reduction, supporting the achievement of “dual carbon” goals and regional coordinated development. [Methods] A spatial association network of carbon sinks in the YREB was constructed at the municipal level using a modified gravity model. Social network analysis was then applied to examine the network’s characteristics and driving factors. [Results] ① From 2001 to 2021, total carbon emissions in the YREB exhibited an increasing trend, with a spatial distribution pattern of higher and lower emissions in the east and west, respectively. Conversely, total carbon sinks followed a fluctuating upward trend, showing a pattern of higher sinks in the west and lower in the east. Net carbon sinks have continuously declined, with a similar west-east gradient. ② The carbon sink network in the YREB showed significant spatial correlation, forming a complex dense in the east and sparse in the west network pattern, with Chongqing and Shanghai City emerging as dual-core nodes. The regional network exhibited high centrality, with cities such as Shanghai and Chongqing City playing key roles. The network’s overall structure demonstrated low stability. ③ Cities were categorized into four groups based on their roles within the network: net exporters, bidirectional exchanges, brokers, and net beneficiaries. Interblock spillover effects were more pronounced than intra-block associations. ④ The primary driving forces behind the spatial association network of carbon sinks were economic development, industrial structure upgrades, energy consumption intensity, and land-use patterns. [Conclusion] In the future, it is essential to consider the spatial network dynamics of net carbon sinks across cities, leveraging complementary strengths to maximize emission reduction benefits.
[Objective] Spatial network characteristics and driving forces of net carbon sequestration in the Yangtze River economic belt (YREB) were analyzed to provide a scientific reference for promoting coordinated carbon emission reduction, supporting the achievement of “dual carbon” goals and regional coordinated development. [Methods] A spatial association network of carbon sinks in the YREB was constructed at the municipal level using a modified gravity model. Social network analysis was then applied to examine the network’s characteristics and driving factors. [Results] ① From 2001 to 2021, total carbon emissions in the YREB exhibited an increasing trend, with a spatial distribution pattern of higher and lower emissions in the east and west, respectively. Conversely, total carbon sinks followed a fluctuating upward trend, showing a pattern of higher sinks in the west and lower in the east. Net carbon sinks have continuously declined, with a similar west-east gradient. ② The carbon sink network in the YREB showed significant spatial correlation, forming a complex dense in the east and sparse in the west network pattern, with Chongqing and Shanghai City emerging as dual-core nodes. The regional network exhibited high centrality, with cities such as Shanghai and Chongqing City playing key roles. The network’s overall structure demonstrated low stability. ③ Cities were categorized into four groups based on their roles within the network: net exporters, bidirectional exchanges, brokers, and net beneficiaries. Interblock spillover effects were more pronounced than intra-block associations. ④ The primary driving forces behind the spatial association network of carbon sinks were economic development, industrial structure upgrades, energy consumption intensity, and land-use patterns. [Conclusion] In the future, it is essential to consider the spatial network dynamics of net carbon sinks across cities, leveraging complementary strengths to maximize emission reduction benefits.
2024,43(5):327-336
, DOI: 10.13961/j.cnki.stbctb.2024.05.035
Abstract:
[Objective] The carbon storage effect and the driving factors in the transformation of productive-living-ecological space in the Xiamen-Zhangzhou-Quanzhou metropolitan area were analyzed in order to provide scientific reference for the high-quality development of the Xiamen-Zhangzhou-Quanzhou metropolitan area under new circumstances. [Methods] Spatial analysis, InVEST, and GeoDetector were comprehensively utilized to reveal the transformation characteristics of the productive-living-ecological space, carbon storage effect, and main influencing factors in the Xiamen-Zhangzhou-Quanzhou metropolitan area. [Results] ① From 2000 to 2020, the living space in the Xiamen-Zhangzhou-Quanzhou metropolitan area continued to expand, while the production and ecological spaces continued to shrink. The transformation of the production-living-ecological space primarily manifested in the shift from agricultural production, woodland ecological, and grassland ecological spaces to industrial production and urban living spaces. ② Over the past 20 years, carbon storage in the Xiamen-Zhangzhou-Quanzhou metropolitan area decreased by 1.57×107 t. The shift of forest ecological space to industrial production (34.75%) and grassland ecological (16.73%) spaces, as well as the shift of agricultural production space to industrial production (12.92%) and urban living (7.63%) spaces, were significant reasons for the decrease in carbon storage. The spatial distribution of carbon storage exhibited a decreasing trend from the hilly mountains in the west to the coastal plains in the east. ③ The natural environment and social economy emerged as the primary factors influencing regional carbon storage, with location conditions exerting minimal influence. Notably, the gross output value of the secondary and tertiary industries, along with slope consistently played significant roles in carbon storage in the Xiamen-Zhangzhou-Quanzhou metropolitan area. Moreover, the interaction among all factors significantly amplified their impact on carbon storage. [Conclusion] Future efforts should prioritize the protection of ecological space and promote the region’s role as a leading economic growth pole to achieve the coordinated progress of carbon emission reduction and economic development in the Xiamen-Zhangzhou-Quanzhou metropolitan area.
[Objective] The carbon storage effect and the driving factors in the transformation of productive-living-ecological space in the Xiamen-Zhangzhou-Quanzhou metropolitan area were analyzed in order to provide scientific reference for the high-quality development of the Xiamen-Zhangzhou-Quanzhou metropolitan area under new circumstances. [Methods] Spatial analysis, InVEST, and GeoDetector were comprehensively utilized to reveal the transformation characteristics of the productive-living-ecological space, carbon storage effect, and main influencing factors in the Xiamen-Zhangzhou-Quanzhou metropolitan area. [Results] ① From 2000 to 2020, the living space in the Xiamen-Zhangzhou-Quanzhou metropolitan area continued to expand, while the production and ecological spaces continued to shrink. The transformation of the production-living-ecological space primarily manifested in the shift from agricultural production, woodland ecological, and grassland ecological spaces to industrial production and urban living spaces. ② Over the past 20 years, carbon storage in the Xiamen-Zhangzhou-Quanzhou metropolitan area decreased by 1.57×107 t. The shift of forest ecological space to industrial production (34.75%) and grassland ecological (16.73%) spaces, as well as the shift of agricultural production space to industrial production (12.92%) and urban living (7.63%) spaces, were significant reasons for the decrease in carbon storage. The spatial distribution of carbon storage exhibited a decreasing trend from the hilly mountains in the west to the coastal plains in the east. ③ The natural environment and social economy emerged as the primary factors influencing regional carbon storage, with location conditions exerting minimal influence. Notably, the gross output value of the secondary and tertiary industries, along with slope consistently played significant roles in carbon storage in the Xiamen-Zhangzhou-Quanzhou metropolitan area. Moreover, the interaction among all factors significantly amplified their impact on carbon storage. [Conclusion] Future efforts should prioritize the protection of ecological space and promote the region’s role as a leading economic growth pole to achieve the coordinated progress of carbon emission reduction and economic development in the Xiamen-Zhangzhou-Quanzhou metropolitan area.
2024,43(5):337-346
, DOI: 10.13961/j.cnki.stbctb.2024.05.036
Abstract:
[Objective] Under the “double carbon” goal, the impact of land use on carbon emission, absorption, and balance was examined to provide a basis for national spatial planning. [Methods] The Chengdu-Chongqing economic zone was taken as the study area, based on land use and socio-economic data, and the coefficient method was adopted to measure the carbon balance of the study area from years 2000 to 2022. The study then explored the differences in the spatial and temporal patterns of the area and conducted carbon balance zoning of the processed results from multiple perspectives using the economic contribution rate and ecological carrying capacity coefficient. Lastly, a targeted strategy was proposed. [Results] ① Carbon emissions generally showed an upward trend, and cropland and construction land were the most important sources of carbon. These land types were spatially distributed mainly in the Chengdu Plain and Chongqing metropolitan areas of the study area. ② The total amount of carbon sequestration showed an upward trend, and the main source of carbon sinks was forest land, which was spatially distributed mainly in the mountainous areas around the study area. ③ Total net carbon emissions increased by 273%. The number of counties achieving carbon balance reduced from 23 to 10. ④ Based on carbon balance analysis, indicators of net carbon emissions, and economic contribution rate, among others, high-quality agricultural production areas were classified as low-carbon development zones, densely populated and narrowly developed core areas as carbon-intensity control zones, traditional industrial areas as high-carbon optimization zones, and ecological barrier zones as carbon sink functional zones. [Conclusion] The spatial and temporal differences in carbon emissions in the Chendu-Chongqing ecomic zone had corresponding regularities, and the carbon absorption space were more stable. Therefore, to promote the low-carbon and sustainable development of the economic zone, the land resource utilization structure can be further adjusted in a more refined way according to the land zoning optimization plan.
[Objective] Under the “double carbon” goal, the impact of land use on carbon emission, absorption, and balance was examined to provide a basis for national spatial planning. [Methods] The Chengdu-Chongqing economic zone was taken as the study area, based on land use and socio-economic data, and the coefficient method was adopted to measure the carbon balance of the study area from years 2000 to 2022. The study then explored the differences in the spatial and temporal patterns of the area and conducted carbon balance zoning of the processed results from multiple perspectives using the economic contribution rate and ecological carrying capacity coefficient. Lastly, a targeted strategy was proposed. [Results] ① Carbon emissions generally showed an upward trend, and cropland and construction land were the most important sources of carbon. These land types were spatially distributed mainly in the Chengdu Plain and Chongqing metropolitan areas of the study area. ② The total amount of carbon sequestration showed an upward trend, and the main source of carbon sinks was forest land, which was spatially distributed mainly in the mountainous areas around the study area. ③ Total net carbon emissions increased by 273%. The number of counties achieving carbon balance reduced from 23 to 10. ④ Based on carbon balance analysis, indicators of net carbon emissions, and economic contribution rate, among others, high-quality agricultural production areas were classified as low-carbon development zones, densely populated and narrowly developed core areas as carbon-intensity control zones, traditional industrial areas as high-carbon optimization zones, and ecological barrier zones as carbon sink functional zones. [Conclusion] The spatial and temporal differences in carbon emissions in the Chendu-Chongqing ecomic zone had corresponding regularities, and the carbon absorption space were more stable. Therefore, to promote the low-carbon and sustainable development of the economic zone, the land resource utilization structure can be further adjusted in a more refined way according to the land zoning optimization plan.
2024,43(5):347-357
, DOI: 10.13961/j.cnki.stbctb.2024.05.037
Abstract:
[Objective] The measurement of land space use efficiency and comprehensive spatial zoning in Yunnan Province were studied, considering carbon neutrality, provide a reference for proposing differentiated low-carbon and high-efficiency land space development strategies. [Methods] Using 2020 panel data of 16 municipal units in Yunnan Province, the spatial utilization efficiency of the national territory under the low-carbon perspective were measured based on the non-expected output super-efficiency SBM model, and comprehensive zoning were performed considering the carbon efficiency index; subsequently, optimization suggestions for each zone are put forward. [Results] ① The carbon emission in Yunnan Province in 2020 was 1.23×108 tonnes, with production-space-related emissions accounting for a much larger proportion than living-space-related emissions: the former was almost 31 times as much as the latter. Further, carbon absorption was 1.40×107 tonnes, which is only one-tenth of the carbon emission. ② In 2020, the land space utilization efficiency of Yunnan Province was only 0.628, showing a spatial distribution pattern that is higher in central and northwestern Yunnan, and lower in eastern and southwestern Yunnan. Specifically, only Xishuangbanna, Diqing and Yuxi reached high efficiency utilization, with the maximum efficiency of 1.43, while Zhaotong had the lowest utilization efficiency of 0.49. ③ Based on the land space utilization efficiency and the carbon efficiency index, 7 comprehensive zones-Low carbon retention-High efficiency, Carbon sink function-High efficiency, Carbon sink function-Moderate efficiency, Carbon sink function-Low efficiency, Carbon intensity control-High efficiency, Carbon intensity control-Moderate efficiency, and High carbon optimization-Low efficiency-are derived, and a differentiated governance strategy for each zone is put forward. [Conclusion] At present, carbon absorption in Yunnan Province is far from enough to offset carbon emissions, and the overall performance is carbon source. The utilization of territorial space is still relatively extensive, and there is great potential to improve utilization efficiency. The distribution of territorial space utilization efficiency has obvious regional imbalance, and attention should be paid to the formulation of low-carbon development and efficient utilization strategies for territorial space.
[Objective] The measurement of land space use efficiency and comprehensive spatial zoning in Yunnan Province were studied, considering carbon neutrality, provide a reference for proposing differentiated low-carbon and high-efficiency land space development strategies. [Methods] Using 2020 panel data of 16 municipal units in Yunnan Province, the spatial utilization efficiency of the national territory under the low-carbon perspective were measured based on the non-expected output super-efficiency SBM model, and comprehensive zoning were performed considering the carbon efficiency index; subsequently, optimization suggestions for each zone are put forward. [Results] ① The carbon emission in Yunnan Province in 2020 was 1.23×108 tonnes, with production-space-related emissions accounting for a much larger proportion than living-space-related emissions: the former was almost 31 times as much as the latter. Further, carbon absorption was 1.40×107 tonnes, which is only one-tenth of the carbon emission. ② In 2020, the land space utilization efficiency of Yunnan Province was only 0.628, showing a spatial distribution pattern that is higher in central and northwestern Yunnan, and lower in eastern and southwestern Yunnan. Specifically, only Xishuangbanna, Diqing and Yuxi reached high efficiency utilization, with the maximum efficiency of 1.43, while Zhaotong had the lowest utilization efficiency of 0.49. ③ Based on the land space utilization efficiency and the carbon efficiency index, 7 comprehensive zones-Low carbon retention-High efficiency, Carbon sink function-High efficiency, Carbon sink function-Moderate efficiency, Carbon sink function-Low efficiency, Carbon intensity control-High efficiency, Carbon intensity control-Moderate efficiency, and High carbon optimization-Low efficiency-are derived, and a differentiated governance strategy for each zone is put forward. [Conclusion] At present, carbon absorption in Yunnan Province is far from enough to offset carbon emissions, and the overall performance is carbon source. The utilization of territorial space is still relatively extensive, and there is great potential to improve utilization efficiency. The distribution of territorial space utilization efficiency has obvious regional imbalance, and attention should be paid to the formulation of low-carbon development and efficient utilization strategies for territorial space.
2024,43(5):358-368
, DOI: 10.13961/j.cnki.stbctb.2024.05.038
Abstract:
[Objective] The dynamic changes in vegetation carbon use efficiency (CUE) and its relationship with hydrothermal factors in the Inner Mongolia Autonomous Region was investigated to provide a scientific basis for evaluating vegetation carbon sequestration capacity. [Methods] Vegetation CUE was calculated using MOD17A2H data. Trend analysis, Hurst index, and correlation analysis were employed to investigate the spatiotemporal dynamics of vegetation CUE from 2000 to 2022 and the influence of hydrothermal factors on vegetation CUE. [Results] ① During 2000—2022, vegetation CUE increased significantly, with a growth rate of 0.012 per decade (p<0.05). The CUE values of key ecological functional areas in Inner Mongolia followed this order: Daxinganling and Xiaoxinganling Mountains > Hulun Buir > Hunshandake > Khorchin > Northern Yinshan. ② The spatial distribution of vegetation CUE in Inner Mongolia was higher in the west and lower in the east during the growing season, with an average annual value of 0.60. Among the key ecological functional areas, the highest vegetation CUE was observed in Hunshandake, while the lowest was in Khorchin. ③ Vegetation CUE exhibited an increasing trend in 83.53% of the study area, and this trend remained constant during the growing season. However, 72.14% of the study area would experience a decreasing trend in vegetation CUE in the future, with a higher proportion of key ecological functional areas showing a declining trend compared to those with an increasing trend. ④ Overall, vegetation CUE was negatively correlated with average temperature and positively correlated with cumulative precipitation and average soil moisture, with a stronger correlation observed with cumulative precipitation during the growing season. In contrast, vegetation CUE had a stronger correlation with average temperature than with cumulative precipitation and average soil moisture in Khorchin. [Conclusion] The carbon sequestration capacity of vegetation in Inner Mongolia increased significantly from 2000 to 2022 but would decline in the future. Precipitation was the main factor affecting changes in vegetation CUE in key ecological functional areas, while temperature was the dominant influencing factor in Khorchin.
[Objective] The dynamic changes in vegetation carbon use efficiency (CUE) and its relationship with hydrothermal factors in the Inner Mongolia Autonomous Region was investigated to provide a scientific basis for evaluating vegetation carbon sequestration capacity. [Methods] Vegetation CUE was calculated using MOD17A2H data. Trend analysis, Hurst index, and correlation analysis were employed to investigate the spatiotemporal dynamics of vegetation CUE from 2000 to 2022 and the influence of hydrothermal factors on vegetation CUE. [Results] ① During 2000—2022, vegetation CUE increased significantly, with a growth rate of 0.012 per decade (p<0.05). The CUE values of key ecological functional areas in Inner Mongolia followed this order: Daxinganling and Xiaoxinganling Mountains > Hulun Buir > Hunshandake > Khorchin > Northern Yinshan. ② The spatial distribution of vegetation CUE in Inner Mongolia was higher in the west and lower in the east during the growing season, with an average annual value of 0.60. Among the key ecological functional areas, the highest vegetation CUE was observed in Hunshandake, while the lowest was in Khorchin. ③ Vegetation CUE exhibited an increasing trend in 83.53% of the study area, and this trend remained constant during the growing season. However, 72.14% of the study area would experience a decreasing trend in vegetation CUE in the future, with a higher proportion of key ecological functional areas showing a declining trend compared to those with an increasing trend. ④ Overall, vegetation CUE was negatively correlated with average temperature and positively correlated with cumulative precipitation and average soil moisture, with a stronger correlation observed with cumulative precipitation during the growing season. In contrast, vegetation CUE had a stronger correlation with average temperature than with cumulative precipitation and average soil moisture in Khorchin. [Conclusion] The carbon sequestration capacity of vegetation in Inner Mongolia increased significantly from 2000 to 2022 but would decline in the future. Precipitation was the main factor affecting changes in vegetation CUE in key ecological functional areas, while temperature was the dominant influencing factor in Khorchin.
2024,43(5):369-381
, DOI: 10.13961/j.cnki.stbctb.2024.05.039
Abstract:
[Objective] The changes in land cover and carbon stock of the Hangzhou Chengxi Sci-tech Innovation Corridor through high-resolution remote sensing images were analyzed and the development trend of carbon stock under the constraints of the “three zones and three lines” achievements was predicted to provide scientific basis for the optimization of national land space and ecological development of new urban centers. [Methods] Based on four periods of land cover data from 2010, 2015, 2020, and 2023, the GeoSoS-FLUS model was used to simulate both past and future changes in land cover under five different scenarios: the natural growth, extreme construction and development, extreme agricultural production, ecological function services, and urban-rural integration development scenarios up to the year 2035. The model was used as a framework to calculate the changes in carbon stock under the simulated scenarios from 2010 to 2023 and from 2023 to 2035, respectively. [Results] ① The carbon stock of Chengxi Sci-tech Innovation Corridor showed an increasing trend from 2010 to 2023, with a total change of 1 720.69 t, where the carbon stock of vegetation, soil, and water increased to approximately 913.67 t, 566.18 t, and 240.84 t, respectively. ② The internal type transformation of cultivated land resulted in a decrease of 119.33 t in soil carbon stock, while the internal type transformation of forest land accounted for 39.50% of the total change in carbon stock. ③ In the natural growth and ecological function services scenarios, forest land growth was relatively significant, while in the extreme construction and development and extreme agricultural production scenarios, the land cover types were more stable. In the urban-rural integration development scenario, through reasonable replacement between cultivated land, forest land, grassland, and other land cover types, other land cover types obtained greater development space. ④ During 2023—2035, carbon stock will rise by 898.74 t under the natural growth scenario, 538.58 t under the extreme construction and development scenario, 517.45 t under the extreme agricultural production scenario, 813.09 t under the ecological function services scenario, and 356.91 t under the urban-rural integration development scenario. [Conclusion] Development under the constraint of control lines could effectively guarantee the carbon sequestration capacity of cities. Reasonable transformation of land cover types and internal structural adjustments can provide more space for the development of new urban centers.
[Objective] The changes in land cover and carbon stock of the Hangzhou Chengxi Sci-tech Innovation Corridor through high-resolution remote sensing images were analyzed and the development trend of carbon stock under the constraints of the “three zones and three lines” achievements was predicted to provide scientific basis for the optimization of national land space and ecological development of new urban centers. [Methods] Based on four periods of land cover data from 2010, 2015, 2020, and 2023, the GeoSoS-FLUS model was used to simulate both past and future changes in land cover under five different scenarios: the natural growth, extreme construction and development, extreme agricultural production, ecological function services, and urban-rural integration development scenarios up to the year 2035. The model was used as a framework to calculate the changes in carbon stock under the simulated scenarios from 2010 to 2023 and from 2023 to 2035, respectively. [Results] ① The carbon stock of Chengxi Sci-tech Innovation Corridor showed an increasing trend from 2010 to 2023, with a total change of 1 720.69 t, where the carbon stock of vegetation, soil, and water increased to approximately 913.67 t, 566.18 t, and 240.84 t, respectively. ② The internal type transformation of cultivated land resulted in a decrease of 119.33 t in soil carbon stock, while the internal type transformation of forest land accounted for 39.50% of the total change in carbon stock. ③ In the natural growth and ecological function services scenarios, forest land growth was relatively significant, while in the extreme construction and development and extreme agricultural production scenarios, the land cover types were more stable. In the urban-rural integration development scenario, through reasonable replacement between cultivated land, forest land, grassland, and other land cover types, other land cover types obtained greater development space. ④ During 2023—2035, carbon stock will rise by 898.74 t under the natural growth scenario, 538.58 t under the extreme construction and development scenario, 517.45 t under the extreme agricultural production scenario, 813.09 t under the ecological function services scenario, and 356.91 t under the urban-rural integration development scenario. [Conclusion] Development under the constraint of control lines could effectively guarantee the carbon sequestration capacity of cities. Reasonable transformation of land cover types and internal structural adjustments can provide more space for the development of new urban centers.
2024,43(5):382-391
, DOI: 10.13961/j.cnki.stbctb.20240729.001
Abstract:
[Objective] Under the goal of carbon neutrality, we explore the spatial and temporal evolution of the function of productional-living-ecological (P-L-E) in Hunan Province and its distribution pattern of carbon emissions in the future in order to provide strategy-making references for carbon emission reduction in all provinces of the country. [Methods] Based on the P-L-E function evaluation prediction and productional-living-ecological carbon emission distribution measurement models, combined with various data on the regional P-L-E function and the spatial-temporal differentiation law, this study explored the spatial-temporal relationship between the function of P-L-E and the carbon emissions in Hunan Province and the planning strategy of the distribution pattern of carbon emissions in the future. [Results] ① From 2000 to 2020, the spatial and temporal differentiation of P-L-E in counties of Hunan Province was obvious, and the spatial pattern of the ecological function was strong and weak in the west and east, respectively which showed a trend of first decreasing and then increasing, while the production and life functions overall did not change much from 2000 to 2020. ② The county-level carbon emissions in Hunan Province as a whole were not far apart but were concentrated in some areas, and the gap was widening. ③ The spatial-temporal correlation between the P-E-L function and carbon emissions was strong, and the influence degree of different spatial types was different. ④ Considering the general layout of land and space of Hunan Province in 2035, the coefficient of ‘P-E-L’ carbon emissions distribution could be optimised to six combination types in 2035. [Conclusion] Natural endowment and economic development exert a considerable influence on the distribution pattern of ‘P-E-L’ carbon emissions conefficient in counties of Hunan Province. Moreover, regional synergy should be strengthened on the basis of the strategy of main functional zones and refinement control of the county-level P-E-L to achieve the target of carbon neutrality ahead of time.
[Objective] Under the goal of carbon neutrality, we explore the spatial and temporal evolution of the function of productional-living-ecological (P-L-E) in Hunan Province and its distribution pattern of carbon emissions in the future in order to provide strategy-making references for carbon emission reduction in all provinces of the country. [Methods] Based on the P-L-E function evaluation prediction and productional-living-ecological carbon emission distribution measurement models, combined with various data on the regional P-L-E function and the spatial-temporal differentiation law, this study explored the spatial-temporal relationship between the function of P-L-E and the carbon emissions in Hunan Province and the planning strategy of the distribution pattern of carbon emissions in the future. [Results] ① From 2000 to 2020, the spatial and temporal differentiation of P-L-E in counties of Hunan Province was obvious, and the spatial pattern of the ecological function was strong and weak in the west and east, respectively which showed a trend of first decreasing and then increasing, while the production and life functions overall did not change much from 2000 to 2020. ② The county-level carbon emissions in Hunan Province as a whole were not far apart but were concentrated in some areas, and the gap was widening. ③ The spatial-temporal correlation between the P-E-L function and carbon emissions was strong, and the influence degree of different spatial types was different. ④ Considering the general layout of land and space of Hunan Province in 2035, the coefficient of ‘P-E-L’ carbon emissions distribution could be optimised to six combination types in 2035. [Conclusion] Natural endowment and economic development exert a considerable influence on the distribution pattern of ‘P-E-L’ carbon emissions conefficient in counties of Hunan Province. Moreover, regional synergy should be strengthened on the basis of the strategy of main functional zones and refinement control of the county-level P-E-L to achieve the target of carbon neutrality ahead of time.
2024,43(5):392-408
, DOI: 10.13961/j.cnki.stbctb.2024.05.041
Abstract:
[Objective] The shifts of land use gravity centers and carbon emission change and the influencing factors of land-use carbon emissions in the Chengdu Plain were analyzed to provide theoretical and data support for the low-carbon development of the area. [Methods] Based on multi-source data, the barycenter model and IPCC carbon emission coefficient method were used to elucidate the changes in the land use gravity centers and carbon emissions in the Chengdu Plain from 2006 to 2022. Partial least squares regression analysis and the logarithmic mean divisia index (LMDI) model were used to explore the primary factors influencing cultivated and construction land carbon emissions. A patch-generating land use simulation (PLUS) model was used to simulate future land use patterns and carbon emissions. [Results] ① In terms of land use types, the gravity centers of cultivated land, water area, construction land, and unused land shifted 4.23, 5.46, 8.44 km, and 31.58 km to the northeast, respectively, and forest land and grassland shifted 11.12 km and 3.41 km to the southeast. The gravity centers of major food crops, rice and corn, moved 15.47 km and 7.52 km to the northeast, respectively, whereas that of wheat moved 17.77 km to the southwest. ② From 2006 to 2022, the land use carbon emissions of 33 counties in the Chengdu Plain showed an upward trend, with a total increase of 1.36×107 tons; and the carbon sinks continued to decline, with a total reduction of 5.68×105 tons. ③ Under the natural, carbon sink, and carbon emission reduction scenarios, the carbon emissions from land use reduced by 5.39×105, 3.47×105, 4.53×105 tons, respectively, comparing with those in 2022. [Conclusion] During the study period, a significant loss of cultivated land was observed in the Chengdu Plain; most of it was converted to construction land in the central part of the Chengdu Plain and forest land in the Longmen Mountains, Longquan Mountains, and Leshan City. In the future, the protection of cultivated land should be strengthened necessary. Carbon emissions from land use in 33 counties showed an obvious rising trend; however, the primary influencing factors are different. Therefore, source reduction and sequestration measure should be implemented according to local conditions.
[Objective] The shifts of land use gravity centers and carbon emission change and the influencing factors of land-use carbon emissions in the Chengdu Plain were analyzed to provide theoretical and data support for the low-carbon development of the area. [Methods] Based on multi-source data, the barycenter model and IPCC carbon emission coefficient method were used to elucidate the changes in the land use gravity centers and carbon emissions in the Chengdu Plain from 2006 to 2022. Partial least squares regression analysis and the logarithmic mean divisia index (LMDI) model were used to explore the primary factors influencing cultivated and construction land carbon emissions. A patch-generating land use simulation (PLUS) model was used to simulate future land use patterns and carbon emissions. [Results] ① In terms of land use types, the gravity centers of cultivated land, water area, construction land, and unused land shifted 4.23, 5.46, 8.44 km, and 31.58 km to the northeast, respectively, and forest land and grassland shifted 11.12 km and 3.41 km to the southeast. The gravity centers of major food crops, rice and corn, moved 15.47 km and 7.52 km to the northeast, respectively, whereas that of wheat moved 17.77 km to the southwest. ② From 2006 to 2022, the land use carbon emissions of 33 counties in the Chengdu Plain showed an upward trend, with a total increase of 1.36×107 tons; and the carbon sinks continued to decline, with a total reduction of 5.68×105 tons. ③ Under the natural, carbon sink, and carbon emission reduction scenarios, the carbon emissions from land use reduced by 5.39×105, 3.47×105, 4.53×105 tons, respectively, comparing with those in 2022. [Conclusion] During the study period, a significant loss of cultivated land was observed in the Chengdu Plain; most of it was converted to construction land in the central part of the Chengdu Plain and forest land in the Longmen Mountains, Longquan Mountains, and Leshan City. In the future, the protection of cultivated land should be strengthened necessary. Carbon emissions from land use in 33 counties showed an obvious rising trend; however, the primary influencing factors are different. Therefore, source reduction and sequestration measure should be implemented according to local conditions.
Display Method:
Abstract:
[Objective] To provide a technical approach and theoretical basis by finding the optimal organic fertilizer application amount and the optimal water retaining agent ratio for the improvement of brown soil tillage, the study investigated the effect of organic fertilizer with water retaining agent on the hydraulic properties of brown soil tillage . [Methods]A split-plot experimental design was conducted, using the topsoil of the brown soil in Shanxi Province. The main plot treatments were based on organic fertilizer application amount: F1 (0 t/hm2), F2 (45 t/hm2), F3 (60 t/hm2) and F4 (75 t/hm2). The sub-plot treatments included four water-retaining agent application amount: B1（0 kg/hm2）、B2（300 kg/hm2）、B3（600 kg/hm2）and B4（900 kg/hm2). The effects of the application amount of organic fertilizer and water retaining agent on soil water characteristic curve, specific water capacity and available water content were studied. [Results]① Soil water holding capacity and water supply capacity were enhanced in the organic fertilizer combined with water retaining agent treatment compared to water retaining agent alone. Besides, effective water content was increased. ②The improvement effect of organic fertilizer combined with water retaining agent on soil hydraulic properties varied with different application amount of organic fertilizer. The water-holding capacity at low water suction of the test soil was F3>F2>F4>F1, the water-supplying capacity was F3>F2>F4>F1, and the content of effective water was F3>F2>F4>F1. ③ Under the treatment of F3, the water holding capacity and water supply capacity of the soil showed a tendency of increasing and then decreasing with the increase of the proportion of water retaining agent. There was a parabolic relation- ship between soil effective water content and water retaining agent application ratio, and the relation equation was Y=12.87+1.74X-0.95X2 (R2=0.9493). [Conclusion]The improvement effect is the best under the treatment of medium amount of organic fertilizer(60 t/hm2) combined with water retaining agent, and the optimum proportion of water retaining agent under this amount of organic fertilizer is 0.91%.
[Objective] To provide a technical approach and theoretical basis by finding the optimal organic fertilizer application amount and the optimal water retaining agent ratio for the improvement of brown soil tillage, the study investigated the effect of organic fertilizer with water retaining agent on the hydraulic properties of brown soil tillage . [Methods]A split-plot experimental design was conducted, using the topsoil of the brown soil in Shanxi Province. The main plot treatments were based on organic fertilizer application amount: F1 (0 t/hm2), F2 (45 t/hm2), F3 (60 t/hm2) and F4 (75 t/hm2). The sub-plot treatments included four water-retaining agent application amount: B1（0 kg/hm2）、B2（300 kg/hm2）、B3（600 kg/hm2）and B4（900 kg/hm2). The effects of the application amount of organic fertilizer and water retaining agent on soil water characteristic curve, specific water capacity and available water content were studied. [Results]① Soil water holding capacity and water supply capacity were enhanced in the organic fertilizer combined with water retaining agent treatment compared to water retaining agent alone. Besides, effective water content was increased. ②The improvement effect of organic fertilizer combined with water retaining agent on soil hydraulic properties varied with different application amount of organic fertilizer. The water-holding capacity at low water suction of the test soil was F3>F2>F4>F1, the water-supplying capacity was F3>F2>F4>F1, and the content of effective water was F3>F2>F4>F1. ③ Under the treatment of F3, the water holding capacity and water supply capacity of the soil showed a tendency of increasing and then decreasing with the increase of the proportion of water retaining agent. There was a parabolic relation- ship between soil effective water content and water retaining agent application ratio, and the relation equation was Y=12.87+1.74X-0.95X2 (R2=0.9493). [Conclusion]The improvement effect is the best under the treatment of medium amount of organic fertilizer(60 t/hm2) combined with water retaining agent, and the optimum proportion of water retaining agent under this amount of organic fertilizer is 0.91%.
Wang Shangxiao, ZHANG Xiaodong, ZHANG Ming, NIU Xiaonan, ZHOU Mo, TANG Zhimin, ZHANG Jie, ZONG Leli, XU Shui
Abstract:
[Objective] To quickly and accurately obtain the effective soil thickness in a region, evaluate its spatial distribution characteristics and identify the influencing factors, which is of considerable importance for vegetation growth, soil conservation and food security. [Methods] Taking the Xin'an River Basin as the research area, combining field survey data, topography, lithology, and climate and other soil-forming factors, the Empirical Bayesian Kriging Regression Prediction (EBKRP) and Random Forest (RF) algorithms were used to obtain the effective soil thickness inversion results. The relationship between this data and environmental variables was also analysed. [Results] ①The average effective soil thickness in the region is 0.2-0.3 m, with higher soil thickness in basins and plains where urban construction is concentrated and human activities are intensive, and lower soil thickness in hilly and mountainous areas. ②From the three accuracy evaluation indicators of MAE (Mean Absolute Error), R2 (Coefficient of Determination) and RMSE (Root Mean Square Error), the prediction results of RF algorithm are significantly better than those of EBKRP algorithm, and it can better display the spatial heterogeneity distribution characteristics of soil thickness, improving the effect of soil thickness digital mapping to a certain extent. The effective soil thickness estimation is greatly influenced by topography and climate variables, which account for 46.77% and 18.78% of the variable importance, respectively. [Conclusion] The RF algorithm is an effective method for inverting regional effective soil thickness, overcoming the characteristics of spatial heterogeneity of soil thickness. Furthermore, it is more accurate and has higher resolution compared to models with limited sampling.
[Objective] To quickly and accurately obtain the effective soil thickness in a region, evaluate its spatial distribution characteristics and identify the influencing factors, which is of considerable importance for vegetation growth, soil conservation and food security. [Methods] Taking the Xin'an River Basin as the research area, combining field survey data, topography, lithology, and climate and other soil-forming factors, the Empirical Bayesian Kriging Regression Prediction (EBKRP) and Random Forest (RF) algorithms were used to obtain the effective soil thickness inversion results. The relationship between this data and environmental variables was also analysed. [Results] ①The average effective soil thickness in the region is 0.2-0.3 m, with higher soil thickness in basins and plains where urban construction is concentrated and human activities are intensive, and lower soil thickness in hilly and mountainous areas. ②From the three accuracy evaluation indicators of MAE (Mean Absolute Error), R2 (Coefficient of Determination) and RMSE (Root Mean Square Error), the prediction results of RF algorithm are significantly better than those of EBKRP algorithm, and it can better display the spatial heterogeneity distribution characteristics of soil thickness, improving the effect of soil thickness digital mapping to a certain extent. The effective soil thickness estimation is greatly influenced by topography and climate variables, which account for 46.77% and 18.78% of the variable importance, respectively. [Conclusion] The RF algorithm is an effective method for inverting regional effective soil thickness, overcoming the characteristics of spatial heterogeneity of soil thickness. Furthermore, it is more accurate and has higher resolution compared to models with limited sampling.
Abstract:
[Objective] To explore the characteristics of water evaporation in soil cracks treated by different backfill techniques. [Methods] The soil was collected from the surface of the west dump of Haizhou open-pit mine, and the soil cracks were simulated by backfilling treatment and analyzed by simulated evaporation test in the laboratory. [Results] The daily evaporation of cracks showed obvious three-stage evaporation rule in the test, and different backfilling treatments had little effect on the daily evaporation of cracks; With the increase of crack width, the cumulative evaporation of cracks increases, and backfill treatment can effectively reduce the cumulative evaporation of cracks. The cumulative evaporation of cracks with a backfilling ratio of 1:1 is the minimum value under the same group of cracks backfilling. The appearance of cracks will lead to the reduction of soil moisture content, but backfill treatment can improve the moisture content of cracks, and the water content of treatment 1 with backfilling ratio of 1:1 is the highest value of the three groups of cracks, with an average value of 29.74%; The increase of crack width also has an impact on the evaporative water-loss ratio, and the backfill treatment can reduce the evaporative water-loss ratio, and the backfill ratio of 1:1 treatment 1 has the best performance in reducing the evaporative water-loss ratio. [Conclusion] The existence of cracks has an effect on the daily evaporation, cumulative evaporation, water content and evaporation water loss ratio of cracks, and the 1:1 backfill ratio of treatment 1 has the best performance in the study of water evaporation of soil cracks in the dump.
[Objective] To explore the characteristics of water evaporation in soil cracks treated by different backfill techniques. [Methods] The soil was collected from the surface of the west dump of Haizhou open-pit mine, and the soil cracks were simulated by backfilling treatment and analyzed by simulated evaporation test in the laboratory. [Results] The daily evaporation of cracks showed obvious three-stage evaporation rule in the test, and different backfilling treatments had little effect on the daily evaporation of cracks; With the increase of crack width, the cumulative evaporation of cracks increases, and backfill treatment can effectively reduce the cumulative evaporation of cracks. The cumulative evaporation of cracks with a backfilling ratio of 1:1 is the minimum value under the same group of cracks backfilling. The appearance of cracks will lead to the reduction of soil moisture content, but backfill treatment can improve the moisture content of cracks, and the water content of treatment 1 with backfilling ratio of 1:1 is the highest value of the three groups of cracks, with an average value of 29.74%; The increase of crack width also has an impact on the evaporative water-loss ratio, and the backfill treatment can reduce the evaporative water-loss ratio, and the backfill ratio of 1:1 treatment 1 has the best performance in reducing the evaporative water-loss ratio. [Conclusion] The existence of cracks has an effect on the daily evaporation, cumulative evaporation, water content and evaporation water loss ratio of cracks, and the 1:1 backfill ratio of treatment 1 has the best performance in the study of water evaporation of soil cracks in the dump.
Abstract:
[Objective] A comprehensive understanding of plant composition within typical catchments plays a crucial role in assessing the ecological restoration status of the Loess Plateau and further implementing vegetation restoration measures to enhance the effectiveness of soil and water conservation efforts. [Methods] In this paper, the Heshui (HS) and Jingbian (JB) landslide-dammed reservoirs catchments, which local at the plateau-gully region in southcentral area and the hill-gully region in northcentral area on the Loess Plateau, respectively, were choose as the study catchments. Then, existing vegetation types were detailly investigated, and pollen composition in topsoil was identified. Meanwhile, topsoil physical characteristics (such as water content, grain size, loss on ignition at 550 ℃) at the two catchments were analyzed. [Results] 230 genera from 84 families were identified in the HS catchment, while 223 genera from 78 families in the JB catchment. Nevertheless, there was a higher abundance of woody plants, moisture-loving grasses, herbs around the HS catchment (accounting for 51.74%), whereas xerophytic shrubs and herbs dominated around the JB catchment (accounting for 56.50%). These patterns reflected a combination of climate conditions, soil properties, land use, and agricultural economic development. In addition, current high vegetation coverage area accounted for 82.61% and 37.80% around the HS and JB catchments under the “Grain for Green” project, respectively. However, certain adverse phenomena had been observed, including invasive non-native plant species, a low proportion of indigenous flora, and noticeable presence of artificial plants. [Conclusion] Ecological restoration of small catchments on the Loess Plateau should fully consider local climate condition, as well as the characteristics of forest and vegetation, to ensure comprehensive ecological protection for the region.
[Objective] A comprehensive understanding of plant composition within typical catchments plays a crucial role in assessing the ecological restoration status of the Loess Plateau and further implementing vegetation restoration measures to enhance the effectiveness of soil and water conservation efforts. [Methods] In this paper, the Heshui (HS) and Jingbian (JB) landslide-dammed reservoirs catchments, which local at the plateau-gully region in southcentral area and the hill-gully region in northcentral area on the Loess Plateau, respectively, were choose as the study catchments. Then, existing vegetation types were detailly investigated, and pollen composition in topsoil was identified. Meanwhile, topsoil physical characteristics (such as water content, grain size, loss on ignition at 550 ℃) at the two catchments were analyzed. [Results] 230 genera from 84 families were identified in the HS catchment, while 223 genera from 78 families in the JB catchment. Nevertheless, there was a higher abundance of woody plants, moisture-loving grasses, herbs around the HS catchment (accounting for 51.74%), whereas xerophytic shrubs and herbs dominated around the JB catchment (accounting for 56.50%). These patterns reflected a combination of climate conditions, soil properties, land use, and agricultural economic development. In addition, current high vegetation coverage area accounted for 82.61% and 37.80% around the HS and JB catchments under the “Grain for Green” project, respectively. However, certain adverse phenomena had been observed, including invasive non-native plant species, a low proportion of indigenous flora, and noticeable presence of artificial plants. [Conclusion] Ecological restoration of small catchments on the Loess Plateau should fully consider local climate condition, as well as the characteristics of forest and vegetation, to ensure comprehensive ecological protection for the region.
Abstract:
[Objective] To explore the spatial and temporal changes and causes of water and soil conservation services in the Sanjiangyuan region.[Methods] Based on NPP quantification, soil and water conservation services from 2000-2020, and driver analysis with parameter optimal geographic detector.[Results] The results show that: (1) from 2000 to 2020, the land use in Sanjiangyuan area, cultivated land, grassland, water area and construction land area are expanding, and forest land and unused land area decrease; the Sanjiangyuan area is mainly grassland, followed by water area and woodland, while cultivated land and construction land area is relatively small. In 20 years, the vegetation coverage basically showed a trend of steady increase, with a whole spatial distribution pattern of "high in the east and low in the west".(2) From 2000 to 2020, the soil conservation service capacity index in Sanjiangyuan shows the "N" type trend, but generally increasing trend, the growth rate is 26.13%, and the soil conservation service capacity is significantly improved; the distribution of soil conservation service capacity is consistent, showing the spatial distribution pattern of "high in east and low in west". From 2000 to 2020, the center of gravity of the Sanjiangyuan area is always in the west of Maqin County. The soil and water conservation capacity increases to the northwest direction and extends in multiple directions, and the project implementation effect is remarkable.(3) Vegetation coverage, GDP per land, and grazing intensity have a great impact on water and soil conservation services. The explanatory power of many factors, such as vegetation coverage, ground average GDP, annual average rainfall and grazing intensity, is strong.[Conclusion] We should continue to implement natural forest protection projects, carry out forest conservation and restoration to greatly increase the forest stock; take reasonable grazing, artificial grassland construction, fencing and replanting measures to protect the ecology.The research results can provide scientific basis and data support for the ecological environment protection and sustainable development in Sanjiangyuan.
[Objective] To explore the spatial and temporal changes and causes of water and soil conservation services in the Sanjiangyuan region.[Methods] Based on NPP quantification, soil and water conservation services from 2000-2020, and driver analysis with parameter optimal geographic detector.[Results] The results show that: (1) from 2000 to 2020, the land use in Sanjiangyuan area, cultivated land, grassland, water area and construction land area are expanding, and forest land and unused land area decrease; the Sanjiangyuan area is mainly grassland, followed by water area and woodland, while cultivated land and construction land area is relatively small. In 20 years, the vegetation coverage basically showed a trend of steady increase, with a whole spatial distribution pattern of "high in the east and low in the west".(2) From 2000 to 2020, the soil conservation service capacity index in Sanjiangyuan shows the "N" type trend, but generally increasing trend, the growth rate is 26.13%, and the soil conservation service capacity is significantly improved; the distribution of soil conservation service capacity is consistent, showing the spatial distribution pattern of "high in east and low in west". From 2000 to 2020, the center of gravity of the Sanjiangyuan area is always in the west of Maqin County. The soil and water conservation capacity increases to the northwest direction and extends in multiple directions, and the project implementation effect is remarkable.(3) Vegetation coverage, GDP per land, and grazing intensity have a great impact on water and soil conservation services. The explanatory power of many factors, such as vegetation coverage, ground average GDP, annual average rainfall and grazing intensity, is strong.[Conclusion] We should continue to implement natural forest protection projects, carry out forest conservation and restoration to greatly increase the forest stock; take reasonable grazing, artificial grassland construction, fencing and replanting measures to protect the ecology.The research results can provide scientific basis and data support for the ecological environment protection and sustainable development in Sanjiangyuan.
Abstract:
[Objective] To clarify the distribution characteristics and laws of benggang in Shangyou County, and to provide data support and scientific basis for the priority decision-making of benggang governance by studying scientific research methods. [Methods] Shangyou County, Jiangxi Province was taken as the research area. Based on the comprehensive investigation of benggang and its hazard characteristics, according to the principle of " three elements " of benggang risk, the scale and development status of benggang were selected as the main risk potential indicators of the main body of benggang, and the hazard receptors such as houses, roads and farmland were selected, and combined with the hazard distance as the receptor degree index. The risk evaluation index system of benggang based on matrix discriminant method was constructed to explore the applicability and accuracy of matrix discrimination method to evaluate the benggang risk. [Results] There are 227 benggang in Shangyou County, of which 25 have been controlled and 202 have not been controlled. The development status is mostly active type, the scale is mostly large, the morphological type is mainly dipper type, the hazard object is mainly farmland, and the hazard distance is mainly less than 10 m. The ratio of the number of benggang in the five risk levels of no, small, medium, large, and great in the county to the number of benggang was 47.5 %, 14.9 %, 15.8 %, 14.9 %, and 6.9 %, respectively. The accuracy of on-site review verification reached 80 %.[Conclusion] The matrix discriminant method proposed in this study has good applicability and accuracy, and the indicators are easy to obtain and the method is easy to operate.
[Objective] To clarify the distribution characteristics and laws of benggang in Shangyou County, and to provide data support and scientific basis for the priority decision-making of benggang governance by studying scientific research methods. [Methods] Shangyou County, Jiangxi Province was taken as the research area. Based on the comprehensive investigation of benggang and its hazard characteristics, according to the principle of " three elements " of benggang risk, the scale and development status of benggang were selected as the main risk potential indicators of the main body of benggang, and the hazard receptors such as houses, roads and farmland were selected, and combined with the hazard distance as the receptor degree index. The risk evaluation index system of benggang based on matrix discriminant method was constructed to explore the applicability and accuracy of matrix discrimination method to evaluate the benggang risk. [Results] There are 227 benggang in Shangyou County, of which 25 have been controlled and 202 have not been controlled. The development status is mostly active type, the scale is mostly large, the morphological type is mainly dipper type, the hazard object is mainly farmland, and the hazard distance is mainly less than 10 m. The ratio of the number of benggang in the five risk levels of no, small, medium, large, and great in the county to the number of benggang was 47.5 %, 14.9 %, 15.8 %, 14.9 %, and 6.9 %, respectively. The accuracy of on-site review verification reached 80 %.[Conclusion] The matrix discriminant method proposed in this study has good applicability and accuracy, and the indicators are easy to obtain and the method is easy to operate.
Abstract:
[Objective] To study the characteristics of vertical changes in soil C, N and P contents and their ecological stoichiometry in sand-fixing vegetation in arid zones. [Methods] Taking the flower stick community in the 1992 fly-seeded afforestation area at the northeastern edge of the Tengger Desert as the research object, and using the soil under the native vegetation of Artemisia oleifera thickets and the quicksand land without vegetation restoration measures as the control (CK), we analyzed the vertical change patterns of the content of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) in the depths of 0-200cm and their stoichiometric characteristics in the flower stick community. [Results] (1) The soil SOC, TN and TP contents of the flower stick community were increased by 73.2%, 50% and 145.5%, respectively, compared with that of the non-flight-seeded quicksand land in more than 30 years of fly-seeding. The SOC and TN contents of flower stick decreased with the increase of soil depth, and the TP content decreased slowly with the increase of soil depth, and the change was not obvious. (2) The C:P and N:P of flower stick soil decreased by 30.5% and 48%, and the C:N increased by 31.6% compared with bare sand. Flower stick C:P and N:P decreased with the increase of soil depth, and C:N showed a tendency of increasing first and then decreasing. The mean value of N:P content of flower stick soil (0-200 cm) was 0.13, which was much less than 14. [Conclusion] With the restoration of flower stick community vegetation, the accumulation of soil nutrients gradually increased. The growth of flower stick community was limited by N, and the limiting effect of N increased with the increase of soil depth. The mineralization rate of organic matter was low, and the decomposition rate of SOC was less than the accumulation rate. The soil environment and climate conditions in the study area were favorable to the accumulation of C in the flower stick soil. The results of this study provide a scientific basis for accurately assessing the influence of flower stick communities on soil nutrients in arid environments.
[Objective] To study the characteristics of vertical changes in soil C, N and P contents and their ecological stoichiometry in sand-fixing vegetation in arid zones. [Methods] Taking the flower stick community in the 1992 fly-seeded afforestation area at the northeastern edge of the Tengger Desert as the research object, and using the soil under the native vegetation of Artemisia oleifera thickets and the quicksand land without vegetation restoration measures as the control (CK), we analyzed the vertical change patterns of the content of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) in the depths of 0-200cm and their stoichiometric characteristics in the flower stick community. [Results] (1) The soil SOC, TN and TP contents of the flower stick community were increased by 73.2%, 50% and 145.5%, respectively, compared with that of the non-flight-seeded quicksand land in more than 30 years of fly-seeding. The SOC and TN contents of flower stick decreased with the increase of soil depth, and the TP content decreased slowly with the increase of soil depth, and the change was not obvious. (2) The C:P and N:P of flower stick soil decreased by 30.5% and 48%, and the C:N increased by 31.6% compared with bare sand. Flower stick C:P and N:P decreased with the increase of soil depth, and C:N showed a tendency of increasing first and then decreasing. The mean value of N:P content of flower stick soil (0-200 cm) was 0.13, which was much less than 14. [Conclusion] With the restoration of flower stick community vegetation, the accumulation of soil nutrients gradually increased. The growth of flower stick community was limited by N, and the limiting effect of N increased with the increase of soil depth. The mineralization rate of organic matter was low, and the decomposition rate of SOC was less than the accumulation rate. The soil environment and climate conditions in the study area were favorable to the accumulation of C in the flower stick soil. The results of this study provide a scientific basis for accurately assessing the influence of flower stick communities on soil nutrients in arid environments.
Abstract:
[Objective] The characteristics of cultivated land use transformation and the differences in spatial and temporal distribution of carbon emissions were analyzed to explore the role mechanisms of influencing factors in the process of cultivated land use transformation carbon emissions, and to provide scientific basis for the low-carbonization of cultivated land use. [Methods] Based on the land use data and the carbon emission coefficients, the temporal evolution characteristics of cultivated land use transformation and its carbon emissions during 2000-2020 in Hu’nan Province were revealed at the county and 5 km grid scales, and the spatial distribution characteristics of carbon emissions were identified and analyzed with the help of spatial autocorrelation method; the optimal parameter geodetector model was used to assess the depth of the influence of factors and the degree of interaction between the factors. [Results] ①During the study period, the area of cultivated land in Hu’nan Province has been shrinking continuously, accompanied by a large number of frequent conversion activities between cultivated land and forest land, water area and construction land, the carbon emission shows a fluctuating and increasing dynamic change trend.②The spatial autocorrelation analysis shows that the carbon emissions from the transformation of cultivated land utilization have significant high-high concentration and low-low concentration phenomena in both scales, indicating that the carbon emissions from the transformation of cultivated land utilization have strong concentration distribution characteristics in both spatial and temporal dimensions. ③The interactions among the factors are stronger than the single factor, and the interactions of socio-economic factors and locational conditions have significant explanatory power at both scales. [Conclusion] The impact of cultivated land use transformation on carbon emissions in Hu’nan Province is significant, and there are obvious differences in carbon emission characteristics and drivers at different spatial scales. In the future, carbon emission reduction measures and cultivated land use planning should be formulated more scientifically and rationally.
[Objective] The characteristics of cultivated land use transformation and the differences in spatial and temporal distribution of carbon emissions were analyzed to explore the role mechanisms of influencing factors in the process of cultivated land use transformation carbon emissions, and to provide scientific basis for the low-carbonization of cultivated land use. [Methods] Based on the land use data and the carbon emission coefficients, the temporal evolution characteristics of cultivated land use transformation and its carbon emissions during 2000-2020 in Hu’nan Province were revealed at the county and 5 km grid scales, and the spatial distribution characteristics of carbon emissions were identified and analyzed with the help of spatial autocorrelation method; the optimal parameter geodetector model was used to assess the depth of the influence of factors and the degree of interaction between the factors. [Results] ①During the study period, the area of cultivated land in Hu’nan Province has been shrinking continuously, accompanied by a large number of frequent conversion activities between cultivated land and forest land, water area and construction land, the carbon emission shows a fluctuating and increasing dynamic change trend.②The spatial autocorrelation analysis shows that the carbon emissions from the transformation of cultivated land utilization have significant high-high concentration and low-low concentration phenomena in both scales, indicating that the carbon emissions from the transformation of cultivated land utilization have strong concentration distribution characteristics in both spatial and temporal dimensions. ③The interactions among the factors are stronger than the single factor, and the interactions of socio-economic factors and locational conditions have significant explanatory power at both scales. [Conclusion] The impact of cultivated land use transformation on carbon emissions in Hu’nan Province is significant, and there are obvious differences in carbon emission characteristics and drivers at different spatial scales. In the future, carbon emission reduction measures and cultivated land use planning should be formulated more scientifically and rationally.
Abstract:
[Objective] To scientifically identify the agglomeration characteristics and evolution trend of land use conflicts, so as to provide important reference for promoting the rational layout of territorial space and promoting regional sustainable development. [Methods] The spatial and temporal evolution trend of land use conflict in Wanjiang Urban Belt from 1990 to 2020 was quantitatively analyzed by constructing a land use conflict measurement model based on landscape index, and the distance weight matrix was determined by setting the optimal spatial threshold, so as to explore the agglomeration effect of regional conflict more accurately.[Results] (1) Great changes have taken place in the land use structure of Wanjiang Urban Belt in recent 30 years. The area of cultivated land and forest land has been continuously reduced, and the scale of construction land has increased significantly. (2) The distribution pattern of regional land use conflicts is "high in the north and low in the south", and the area of weak and medium spatial conflicts occupies the main position; The serious conflict areas are concentrated in Hefei City, Wuhu City, Lu 'an Jin 'an District and the coastal areas on both sides of the Yangtze River system; (3) The land use conflict index changed significantly in urban areas during the study period, especially in the east of Hefei, the north of Wuhu and the southeast of Chuzhou. Under the influence of urbanization development, the center of gravity of conflict gradually shifted to the south, and the serious conflict zone shifted to the northwest to the southeast. (4) 5km was selected as the optimal distance analysis threshold. The high-high aggregation conflict zone was distributed in sections centered on Hefei City, while the low-low aggregation conflict zone did not have agglomeration phenomenon. [Conclusion] The land use conflict in Wanjiang Urban Belt has potential to intensify, and the main conflict areas show a shifting trend. In the future, it is necessary to strengthen the rational distribution of regional land use and pay attention to the balance and stability between urbanization development and ecological protection. The results of this study can provide practical basis and reference for conflict management in Jianghuai region and other small and medium-sized urban belt.
[Objective] To scientifically identify the agglomeration characteristics and evolution trend of land use conflicts, so as to provide important reference for promoting the rational layout of territorial space and promoting regional sustainable development. [Methods] The spatial and temporal evolution trend of land use conflict in Wanjiang Urban Belt from 1990 to 2020 was quantitatively analyzed by constructing a land use conflict measurement model based on landscape index, and the distance weight matrix was determined by setting the optimal spatial threshold, so as to explore the agglomeration effect of regional conflict more accurately.[Results] (1) Great changes have taken place in the land use structure of Wanjiang Urban Belt in recent 30 years. The area of cultivated land and forest land has been continuously reduced, and the scale of construction land has increased significantly. (2) The distribution pattern of regional land use conflicts is "high in the north and low in the south", and the area of weak and medium spatial conflicts occupies the main position; The serious conflict areas are concentrated in Hefei City, Wuhu City, Lu 'an Jin 'an District and the coastal areas on both sides of the Yangtze River system; (3) The land use conflict index changed significantly in urban areas during the study period, especially in the east of Hefei, the north of Wuhu and the southeast of Chuzhou. Under the influence of urbanization development, the center of gravity of conflict gradually shifted to the south, and the serious conflict zone shifted to the northwest to the southeast. (4) 5km was selected as the optimal distance analysis threshold. The high-high aggregation conflict zone was distributed in sections centered on Hefei City, while the low-low aggregation conflict zone did not have agglomeration phenomenon. [Conclusion] The land use conflict in Wanjiang Urban Belt has potential to intensify, and the main conflict areas show a shifting trend. In the future, it is necessary to strengthen the rational distribution of regional land use and pay attention to the balance and stability between urbanization development and ecological protection. The results of this study can provide practical basis and reference for conflict management in Jianghuai region and other small and medium-sized urban belt.
Abstract:
[Objective] To clarify the influence mechanism of overlying carbonate red soil on the infiltration characteristics of phosphogypsum, and provide experimental basis for rational disposal and utilization of phosphogypsum storage yard in southwest karst area. [Methods] The influences of three kinds of phosphogypsum bulk density (1.2, 1.3, 1.4 g/cm3) and three kinds of overburden thickness (0, 6, 12 cm) on the water infiltration process of phosphogypsum were studied through the indoor flat soil column infiltration test, and the infiltration process was numerically simulated by the improved layered Green-Ampt model. [Results] ① There was no significant difference in infiltration time to the bottom under the treatment of 6, 12 cm soil cover thickness (P>0.05), but there was significant difference in infiltration time among other soil cover thicknesses (P<0.05). The initial infiltration rate, average infiltration rate and stable infiltration rate of 0 cm soil cover are significantly higher than those of 6, 12 cm soil cover (P<0.05), and the stable infiltration rate decreases significantly with the increase of soil cover thickness. There is no significant difference in cumulative infiltration between 6 cm and 12 cm cover soil thickness (P>0.05), but there is significant difference among other cover soil thicknesses (P<0.05). ② Under the same cover thickness, the influence of phosphogypsum bulk density on initial infiltration rate, average infiltration rate and stable infiltration rate is not significant (P>0.05). ③ When the soil is covered with 6, 12 cm, the variation range of the determination coefficient (R2) between the measured value and the simulated value is 0.951~0.995, the root mean square error (RMSE) is 12.174~40.856, and the average absolute percentage error (MAPE) is 0.070~0.227. The variation range of determination coefficient (R2) between measured and simulated cumulative infiltration is 0.963~0.999, root mean square error (RMSE) is 1.471~11.201, and mean absolute percentage error (MAPE) is 0.046~0.169. [Conclusion] There are significant differences in soil water infiltration characteristics between phosphogypsum covered soil and uncovered soil, and the improved layered Green-Ampt model can be used to simulate the infiltration process of phosphogypsum under the condition of overlying soil.
[Objective] To clarify the influence mechanism of overlying carbonate red soil on the infiltration characteristics of phosphogypsum, and provide experimental basis for rational disposal and utilization of phosphogypsum storage yard in southwest karst area. [Methods] The influences of three kinds of phosphogypsum bulk density (1.2, 1.3, 1.4 g/cm3) and three kinds of overburden thickness (0, 6, 12 cm) on the water infiltration process of phosphogypsum were studied through the indoor flat soil column infiltration test, and the infiltration process was numerically simulated by the improved layered Green-Ampt model. [Results] ① There was no significant difference in infiltration time to the bottom under the treatment of 6, 12 cm soil cover thickness (P>0.05), but there was significant difference in infiltration time among other soil cover thicknesses (P<0.05). The initial infiltration rate, average infiltration rate and stable infiltration rate of 0 cm soil cover are significantly higher than those of 6, 12 cm soil cover (P<0.05), and the stable infiltration rate decreases significantly with the increase of soil cover thickness. There is no significant difference in cumulative infiltration between 6 cm and 12 cm cover soil thickness (P>0.05), but there is significant difference among other cover soil thicknesses (P<0.05). ② Under the same cover thickness, the influence of phosphogypsum bulk density on initial infiltration rate, average infiltration rate and stable infiltration rate is not significant (P>0.05). ③ When the soil is covered with 6, 12 cm, the variation range of the determination coefficient (R2) between the measured value and the simulated value is 0.951~0.995, the root mean square error (RMSE) is 12.174~40.856, and the average absolute percentage error (MAPE) is 0.070~0.227. The variation range of determination coefficient (R2) between measured and simulated cumulative infiltration is 0.963~0.999, root mean square error (RMSE) is 1.471~11.201, and mean absolute percentage error (MAPE) is 0.046~0.169. [Conclusion] There are significant differences in soil water infiltration characteristics between phosphogypsum covered soil and uncovered soil, and the improved layered Green-Ampt model can be used to simulate the infiltration process of phosphogypsum under the condition of overlying soil.
Abstract:
Abstract： [Objective] To investigate the spatial and temporal variations of urban land green utilization efficiency and the influencing factors, so as to provide scientific basis for optimizing the development and protection pattern of national land space and promoting the sustainable development of urban land. [Methods] The slack based measure - directional distance function (SBM-DDF) model was used to measure the green land use efficiency of urban land in Anhui Province from 2008 to 2022, and the kernel density analysis and center of gravity migration models were selected to analyze the spatial and temporal variations, while the geodetector and geographic time weighted regression (GTWR) models were combined to study the factors influencing the urban land use efficiency. [Results] ① The average value of green land use efficiency of urban land in Anhui Province within 2008-2022 is 0.77, and the whole is divided into two phases of straight-line decline from 2008-2014 and fluctuating increase from 2015-2022. ② polarization phenomenon in the region, the low value of the city increased, the high value of the city is more stable, the regional gap is gradually expanding; efficiency value of the province's center of gravity trajectory first to the southeast and then migrate to the northwest, northwestern and southeastern regions to improve the more pronounced, but is still “high in the south and low in the north,” unbalanced spatial characteristics. ③ The factors are environmental protection inputs, urban and rural structure, urban greening, environmental regulation and industrial structure, among which the interaction between industrial structure and environmental protection inputs is the strongest, with a q-value of 0.82. The spatial heterogeneity of the leading factors is significant, with urban greening influencing all cities positively, urban and rural structure, environmental regulation and environmental protection inputs influencing the central and southern regions positively and negatively in the northern region, and the negative influence of industrial structure on the resource cities is prominent. The negative influence of industrial structure on resource-oriented cities is prominent. [Conclusion] It is suggested that strict land use control, promotion of industrial structure upgrading, increasing ecological and environmental protection, strengthening the overall collaborative development, and formulating differentiated development paths should be used to promote the overall improvement of green land use efficiency in urban areas of Anhui Province.
Abstract： [Objective] To investigate the spatial and temporal variations of urban land green utilization efficiency and the influencing factors, so as to provide scientific basis for optimizing the development and protection pattern of national land space and promoting the sustainable development of urban land. [Methods] The slack based measure - directional distance function (SBM-DDF) model was used to measure the green land use efficiency of urban land in Anhui Province from 2008 to 2022, and the kernel density analysis and center of gravity migration models were selected to analyze the spatial and temporal variations, while the geodetector and geographic time weighted regression (GTWR) models were combined to study the factors influencing the urban land use efficiency. [Results] ① The average value of green land use efficiency of urban land in Anhui Province within 2008-2022 is 0.77, and the whole is divided into two phases of straight-line decline from 2008-2014 and fluctuating increase from 2015-2022. ② polarization phenomenon in the region, the low value of the city increased, the high value of the city is more stable, the regional gap is gradually expanding; efficiency value of the province's center of gravity trajectory first to the southeast and then migrate to the northwest, northwestern and southeastern regions to improve the more pronounced, but is still “high in the south and low in the north,” unbalanced spatial characteristics. ③ The factors are environmental protection inputs, urban and rural structure, urban greening, environmental regulation and industrial structure, among which the interaction between industrial structure and environmental protection inputs is the strongest, with a q-value of 0.82. The spatial heterogeneity of the leading factors is significant, with urban greening influencing all cities positively, urban and rural structure, environmental regulation and environmental protection inputs influencing the central and southern regions positively and negatively in the northern region, and the negative influence of industrial structure on the resource cities is prominent. The negative influence of industrial structure on resource-oriented cities is prominent. [Conclusion] It is suggested that strict land use control, promotion of industrial structure upgrading, increasing ecological and environmental protection, strengthening the overall collaborative development, and formulating differentiated development paths should be used to promote the overall improvement of green land use efficiency in urban areas of Anhui Province.
Abstract:
[Objective] Clarify the spatio-temporal pattern evolution law of the coupling coordination between the recessive form of urban land use and ecological welfare performance along the lower Yellow River, reveal the direction of its influencing factors, and promote the green development of urban agglomerations along the lower Yellow River. [Methods] Based on the panel data of 17 prefecture-level cities along the lower Yellow River from 2012 to 2021, comprehensive index model and Super-SBM model were used to measure the recessive form of land use and ecological welfare performance. In addition, ArcGIS visualization, kernel density analysis and coupled coordination model were used to deeply analyze the evolution trend of the recessive form of land use, the performance level of ecological welfare and the coupling coordination degree of the two cities in the spatial and temporal dimension, and the influencing factors were analyzed with the help of Tobit regression model. [Results] (1) The recessive form of land use in each city was stable but improved, and the ecological welfare performance experienced a phased evolution process of "first decreasing and then increasing". (2) During the study period, the coupling coordination degree of the overall ecological welfare performance of cities along the lower Yellow River and the recessive form of land use experienced a change from "near disharmony to barely coordination", and tended to change to primary coordination. (3) Opening to the outside world, industrial structure and spatial agglomeration have significant positive effects on coupling coordination; Scientific and technological innovation and urban environment have obvious inhibition effect on coupling coordination. The elevation, slope and ten thousand students do not affect the coupling coordination. [Conclusion] In the future, it is necessary to promote the rational use of land according to local conditions, formulate scientific environmental protection policies, strengthen the monitoring and management of cities, strengthen the radiating leading role of provincial capitals, and promote the green coordinated development among cities.
[Objective] Clarify the spatio-temporal pattern evolution law of the coupling coordination between the recessive form of urban land use and ecological welfare performance along the lower Yellow River, reveal the direction of its influencing factors, and promote the green development of urban agglomerations along the lower Yellow River. [Methods] Based on the panel data of 17 prefecture-level cities along the lower Yellow River from 2012 to 2021, comprehensive index model and Super-SBM model were used to measure the recessive form of land use and ecological welfare performance. In addition, ArcGIS visualization, kernel density analysis and coupled coordination model were used to deeply analyze the evolution trend of the recessive form of land use, the performance level of ecological welfare and the coupling coordination degree of the two cities in the spatial and temporal dimension, and the influencing factors were analyzed with the help of Tobit regression model. [Results] (1) The recessive form of land use in each city was stable but improved, and the ecological welfare performance experienced a phased evolution process of "first decreasing and then increasing". (2) During the study period, the coupling coordination degree of the overall ecological welfare performance of cities along the lower Yellow River and the recessive form of land use experienced a change from "near disharmony to barely coordination", and tended to change to primary coordination. (3) Opening to the outside world, industrial structure and spatial agglomeration have significant positive effects on coupling coordination; Scientific and technological innovation and urban environment have obvious inhibition effect on coupling coordination. The elevation, slope and ten thousand students do not affect the coupling coordination. [Conclusion] In the future, it is necessary to promote the rational use of land according to local conditions, formulate scientific environmental protection policies, strengthen the monitoring and management of cities, strengthen the radiating leading role of provincial capitals, and promote the green coordinated development among cities.
Abstract:
[Objective] To provide theoretical reference for realizing sustainable development and ecological civilization construction in the Weihe River Basin.[Method] Build remote sensing ecological index (RSEI) based on GEE platform to dynamically evaluate the change of ecological environment quality in the Weihe River Basin from 2000 to 2020, and explore the impact of climate, vegetation, terrain, soil and socio-economic factors on ecological environment quality based on the optimal parameter geographic detector model. The results show that: [Results] (1) from 2000 to 2020, the ecological environment quality in the region increases; the ecological environment quality grade is mainly poor and poor, accounting for more than 60% of the total area.; In 20 years, the ecological environment quality grade area increased more for the middle, good and excellent ecological environment quality.(2) The ecological environment quality grade has a spatial distribution pattern of "high in the south and low in the north, high in the east and low in the west". The poor ecological environment area has the largest area.73 43% of the Weihe River Basin is in the ecological environment quality increase area of 12.09×104km2;during the study period, the area where the ecological environment quality increases and the reduced area keeps increasing, and the overall ecological environment quality of the research area develops in a better direction. The area of excellent ecological environment quality is still inclined in the overall distribution along the southeast-northwest direction.(3) Rainfall, elevation and soil organic carbon content are the main factors affecting the ecological environment quality of the Weihe River Basin;.[Conclusion] In the process of improving the ecological environment quality of the Weihe River Basin, the distribution law of slope should be fully considered to optimize the governance scheme.
[Objective] To provide theoretical reference for realizing sustainable development and ecological civilization construction in the Weihe River Basin.[Method] Build remote sensing ecological index (RSEI) based on GEE platform to dynamically evaluate the change of ecological environment quality in the Weihe River Basin from 2000 to 2020, and explore the impact of climate, vegetation, terrain, soil and socio-economic factors on ecological environment quality based on the optimal parameter geographic detector model. The results show that: [Results] (1) from 2000 to 2020, the ecological environment quality in the region increases; the ecological environment quality grade is mainly poor and poor, accounting for more than 60% of the total area.; In 20 years, the ecological environment quality grade area increased more for the middle, good and excellent ecological environment quality.(2) The ecological environment quality grade has a spatial distribution pattern of "high in the south and low in the north, high in the east and low in the west". The poor ecological environment area has the largest area.73 43% of the Weihe River Basin is in the ecological environment quality increase area of 12.09×104km2;during the study period, the area where the ecological environment quality increases and the reduced area keeps increasing, and the overall ecological environment quality of the research area develops in a better direction. The area of excellent ecological environment quality is still inclined in the overall distribution along the southeast-northwest direction.(3) Rainfall, elevation and soil organic carbon content are the main factors affecting the ecological environment quality of the Weihe River Basin;.[Conclusion] In the process of improving the ecological environment quality of the Weihe River Basin, the distribution law of slope should be fully considered to optimize the governance scheme.
CHEN Fengting, TAN Qingfang, HUANG Yuhan, ZHAO Mingquan, CHANG Zhiyong, WU Di, HUANG Zixyuan, WEI Juan
Abstract:
Abstract：[Objective] This study aims to examine the hydrodynamic properties of red soil slopes under varying surface roughness, slope, and flow rate. The findings will contribute to a better understanding and prediction of sheet erosion on red soil slopes. [Methods] A study was conducted to simulate red soil slopes with varying surface roughness using different particle sizes (0.25~1, 1~3, 3~5, 5~7, 7~10 mm). The experiments involved four flow rates (2, 4, 8, and 16 L?min-1) and four slopes (5°, 10°, 15°, and 20°). Photogrammetry, based on the structure from motion technique, and electrolyte tracing method were used to determine the surface roughness and flow velocity on the slope. The data collected was used to calculate the surface roughness and hydrodynamic parameters for each condition. The study aimed to analyze the changes in flow hydrodynamic parameters of the red soil slope under different surface roughnesses, flow velocity, and slope. [Results] The mean flow velocity varied between 0.022 and 0.531 m?s-1 under the experimental design conditions. The Reynolds numbers ranged from 63 to 1155, the Froude numbers ranged from 0.1 to 4.1, and the resistance coefficients were within the range of 0.13 to 68.86. Surface roughness is positively correlated with the resistance coefficient (p<0.01), and negatively correlated with the Reynolds number (p<0.05), the Froude number, and flow velocity (p<0.01). Slope is positively correlated with the unit-width discharge of overland flow and the Froude number (p<0.01). Unit-width discharge is positively correlated with the Reynolds number, the Froude number, and average flow velocity (p<0.01), and negatively correlated with the resistance coefficient (p<0.01). [Conclusion] Increased surface roughness augments the resistance of overland flow and reduces the influence of flow inertia, serving as a crucial factor in determining mean flow velocity, Froude number, and resistance coefficient. Unit-width discharge primarily influences the Reynolds number by altering the water depth and flow inertia of overland flow. Compared to surface roughness and unit-width discharge, slope has the least impact on mean flow velocity, Reynolds number, Froude number, and resistance coefficient. The relationship of mean flow velocity and Froude number between surface roughness, unit-width discharge and slope respectively could be described well in the power function. Similarly, the Reynolds number and resistance coefficient exhibit a strong power function relationship with unit-width discharge and surface roughness.
Abstract：[Objective] This study aims to examine the hydrodynamic properties of red soil slopes under varying surface roughness, slope, and flow rate. The findings will contribute to a better understanding and prediction of sheet erosion on red soil slopes. [Methods] A study was conducted to simulate red soil slopes with varying surface roughness using different particle sizes (0.25~1, 1~3, 3~5, 5~7, 7~10 mm). The experiments involved four flow rates (2, 4, 8, and 16 L?min-1) and four slopes (5°, 10°, 15°, and 20°). Photogrammetry, based on the structure from motion technique, and electrolyte tracing method were used to determine the surface roughness and flow velocity on the slope. The data collected was used to calculate the surface roughness and hydrodynamic parameters for each condition. The study aimed to analyze the changes in flow hydrodynamic parameters of the red soil slope under different surface roughnesses, flow velocity, and slope. [Results] The mean flow velocity varied between 0.022 and 0.531 m?s-1 under the experimental design conditions. The Reynolds numbers ranged from 63 to 1155, the Froude numbers ranged from 0.1 to 4.1, and the resistance coefficients were within the range of 0.13 to 68.86. Surface roughness is positively correlated with the resistance coefficient (p<0.01), and negatively correlated with the Reynolds number (p<0.05), the Froude number, and flow velocity (p<0.01). Slope is positively correlated with the unit-width discharge of overland flow and the Froude number (p<0.01). Unit-width discharge is positively correlated with the Reynolds number, the Froude number, and average flow velocity (p<0.01), and negatively correlated with the resistance coefficient (p<0.01). [Conclusion] Increased surface roughness augments the resistance of overland flow and reduces the influence of flow inertia, serving as a crucial factor in determining mean flow velocity, Froude number, and resistance coefficient. Unit-width discharge primarily influences the Reynolds number by altering the water depth and flow inertia of overland flow. Compared to surface roughness and unit-width discharge, slope has the least impact on mean flow velocity, Reynolds number, Froude number, and resistance coefficient. The relationship of mean flow velocity and Froude number between surface roughness, unit-width discharge and slope respectively could be described well in the power function. Similarly, the Reynolds number and resistance coefficient exhibit a strong power function relationship with unit-width discharge and surface roughness.
MA Zhiliang, ZHUANG Jianqi, WU Jing, CAO Yanbo, CHEN Shengyin, CHANG Lei, ZHAN Jiewei, MA Penghui, KONG Jiaxu
Abstract:
[Objective] Extremely heavy rainfall in a short time can induce extremely low frequency debris flow in mountain area, which brings serious threat to human security and ecological environment in mountain area. In this paper, the characteristics and causes of the 2023“8.11” Jiwozi flash flood and debris flow are analyzed, and its risk is evaluated. [Methods] The formation process of the “8.11” 2023 Jiwozi flash flood and debris flow was retrieved by means of field investigation, numerical simulation and actual precipitation frequency. [Results] The results are as follows: (1) The rapid confluence of extremely short duration and strong rainfall resulted in a flood, which resulted in the erosion of loose materials in the gully, formed the effect of “Fire hose”, and caused a small-scale collapse of the mountain, flash flood debris flow is formed in the gully, and the gully is eroded by the help of steep terrain. (2) Under the actual rainfall frequency, the final depth of debris flow is between 0.04 m and 5.63 m, the maximum velocity is 7.43 m/s, and the one-time discharge is 78271 m3. (3) Based on the velocity of flow, depth of mud and hazard range, three high, middle and low risk areas are given, and the high terrain area on the west side of the accumulation fan is the low risk area, which accounts for about 10% of the accumulation fan area, the middle area and the area from the edge of the pile to the road are medium-risk areas, accounting for 62% of the area, while the areas of the south-east and south-west of the pile fan are high-risk areas, accounting for 28% of the area. The research results can provide scientific reference for the risk control of extremely low frequency flash floods and debris flows in the mountainous areas of Qinling Mountains. [Conclusion] The 2023“8.11” Jiwozi flash flood and debris flow is a typical low-frequency flash flood and debris flow disaster induced by extremely short-term heavy rainfall, and the FLO-2D model effectively simulates the movement and sedimentation process of the debris flow, and determines the danger range of the debris flow. The research results can provide a reference for disaster prevention and mitigation of similar low-frequency debris flows in Qinling Mountains.
[Objective] Extremely heavy rainfall in a short time can induce extremely low frequency debris flow in mountain area, which brings serious threat to human security and ecological environment in mountain area. In this paper, the characteristics and causes of the 2023“8.11” Jiwozi flash flood and debris flow are analyzed, and its risk is evaluated. [Methods] The formation process of the “8.11” 2023 Jiwozi flash flood and debris flow was retrieved by means of field investigation, numerical simulation and actual precipitation frequency. [Results] The results are as follows: (1) The rapid confluence of extremely short duration and strong rainfall resulted in a flood, which resulted in the erosion of loose materials in the gully, formed the effect of “Fire hose”, and caused a small-scale collapse of the mountain, flash flood debris flow is formed in the gully, and the gully is eroded by the help of steep terrain. (2) Under the actual rainfall frequency, the final depth of debris flow is between 0.04 m and 5.63 m, the maximum velocity is 7.43 m/s, and the one-time discharge is 78271 m3. (3) Based on the velocity of flow, depth of mud and hazard range, three high, middle and low risk areas are given, and the high terrain area on the west side of the accumulation fan is the low risk area, which accounts for about 10% of the accumulation fan area, the middle area and the area from the edge of the pile to the road are medium-risk areas, accounting for 62% of the area, while the areas of the south-east and south-west of the pile fan are high-risk areas, accounting for 28% of the area. The research results can provide scientific reference for the risk control of extremely low frequency flash floods and debris flows in the mountainous areas of Qinling Mountains. [Conclusion] The 2023“8.11” Jiwozi flash flood and debris flow is a typical low-frequency flash flood and debris flow disaster induced by extremely short-term heavy rainfall, and the FLO-2D model effectively simulates the movement and sedimentation process of the debris flow, and determines the danger range of the debris flow. The research results can provide a reference for disaster prevention and mitigation of similar low-frequency debris flows in Qinling Mountains.
Abstract:
[Objective]Analyze the changes in soil properties and microbial community structure under different land use types in wetlands, and explore the characteristics of changes in soil carbon fixing microbial communities and functional genes under different land use types.[Methods]We uses high-throughput sequencing technology to sequence and analyze soil microbial communities and functional genes in Xianshan Lake National Wetland Park in Changxing, Zhejiang Province.[Results]The carbon sequestration capacity of Xianshan Lake wetland is as follows: sedge swamp>natural coastal forest>bamboo forest>nursery>artificially intervened riverbank forest (Chinese fir forest)>artificial pine forest>broad-leaved forest>artificially intervened coastal vegetation>artificially intervened riverbank forest (willow swamp)>reed marsh>reed and willow coastal vegetation. The organic carbon storage of sedge swamp is the highest (38.68 ±0.56 t/hm2), accounting for 171% of forest organic carbon storage, and its soil microbial carbon utilization efficiency (0.66±0.005) is 150% of bamboo forest microbial carbon utilization efficiency.The carbon sequestration pathways of microorganisms in the Xianshan Lake wetland are mainly through the Calvin cycle, reducing tricarboxylic acid cycle, and reducing acetyl CoA pathway, with Proteobacteria, Bacteroidetes, Acidobacteria, and Chloroflexia as the main carbon sequestration microbial communities. The relative abundance of Proteobacteria and Bacteroidetes in the soil of sedge swamp is 56.40% and 17.40%, respectively. The relative abundance of Proteobacteria in natural coastal forest soil is 59.60%, and the relative abundance of Acidobacteria in bamboo forest soil is 36.00%. There is a positive correlation between organic carbon storage and soil carbon fixing bacteria abundance in Xianshan Lake wetland.[Conclusion]In wetland ecosystems, changes in soil carbon sequestration microbial communities and functional genes under different land use patterns affect the carbon sequestration capacity of wetland microorganisms. This study helps to better understand the characteristics of soil carbon fixing microbial communities and functional gene changes, and has important guiding significance for small and micro ecological restoration and carbon sequestration.
[Objective]Analyze the changes in soil properties and microbial community structure under different land use types in wetlands, and explore the characteristics of changes in soil carbon fixing microbial communities and functional genes under different land use types.[Methods]We uses high-throughput sequencing technology to sequence and analyze soil microbial communities and functional genes in Xianshan Lake National Wetland Park in Changxing, Zhejiang Province.[Results]The carbon sequestration capacity of Xianshan Lake wetland is as follows: sedge swamp>natural coastal forest>bamboo forest>nursery>artificially intervened riverbank forest (Chinese fir forest)>artificial pine forest>broad-leaved forest>artificially intervened coastal vegetation>artificially intervened riverbank forest (willow swamp)>reed marsh>reed and willow coastal vegetation. The organic carbon storage of sedge swamp is the highest (38.68 ±0.56 t/hm2), accounting for 171% of forest organic carbon storage, and its soil microbial carbon utilization efficiency (0.66±0.005) is 150% of bamboo forest microbial carbon utilization efficiency.The carbon sequestration pathways of microorganisms in the Xianshan Lake wetland are mainly through the Calvin cycle, reducing tricarboxylic acid cycle, and reducing acetyl CoA pathway, with Proteobacteria, Bacteroidetes, Acidobacteria, and Chloroflexia as the main carbon sequestration microbial communities. The relative abundance of Proteobacteria and Bacteroidetes in the soil of sedge swamp is 56.40% and 17.40%, respectively. The relative abundance of Proteobacteria in natural coastal forest soil is 59.60%, and the relative abundance of Acidobacteria in bamboo forest soil is 36.00%. There is a positive correlation between organic carbon storage and soil carbon fixing bacteria abundance in Xianshan Lake wetland.[Conclusion]In wetland ecosystems, changes in soil carbon sequestration microbial communities and functional genes under different land use patterns affect the carbon sequestration capacity of wetland microorganisms. This study helps to better understand the characteristics of soil carbon fixing microbial communities and functional gene changes, and has important guiding significance for small and micro ecological restoration and carbon sequestration.
Abstract:
[Objective] To optimize the spatial land use resources of ChangZhuTan City Cluster from the perspective of carbon balance, and to provide theoretical support for the sustainable development of the region's society and economy. [Methods] Calculate the carbon sinks and carbon emissions of ChangZhuTan City Cluster from the perspective of land use, carry out carbon balance zoning based on the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, and put forward the optimization strategy of land use for each type of cities and counties, and set up economic benefit, carbon sink benefit, compactness and conversion cost as the optimization function of the multi-objective algorithm, and then get the more scientific spatial structure of land use through the CoMOLA model. Optimization. [Results] From 2000 to 2020, the total carbon emission of ChangZhuTan urban agglomeration showed a rising trend year by year, and the carbon sink level of all districts and counties was relatively stable, but the overall trend was slightly decreasing; based on the coefficient of carbon ecological carrying capacity and the coefficient of carbon economic contribution, the ChangZhuTan urban agglomeration was divided into the carbon sink development area, the economic development area, the comprehensive optimization area, and the green development area; the optimized economic benefit of the land use increased by 31.2%, carbon sink increased by 6.3%, and compactness increased by 5.5%. [Conclusion] The optimized land resources can better meet the economic and ecological sustainable development of ChangZhuTan City Cluster, and the spatial layout of land use is more reasonable, which provides a basis for decision-making on the allocation of land resources in the future.
[Objective] To optimize the spatial land use resources of ChangZhuTan City Cluster from the perspective of carbon balance, and to provide theoretical support for the sustainable development of the region's society and economy. [Methods] Calculate the carbon sinks and carbon emissions of ChangZhuTan City Cluster from the perspective of land use, carry out carbon balance zoning based on the carbon ecological carrying capacity coefficient and the carbon economic contribution coefficient, and put forward the optimization strategy of land use for each type of cities and counties, and set up economic benefit, carbon sink benefit, compactness and conversion cost as the optimization function of the multi-objective algorithm, and then get the more scientific spatial structure of land use through the CoMOLA model. Optimization. [Results] From 2000 to 2020, the total carbon emission of ChangZhuTan urban agglomeration showed a rising trend year by year, and the carbon sink level of all districts and counties was relatively stable, but the overall trend was slightly decreasing; based on the coefficient of carbon ecological carrying capacity and the coefficient of carbon economic contribution, the ChangZhuTan urban agglomeration was divided into the carbon sink development area, the economic development area, the comprehensive optimization area, and the green development area; the optimized economic benefit of the land use increased by 31.2%, carbon sink increased by 6.3%, and compactness increased by 5.5%. [Conclusion] The optimized land resources can better meet the economic and ecological sustainable development of ChangZhuTan City Cluster, and the spatial layout of land use is more reasonable, which provides a basis for decision-making on the allocation of land resources in the future.
Abstract:
Abstract: [Objective] The construction of the changing slope cropland to terrace project plays a crucial role in preserving cropland resources, reducing soil erosion, and promoting grain production. In the process of selecting sites and constructing terrace projects, balancing the benefits of soil and water conservation with economic returns is key to achieving a win-win situation for both soil conservation and food security. [Methods] Using remote sensing and spatial analysis techniques, the spatial distribution of terraces in Danjiangkou City was identified, and small watersheds were delineated. By combining the Chinese Soil Loss Equation (CSLE) model with field investigations, the tradeoff between soil and water conservation benefits and crop value-added in the changing slope cropland to terrace project was evaluated. A linear optimization method was employed to search for the optimal spatial layout of the project under multiple scenarios. [Results] The terraces and slope cropland in Danjiangkou City are mainly distributed in the central and northern watersheds, where they exhibit higher total benefits in terms of soil and water conservation and crop value-added economic benefits. The results of the spatial optimization analysis for each small watershed indicate that under the soil and water conservation priority scenario, the changing slope cropland to terrace project is primarily concentrated in the southwestern watershed, whereas under the crop value-added economic benefits priority scenario, the project is more concentrated in the central watershed. The linear optimization results under multiple scenarios show a significant tradeoff between the soil and water conservation priority and the crop value-added economic benefits priority: in the scenarios, the maximum soil and water conservation benefit is a reduction of approximately 3.207 million tons of erosion, with crop value-added economic benefits of around 1.7811 billion yuan. Conversely, the maximum crop value-added economic benefit is about 1.8745 billion yuan, with soil and water conservation benefits reduced to approximately 3.013 million tons. The Pareto optimal solutions reflect the tradeoff between the two. [Conclusion] This study quantifies the tradeoff between soil and water conservation and crop value-added economic benefits in the changing slope cropland to terrace project through spatial optimization methods and provides a series of Pareto solutions for decision-makers. The research results offer valuable insights for high-standard cropland development and integrated small watershed management in China.
Abstract: [Objective] The construction of the changing slope cropland to terrace project plays a crucial role in preserving cropland resources, reducing soil erosion, and promoting grain production. In the process of selecting sites and constructing terrace projects, balancing the benefits of soil and water conservation with economic returns is key to achieving a win-win situation for both soil conservation and food security. [Methods] Using remote sensing and spatial analysis techniques, the spatial distribution of terraces in Danjiangkou City was identified, and small watersheds were delineated. By combining the Chinese Soil Loss Equation (CSLE) model with field investigations, the tradeoff between soil and water conservation benefits and crop value-added in the changing slope cropland to terrace project was evaluated. A linear optimization method was employed to search for the optimal spatial layout of the project under multiple scenarios. [Results] The terraces and slope cropland in Danjiangkou City are mainly distributed in the central and northern watersheds, where they exhibit higher total benefits in terms of soil and water conservation and crop value-added economic benefits. The results of the spatial optimization analysis for each small watershed indicate that under the soil and water conservation priority scenario, the changing slope cropland to terrace project is primarily concentrated in the southwestern watershed, whereas under the crop value-added economic benefits priority scenario, the project is more concentrated in the central watershed. The linear optimization results under multiple scenarios show a significant tradeoff between the soil and water conservation priority and the crop value-added economic benefits priority: in the scenarios, the maximum soil and water conservation benefit is a reduction of approximately 3.207 million tons of erosion, with crop value-added economic benefits of around 1.7811 billion yuan. Conversely, the maximum crop value-added economic benefit is about 1.8745 billion yuan, with soil and water conservation benefits reduced to approximately 3.013 million tons. The Pareto optimal solutions reflect the tradeoff between the two. [Conclusion] This study quantifies the tradeoff between soil and water conservation and crop value-added economic benefits in the changing slope cropland to terrace project through spatial optimization methods and provides a series of Pareto solutions for decision-makers. The research results offer valuable insights for high-standard cropland development and integrated small watershed management in China.
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[Objective] Finding out the response and vulnerability of carbon storage to land use change in Dawen River Basin can promote the green and sustainable development of the basin, and also provide reference for land use optimization management and control. [Methods] Based on land use data, InVEST model was utilized to study the impact of land use change on carbon storage evolution in Dawen River Basin from 2000 to 2020, and the potential impact index (PI) was used to assess the vulnerability of ecosystem carbon storage. [Results] The results indicated that: (1) From 2000 to 2020, the land use structure of the study area has changed significantly, mainly as a large decrease of cultivated land (316.44 km2) and a sharp increase of construction land (523.98 km2). The conversion of cultivated land to construction land was the main land transfer type. (2) During 2000-2020, the carbon storage decreased by 1087.46×104 t, and the transfer of cultivated to construction land was the leading factor of the decrease. The spatial distribution characteristics of basin carbon storage were "overall high in the north and low in the south, and significantly high or significantly low in local areas". (3) The land use degree index increased by 8.12. The PI for the first and last 10 years was -1.33 and -1.42, respectively, indicating that the vulnerability of carbon storage service was increasing. [Conclusion] The reduction of cultivated land, grassland and forest land and the expansion of construction land in the study area have significant effects on carbon storage and its vulnerability. In the future, carbon storage should be taken as an important reference factor in land use planning to achieve the optimal balance of carbon storage functions.
[Objective] Finding out the response and vulnerability of carbon storage to land use change in Dawen River Basin can promote the green and sustainable development of the basin, and also provide reference for land use optimization management and control. [Methods] Based on land use data, InVEST model was utilized to study the impact of land use change on carbon storage evolution in Dawen River Basin from 2000 to 2020, and the potential impact index (PI) was used to assess the vulnerability of ecosystem carbon storage. [Results] The results indicated that: (1) From 2000 to 2020, the land use structure of the study area has changed significantly, mainly as a large decrease of cultivated land (316.44 km2) and a sharp increase of construction land (523.98 km2). The conversion of cultivated land to construction land was the main land transfer type. (2) During 2000-2020, the carbon storage decreased by 1087.46×104 t, and the transfer of cultivated to construction land was the leading factor of the decrease. The spatial distribution characteristics of basin carbon storage were "overall high in the north and low in the south, and significantly high or significantly low in local areas". (3) The land use degree index increased by 8.12. The PI for the first and last 10 years was -1.33 and -1.42, respectively, indicating that the vulnerability of carbon storage service was increasing. [Conclusion] The reduction of cultivated land, grassland and forest land and the expansion of construction land in the study area have significant effects on carbon storage and its vulnerability. In the future, carbon storage should be taken as an important reference factor in land use planning to achieve the optimal balance of carbon storage functions.
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[ Objective ] Exploring the coupling and coordination relationship between soil and water conservation policy and agricultural eco-efficiency and its driving factors is conducive to promoting the harmonious coexistence of economy, resources and environment in the agricultural field under the guidance of policy. [ Methods ] Taking the Three Gorges Reservoir Area ( Chongqing section ) as the research area, the evaluation index system of soil and water conservation policy intensity and agricultural eco-efficiency was established. The coupling coordination degree model, geographical detector model and OLS regression were used to analyze the coupling relationship between soil and water conservation policy and agricultural eco-efficiency and its driving mechanism in the region from 2015 to 2022. [ Results ] ① There were significant differences in policy intensity and ecological efficiency among the regions in the Three Gorges Reservoir Area ( Chongqing section ). The maintenance area of soil-conserving human settlements in Fangshan Hills and the maintenance area of soil-conserving human settlements in parallel ridges and valleys showed a strong growth momentum in policy implementation, while the rest of the region was relatively stable. The agricultural ecological efficiency of the urban landscape living environment maintenance area is excellent, while that of the Wuling Mountain water conservation and soil conservation area is relatively low, showing an obvious polarization trend. ②The coupling coordination degree between soil and water conservation policies and agricultural ecological efficiency showed an overall upward trend, and the coordination degree of urban landscape human settlement environment maintenance area and Fangshan hilly soil conservation human settlement environment maintenance area was particularly prominent. However, there is a significant imbalance in Kaizhou District in the area of soil conservation and human settlements in the parallel ridge valley of Yuzhong.③The results of the driving mechanism show that the input of farmland water conservancy facilities is helpful to improve the coordination level between the two, and the reasonable control of the planting area can also more positively affect the coordination relationship between the soil and water conservation policy and the agricultural ecological efficiency. The robustness of the regression results is further confirmed by the counterfactual test. [ Conclusion ] In order to effectively maintain water and soil resources and agricultural ecological security, the Three Gorges Reservoir Area ( Chongqing section ) should adhere to the principle of local governance and regional linkage, actively guide all parties in society to participate in the formation of governance synergy, and jointly promote the development of a diversified support model combining poverty alleviation, soil conservation and agricultural assistance.
[ Objective ] Exploring the coupling and coordination relationship between soil and water conservation policy and agricultural eco-efficiency and its driving factors is conducive to promoting the harmonious coexistence of economy, resources and environment in the agricultural field under the guidance of policy. [ Methods ] Taking the Three Gorges Reservoir Area ( Chongqing section ) as the research area, the evaluation index system of soil and water conservation policy intensity and agricultural eco-efficiency was established. The coupling coordination degree model, geographical detector model and OLS regression were used to analyze the coupling relationship between soil and water conservation policy and agricultural eco-efficiency and its driving mechanism in the region from 2015 to 2022. [ Results ] ① There were significant differences in policy intensity and ecological efficiency among the regions in the Three Gorges Reservoir Area ( Chongqing section ). The maintenance area of soil-conserving human settlements in Fangshan Hills and the maintenance area of soil-conserving human settlements in parallel ridges and valleys showed a strong growth momentum in policy implementation, while the rest of the region was relatively stable. The agricultural ecological efficiency of the urban landscape living environment maintenance area is excellent, while that of the Wuling Mountain water conservation and soil conservation area is relatively low, showing an obvious polarization trend. ②The coupling coordination degree between soil and water conservation policies and agricultural ecological efficiency showed an overall upward trend, and the coordination degree of urban landscape human settlement environment maintenance area and Fangshan hilly soil conservation human settlement environment maintenance area was particularly prominent. However, there is a significant imbalance in Kaizhou District in the area of soil conservation and human settlements in the parallel ridge valley of Yuzhong.③The results of the driving mechanism show that the input of farmland water conservancy facilities is helpful to improve the coordination level between the two, and the reasonable control of the planting area can also more positively affect the coordination relationship between the soil and water conservation policy and the agricultural ecological efficiency. The robustness of the regression results is further confirmed by the counterfactual test. [ Conclusion ] In order to effectively maintain water and soil resources and agricultural ecological security, the Three Gorges Reservoir Area ( Chongqing section ) should adhere to the principle of local governance and regional linkage, actively guide all parties in society to participate in the formation of governance synergy, and jointly promote the development of a diversified support model combining poverty alleviation, soil conservation and agricultural assistance.
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Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
Abstract: [Objective]Research on carbon emission effect of“Production-living-Ecological” function change can provide reference for territorial and spatial planning under the background of “carbon peaking and carbon neutrality goals”.[Methods]The research applied the methods including evaluation assignment method, energy consumption method and geographical weighted regression model to reveal the spatial-temporal evolution characteristics of the "production-living-ecology" functions and its effect the carbon emission in Liaoning Province from 2005 to 2020. [Results]① the spatial distribution pattern of the "production-living-ecology" functions in Liaoning Province had not changed much from 2005 to 2020. Most of the areas were dominated by production and ecological functions, the living function areas were obviously expanded, and the spatial difference mainly occurs between the central urban and the surrounding areas; ② From 2005 to 2013, the carbon emissions of counties in Liaoning Province increased rapidly, and from 2013 to 2020, the growth rate was slower but its spatial difference became more obvious. The high carbon emissions were significantly concentrated in Shenyang and Dalian cities；③ At the aspects of spatial pattern and quantitive change, the overall correlation between the "production-living-ecology" function and carbon emission is strong, meanwhile, the spatial differences were obvious and its influenced factors were complex. [Conclusion] Under the constraints of natural conditions and guided by their social and economic development needs, counties in Liaoning province need to clarify the main functions of the land and promote the regional cooperation on the basis of their own advantages and resource endowment, in order to realize of carbon emission reduction of the whole region.
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[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
[Objective] Under the background of “double carbon”, exploring the carbon emission efficiency of grain production in North China and quantifying its spatial differentiation and dynamic evolution, and analyzing the current situation of carbon emission efficiency of grain production in North China are conducive to promoting green and low-carbon grain production in North China. [Method] The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure the carbon emission and carbon emission efficiency of grain production in North China from 2011 to 2020, and then the Theil index and kernel density estimation were used to explore the regional differences and dynamic evolution of carbon emission efficiency of grain production. [Result] ①During the study period, the carbon emissions of grain production in North China showed an “M” type fluctuation downward trend, but the decline was slow. Among them, the use of chemical fertilizers is the main cause of grain carbon emissions. ②The carbon emission efficiency of grain production in North China showed an evolution trend of decreasing first and then increasing. The average efficiency of the first stage was 0.59. Excluding the influence of environmental variables and random errors on the efficiency value, the average efficiency of the third stage was 0.48, which was 18.6 % lower than the efficiency value of the first stage. Chuzhou, Zhumadian, Dezhou and other places have higher efficiency values, while Huangshan, Weihai and other places have lower efficiency values. ③The spatial difference of carbon emission efficiency of grain production is on the rise, and the regional difference is the main factor affecting the overall difference, among which the difference among cities in Henan Province is the most significant. ④During the investigation period of the sample, the kernel density function. changed from “single peak” to “double peak”, the main peak showed a fluctuating rise and a slight right shift trend, and the side peak uplift was small. [Conclusion] The overall level of carbon emission efficiency of grain production in North China is low, and there are obvious spatial differentiation characteristics. In the future, all regions should reduce the redundancy of material input such as chemical fertilizer, and adopt the strategy of “counterpart assistance ” to promote the benign interaction of grain production technology, so as to narrow the regional differences in carbon emission efficiency of grain production among regions.
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[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
[Objective] To investigate the influence of land use change patterns on the spatial distribution of carbon sinks in the Inner Mongolia section of the Yellow River Basin, and to identify the main driving factors behind, so as to provide a basis for ecological spatial development directions and sink enhancement policies in the study area.[Methods] Taking the Inner Mongolia section of the Yellow River Basin as an example, we used the InVEST-FLUS model to analyze the changes of carbon sink capacity in each period based on land use data in 2000, 2010 and 2020, and simulated the patterns of carbon stock changes in 2040 under three different scenarios of natural development, ecological conservation and agricultural priority, and identified the factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. The main driving factors behind the differences in spatial distribution of carbon sinks are identified with the help of geographic probes. [Results]① From 2000 to 2020, carbon storage in the Mongolian section of the Yellow River Basin increased first and then decreased, with an overall increase of 8.63×106t, in which subsurface biological carbon storage increased by 3.91×106t and soil carbon storage increased by 2.28×106t. ②Carbon storage continued to decrease by 3.92×106t in the future natural development scenario, but increased by 22.1×106t in the ecological protection scenario, which was higher than that of 4.99×106t in the agricultural priority scenario. Soil carbon storage was the key to the incremental difference. ③The unbalanced distribution of annual mean rainfall and annual mean temperature is the main factor that causes the difference of various carbon pools in the Mongolian section of the Yellow River Basin. [Conclusion] Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological high-quality development, and in the future, we should pay attention to desertification prevention and control and promote forest and grassland construction, so as to provide a guarantee for improving the regional ecological security pattern and sink enhancement policies.
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[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
[Objective] To analyze the temporal and spatial characteristics of net carbon emissions from agriculture at the county scale in Fujian Province, with a view to providing a reference basis for the formulation of carbon emission reduction countermeasures in Fujian Province and other provinces and municipalities. [Methods] We constructed an accounting inventory of agricultural carbon emissions based on 12 carbon sources in plantation and livestock industries, and measured the total agricultural carbon emissions by using the carbon emission factor method; selected seven major crops to calculate the carbon uptake by combining with the agricultural characteristics of Fujian Province; and analyzed the spatial and temporal characteristics of the net agricultural carbon emissions in Fujian Province from 2001 to 2020 by using the exploratory spatial analysis method. [Results] ① During the study period, the net carbon emissions showed an inverted "V" trend of first increasing and then decreasing. In terms of carbon sources, carbon emissions from agricultural land use accounted for a larger proportion; in terms of carbon sinks, rice, vegetables and sugarcane contributed more to carbon sequestration. The intensity of agricultural carbon emissions in most counties (cities) showes a decreasing trend, but the average annual decline is small. ② There is a significant global spatial positive correlation of carbon emissions in counties in Fujian Province, showing spatial agglomeration characteristics, and the agglomeration pattern is dominated by high-high and low-low agglomeration. The spatial distribution pattern of the intensity of agricultural carbon emissions changes considerably, with an overall decreasing trend, in which about half of the counties (cities) are in the lower intensity zone. ③ The spatial class distribution pattern of counties (cities) in Fujian Province from 2001 to 2020 has changed to a certain extent, with an increase in the number of medium-emission zones and medium-low-emission zones, and a decrease in the number of high-emission zones, medium-high-emission zones and low-emission zones, and the polarization has been alleviated. [Conclusion] In recent years, most counties inFujian Province have shown a decreasing trend in agricultural carbon emissions and carbon emission intensity, and carbon emission reduction has achieved certain results, but the decline is not large, the future should also be from the policy incentives, optimization of industrial structure and other aspects of the measures taken to strengthen the effect of emission reduction, and to promote the transformation of agriculture low-carbon.
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[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
[Objective] The succession of vegetation community in the process of grassland shrub encroachment will affect the soil organic carbon pool, and the active components of soil organic carbon ( SOC ) can quickly reflect the change of soil organic carbon pool. By exploring the effect of shrub encroachment on the active components of SOC in alpine meadow, it is expected to provide data support for the study of soil organic carbon pool change and carbon sequestration in grassland of Qinghai-Tibet Plateau under the background of global climate change. [Methods] Taking the Caragana erinacea shrub meadow in the Qinghai-Tibet Plateau as the research object, the changes of soil physical and chemical properties, carbon cycle enzyme activities and SOC active components in 0-10 cm, 10-20 cm and 20-40 cm at different shrub encroachment stages ( non-shrub, moderate-shrub and severe-shrub meadow ) were analyzed. [Results] ① The soil water content ( SWC ) in the 0-20 cm soil layer decreased significantly, and the SOC content in each soil layer was the highest in the heavy shrub meadow, and the soil pH increased significantly in the moderate shrub meadow. ② The soil amylase activity ( SAA ) of moderate shrub meadow was significantly lower than that of non-shrub meadow, and the soil sucrase activity ( SSA ) of 10-40 cm soil layer was also significantly lower. SSA was significantly stronger than that of non-shrub meadow in the severe shrub stage. ③Compared with non-shrub meadow, the content of readily oxidizable organic carbon ( ROOC ) in 0-10 cm, 10-20 cm and 20-40 cm of moderate shrub meadow decreased by 16.79 %, 21.73 % and 31.11 %, respectively, and the content of dissolved organic carbon ( DOC ) and microbial biomass carbon ( MBC ) in 0-10 cm soil also decreased significantly. The contents of particulate organic carbon ( POC ) and ROOC in 0-10 cm soil increased significantly by 24.37 % and 29.54 %, respectively. The contents of MBC and DOC in 10-20 cm soil increased significantly by 12.96 % and 10.38 %, respectively. The contents of MBC and DOC in 20-40 cm soil increased significantly by 57.62 % and 22.10 %, respectively. ④ Soil organic carbon active components were significantly positively correlated with TN, SWC, SOC and carbon cycle enzyme activity, and ROOC was significantly negatively correlated with pH. [Conclusion] The content of soil organic carbon active components in the early stage of Caragana erinacea shrub encroachment in the study area decreased, while the soil organic carbon and its active components were accumulated in the later stage of shrub encroachment, which may have a positive effect on the accumulation of soil organic carbon and the improvement of soil quality in this area.
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[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
[Objective] The desertification and its driving factors in Gansu Province was analyzed to provide a scientific basis for the comprehensive prevention and control of desertification and the promotion of ecological projects such as the "Three Norths". [Methods] Trend analysis and spatial autocorrelation analysis were used to characterize the spatial and temporal distribution of desertification in Gansu Province from 2000 to 2022, and geographically and temporally weighted regression was used to analyze the influencing factors. [Results] ○1The overall desertification in Gansu Province presented the characteristics of "desertification in the northwest and greenness in the southeast". The north-west region, which was affected by both wind erosion and salinization, had the most serious desertification, which gradually decreased towards the south-east; the central region, which was affected by soil and water loss, still had a serious degree of desertification; while the south region had a less serious degree of desertification. In terms of time, the degree of desertification in Gansu Province gradually improved during the 23-year period, and the degree of improvement was stronger in the southern region than in the northern region. ○2In terms of spatial autocorrelation, desertification in Gansu Province was mainly characterized by aggregation, i.e., the degree of desertification showed obvious positive spatial correlation. ○3Increased precipitation was most beneficial in mitigating desertification and had a greater impact in the northwest than in the southeast, while wind speed and population exacerbated desertification, and desertification was exacerbated by warmer temperatures in the southwest and vice versa in the rest of the region. [Conclusion] From 2000 to 2022, desertification in Gansu Province showed an improving trend, while desertification in the northwestern part of the province was still serious, and there was obvious spatial and temporal heterogeneity in the drivers of desertification in Gansu Province, and the most important factor affecting desertification was precipitation.
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[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
[Objective]To carry out research on the evaluation of the ecosystem health level of the Gansu section of the Yellow River Basin, and to provide theoretical reference and decision-making basis for the ecological protection and high-quality development of the basin.[Methods] Based on the 2011-2021 panel data, the PSR model was used to construct an ecosystem health evaluation index system for the Gansu section of the Yellow River Basin, the entropy value method and the comprehensive index method were used to comprehensively evaluate the ecosystem health level, and the GM-ARIMA model was used to predict the ecosystem health changes in the next ten years.［Results］(1) From 2011 to 2021, the overall ecosystem health index of each city and state shows an upward trend, with Gannan ecosystem health in the Gannan Yellow River Important Water Supply Ecological Functional Area, in which Gannan ecosystem health is ranked as "inferior", Linxia ecosystem health from "inferior" to "poor", Loess Plateau Area, in which Lanzhou ecosystem health is ranked as "medium" to "good", Tianshui, Dingxi, and Pingliang ecosystem health is from "inferior" to "poor", Baiyin and Qingyang ecosystem health is in the "inferior" range, and Wuwei, a wind-sand comprehensive prevention and control area, has ecosystem health ranked as "inferior"; (2) The projected results of the ecosystem composite index for the period 2022-2031 show an increasing trend, but there is no significant change in the ecosystem health rating.[Conclusion] The overall level of ecosystem health in the Gansu section of the Yellow River Basin is not high, and current ecological protection and environmental improvement measures have not yet fully resolved the challenges facing the region''s ecosystem, which will need to be further strengthened in the future by enhancing regulation and management to improve the health of the region''s ecosystems.
Abstract:
[Objective] Analyzing the spatial-temporal evolution and influencing factors of carbon emissions in Qingdao City is of great significance for ecological protection and high-quality development.[Methods] Based on the land use data, nighttime light data, and social and economic data of Qingdao city from 2000 to 2020, carbon emissions from land use were calculated. By constructing a fitting model between carbon emissions and nighttime light values, the spatial distribution difference and trend of carbon emissions of different land use types in Qingdao city were revealed. The decoupling status between carbon emissions and economic development in Qingdao city was analyzed through the Tapio decoupling model. The contribution degree of various influencing factors of land use carbon emissions was analyzed by using Kaya decomposition and LMDI models. [Results] ①The net carbon emissions from land use in Qingdao city generally showed an increasing trend from 2000 to 2020. From 13,096,400 tons in 2000 to 36.4820 million tons in 2020, an increase of nearly 1.79 times;②The overall carbon emissions in Qingdao city presented a spatial distribution pattern of "high in the middle and low around", and industrial energy consumption was the main source of carbon emissions from construction land, with high carbon emission areas mainly concentrated in the Jiaozhou Bay area;③The relationship between economic development and carbon emissions in Qingdao city has undergone a transition from "expansion link to weak decoupling to strong decoupling";④The factors that promote the growth of carbon emissions in Qingdao are population size and economic effect, and the factors that inhibit the growth of carbon emissions in Qingdao are energy structure and energy intensity. [Conclusion] In the future, it is necessary to further adjust the industrial structure, accelerate the development of a low-carbon economy, and reduce carbon emissions from the source through measures such as technological innovation and energy structure adjustment.
[Objective] Analyzing the spatial-temporal evolution and influencing factors of carbon emissions in Qingdao City is of great significance for ecological protection and high-quality development.[Methods] Based on the land use data, nighttime light data, and social and economic data of Qingdao city from 2000 to 2020, carbon emissions from land use were calculated. By constructing a fitting model between carbon emissions and nighttime light values, the spatial distribution difference and trend of carbon emissions of different land use types in Qingdao city were revealed. The decoupling status between carbon emissions and economic development in Qingdao city was analyzed through the Tapio decoupling model. The contribution degree of various influencing factors of land use carbon emissions was analyzed by using Kaya decomposition and LMDI models. [Results] ①The net carbon emissions from land use in Qingdao city generally showed an increasing trend from 2000 to 2020. From 13,096,400 tons in 2000 to 36.4820 million tons in 2020, an increase of nearly 1.79 times;②The overall carbon emissions in Qingdao city presented a spatial distribution pattern of "high in the middle and low around", and industrial energy consumption was the main source of carbon emissions from construction land, with high carbon emission areas mainly concentrated in the Jiaozhou Bay area;③The relationship between economic development and carbon emissions in Qingdao city has undergone a transition from "expansion link to weak decoupling to strong decoupling";④The factors that promote the growth of carbon emissions in Qingdao are population size and economic effect, and the factors that inhibit the growth of carbon emissions in Qingdao are energy structure and energy intensity. [Conclusion] In the future, it is necessary to further adjust the industrial structure, accelerate the development of a low-carbon economy, and reduce carbon emissions from the source through measures such as technological innovation and energy structure adjustment.
Abstract:
[Objective]Within the framework of the dual carbon target vision, addressing the scale effects of forest land changes and quantifying the carbon sequestration benefits at multiple watershed levels not only introduce a fresh perspective into forest land research but also aid in cording and optimizing the forest land pattern. That holds great significance in enhancing future regional carbon sequestration potential.[Methods]Focusing on Chongqing as the study area, we analyzed the spatiotemporal dynamic changes in forest land and carbon storage from 2000 to 2030 at the multi-watershed scale, utilizing PLUS model, landscape pattern indices, biomass expansion factor method and grey correlation degree. Furthermore, we explored the correlation between forest land pattern changes and carbon storage under natural development scenarios.[Results](1)Between 2000 and 2020,the forest area increased by 3404.55 km2,primarily due to the conversion of cultivated land. The forest landscape pattern in the first-grade watershed showed a tendency towards clustering and regularity, with a relatively reduced degree of fragmentation. There were distinct differences in the historical laws and future trends of forest landscape pattern changes in the secondary watershed’s “district and group”.(2)In the initial two decades, the carbon storage of forest land exhibited an increasing-decreasing trend, resulting in an overall increase. The Dongting Lake system in the first level basin witnessed the highest increase in carbon storage, and the high-value area of carbon storage increment in the seconde level basin shifted from north to south.(3)The total carbon storage is predicted to increase by 2030 which is strongly correlated with the irregular index. The scale effect leads to the spatial heterogeneity of landscape pattern change and the correlation degree between landscape pattern index and carbon storage in the primary and secondary basins.[Conclusion]The research outcome contribute to understanding the patterns of forest land changes from a cross-watershed scale perspective. This, in turn, provides a scientific foundation for the Ministry of Natural Resource or relevant forestry departments to formulate effective utilization and protection policies for forest land resources at different scales, It also supports the sustainable development of Chongqing, enhances carbon sink efficiency, and facilitates the achievement of carbon neutrality goals.
[Objective]Within the framework of the dual carbon target vision, addressing the scale effects of forest land changes and quantifying the carbon sequestration benefits at multiple watershed levels not only introduce a fresh perspective into forest land research but also aid in cording and optimizing the forest land pattern. That holds great significance in enhancing future regional carbon sequestration potential.[Methods]Focusing on Chongqing as the study area, we analyzed the spatiotemporal dynamic changes in forest land and carbon storage from 2000 to 2030 at the multi-watershed scale, utilizing PLUS model, landscape pattern indices, biomass expansion factor method and grey correlation degree. Furthermore, we explored the correlation between forest land pattern changes and carbon storage under natural development scenarios.[Results](1)Between 2000 and 2020,the forest area increased by 3404.55 km2,primarily due to the conversion of cultivated land. The forest landscape pattern in the first-grade watershed showed a tendency towards clustering and regularity, with a relatively reduced degree of fragmentation. There were distinct differences in the historical laws and future trends of forest landscape pattern changes in the secondary watershed’s “district and group”.(2)In the initial two decades, the carbon storage of forest land exhibited an increasing-decreasing trend, resulting in an overall increase. The Dongting Lake system in the first level basin witnessed the highest increase in carbon storage, and the high-value area of carbon storage increment in the seconde level basin shifted from north to south.(3)The total carbon storage is predicted to increase by 2030 which is strongly correlated with the irregular index. The scale effect leads to the spatial heterogeneity of landscape pattern change and the correlation degree between landscape pattern index and carbon storage in the primary and secondary basins.[Conclusion]The research outcome contribute to understanding the patterns of forest land changes from a cross-watershed scale perspective. This, in turn, provides a scientific foundation for the Ministry of Natural Resource or relevant forestry departments to formulate effective utilization and protection policies for forest land resources at different scales, It also supports the sustainable development of Chongqing, enhances carbon sink efficiency, and facilitates the achievement of carbon neutrality goals.
Abstract:
[Objective] To In order to better monitor and evaluate the ecological quality of hilly areas, it is necessary to construct a accurate remote sensing ecological index of middle and high vegetation areas, and explore the influencing factors of its ecological quality, so as to provide scientific support for the balance between development and ecology in Taojiang County. [Method] To address the saturation issue of the Normalized Difference Vegetation Index (NDVI) in densely vegetated areas, this study introduces the kernel Normalized Difference Vegetation Index (kNDVI) and integrates it with humidity, dryness, and heat factors to formulate a Modified Remote Sensing Ecology Index (MRSEI). Utilizing this index, the ecological environment quality and its temporal variation in Taojiang County from 2000 to 2021 were quantified. Additionally, a parameter optimized geographic detector model was employed to analyze the driving forces of six influencing factors, including vegetation coverage, precipitation, temperature, land use, altitude, and population density. [Result] (1) Compared with the RSEI model, the MRSEI model can effectively address the issue of NDVI saturation in areas with high vegetation cover, enabling a more precise monitoring of the ecological environment in Taojiang County; (2) The average RSEI values for the five periods from 2000 to 2021 in the study area were 0.77, 0.84, 0.83, 0.75 and 0.79, respectively, indicating a satisfactory performance in ecological environment quality with a trend of improvement-deterioration-improvement; (3) From the analysis of the factors influencing ecological environment quality, land use emerges as a key factor determinant in the study area. In the factor interactive detection analysis, the interaction between land use and elevation were strongest. [Conclusion] In summary, variation of the ecological environment quality in Taojiang County is primarily influenced by a combination of natural and anthropogenic factors. The research results can provide technical reference for carrying out effective ecological environment protection and restoration measures in Taojiang County.
[Objective] To In order to better monitor and evaluate the ecological quality of hilly areas, it is necessary to construct a accurate remote sensing ecological index of middle and high vegetation areas, and explore the influencing factors of its ecological quality, so as to provide scientific support for the balance between development and ecology in Taojiang County. [Method] To address the saturation issue of the Normalized Difference Vegetation Index (NDVI) in densely vegetated areas, this study introduces the kernel Normalized Difference Vegetation Index (kNDVI) and integrates it with humidity, dryness, and heat factors to formulate a Modified Remote Sensing Ecology Index (MRSEI). Utilizing this index, the ecological environment quality and its temporal variation in Taojiang County from 2000 to 2021 were quantified. Additionally, a parameter optimized geographic detector model was employed to analyze the driving forces of six influencing factors, including vegetation coverage, precipitation, temperature, land use, altitude, and population density. [Result] (1) Compared with the RSEI model, the MRSEI model can effectively address the issue of NDVI saturation in areas with high vegetation cover, enabling a more precise monitoring of the ecological environment in Taojiang County; (2) The average RSEI values for the five periods from 2000 to 2021 in the study area were 0.77, 0.84, 0.83, 0.75 and 0.79, respectively, indicating a satisfactory performance in ecological environment quality with a trend of improvement-deterioration-improvement; (3) From the analysis of the factors influencing ecological environment quality, land use emerges as a key factor determinant in the study area. In the factor interactive detection analysis, the interaction between land use and elevation were strongest. [Conclusion] In summary, variation of the ecological environment quality in Taojiang County is primarily influenced by a combination of natural and anthropogenic factors. The research results can provide technical reference for carrying out effective ecological environment protection and restoration measures in Taojiang County.
Abstract:
[Objective] In order to understand the effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after highway project disturbance in alpine wetland, we aim to provide theoretical reference basis for the screening of vegetation restoration model in alpine wetland, the management of soil erosion and the improvement of ecological environment. [Method] The three treatment slopes of natural succession, spraying grass planting and turf mulching and the original undisturbed control vegetation were taken as the research objects, and the soil physicochemical indexes and soil enzyme activities were measured to analyze their interrelationships and influencing factors. [Result] 1) All three restoration measures resulted in a significant increase (P<0.05) in soil pH and total potassium, and a significant decrease (P<0.05) in soil organic matter, total nitrogen, total phosphorus, and fine root biomass compared to the control; effective phosphorus increased and quick-acting potassium decreased compared to the control; the proportion of clayey silt particles in soil particles of the natural succession was not significantly different from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) in the spraying of grasses and turf mulch treatment; the turf mulch richness index did not differ significantly from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) under spraying of grasses and natural succession. The proportion of sticky powder particles in soil particles in the natural succession was not significantly different from that of the control, and the proportion of sticky powder particles in soil particles in the spraying and sodding treatments was significantly lower (P<0.05); the richness indices of sodding were not significantly different from that of the control, and those of spraying and sodding were significantly lower than that of the control (P<0.05), and the soil pH, organic matter, total nitrogen, quick-acting potassium, fine root biomass, and their richness indices in the sodding and sodding treatments were higher than those in the natural succession (P<0.05).2) Sprayed grass and turf replanting restored the four soil enzymes better than natural succession, and even catalase activity was restored to near control levels. 3)The correlation between the four enzyme activities and soil physicochemical properties was significant, and the urease activity was the most sensitive to soil physicochemical properties, which was able to evaluate the soil fertility of plateau wetland slope well. [Conclusion] Compared with natural succession, spraying grass and turf can effectively improve soil physicochemical properties and soil enzyme activity, and soil enzyme can be used as a sensitive indicator for evaluating soil fertility on slopes in plateau wetlands.
[Objective] In order to understand the effects of soil physicochemical properties and enzyme activities on slopes under different restoration measures after highway project disturbance in alpine wetland, we aim to provide theoretical reference basis for the screening of vegetation restoration model in alpine wetland, the management of soil erosion and the improvement of ecological environment. [Method] The three treatment slopes of natural succession, spraying grass planting and turf mulching and the original undisturbed control vegetation were taken as the research objects, and the soil physicochemical indexes and soil enzyme activities were measured to analyze their interrelationships and influencing factors. [Result] 1) All three restoration measures resulted in a significant increase (P<0.05) in soil pH and total potassium, and a significant decrease (P<0.05) in soil organic matter, total nitrogen, total phosphorus, and fine root biomass compared to the control; effective phosphorus increased and quick-acting potassium decreased compared to the control; the proportion of clayey silt particles in soil particles of the natural succession was not significantly different from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) in the spraying of grasses and turf mulch treatment; the turf mulch richness index did not differ significantly from the control, and the proportion of clayey silt particles in soil particles was significantly lower (P<0.05) under spraying of grasses and natural succession. The proportion of sticky powder particles in soil particles in the natural succession was not significantly different from that of the control, and the proportion of sticky powder particles in soil particles in the spraying and sodding treatments was significantly lower (P<0.05); the richness indices of sodding were not significantly different from that of the control, and those of spraying and sodding were significantly lower than that of the control (P<0.05), and the soil pH, organic matter, total nitrogen, quick-acting potassium, fine root biomass, and their richness indices in the sodding and sodding treatments were higher than those in the natural succession (P<0.05).2) Sprayed grass and turf replanting restored the four soil enzymes better than natural succession, and even catalase activity was restored to near control levels. 3)The correlation between the four enzyme activities and soil physicochemical properties was significant, and the urease activity was the most sensitive to soil physicochemical properties, which was able to evaluate the soil fertility of plateau wetland slope well. [Conclusion] Compared with natural succession, spraying grass and turf can effectively improve soil physicochemical properties and soil enzyme activity, and soil enzyme can be used as a sensitive indicator for evaluating soil fertility on slopes in plateau wetlands.
Abstract:
[Objective] This study explores the effects of long-term Caragana korshinskii (C. korshinskii) plantation on the stability of soil aggregates and erodibility on the loess hilly slopes, providing theoretical support for artificial vegetation construction and ecological restoration in the Loess Plateau region. [Methods] Grassy slope was used as a comparison, C. korshinskii plots with different plantation durations (15, 25, 35 years) along contour lines on slopes were selected as research subjects. The study analyzed the characteristics of changes in soil aggregate stability and erodibility due to long-term C. korshinskii plantation, as well as the main influencing factors. [Results] (1) The soil aggregate stability indicators, mean weight diameter (MWD), geometric mean diameter (GMD), and the content of aggregates >0.25 mm (WR0.25), generally showed a trend of 15-year C. korshinskii plantation > barren grassy land > 25-year C. korshinskii plantation > 35-year C. korshinskii plantation. In terms of slope position, the order was bottom slope > top slope > mid-slope > upper slope. Conversely, the soil erodibility K factor exhibited an opposite trend. (2) With the increase in the plantation duration of C. korshinskii compared to barren grassy land, soil aggregate stability indicators initially increased and then decreased, while the stability in the intervals of barren grassy strips continuously declined. The difference between the two became more pronounced after the plantation duration exceeded 15 years, especially at the bottom slope. (3) Soil organic carbon and slope position were the main factors influencing the soil aggregation stability and erodibility on the slope, explaining 38% and 4.1% of the variation, respectively, followed by planting duration and altitude. [Conclusion] Strip plantation of C. korshinskii on the loess hilly slopes affects the distribution of soil organic carbon, thereby influencing soil aggregate stability and erodibility. Plantation for less than 15 years contributes to the improvement of soil aggregate stability and the reduction of erodibility, but a reverse trend gradually emerges with more extended plantation, particularly at the bottom slope locations.
[Objective] This study explores the effects of long-term Caragana korshinskii (C. korshinskii) plantation on the stability of soil aggregates and erodibility on the loess hilly slopes, providing theoretical support for artificial vegetation construction and ecological restoration in the Loess Plateau region. [Methods] Grassy slope was used as a comparison, C. korshinskii plots with different plantation durations (15, 25, 35 years) along contour lines on slopes were selected as research subjects. The study analyzed the characteristics of changes in soil aggregate stability and erodibility due to long-term C. korshinskii plantation, as well as the main influencing factors. [Results] (1) The soil aggregate stability indicators, mean weight diameter (MWD), geometric mean diameter (GMD), and the content of aggregates >0.25 mm (WR0.25), generally showed a trend of 15-year C. korshinskii plantation > barren grassy land > 25-year C. korshinskii plantation > 35-year C. korshinskii plantation. In terms of slope position, the order was bottom slope > top slope > mid-slope > upper slope. Conversely, the soil erodibility K factor exhibited an opposite trend. (2) With the increase in the plantation duration of C. korshinskii compared to barren grassy land, soil aggregate stability indicators initially increased and then decreased, while the stability in the intervals of barren grassy strips continuously declined. The difference between the two became more pronounced after the plantation duration exceeded 15 years, especially at the bottom slope. (3) Soil organic carbon and slope position were the main factors influencing the soil aggregation stability and erodibility on the slope, explaining 38% and 4.1% of the variation, respectively, followed by planting duration and altitude. [Conclusion] Strip plantation of C. korshinskii on the loess hilly slopes affects the distribution of soil organic carbon, thereby influencing soil aggregate stability and erodibility. Plantation for less than 15 years contributes to the improvement of soil aggregate stability and the reduction of erodibility, but a reverse trend gradually emerges with more extended plantation, particularly at the bottom slope locations.
Abstract:
［Objective］To explore the effects of snow removal during freezing-thawing period on soil organic carbon components and carbon pool stability in Bayanbulak alpine wetland. ［Methods］A field experiment was conducted in September 2022, with two treatments: snow removal and natural snowfall. The samples were collected during the initial freezing period (November), freezing period (March), and thawing period (July) of the freezing-thawing period, and the soil water content (SWC), electrical conductivity (EC), pH value, soil organic carbon (SOC), very unstable organic carbon (F1), unstable organic carbon (F2), stable organic carbon (F3), and inert organic carbon (F4) were determined. ［Results］There were significant differences in the organic carbon content of F1 and F2 components after snow removal in the initial freezing period (P<0.05), compared with the natural snowfall, the organic carbon content of the two components decreased by 8.72% and 12.26%, respectively. There were significant differences in the organic carbon content of F3 components between different treatments in the freezing period (P<0.05), and the organic carbon content of F3 components decreased by 25.57% after snow removal. There were significant differences in the organic carbon content of F1, F2 and F3 in the thawing period (P<0.05), among which F1 and F3 decreased by 22.10% and 25.57%, respectively, and F2 increased by 34.92%, while there were no significant differences in other components. After snow removal, compared with the natural snowfall treatment, the carbon pool activity increased by 5.99%, 9.71% and 20.39% in the three periods, respectively.［Conclusion］The freeze-thaw cycle and snow removal had no significant effect on the organic carbon content and carbon pool stability, but the effect of snow removal on soil was greater than the freeze-thaw change. Snow removal led to the decrease of soil organic carbon content and the increase of soil organic carbon pool stability, which affected the original stable relationship between soil organic carbon components. With the freeze-thaw process, the soil organic carbon content showed a trend of first decrease and then increase, while the soil carbon pool stability showed a trend of first increase and then decrease.
［Objective］To explore the effects of snow removal during freezing-thawing period on soil organic carbon components and carbon pool stability in Bayanbulak alpine wetland. ［Methods］A field experiment was conducted in September 2022, with two treatments: snow removal and natural snowfall. The samples were collected during the initial freezing period (November), freezing period (March), and thawing period (July) of the freezing-thawing period, and the soil water content (SWC), electrical conductivity (EC), pH value, soil organic carbon (SOC), very unstable organic carbon (F1), unstable organic carbon (F2), stable organic carbon (F3), and inert organic carbon (F4) were determined. ［Results］There were significant differences in the organic carbon content of F1 and F2 components after snow removal in the initial freezing period (P<0.05), compared with the natural snowfall, the organic carbon content of the two components decreased by 8.72% and 12.26%, respectively. There were significant differences in the organic carbon content of F3 components between different treatments in the freezing period (P<0.05), and the organic carbon content of F3 components decreased by 25.57% after snow removal. There were significant differences in the organic carbon content of F1, F2 and F3 in the thawing period (P<0.05), among which F1 and F3 decreased by 22.10% and 25.57%, respectively, and F2 increased by 34.92%, while there were no significant differences in other components. After snow removal, compared with the natural snowfall treatment, the carbon pool activity increased by 5.99%, 9.71% and 20.39% in the three periods, respectively.［Conclusion］The freeze-thaw cycle and snow removal had no significant effect on the organic carbon content and carbon pool stability, but the effect of snow removal on soil was greater than the freeze-thaw change. Snow removal led to the decrease of soil organic carbon content and the increase of soil organic carbon pool stability, which affected the original stable relationship between soil organic carbon components. With the freeze-thaw process, the soil organic carbon content showed a trend of first decrease and then increase, while the soil carbon pool stability showed a trend of first increase and then decrease.
Abstract:
[Objective] A large number of red clay slopes exist in Guizhou Province, and soil erosion and shallow landslides are prominent problems. The use of herbaceous plants to protect red clay slopes is of great significance for shallow landslide management and soil and water conservation in Guizhou Province, but there are fewer related studies. [Methods] With red clay slope as the research object, Cynodon dactylon and Vetiver grass were selected as slope protection plants. The slope protection effect of the two herbaceous plants was investigated through planting test, root tensile test, straight shear test, and indoor simulated scouring test. [Results] ① Within 150 days of planting, both herbaceous plants grew steadily and the tensile strength of the root system continued to increase. From 30 to 150 days of growth, the maximum tensile strength of Cynodon dactylon increased from 0.84N to 8.59N, and that of Vetiver grass increased from 4.78N to 89.89N. ② Comparing the rootless soil at 120 days of growth, the cohesion of Cynodon dactylon root-soil complex increased by 91.1% and the angle of internal friction by 12.45%; the cohesion of Vetiver grass root-soil complex increased by 107.47% and the angle of internal friction by 12.74%. ③ Comparing the bare slope at 150 days of growth, the runoff rate of Cynodon dactylon slope decreased by 45.02% to 54.15%, the sediment yield rate decreased by 58.3% to 93.85%, and the 60-min cumulative sediment yield decreased by 81.02%; the runoff rate of Vetiver grass slope decreased by 35.46% to 46.48%, the sediment yield decreased rate by 46.8% to 89.44%, and the 60-min cumulative sediment yield decreased by 74.61%. [Conclusion] Both herbaceous plants have excellent soil consolidation and slope protection effects on red clay slopes, with Vetiver grass having a more pronounced effect on the increase in soil shear strength, and Cynodon dactylon having a more significant effect on soil and water conservation.
[Objective] A large number of red clay slopes exist in Guizhou Province, and soil erosion and shallow landslides are prominent problems. The use of herbaceous plants to protect red clay slopes is of great significance for shallow landslide management and soil and water conservation in Guizhou Province, but there are fewer related studies. [Methods] With red clay slope as the research object, Cynodon dactylon and Vetiver grass were selected as slope protection plants. The slope protection effect of the two herbaceous plants was investigated through planting test, root tensile test, straight shear test, and indoor simulated scouring test. [Results] ① Within 150 days of planting, both herbaceous plants grew steadily and the tensile strength of the root system continued to increase. From 30 to 150 days of growth, the maximum tensile strength of Cynodon dactylon increased from 0.84N to 8.59N, and that of Vetiver grass increased from 4.78N to 89.89N. ② Comparing the rootless soil at 120 days of growth, the cohesion of Cynodon dactylon root-soil complex increased by 91.1% and the angle of internal friction by 12.45%; the cohesion of Vetiver grass root-soil complex increased by 107.47% and the angle of internal friction by 12.74%. ③ Comparing the bare slope at 150 days of growth, the runoff rate of Cynodon dactylon slope decreased by 45.02% to 54.15%, the sediment yield rate decreased by 58.3% to 93.85%, and the 60-min cumulative sediment yield decreased by 81.02%; the runoff rate of Vetiver grass slope decreased by 35.46% to 46.48%, the sediment yield decreased rate by 46.8% to 89.44%, and the 60-min cumulative sediment yield decreased by 74.61%. [Conclusion] Both herbaceous plants have excellent soil consolidation and slope protection effects on red clay slopes, with Vetiver grass having a more pronounced effect on the increase in soil shear strength, and Cynodon dactylon having a more significant effect on soil and water conservation.
Abstract:
［Objective］This study aims to investigate the soil runoff characteristics on the southern slopes of the Taihang Mountains and explore the influencing factors. The goal is to provide scientific basis for soil erosion control and ecological environment protection in the southern foothills of the Taihang Mountains. ［Methods］The study focuses on the fish scale pits and natural barren slopes on the southern foothills of the Taihang Mountains. The runoff characteristics on the slopes under different vegetation types including herbs, shrubs, and trees were measured, and the influencing factors were analyzed. The geographic detector statistical method was used to quantify the individual and interactive effects of various factors on slope runoff. ［Results］The results indicate the following: (1) There was no significant difference in the average runoff depth between herb, shrub, and tree communities on the fish scale pits. However, the average runoff depth of the shrub and herb communities on the natural barren slopes was significantly greater than that of the tree community. Compared to the natural barren slopes, the average runoff depth decreased by 56.61%, 72.80%, and 39.58% in the herb, shrub, and tree communities on the fish scale pits, respectively. The average runoff depth showed a decreasing trend with increasing gravel content. The control effect of gravel coverage on slope runoff had a threshold, and the minimum slope runoff depth was observed when the gravel coverage ranged from 6% to 9%. (2) The single-factor influence of gravel coverage (0.31) was the highest on slope runoff in the southern foothills of the Taihang Mountains, followed by vegetation coverage (0.29). (3) The interaction of slope runoff influencing factors mostly exhibited nonlinear enhancement and dual-factor enhancement effects. The interaction between rainfall and non-rainfall factors showed nonlinear enhancement effects. ［Conclusion］The presence of a large amount of gravel contributes to the complexity of slope runoff processes in the southern foothills of the Taihang Mountains. Increasing vegetation coverage is an important measure to reduce slope runoff in this region.
［Objective］This study aims to investigate the soil runoff characteristics on the southern slopes of the Taihang Mountains and explore the influencing factors. The goal is to provide scientific basis for soil erosion control and ecological environment protection in the southern foothills of the Taihang Mountains. ［Methods］The study focuses on the fish scale pits and natural barren slopes on the southern foothills of the Taihang Mountains. The runoff characteristics on the slopes under different vegetation types including herbs, shrubs, and trees were measured, and the influencing factors were analyzed. The geographic detector statistical method was used to quantify the individual and interactive effects of various factors on slope runoff. ［Results］The results indicate the following: (1) There was no significant difference in the average runoff depth between herb, shrub, and tree communities on the fish scale pits. However, the average runoff depth of the shrub and herb communities on the natural barren slopes was significantly greater than that of the tree community. Compared to the natural barren slopes, the average runoff depth decreased by 56.61%, 72.80%, and 39.58% in the herb, shrub, and tree communities on the fish scale pits, respectively. The average runoff depth showed a decreasing trend with increasing gravel content. The control effect of gravel coverage on slope runoff had a threshold, and the minimum slope runoff depth was observed when the gravel coverage ranged from 6% to 9%. (2) The single-factor influence of gravel coverage (0.31) was the highest on slope runoff in the southern foothills of the Taihang Mountains, followed by vegetation coverage (0.29). (3) The interaction of slope runoff influencing factors mostly exhibited nonlinear enhancement and dual-factor enhancement effects. The interaction between rainfall and non-rainfall factors showed nonlinear enhancement effects. ［Conclusion］The presence of a large amount of gravel contributes to the complexity of slope runoff processes in the southern foothills of the Taihang Mountains. Increasing vegetation coverage is an important measure to reduce slope runoff in this region.
Abstract:
Abstract：[Objective] To support building a low-carbon agricultural model, promoting agricultural carbon reduction and high-quality regional agriculture development. [Methods] The estimation model of carbon emission from cultivated land and ArcGIS calculation were used to analyze the temporal and spatial characteristics of carbon emission from cultivated land in the urban belt along the Yellow River in Ningxia, and the unexpected output super-efficiency model (SBM) was used to evaluate the ecological efficiency of cultivated land. [Results] (1) The total carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia showed an overall downward trend from 2011 to 2020, and chemical fertilizer and agricultural diesel were the primary sources of carbon emission from cultivated land. (2) The carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia shows a spatial distribution pattern of high in the north-south and low in the middle. Pingluo County and Zhongning County are the largest cultivated land carbon emission cities. (3) The trend of carbon emission intensity of cultivated land in the urban belt along the Yellow River in Ningxia is similar to that of cultivated land. (4) The ecological efficiency of cultivated land use in the urban belt along the Yellow River in Ningxia fluctuates as a whole, and the ecological efficiency of cultivated land in the Litong area is low, so it is necessary to adjust the input factors in the agricultural production process. [Conclusion] To study the temporal and spatial evolution characteristics of carbon emission and ecological efficiency of cultivated land in the urban belt along the Yellow River in Ningxia and explore their key influencing factors. The relevant conclusions can provide a reference for the construction of low-carbon agriculture and accurate policy implementation in Ningxia.
Abstract：[Objective] To support building a low-carbon agricultural model, promoting agricultural carbon reduction and high-quality regional agriculture development. [Methods] The estimation model of carbon emission from cultivated land and ArcGIS calculation were used to analyze the temporal and spatial characteristics of carbon emission from cultivated land in the urban belt along the Yellow River in Ningxia, and the unexpected output super-efficiency model (SBM) was used to evaluate the ecological efficiency of cultivated land. [Results] (1) The total carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia showed an overall downward trend from 2011 to 2020, and chemical fertilizer and agricultural diesel were the primary sources of carbon emission from cultivated land. (2) The carbon emission of cultivated land in the urban belt along the Yellow River in Ningxia shows a spatial distribution pattern of high in the north-south and low in the middle. Pingluo County and Zhongning County are the largest cultivated land carbon emission cities. (3) The trend of carbon emission intensity of cultivated land in the urban belt along the Yellow River in Ningxia is similar to that of cultivated land. (4) The ecological efficiency of cultivated land use in the urban belt along the Yellow River in Ningxia fluctuates as a whole, and the ecological efficiency of cultivated land in the Litong area is low, so it is necessary to adjust the input factors in the agricultural production process. [Conclusion] To study the temporal and spatial evolution characteristics of carbon emission and ecological efficiency of cultivated land in the urban belt along the Yellow River in Ningxia and explore their key influencing factors. The relevant conclusions can provide a reference for the construction of low-carbon agriculture and accurate policy implementation in Ningxia.
Abstract:
[Objective]This study aims to analyze the carbon emission characteristics and driving factors of agriculture and animal husbandry in Qinghai Province, and to provide theoretical and empirical evidence for Qinghai government on how to promote scientifically and orderly the green and low-carbon development of agriculture and animal husbandry.[Methods] Carbon emissions from agriculture and animal husbandry in Qinghai Province during 2000 to 2021 are calculated from consumption of agricultural materials, livestock and poultry breeding, and crop growth. The methods of LMDI and Tapio decoupling models are used to examine the driving factors and decoupling state of carbon emissions from agriculture and animal husbandry, and the future development tendency from 2022 to 2035 is predicted.[Results]①Carbon emissions from agriculture and animal husbandry in Qinghai Province shows a fluctuating upward trend during 2000 to 2021, with an average annual growth rate of 1.61%. Intestinal fermentation and manure management during livestock and poultry breeding are the main sources of carbon emissions, accounting for 94.94% per year.②The effect of the level of agricultural economic development and agricultural structure can increase the carbon emissions, with the annual contribution rates of 39.40% and 16.53%; The effect of agricultural production technology and agricultural labor force can inhibit the carbon emissions , with the annual contribution rates of -37.45% and -6.63%.③On the whole, the decoupling state between carbon emissions and economic growth of agricultural and animal husbandry in Qinghai Province is in weak decoupling. Agricultural production technology and agricultural labor force scale have weak decoupling efforts, while agricultural structure has no decoupling efforts.④From 2022 to 2035, the carbon emissions from agriculture and animal husbandry shows an increasing trend, with an average annual growth rate of 1.23%, and 0.38% lower than that from 2000 to 2021.[Conclusion]: This study contributes to call the attention of Qinghai government and relevant authorities to achieve low-carbon development in agriculture and animal husbandry. Some useful suggestions are put forward as follows: enhance the carbon sequestration capacity of farmland soil, reduce the intensity of intestinal methane emissions from livestock and poultry products, strengthen the leadership of carbon reduction and fixation technology in agriculture and animal husbandry, cultivate high-quality talents in agriculture and animal husbandry.
[Objective]This study aims to analyze the carbon emission characteristics and driving factors of agriculture and animal husbandry in Qinghai Province, and to provide theoretical and empirical evidence for Qinghai government on how to promote scientifically and orderly the green and low-carbon development of agriculture and animal husbandry.[Methods] Carbon emissions from agriculture and animal husbandry in Qinghai Province during 2000 to 2021 are calculated from consumption of agricultural materials, livestock and poultry breeding, and crop growth. The methods of LMDI and Tapio decoupling models are used to examine the driving factors and decoupling state of carbon emissions from agriculture and animal husbandry, and the future development tendency from 2022 to 2035 is predicted.[Results]①Carbon emissions from agriculture and animal husbandry in Qinghai Province shows a fluctuating upward trend during 2000 to 2021, with an average annual growth rate of 1.61%. Intestinal fermentation and manure management during livestock and poultry breeding are the main sources of carbon emissions, accounting for 94.94% per year.②The effect of the level of agricultural economic development and agricultural structure can increase the carbon emissions, with the annual contribution rates of 39.40% and 16.53%; The effect of agricultural production technology and agricultural labor force can inhibit the carbon emissions , with the annual contribution rates of -37.45% and -6.63%.③On the whole, the decoupling state between carbon emissions and economic growth of agricultural and animal husbandry in Qinghai Province is in weak decoupling. Agricultural production technology and agricultural labor force scale have weak decoupling efforts, while agricultural structure has no decoupling efforts.④From 2022 to 2035, the carbon emissions from agriculture and animal husbandry shows an increasing trend, with an average annual growth rate of 1.23%, and 0.38% lower than that from 2000 to 2021.[Conclusion]: This study contributes to call the attention of Qinghai government and relevant authorities to achieve low-carbon development in agriculture and animal husbandry. Some useful suggestions are put forward as follows: enhance the carbon sequestration capacity of farmland soil, reduce the intensity of intestinal methane emissions from livestock and poultry products, strengthen the leadership of carbon reduction and fixation technology in agriculture and animal husbandry, cultivate high-quality talents in agriculture and animal husbandry.
WANG Jingzheng, ZHAO Chuanchuan, WANG Yuqin, XIE Linghua, WANG Yuqin, WANG Jiayi, ZHANG Sha, JIA Dongjin
Abstract:
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott''s second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
[Objective] This study aims to investigate the improvement effect of cellulose-based soil amendments prepared from corn cob and humic acid on the erosion resistance of sandy soil. [Methods] One or two mixtures of laccase and lignin peroxidase, three enzyme activity gradient levels, two corn cob addition masses, and a fixed amount of humic acid, were set to synthesize cellulose-based soil amendments through an aqueous solution polymerization method. Meantime, the characteristics of enzymatic hydrolysis products and functional groups of amendments were performed using infrared spectroscopy. The water retention capacity and network characteristics of the amendments were analyzed based on their swelling characteristics. In addition, the improvement effect of amendments on the erosion resistance of sandy soil was also evaluated based on the parameters related to mechanical and water stable aggregates. [Results] (1) The water absorbency of the cellulose-based soil amendments was about 0.61-4.84 times that of pure humic acid based amendments. In which, the soil amendment prepared by adding 4 g of enzymatic hydrolysis products of laccase (20 U) and lignin peroxidase (20 U) hydrolysate, had the highest water absorbency with a value of 66.7 g/g. The swelling process of the soil amendment corresponded to Schott''s second-order kinetic model. (2) Compared to the control group (CK) , the addition of 1% amendments (Lac3-4, Lip3-4 and LLP3-4) synthesized by the three different enzymatic hydrolysis schemes increased the soil saturated water content by 20%-60%. LLP3-4 can increase the content of mechanical large aggregates and water stable large aggregates (>0.25 mm) by 6.15 and 14 times, increase the average weight diameter and geometric average diameter of soil by 45% and 46.67%, and reduce the fractal dimension by 21.36%, respectively. [Conclusion] Cellulose-based soil amendments prepared by dual enzyme pretreatment scheme can significantly enhance the water retention capacity and corrosion resistance of sandy soil.
Abstract:
[Purpose] The proposal of the dual carbon target has put forward higher requirements for the development of agriculture in China. This study takes the Beijing Tianjin Hebei region as the research object, divides the region into six major agricultural regions based on agricultural carbon emissions, and proposes corresponding emission reduction optimization paths, aiming to provide policy recommendations for the development of low-carbon agriculture in the Beijing Tianjin Hebei region Method: This study calculated agricultural carbon emissions based on the IPCC guidelines, and used trend analysis to study the linear changes in agricultural carbon emissions in the Beijing Tianjin Hebei region. ArcGIS breakpoint analysis and kernel density method were used to analyze the spatial evolution trends of the six major agricultural regions in the Beijing Tianjin Hebei region The study found that, in terms of time, the overall carbon emissions and carbon intensity of agriculture in the Beijing Tianjin Hebei region have shown a downward trend, especially the carbon emission intensity, which has been rapidly decreasing since 2005. Compared with the whole country, although the proportion of total agricultural carbon emissions is small, the carbon emission intensity is higher than the national level, with the highest carbon emission levels in the Bashang Agricultural Zone and the Jinan Agricultural Zone. From a spatial perspective, the northern part of the Bashang Agricultural Area, far from Beijing and Tianjin, as well as some counties in the Central Plains and Southern Hebei Agricultural Areas, have higher carbon emission intensity. However, the suburban agricultural area of Beijing and Tianjin, as well as the southern part of the adjacent Bashang Agricultural Area, maintain a light and low emission state. In addition, according to the results of nuclear density analysis, the overall carbon emission intensity of the six major agricultural regions is decreasing, with a greater degree of internal differentiation in carbon emission intensity between the Beijing Tianjin suburban agricultural region and the Hebei Central Plain agricultural region Conclusion: Based on the research results, an optimization path for carbon reduction in the Beijing Tianjin Hebei region is proposed from four aspects: agricultural positioning, resource sharing, carbon reduction and sink enhancement, and cross industry cooperation.
[Purpose] The proposal of the dual carbon target has put forward higher requirements for the development of agriculture in China. This study takes the Beijing Tianjin Hebei region as the research object, divides the region into six major agricultural regions based on agricultural carbon emissions, and proposes corresponding emission reduction optimization paths, aiming to provide policy recommendations for the development of low-carbon agriculture in the Beijing Tianjin Hebei region Method: This study calculated agricultural carbon emissions based on the IPCC guidelines, and used trend analysis to study the linear changes in agricultural carbon emissions in the Beijing Tianjin Hebei region. ArcGIS breakpoint analysis and kernel density method were used to analyze the spatial evolution trends of the six major agricultural regions in the Beijing Tianjin Hebei region The study found that, in terms of time, the overall carbon emissions and carbon intensity of agriculture in the Beijing Tianjin Hebei region have shown a downward trend, especially the carbon emission intensity, which has been rapidly decreasing since 2005. Compared with the whole country, although the proportion of total agricultural carbon emissions is small, the carbon emission intensity is higher than the national level, with the highest carbon emission levels in the Bashang Agricultural Zone and the Jinan Agricultural Zone. From a spatial perspective, the northern part of the Bashang Agricultural Area, far from Beijing and Tianjin, as well as some counties in the Central Plains and Southern Hebei Agricultural Areas, have higher carbon emission intensity. However, the suburban agricultural area of Beijing and Tianjin, as well as the southern part of the adjacent Bashang Agricultural Area, maintain a light and low emission state. In addition, according to the results of nuclear density analysis, the overall carbon emission intensity of the six major agricultural regions is decreasing, with a greater degree of internal differentiation in carbon emission intensity between the Beijing Tianjin suburban agricultural region and the Hebei Central Plain agricultural region Conclusion: Based on the research results, an optimization path for carbon reduction in the Beijing Tianjin Hebei region is proposed from four aspects: agricultural positioning, resource sharing, carbon reduction and sink enhancement, and cross industry cooperation.
Abstract:
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
[Objective] To explore the spatiotemporal evolution and influencing factors of low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province, which is of great significance for the low-carbon and efficient utilization of regional arable land resources and the promotion of sustainable agricultural development. [Methods] This study used the super efficiency SBM model to measure the low-carbon utilization efficiency of arable land in 33 counties (cities) in the Songnen Plain region of Heilongjiang Province from 2005 to 2020 , Using spatial autocorrelation and kernel density methods to analyze the spatiotemporal pattern evolution characteristics of low-carbon utilization efficiency of farmland in various counties (cities), and then using a geographically weighted regression model to explore its influencing factors. [Results] (1) During the research period, the low-carbon utilization efficiency of arable land in the Songnen Plain area of Heilongjiang Province showed an upward downward upward trend, with an average of 0.80, which did not reach the forefront of the most effective production; (2) From a spatial perspective, there is a significant positive spatial correlation between the low-carbon utilization efficiency of arable land, and there is a strong clustering distribution trend of high and low values in some areas. The phenomenon of multi core polarization of hot spots is significant, mainly distributed in the northern and southern regions of the region; From the perspective of time dimension, the low-carbon utilization efficiency of arable land exhibits varying degrees of polarization characteristics, and the internal differences show a gradual narrowing trend of evolution; (3) From the perspective of influencing factors, the per capita sown area, the amount of fertilizer used per unit of arable land, the per capita disposable income of rural residents, and agricultural expenses have a positive impact on the low-carbon utilization efficiency of arable land. The multiple cropping index, the amount of machinery used per unit of arable land, and the urbanization rate have a negative impact on efficiency. The per capita GDP has different degrees and directions of impact on the low-carbon utilization efficiency of arable land in different years. [Conclusion] The overall low-carbon utilization efficiency of arable land in the Songnen Plain region of Heilongjiang Province is on the rise, and there are significant differences between regions. In the future, it is necessary to optimize resource allocation efficiency, establish regional synergy mechanisms, play a role in demonstration of hot areas,and promote the improvement of low-carbon utilization efficiency of arable land in various regions.
Abstract:
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:[Objective]?To?clarify?the?spatio-temporal?evolution?characteristics?of?carbon?stocks?under?historical?and?future?time?series?is?of?great?significance?for?promoting?regional?sustainable?development.?[Methods]?Taking?Guiyang?City?as?an?example,?ArcGIS?was?used?to?evaluate?the?spatio-temporal?evolution?characteristics?of?land?use?change?and?carbon?storage?in?Guiyang?from?2000?to?2020,?and?coupled?with?PLUS-InVEST?model?to?predict?the?spatial?pattern?of?land?use?and?its?carbon?storage?changes?under?different?development?scenarios?in?2030.?[Results]?(1)?The?land?use?change?of?Guiyang?City?from?2000?to?2020?was?cultivated?land?and?grassland?transformed?into?water?area?construction?land;?The?cultivated?land?area?decreased?by?190km2.?The?grassland?area?decreased?by?188km2;?Water?area?increased?by?43km2;?Construction?land?area?increased?by?367km2.?(2)?From?2000?to?2020,?the?total?carbon?storage?showed?a?trend?of?first?increase?and?then?decline,?with?a?total?decrease?of?21.97×105t,?showing?a?spatial?distribution?pattern?of?higher?in?the?north?and?lower?in?the?south.?The?northern?region?is?the?main?carbon?sink?function?area?of?Guiyang?City,?and?the?expansion?of?construction?land?is?the?main?reason?for?the?decrease?of?carbon?storage.?(3)?Under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030,?the?construction?land?will?expand?by?279km2,?193km2?and?175km2,?respectively,?with?an?increase?of?51.48%,?35.61%?and?32.29%.?(4)?The?total?carbon?storage?under?the?natural?scenario,?cultivated?land?protection?and?ecological?protection?scenarios?in?2030?is?1399.73×105t,?1398.44×105t?and?1409.55×105t,?respectively,?which?is?decreasing?compared?with?2020.?The?spatial?distribution?pattern?of?carbon?storage?is?always?high?in?the?north?and?low?in?the?south,?and?the?ecological?protection?scenario?is?more?conducive?to?slowing?down?the?decline?trend?of?carbon?storage?in?the?study?area.?[Conclusion]?In?the?future,?in?terms?of?ecological?environment,?we?can?continue?to?strengthen?the?policy?of?returning?farmland?to?forest?to?restore?the?level?of?carbon?storage,?and?in?terms?of?urban?development,?we?should?formulate?a?more?reasonable?comprehensive?development?strategy?to?take?into?account?both?economic?development?and?ecological?protection..
Abstract:
[Objective]The morphological characteristics and influencing factors of gully head in the mollisols farmland area were studied to provide basic data and theoretical support for gully head were investigated in the controlling gully erosion in the mollisols farmland area. [Methods]Taking the gully head in Hainan town small field, and the active state of gully watershed of Hailun as the research object, the morphological characteristics, soil
[Objective]The morphological characteristics and influencing factors of gully head in the mollisols farmland area were studied to provide basic data and theoretical support for gully head were investigated in the controlling gully erosion in the mollisols farmland area. [Methods]Taking the gully head in Hainan town small field, and the active state of gully watershed of Hailun as the research object, the morphological characteristics, soil
Abstract:
Abstract: The eastern foothills of Helan Mountain is a wonderful wine grape producing area in China. Exploring the carbon sequestration potential of the cultivated vineyards in the desert steppe area is crucial for achieving China's dual carbon goals in the region. To quantify soil carbon storage characteristics in grape plantations, this study focused on a typical vineyard of Xinhuibin, conducting a sampling investigation and analyzing soil organic carbon at the vineyard scale, examining its content, density, and composition. The results indicated that （1）in the 0-100 cm soil layer of the vineyard, the average soil organic carbon content was 4.65 g/kg, and the density was 64.5 t/hm2. Despite the low soil organic matter content and nutrient scarcity, it still constituted the main component of the vineyard's carbon pool. （2）Vertically, the soil organic carbon content decreased with depth, showing a significant difference between the 0-40 cm surface layer and the 40-100 cm deeper layer. The enrichment coefficient of organic carbon in the surface soil exceeded 1, indicating its enhanced ability to retain organic carbon. （3）Within the vineyard, soil organic carbon content exhibited spatial heterogeneity. This spatial heterogeneity, especially in the surface soil, was influenced by varied reclamation activities, including different grape varieties and fertilization practices across plots. The spatial heterogeneity of organic carbon in deep soil was determined by the formation of the original soil.（4）The ratio of active, neutral, and inert soil organic carbon components was approximately 1:2:5. This indicates a relatively high proportion of inert components, signifying a low active carbon pool with strong stability. While the inert organic carbon content governs the level of total organic carbon, variations in neutral organic carbon content also influence both total organic carbon and total carbon levels. These research findings provide valuable insights into the mechanisms of carbon sink formation and the potential for carbon sequestration in vineyards in arid regions.
Abstract: The eastern foothills of Helan Mountain is a wonderful wine grape producing area in China. Exploring the carbon sequestration potential of the cultivated vineyards in the desert steppe area is crucial for achieving China's dual carbon goals in the region. To quantify soil carbon storage characteristics in grape plantations, this study focused on a typical vineyard of Xinhuibin, conducting a sampling investigation and analyzing soil organic carbon at the vineyard scale, examining its content, density, and composition. The results indicated that （1）in the 0-100 cm soil layer of the vineyard, the average soil organic carbon content was 4.65 g/kg, and the density was 64.5 t/hm2. Despite the low soil organic matter content and nutrient scarcity, it still constituted the main component of the vineyard's carbon pool. （2）Vertically, the soil organic carbon content decreased with depth, showing a significant difference between the 0-40 cm surface layer and the 40-100 cm deeper layer. The enrichment coefficient of organic carbon in the surface soil exceeded 1, indicating its enhanced ability to retain organic carbon. （3）Within the vineyard, soil organic carbon content exhibited spatial heterogeneity. This spatial heterogeneity, especially in the surface soil, was influenced by varied reclamation activities, including different grape varieties and fertilization practices across plots. The spatial heterogeneity of organic carbon in deep soil was determined by the formation of the original soil.（4）The ratio of active, neutral, and inert soil organic carbon components was approximately 1:2:5. This indicates a relatively high proportion of inert components, signifying a low active carbon pool with strong stability. While the inert organic carbon content governs the level of total organic carbon, variations in neutral organic carbon content also influence both total organic carbon and total carbon levels. These research findings provide valuable insights into the mechanisms of carbon sink formation and the potential for carbon sequestration in vineyards in arid regions.
Abstract:
[Objective] In the construction of high-standard farmland, it is essential to consider carbon emissions and absorption in the agricultural production process while ensuring food security, in order to achieve China"s goal of carbon neutrality and contribute to the development of a strong agricultural sector.[Methods] This study measures the profit and loss of farmland in 60 cities within the Yellow River Basin from the perspective of food security, establishes a standard for farmland ecological compensation based on opportunity cost method, calculates carbon emissions from agricultural resources used in production and crop growth across these cities, estimates total carbon absorption through photosynthesis during crop growth, and determines the net carbon sink of farmland in this region by considering both sources and sinks. The average carbon trading price in 2021 serves as the compensation standard for calculating regional farmland ecological compensation from a "dual-carbon" perspective. Finally, by calculating farmland ecological compensation amounts separately under perspectives of food security and "double-carbon", we obtain comprehensive figures for dual-perspective ecological compensation within the Yellow River basin.[Results] Results indicate that most cities along Qinghai and Henan provinces where Yellow River flows accept certain levels of compensation.[Conclusion] Provincial capitals such as Xi"an, Zhengzhou, and Taiyuan need to pay higher amounts due to their significant urbanization level, industrialization progress, and robust economic development. These findings highlight a more pronounced conflict between local farmland security on one hand and food/ecological security on another.
Keywords:Yellow River Basin; Farmland ecological compensation; Food security;Carbon source；Carbon sink
[Objective] In the construction of high-standard farmland, it is essential to consider carbon emissions and absorption in the agricultural production process while ensuring food security, in order to achieve China"s goal of carbon neutrality and contribute to the development of a strong agricultural sector.[Methods] This study measures the profit and loss of farmland in 60 cities within the Yellow River Basin from the perspective of food security, establishes a standard for farmland ecological compensation based on opportunity cost method, calculates carbon emissions from agricultural resources used in production and crop growth across these cities, estimates total carbon absorption through photosynthesis during crop growth, and determines the net carbon sink of farmland in this region by considering both sources and sinks. The average carbon trading price in 2021 serves as the compensation standard for calculating regional farmland ecological compensation from a "dual-carbon" perspective. Finally, by calculating farmland ecological compensation amounts separately under perspectives of food security and "double-carbon", we obtain comprehensive figures for dual-perspective ecological compensation within the Yellow River basin.[Results] Results indicate that most cities along Qinghai and Henan provinces where Yellow River flows accept certain levels of compensation.[Conclusion] Provincial capitals such as Xi"an, Zhengzhou, and Taiyuan need to pay higher amounts due to their significant urbanization level, industrialization progress, and robust economic development. These findings highlight a more pronounced conflict between local farmland security on one hand and food/ecological security on another.
Keywords:Yellow River Basin; Farmland ecological compensation; Food security;Carbon source；Carbon sink
Abstract:
[Objective] In order to investigate the rainstorms and floods process and the soil erosion caused by rainstorms in small watershed, it is urgent to carry out the investigation of rainstorms and floods process and soil and water conservation, so as to provide scientific support for the next soil and water conservation decision. [Methods] The flood marks were measured and investigated in Huangmi East Ditch and Liangjiazhuang West Ditch by field investigation method, and the flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm flood to small watershed. [Results]① The rainfall lasted for a long time and was strong. The cumulative rainfall in Liangjiazhuang West Ditch Valley and Huangmi East Ditch Valley reached 1008.5mm and 613.6mm, respectively. According to the flood mark survey, the peak discharge modulus of Huangmi East Ditch and Liangjiazhuang West Ditch watershed are 10.80m3/s·km2 and 36.07m3/s·km2 respectively. Slope and soil and water conservation measures are the main factors affecting flood peak discharge. Larger slope will increase flood peak discharge, and perfect soil and water conservation measures can play an effective role in peak reduction. (3) The investigated small watershed is located in the upper reaches of 泜 river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watershed is larger than that of the downstream hydrology station. (4) The erosion situation of Liangjiazhuang West Ditch is more serious than that of Huangmi East Ditch, mainly because the area proportion of orchards, terraces and check dam in Huangmi East Ditch is larger than that of Huangmi West Ditch, the average slope of Huangmi East Ditch is smaller than that of Liangjiazhuang West Ditch, and the peak duration of rainfall at Liangjiazhuang rain measuring station is longer. [Conclusion] It is necessary and effective to implement soil and water conservation measures, and to further improve the construction of terrace and terrace valley. Good soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon.
[Objective] In order to investigate the rainstorms and floods process and the soil erosion caused by rainstorms in small watershed, it is urgent to carry out the investigation of rainstorms and floods process and soil and water conservation, so as to provide scientific support for the next soil and water conservation decision. [Methods] The flood marks were measured and investigated in Huangmi East Ditch and Liangjiazhuang West Ditch by field investigation method, and the flood peak discharge modulus was calculated to analyze the erosion damage caused by rainstorm flood to small watershed. [Results]① The rainfall lasted for a long time and was strong. The cumulative rainfall in Liangjiazhuang West Ditch Valley and Huangmi East Ditch Valley reached 1008.5mm and 613.6mm, respectively. According to the flood mark survey, the peak discharge modulus of Huangmi East Ditch and Liangjiazhuang West Ditch watershed are 10.80m3/s·km2 and 36.07m3/s·km2 respectively. Slope and soil and water conservation measures are the main factors affecting flood peak discharge. Larger slope will increase flood peak discharge, and perfect soil and water conservation measures can play an effective role in peak reduction. (3) The investigated small watershed is located in the upper reaches of 泜 river basin, which is the main runoff producing area of the rainstorm center and flood. The peak flood discharge modulus of the small watershed is larger than that of the downstream hydrology station. (4) The erosion situation of Liangjiazhuang West Ditch is more serious than that of Huangmi East Ditch, mainly because the area proportion of orchards, terraces and check dam in Huangmi East Ditch is larger than that of Huangmi West Ditch, the average slope of Huangmi East Ditch is smaller than that of Liangjiazhuang West Ditch, and the peak duration of rainfall at Liangjiazhuang rain measuring station is longer. [Conclusion] It is necessary and effective to implement soil and water conservation measures, and to further improve the construction of terrace and terrace valley. Good soil and water conservation measures can effectively reduce the occurrence of flood peak discharge and erosion phenomenon.
Abstract:
[Objective] Weathering degree and provenance of Pisha Sandstone were studied aiming to provide a basic theoretical basis for further research on Pisha Sandstone and prevention and control of soil erosion.[Methods] Taking the Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia as the research object, through field investigation and experimental research including major element, trace element and rare earth element geochemical characteristics, the Chemical Alteration Index (CIA), Plagioclase Alteration Index (PIA), ratios of light to heavy rare earth element (LREE/HREE) and related trace and rare earth element relationships of Pisha Sandstone were analyzed.[Results] ① Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar is mainly composed of SiO2 and Al2O3, with most of the major elements having lower content than the average upper crust (UCC); The geochemical classification diagram shows that Pisha Sandstone consists of shale, feldspar sandstone and lithic sandstone; The CIA value of Pisha Sandstone ranges from 64.95 to 86.57, with an average value of 77.46. This is consistent with the characteristics of the Pisha Sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering.② The trace element contents in siltstone and mudstone are higher than that in sandstone, with the highest content of Ba followed by Zr; The paleotemperature for the formation of Pisha Sandstone is 10.67 ℃~22.78 ℃, with an average value of 17.68 ℃ and the PIA value of Pisha Sandstone is 70.48~97.13, with an average of 89.76.③ The rare earth element distribution pattern of Pisha Sandstone is consistent with UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies; The total rare earth (∑REE), ratio of light rare earth to heavy rare earth (LREE/HREE) and (La/Yb)N values of siltstone and mudstone are all higher than those of sandstone. The differentiation is mainly due to the attraction of most of trace elements released by rock weathering during epigenetic processes by clay minerals or due to hydraulic sorting.[Conclusion] The Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia is a set of terrestrial clastic sedimentary rock with low compositional maturity and sorting degree, and the source area had experienced moderate to strong chemical weathering; The formation of Pisha Sandstone was under arid to semi-humid conditions; The Pisha Sandstone rare earth element distribution pattern, combined with the discrimination diagram of major and trace elements, indicates that the studied Pisha Sandstone from Yan'an Formation originated from the Hercynian-Indosinian granites in Yinshan-Daqingshan area to the northern Ordos Basin.
[Objective] Weathering degree and provenance of Pisha Sandstone were studied aiming to provide a basic theoretical basis for further research on Pisha Sandstone and prevention and control of soil erosion.[Methods] Taking the Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia as the research object, through field investigation and experimental research including major element, trace element and rare earth element geochemical characteristics, the Chemical Alteration Index (CIA), Plagioclase Alteration Index (PIA), ratios of light to heavy rare earth element (LREE/HREE) and related trace and rare earth element relationships of Pisha Sandstone were analyzed.[Results] ① Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar is mainly composed of SiO2 and Al2O3, with most of the major elements having lower content than the average upper crust (UCC); The geochemical classification diagram shows that Pisha Sandstone consists of shale, feldspar sandstone and lithic sandstone; The CIA value of Pisha Sandstone ranges from 64.95 to 86.57, with an average value of 77.46. This is consistent with the characteristics of the Pisha Sandstone from the Middle Triassic Ermaying Formation near the study area, reflecting a common history of rock weathering.② The trace element contents in siltstone and mudstone are higher than that in sandstone, with the highest content of Ba followed by Zr; The paleotemperature for the formation of Pisha Sandstone is 10.67 ℃~22.78 ℃, with an average value of 17.68 ℃ and the PIA value of Pisha Sandstone is 70.48~97.13, with an average of 89.76.③ The rare earth element distribution pattern of Pisha Sandstone is consistent with UCC, showing the characteristics of light rare earth enrichment, heavy rare earth depletion, and weak negative Eu anomalies; The total rare earth (∑REE), ratio of light rare earth to heavy rare earth (LREE/HREE) and (La/Yb)N values of siltstone and mudstone are all higher than those of sandstone. The differentiation is mainly due to the attraction of most of trace elements released by rock weathering during epigenetic processes by clay minerals or due to hydraulic sorting.[Conclusion] The Pisha Sandstone from the Lower Jurassic Yan'an Formation in Jungar, Inner Mongolia is a set of terrestrial clastic sedimentary rock with low compositional maturity and sorting degree, and the source area had experienced moderate to strong chemical weathering; The formation of Pisha Sandstone was under arid to semi-humid conditions; The Pisha Sandstone rare earth element distribution pattern, combined with the discrimination diagram of major and trace elements, indicates that the studied Pisha Sandstone from Yan'an Formation originated from the Hercynian-Indosinian granites in Yinshan-Daqingshan area to the northern Ordos Basin.
Abstract:
[Objective] The coal mining process also causes a series of ecological and environmental problems such as the reduction of biodiversity, the destruction of soil structure and the loss of nutrients. The severe disturbance to the soil structure in the mining area results in the exposure of organic carbon protected by soil aggregates, which is de-composed and mineralized by soil microorganisms, resulting in the loss of soil organic carbon. Vegetation recon-struction in disturbed open pit dump is considered to be an effective measure to improve soil structure and increase biodiversity. In recent years, microbial restoration technology (arbuscular mycorrhizal fungi) has been widely used in ecological restoration of mining areas, and has achieved obvious ecological improvement effect. In addition, exogenous substances such as weathered coal and green fertilizer are also considered to have a positive role in soil improvement. However, the effect of arbuscular mycorrhizal fungi combined with weathering coal and green fertilizer on vegetation growth and soil improvement is still unclear. [Methods] Therefore, based on the sea buckthorns demonstration base in the open pit of Hedaigou, Inner Mongolia, this study analyzed the effects of the combined action of fertilizer modes such as arbuscular mycorrhizal fungi (AMF) and other factors (weathered coal and green fertilizer) on the stability of soil aggregates and organic carbon recovery in the early vegetation resto-ration area of the open pit dump by investigating vegetation populations and collecting soil aggregate samples. [Result] The results showed that under the six treatment modes, the experimental group inoculated with AMF, applied green fertilizer and added weathered coal (sand and green wind) had the best effect on the improvement of understory vegetation diversity, and the diversity index was significantly improved compared with the control treatment. The experimental group inoculated with AMF and applied with green fertilizer (sand green) had the most significant effect on the development and stability of aggregates. The crushing rate of the experimental group was significantly lower than that of the control group, while the mean diameter of aggregate weight and geometric mean diameter were significantly higher than that of the control group. The analysis of the effect of organic carbon and total nitrogen in aggregates showed that the organic carbon and total nitrogen in aggregates treated with sand green were significantly higher than those in the experimental group inoculated only with AMF (sand grafting). [Con-clusion]:Overall, these results evaluated the effects of weathering coal, green fertilizer and AMF inoculation on improving vegetation diversity, aggregate stability and aggregate organic carbon recovery in field trials, and had important reference significance for optimizing artificial ecological restoration strategies in open-pit mines and accelerating soil carbon pool recovery.
[Objective] The coal mining process also causes a series of ecological and environmental problems such as the reduction of biodiversity, the destruction of soil structure and the loss of nutrients. The severe disturbance to the soil structure in the mining area results in the exposure of organic carbon protected by soil aggregates, which is de-composed and mineralized by soil microorganisms, resulting in the loss of soil organic carbon. Vegetation recon-struction in disturbed open pit dump is considered to be an effective measure to improve soil structure and increase biodiversity. In recent years, microbial restoration technology (arbuscular mycorrhizal fungi) has been widely used in ecological restoration of mining areas, and has achieved obvious ecological improvement effect. In addition, exogenous substances such as weathered coal and green fertilizer are also considered to have a positive role in soil improvement. However, the effect of arbuscular mycorrhizal fungi combined with weathering coal and green fertilizer on vegetation growth and soil improvement is still unclear. [Methods] Therefore, based on the sea buckthorns demonstration base in the open pit of Hedaigou, Inner Mongolia, this study analyzed the effects of the combined action of fertilizer modes such as arbuscular mycorrhizal fungi (AMF) and other factors (weathered coal and green fertilizer) on the stability of soil aggregates and organic carbon recovery in the early vegetation resto-ration area of the open pit dump by investigating vegetation populations and collecting soil aggregate samples. [Result] The results showed that under the six treatment modes, the experimental group inoculated with AMF, applied green fertilizer and added weathered coal (sand and green wind) had the best effect on the improvement of understory vegetation diversity, and the diversity index was significantly improved compared with the control treatment. The experimental group inoculated with AMF and applied with green fertilizer (sand green) had the most significant effect on the development and stability of aggregates. The crushing rate of the experimental group was significantly lower than that of the control group, while the mean diameter of aggregate weight and geometric mean diameter were significantly higher than that of the control group. The analysis of the effect of organic carbon and total nitrogen in aggregates showed that the organic carbon and total nitrogen in aggregates treated with sand green were significantly higher than those in the experimental group inoculated only with AMF (sand grafting). [Con-clusion]:Overall, these results evaluated the effects of weathering coal, green fertilizer and AMF inoculation on improving vegetation diversity, aggregate stability and aggregate organic carbon recovery in field trials, and had important reference significance for optimizing artificial ecological restoration strategies in open-pit mines and accelerating soil carbon pool recovery.
Abstract:
[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.
[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.
Abstract:
[Objective] changes in land use and carbon storage in the Maowei Sea were analyzed to provide a scientific basis for increasing its carbon sink and improving ecological value. [Methods] In this study, the remote sensing image data of the Maowei Sea in 2009, 2015 and 2021 were used for interpretation and acquisition by using supervised classification method. Based on the ArcGIS and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the study analyzed the spatiotemporal change of the land use and carbon storage in the Maowei Sea. [Results] The results show that: ①The land types in the Maowei Sea mainly showed the distribution characteristics of "large settlement, small miscellaneous areas", the area of cultivated land, shallow sea waters and fishery breeding areas decreased, and the area of mangrove wetlands, building land, forest grassland and silty tidal flats increased in 2009-2021. ②The carbon storage showed a trend of decline and then increase, the net carbon sequestration and its net present value in the Maowei Sea was increased by -110500 tons, 37700 tons, -72900 tons and -137 million, 47 million, -90 million respectively in 2009-2015, 2015-2021 and 2009-2021. ③The transformation mainly from high carbon sequestration land use types such as fishery breeding areas and forest and grasslands to low carbon sequestration type such as building land in the Maowei Sea in 2009-2021, the largest carbon storage loss caused by the conversion to building land, reaching 285100 tons, and the additional carbon storage increased by the fishery breeding area reached 180,800 tons. [Conclusion] accelerating the transformation and upgrading of farming methods, enhancing the proliferation of mangrove forests in terrestrial and aquatic forested areas and accelerating the construction of forest city in the Maowei Sea to promote its carbon sequestration and sustainable development.
[Objective] changes in land use and carbon storage in the Maowei Sea were analyzed to provide a scientific basis for increasing its carbon sink and improving ecological value. [Methods] In this study, the remote sensing image data of the Maowei Sea in 2009, 2015 and 2021 were used for interpretation and acquisition by using supervised classification method. Based on the ArcGIS and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, the study analyzed the spatiotemporal change of the land use and carbon storage in the Maowei Sea. [Results] The results show that: ①The land types in the Maowei Sea mainly showed the distribution characteristics of "large settlement, small miscellaneous areas", the area of cultivated land, shallow sea waters and fishery breeding areas decreased, and the area of mangrove wetlands, building land, forest grassland and silty tidal flats increased in 2009-2021. ②The carbon storage showed a trend of decline and then increase, the net carbon sequestration and its net present value in the Maowei Sea was increased by -110500 tons, 37700 tons, -72900 tons and -137 million, 47 million, -90 million respectively in 2009-2015, 2015-2021 and 2009-2021. ③The transformation mainly from high carbon sequestration land use types such as fishery breeding areas and forest and grasslands to low carbon sequestration type such as building land in the Maowei Sea in 2009-2021, the largest carbon storage loss caused by the conversion to building land, reaching 285100 tons, and the additional carbon storage increased by the fishery breeding area reached 180,800 tons. [Conclusion] accelerating the transformation and upgrading of farming methods, enhancing the proliferation of mangrove forests in terrestrial and aquatic forested areas and accelerating the construction of forest city in the Maowei Sea to promote its carbon sequestration and sustainable development.
Abstract:
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
[Objective] Scientifically constructing the spatial ecological network of the national territory and identifying key areas for ecological restoration is an important guarantee for promoting the integration of mountains, rivers, forests, fields, lakes, grasslands, and sand in regional landscapes. [Method] Taking Zhengzhou as an example, this study used Morphological Spatial Pattern Analysis (MSPA) to identify ecological source areas, extracted ecological corridors and identified key areas for ecological restoration through landscape connectivity assessment and circuit theory, and finally constructed an ecological network security pattern. [Results] There are a total of 37 ecological source areas in Zhengzhou, covering a total area of 983.29 km2, with a distribution pattern of more in the west and less in the east, and a band-like agglomeration in the north-south direction. A total of 85 ecological corridors were extracted in Zhengzhou, with lengths ranging from 0.11 to 47.92 km, totaling 689.50 km. Among them, there are 19 key ecological corridors, 29 important ecological corridors, and 37 general ecological corridors. Fifty-five ecological pinch points were identified, with a total area of 2.78 km2, mainly concentrated in the southwest of Zhengzhou. The locations of these pinch points have low resistance, and the main land types are forests, grasslands, and water bodies. Three levels of obstacle points were classified based on cumulative current values, with a total area of 1054.31 km2, accounting for 14.16% of the study area. These obstacle points are mainly located in urban areas around major transportation roads in Dengfeng City and Xinmi City. Considering the natural and social status quo of the study area, a "one belt, one ring, two zones, four groups, and multiple points" ecological network security pattern was proposed. [Conclusion] Strategies for ecological restoration were proposed for the identified ecological pinch points and obstacle points: the ecological pinch point areas have relatively good ecological environments, so natural ecological maintenance should be the main focus; the obstacle point areas are mainly construction land with high development intensity and human disturbance, so both artificial and natural restoration should be given equal importance. This study can provide reference for the planning of national spatial ecological restoration in Zhengzhou and other municipal spatial ecological restoration.
Abstract:
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract: The Lingjiang River Basin is an important river in the southern part of Zhejiang Province and a significant area for social and economic activities in Zhejiang. Revealing the hydrochemical characteristics of the surface water in the basin and its suitability for irrigation is of great significance for ecological protection and high-quality development in the region. This study comprehensively analyzed the hydrochemical statistics and origins of the surface water in the basin using methods such as mathematical statistics, Piper trilinear diagram, principal component analysis, and ion ratios. The irrigation suitability of the surface water in the basin was assessed through the Wilcox diagram and the USSL diagram. The results show that the hydrochemical types of the surface water in the Lingjiang River Basin exhibit zonation in spatial variation. The hydrochemical type transitions from an HCO3-Ca type in the middle-upper reaches (Zone I) to a Cl-Na type in the lower reaches and the Wenzhou-Huangyan Plain river network area (Zone II), and eventually to the Taizhou Bay estuary (Zone III). The hydrochemical composition of the basin''s surface water is influenced by natural dissolution processes and human activities. In Zone I, the hydrochemical characteristics of the surface water are mainly influenced by the dissolution of silicate rocks during rock weathering, with a lesser influence from carbonate rock dissolution. Zone I and Zone II surface waters are suitable for agricultural irrigation, mainly influenced by the dissolution of silicate rocks. In Zone III, the surface water is primarily influenced by evaporite rock dissolution, leading to poor irrigation suitability and the potential for salt-alkali damage.In Zones I and II, K+ and Na+ primarily originate from the dissolution of silicate minerals, while Ca2+, Mg2+, HCO3-, and SO42- primarily result from the dissolution of silicate rocks, with a minor contribution from carbonate rock dissolution. NO3-, on the other hand, mainly originates from human activities.
Abstract:
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
[Objective] Taking Shaanxi Province as the study area, the spatial relationship between cultivated lands and construction projects were analyzed, and the method of defining of the upper thresholds of the cultivated land proportions in construction projects were determined, for the sake of formulating measures in controlling cultivated land loss. [Methods] Based on the land change survey data and construction project samples, the index of cultivated land density was constructed. With the integration of GIS spatial overlaying, geomorphic zoning and statistical analysis methods, intensity zoning of cultivated lands in Shaanxi Province was presented and the upper thresholds of cultivated land proportions in construction projects determined. [Results] Combined of geomorphic zoning with cultivated land density grading, and applied the 80% cumulative frequency values as the thresholds, three zones were divided in Shaanxi Province, including Loess Plateau-intensive cultivated land, Guanzhong Plain/Qinba Mountain-intensive cultivated land, and Other regions (non-intensive cultivated land). Furthermore, the upper thresholds of cultivated land proportions in linear projects and the planar project in the three zones are determined to be 26%, 42%, and 22%, 45%, 80%, and 27%, respectively. [Conclusion] By applied the upper thresholds, the effectiveness of preventing cultivated land loss for various projects ranged from 1.2% to 17.9%, which can control 13.9%-22.5% of construction projects against the excessive occupation of cultivated land, and effectively protect the cultivated land resources.
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[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
[Objective] One of the main drivers of terrestrial ecosystem carbon storage is land use change. The spatial-temporal response relationship between land use and carbon storage evolution in Zhengzhou City was analyzed based on the logic of “past-present-future” in order to provide references for realizing ecological security and sustainable development. [Methods] The spatial-temporal distribution of carbon storage from 2005 to 2020 was quantitatively evaluated using GIS and the InVEST model. Then, combined with the PLUS model, the spatial-temporal changes of land use and carbon storage were simulated for 2050 under a natural development scenario and an ecological conservation scenario. The degree of spatial correlation was evaluated at the grid scale using Moran’s I and the Getis-Ord Gi* statistic for hot spot analysis. [Results] (1) From 2005 to 2020, cultivated land was continuously converted to construction land, with a cumulative transfer of 1004.98 km2, resulting in significant changes in the land use structure of Zhengzhou City. The decrease in ecological land area under the ecological conservation scenario was better than under the natural development scenario. (2) The rapid expansion of urbanization in Zhengzhou City produced carbon storage in 2005 and 2020 of 65.93×106 t and 56.72×106 t, respectively. Over the past 15 years, the high-carbon-intensity land class was transferred, and the spatial distribution of carbon storage was characterized by a pattern of "high in the west, low in the east, medium in the north and south, and low in the central region". Under the scenarios of natural development and ecological conservation, the carbon storage decreased by 8.27×106 t and 1.80×106 t, respectively, and cultivated land played an important role as a carbon sink. (3) The spatial distribution of carbon storage was agglomerative, with an uneven distribution of cold and hot spots. The degree of fragmentation of hot spots was moderate under the ecological conservation scenario. Gongyi City and Dengfeng City were always the regions with a high degree of carbon storage agglomeration. [Conclusion] The spatial-temporal distribution characteristics of carbon storage were closely related to changes in land use structure. Future land use planning of Zhengzhou City should take appropriate ecological conservation measures to optimize the land use pattern and to enhance the carbon sequestration capacity of the ecosystem.
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[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
[Objective] Under total carbon emission control, a fair and scientific allocation of carbon emission quota among provinces is a key approach to achieve the goal of "double carbon", as well as an important cornerstone of the carbon emission trading system. The marginal cost of carbon emission reduction in the results of carbon emission quota allocation under different scenarios was analyzed, with a view to determining the optimal carbon emission quota allocation scheme at the lowest cost, providing a theoretical basis for the subsequent regional allocation work and a reference for the formulation of regional carbon emission reduction schemes. [Methods] The ecological index was introduced on the basis of the carbon quota allocation index established by predecessors, and four scenarios including equity, efficiency, ecology and equity-eco-efficiency were set. The SBM dual model was used to calculate the regional marginal carbon emission reduction cost under different scenarios, and the optimal allocation scheme was determined based on this. [Results]The results show that: Under the scenarios of fairness, efficiency, ecology and consideration, the average marginal cost of carbon emission reduction was 0.295 million yuan/t, 0.312 million yuan/t, 0.291 million yuan/t, and 0.309 million yuan/t, respectively. The emission reduction cost of the scheme introducing ecological index is significantly lower, and it can be inferred that the carbon sink offsets part of the carbon emissions which are difficult and costly to reduce emissions. The cost of emission reduction under the balanced scenario is significantly higher than that under the fair and ecological scenarios, indicating that the improvement of carbon emission efficiency will lead to the increase of marginal carbon emission reduction cost. [Conclusion] The carbon emission quota under ecological scenario is the best scheme to achieve the "double carbon" goal with the lowest marginal carbon emission reduction cost, and can be used as a reference for the formulation of regional carbon emission plans.
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[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
[Objective] The ecosystem carbon storage and its response to land use changes in Fujian Province were analysed in order to provide a reference for ecosystem protection. [Methods] Based on land use data and carbon density data, the InVEST model was used to simulate carbon storage in Fujian Province in 1980, 2000, and 2020. The spatiotemporal characteristics of carbon storage and land use were analyzed using the distribution of cold spots and hot spots, transfer maps, and a transfer matrix. The response of carbon storage to land use changes was analyzed. [Results] (1) Carbon storage in Fujian Province was relatively high on the whole, and more than 82.5% of the region was above medium carbon storage (＞3000 t), mainly located in mountainous and hilly areas, which were also hot spots of high carbon storage. Ares of high (hot spots) and low (cold spots) of carbon storage concentration transferred less. Total carbon storage fluctuated slightly from 1980 to 2020, and relatively more carbon storage transferred between different carbon storage levels from 2000 to 2020. (2) Land use/cover in Fujian Province was mainly forest land (61.4%–62.9%), followed by cultivated land (16.9%–18.3%) and grassland (15.2%–17.2%). Land use/cover change was relatively stable from 1980 to 2000, and more intense from 2000 to 2020. (3) Total carbon storage values in forest land, grassland, and cultivated land were relatively high, while total carbon storage in water bodies, construction land, and unused land were relatively low. Total carbon storage in cultivated land decreased over time, while total carbon storage of construction land increased. The area of forest land and grassland both increased and decreased. The largest transfer of total carbon storage caused by land use/cover changes was observed in forest land, followed by grassland and cultivated land. The net transfer of total carbon storage was negative for forest land, and positive for the other land use classes. The largest carbon loss was observed for the transfer of forest land. [Conclusion] Cultivated land, forest land, and grassland were the main types of land use in Fujian Province contributing to higher carbon storage, and their mutual transfer resulted in carbon storage changes.
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[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
[Objective] The spatiotemporal characteristics and factors influencing the value of forest carbon sequestration in Henan Province were analyzed in order to provide a reference for promoting the realization of "carbon peak and carbon neutrality". [Methods] The value of forest carbon sequestration in Henan Province from 2010 to 2020 was evaluated through the stock expansion method and the afforestation cost method, and the temporal variation characteristics of forest carbon sequestration value were analyzed. The Moran index was used to explore the spatial aggregation characteristics, and an extended STIRPAT model was constructed to analyze the factors affecting the value of forest carbon sequestration. [Results] (1) The value of forest carbon sequestration in Henan Province showed a continuous rising trend which increased from 4.18 billion yuan in 2010 to 6.71 billion yuan in 2020. Carbon sequestration values exhibited a pattern of "high in the west and south, low in the east and north" in Henan Province, and there was a significant positive spatial aggregation effect. The areas with significant high carbon sequestration values were located in western and southern Henan Province, while there were only two areas with significant low carbon sequestration values. (2) In addition to the negative impact of carbon sink intensity on the value of forest carbon sequestration in Henan Province, the proportion of forest area, urbanization ratio, forestry industry ratio, and per capita GDP all showed positive impacts. The proportion of forest area was the most important factor promoting the growth of forest carbon sequestration values. [Conclusion] There is great potential for forest carbon sequestration in Henan Province, and the realization of forest carbon sequestration should be promoted regionally in the future.
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[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
[Objective] The temporal and spatial variation of carbon emissions due to land use changes and the factors influencing carbon emissions in Yunnan Province were analyzed in order to provide a theoretical basis for optimizing land use structure and achieving the low-carbon development goal in Yunnan Province. [Methods] Carbon emissions for Yunnan Province were calculated based on land use and fossil energy consumption data in Yunnan Province in 2005, 2010, 2015, and 2020. Spatial visualization and spatial autocorrelation were used to study the temporal and spatial variation and spatial agglomeration characteristics of carbon emissions in the past 15 years. The influencing factors were analyzed by geographical detectors. [Results] (1) From 2005 to 2020, the area of construction land in Yunnan Province increased the most, with a dynamic change of 7.90%. (2) Regional net carbon emissions increased rapidly, with an annual increase of 6.5%. The spatial pattern of carbon emissions was characterized as "high in the central region and low in the surrounding area". The carbon footprint increased significantly during the study period, and the carbon ecological carrying capacity was relatively stable, resulting in an increasing carbon ecological deficit. (3) Population size, economic level, industrial structure, land use, etc. promoted the increase in carbon emissions for cities and counties around Yunnan Province. [Conclusion] Measures should be taken in the future to protect or reasonably increase the area of carbon sinks (such as forest land) and to strengthen dynamic monitoring, control the area of construction land and total energy consumption, explore the carbon compensation mechanism, and employ the radiation effect of carbon sink areas.
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[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
[Objective] Ecosystem services value (ESV) is one of the important measures used to evaluate whether regional land use change is scientific. ESV is related to regional sustainable development. ESV and terrestrial carbon storage (TCS) changes in coastal cities were evaluated in order to provide a basis for economic development and ESV regulation in Dalian City. [Methods] Five periods of land use data and related data from 2000 to 2020 were analyzed in this study. Land dynamics, the equivalent factor method, a land transfer matrix, ESV contribution rate, TCS, and principal component analysis were used to calculate the land use change dynamics in Dalian City and their impacts on ESV, TCS, and terrestrial carbon storage value (TCSV). [Results] (1) Construction land in Dalian City mainly encroached on farmland and forest land in the southwestern coastal area. (2) During the four time periods from 2000 to 2020, ESV in Dalian City initially decreased and then increased, and the decline continued to intensify. The decrease in arable land area and the increase in construction land area had a direct impact on the maintenance of ecosystem service functions. (3) During the four time periods from 2000 to 2020, TCS and TCSV in Dalian City initially increased and then decreased, and the decline continued to intensify. The reduction of forest area directly affected the maintenance of TCS function. (4) In the land use transfer matrix for Dalian City from 2000 to 2020, farmland, forest land, and grassland were mainly transferred out, while construction land was mainly transferred in. The contribution of ecosystem services varied among different land use types, with contributions ranging from cultivated land, forest land, wetlands, water bodies, grasslands, and unused land. (5) The changes in ESV and TCS in Dalian City from 2000 to 2020 were mainly influenced by economic GDP growth, adjustments to the three major industrial structures, and the development of urbanization level. [Conclusion] From the perspective of economic development, ESV improvement, TCS capacity improvement, and sustainable development in Dalian City, it is necessary to focus on the conflict between the expansion of coastal construction land and ecological and agricultural land, strengthen the protection of northern forest and grass ecological land, accelerate the ecological environment restoration work in coastal areas, enhance the carbon sequestration capacity of ecological land, and avoid unrestricted blind expansion of construction land.
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[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
[Objective] Land use change is one of the important driving forces for increasing carbon emissions the deteriorate environmental quality. The temporal and spatial pattern changes and effects of land use carbon emissions were analyzed in order to provide a theoretical basis for the formulation of low-carbon development strategies. [Methods] The internal relationships between land use changes and carbon emissions, carbon emission intensity, and ecological effect were determined based on gray theory and ecological carrying coefficient by using land use and energy consumption data for 22 counties in Ningxia Hui Autonomous Region from 1980 to 2020. [Results] (1) There was a close correlation between carbon emission changes and land use changes. The correlation between construction land and carbon emissions was the largest (0.95). (2) Net carbon emissions of land use types in Ningxia increased by 5.24×107 t and had a growth rate of 625.43% from 1980 to 2020. This pattern was associated with significant increases in construction land area and carbon emissions (average annual rates of 4.42% and 2385.85%, respectively) during the period of 1980–2020. Additionally, grassland area decreased by 2.95?105 hm2, and the carbon sink decreased by 5.80?104 t. Forest land was the main carbon sink, accounting for more than 75% of the carbon sink in 2020, and increased with increasing area. (3) The carbon emission intensity of land use in Ningxia increased at an average annual rate of 0.25 t/hm2 from 1980 to 2020, and the coverage area of moderate and above grades increased gradually. A spatial distribution pattern of carbon emission intensity for cities along the Yellow River developed that was higher than observed for the central and southern regions. (4) Due to differences in county economic level and natural environment, the spatial differences in ecological support coefficients of carbon emissions for the 22 counties in Ningxia Hui Autonomous Region was obvious, and the distribution pattern of carbon sink capacity was weak in the north and strong in the south. [Conclusion] The carbon emission intensity of land use in Ningxia Hui Autonomous Region gradually increased from 1980 to 2020. The carbon ecological capacity of counties along the Yellow River in the north gradually decreased. The carbon ecological capacity of counties in the central and southern regions increased, but the pressure of emission reduction was greater. We recommend optimizing the spatial pattern of construction land, improving soil structure, increasing the area of mixed forests, and enhancing forest carbon sink capacity.
Abstract:
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
[Objective] The temporal and spatial differences of agricultural carbon budget and carbon compensation potential was analyzed based on the dual perspectives of carbon emission and carbon absorption in order to provide a theoretical reference for the comprehensive green transformation and coordinated development of agriculture in Hunan Province. [Methods] Exploratory spatial data analysis, absolute β convergence, parameter comparison, and GIS spatial analysis were used to empirically analyze the spatial and temporal differences of the agricultural carbon budget, spatial correlation and convergence characteristics of the carbon compensation rate, and regional differences in agricultural carbon compensation potential in Hunan Province counties. [Results] The overall agricultural carbon emissions of Hunan Province counties exhibited a structural form of ‘high value areas in the center that gradually decreased outwards’. Farmland soil was the main source of carbon emissions. The agricultural carbon emission intensity of counties exhibited a pattern of ‘high in the southwest–low in the northeast’ and significantly decreased year by year. The overall agricultural carbon sequestration in the counties exhibited a spatial pattern of ‘high in the east, central, and north regions–low in the southwest’. Agricultural carbon sequestration capacity gradually increased across the region. Rice contributed the most to agricultural carbon sequestration, and agricultural carbon absorption intensity significantly increased and its spatial pattern significantly changed. The agricultural carbon compensation rate in the counties was a net carbon source, with significant positive spatial correlation and convergence, and the spatial clustering and correlation characteristics were obvious. The potential of agricultural carbon compensation in the counties showed a significant imbalance in space, with the proportion of medium and high carbon compensation counties reaching 60.66%, indicating that the agricultural carbon compensation rates of counties in Hunan Province were low, and that there was still a large potential for increasing carbon compensation. [Conclusion] Regional cooperation should be further strengthened, and green transformation should be jointly promoted by interested parties who should give full attention to the radiation driving effect of agricultural carbon compensation rate hot spots in order to maintain the development of excellent low-carbon agriculture in regions with high agricultural carbon compensation capacity. The future focus should be on the development of green agriculture in regions with medium and high carbon compensation potential, and on narrowing the development gap of low-carbon agriculture in all Hunan Province counties.
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[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
[Objective] The influence of land use changes on carbon storage were studied under the expansion of urbanization in Hainan Island to reveal the spatial-temporal evolution pattern of carbon storage and to predict future development trends in order to provide scientific evidence for optimizing the spatial layout of the national territory and for protecting ecologically sensitive areas. [Methods] Based on land use data from 1980 to 2020, this research showed the spatial-temporal changes of carbon storage for Hannan Island. The data were used with the carbon storage module of the InVEST model. The FLUS model and the InVEST model were coupled to simulate land use and carbon storage changes for Hainan Island in 2030 under three scenarios: the natural development scenario, the rapid development scenario, and the ecological protection scenario. [Results] (1) The main types of land use on Hainan Island were forest land and cultivated land. From 1980 to 2020, the areas of cultivated land, grassland, forest land, and unused land decreased to varying degrees. The area of construction land and water increased over this time period, with the fastest growth rate being 83.4% for construction land. (2) Carbon storage for Hainan Island was generally characterized as “high in the middle and low in the surrounding areas”. Carbon storage changed slightly from 1980 to 2000, with a decrease of about 0.03%. From 2000 to 2020, the urbanization process on Hainan Island accelerated, and the loss of carbon storage also increased. The average annual loss was about 372 t, and the cumulative loss of carbon storage was 7439 t. (3) The prediction results showed that construction land will continue to expand in the future, and carbon storage on Hainan Island in 2030 will decrease under the three scenarios. Under the rapid development scenario, the land use change of construction land was the largest, and carbon storage was the most vulnerable to loss, followed by the natural development scenario. The ecological protection scenario had the smallest change. [Conclusion] Land use planning for Hainan Free Trade Port in the future should focus on the protecting key ecological areas such as the central mountainous areas, strengthening the nature reserves of Hainan Island, optimizing the land use pattern, and strictly controlling the transformation of forest land, cultivated land, and wetlands into construction land. The efficiency of carbon sequestration should be improved, and forest carbon sinks should be increased to achieve regional sustainable development.
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[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
[Objective] The changes in land use under different low-carbon scenarios were simulated, and the differences in carbon storage and carbon emissions under multiple scenarios were compared in order to provide relevant suggestions for the low-carbon development of Nanchang City. [Methods] The land use structure in 2030 was optimized based on the maximum carbon storage scenario and the minimum carbon emission scenario. The FLUS model was used to simulate the spatial distribution characteristics of land use in Nanchang under multiple scenarios. [Results] 1) According to the optimization results of the quantity structure, the carbon emissions of land use under the maximum carbon storage and minimum carbon emission scenarios were smaller than under the natural development scenario, and carbon storage was greater than under the natural development scenario. In a comprehensive view, the effect of quantitative structure optimization of land use under the scenario of maximum carbon sink was better. 2) According to the spatial structure simulation results, construction land under the low-carbon scenario was relatively concentrated in spatial distribution compared with the natural development scenario. The areas of carbon emission reduction and carbon storage increase were mainly located in the central and southern regions. [Conclusion] Optimizing land use structure, implementing ecological protection and cultivated land protection policies, limiting excessive expansion of construction land, and strengthening the regulation of key areas will help Nanchang City achieve the goal of carbon peak and carbon neutrality as soon as possible.
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[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
[Objective] Agriculture is an important source of carbon that affects climate change, and its emission reduction and carbon sequestration play an important role in achieving the "double carbon" target and building a strong agricultural country. [Methods] The total, intensity and structure of agricultural carbon emissions in Xuzhou City from 2000 to 2020 were measured using the emission coefficient method, and then the decoupling relationship between agricultural economic development was analyzed based on the Tapio decoupling model. [Results] ①The overall trend of agricultural carbon emissions in Xuzhou city is "rapid rise - fluctuating rise - rapid decline", from 1.61×106 t in 2000 to 1.69×106 t in 2020. It is in the shape of an "M". The contribution to agricultural carbon emissions is in the order of arable land use (46.44%), crop cultivation (31.90%) and livestock breeding (21.66%), with chemical fertilizers being the most important carbon source; ②Agricultural carbon emissions in Xuzhou city vary significantly among districts (counties and cities) and have undergone a long-term evolutionary process from rising to falling, with a spatial distribution pattern of "high in the middle and low in the periphery", with Pizhou city being the most prominent; ③Xuzhou''s agricultural carbon emissions and agricultural economic development have generally undergone a process of "weak decoupling - strong negative decoupling - expansion of negative decoupling - strong decoupling", and the main performance since the 13th Five-Year Plan is strong decoupling. [Conclusion] Xuzhou''s agricultural carbon emissions are becoming more and more reasonable as the concept of low-carbon emission reduction continues to deepen, and the agricultural economic development has also achieved certain results.
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[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
[Objective] Understanding the response of soil labile organic C fractions and enzyme activities to native forest conversion is of great significance for predicting regional soil health and environmental change. [Methods] Hereby the native evergreen broad-leaved forest and the converted conifer plantation, orchard, sloping tillage, and paddy with similar geographical background and clear land use history were selected. The responses of labile organic C fractions and enzyme activities in topsoil to the native forest conversion were investigated using various physical, chemical, and biochemical techniques. [Results] The native forest conversion to orchard, sloping tillage, and paddy significantly lowered the soil organic C content, labile C fractions contents, and enzyme activities by 42% ~ 67%, 47% ~ 88%, and 36% ~ 89%, respectively. Notably, the readily oxidizable organic C, microbial biomass C, and invertase activity had the highest reduction with the native forest conversion, sensitively indicating the reduction in soil organic C content and its lability. The readily oxidizable organic C was a practical index. The reductions in soil labile organic C fractions and enzyme activities were lower by the native forest conversion to plantation than by the native forest conversion to orchard and sloping, showing the preservation capacity of soil labile C in plantation. The ratio of labile organic C to total organic C in soil reduced significantly after the native forest conversion to plantation, sensitively reflecting the reduction in soil C quality. [Conclusion] The native forest conversion led to substantial reductions in labile organic C quantity, C quality, and related enzyme activities in soil, suggesting the degradation of soil biological health and decline in soil quality.
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[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
[Objective] To explore the effects of ecological engineering restoration technology on soil aggregate stability and organic carbon distribution, and to provide scientific basis for improving soil structure stability and carbon sink function of different ecological restoration slopes in Xiangjiaba Hydropower Station. [Method] In this paper, four different ecological restoration slopes of Xiangjiaba Hydropower Station were studied: vegetation concrete (CBS), thick base material spraying(TB), frame beam covering soil (FB), and external soil spraying (SS). The distribution and stability of soil aggregates and the characteristics of organic carbon content were studied by wet sieve method two natural restoration slopes of natural forest (NF) and abandoned land (AS) as control. [Result] The results show that: (1) The soil of each slope is dominated by large aggregates > 0.25 mm. The content of macroaggregates in natural forest is the highest (81.83%). The vegetation concrete and thick base material slope are the second, and the content of waste residue land is the lowest, only 55.19 %. The MWD and GMD of the four artificial ecological restoration slopes are lower than those of the natural forest and higher than those of the waste residue land. The value of the thick substrate slope is the highest, which is 2.96 mm and 1.47 mm, respectively. The fractal dimension ( D ) of the soil spray seeding and slag field is significantly higher (p< 0.05) than the other four slopes. (2) The organic carbon content of large aggregates with particle size > 0.25 mm is the highest in all ecological restoration slope measures. In addition to soil spray seeding and waste residue land, other restoration measures and natural forests have the largest contribution rate of > 2mm soil aggregates. (3) Correlation analysis shows that soil SOC is significantly positively correlated with MWD, GMD and R0.25(p< 0.01), > 5mm and 5-2mm aggregates are significantly positively correlated with soil MWD, GMD, R0.25 and SOC (p< 0.01), and significantly negatively correlated with D (p< 0.01). [Conclusion] In the study area of Xiangjiaba Hydropower Station, the improvement effect of thick substrate spraying technology and vegetation concrete ecological restoration technology on soil structure and organic carbon pool is close to that of natural forest, and the improvement effect of external soil spraying technology is poor.
Abstract:
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
[Objective] Regional carbon storage can be improved by optimizing and adjusting management. Investigating the service function of carbon storage is a crucial guarantee for maintaining ecosystem stability and has a significant influence on ecological environment conservation. [Methods] The Carbon storage module of the InVEST model was used to quantitatively evaluate and study the spatial distribution of carbon storage, explore the effects of land use degree, topography, meteorology, soil erosion, and other factors, and calculate the hot spots of carbon storage based on correlation analysis superposition, using land use data from 2010, 2015, and 2021 in Wuhu. [Results] (1) Carbon storage in Wuhu City has declined by 4.15105 t in recent years due to land use change, with an annual decrease trend. The carbon sequestration capacity of grassland was lower than that of cultivated land, and the carbon storage capacity of cultivated land was 7.41×106 t, while that of forest was 5489.01t/km2. (2) Among natural factors, land use type, elevation, slope, and land use degree were the most important in determining the spatial distribution of carbon stocks, which increased gradually step by step with altitude and slope, and the overall distribution of carbon stocks was "low in the north and high in the south." (3) Carbon storage and soil conservation are highly positively associated, mutually reinforcing, and synergistic among ecological and environmental variables; yet, there is a trade-off with soil erosion. (4) The ratio of "high-high accumulation" in southern China was 18.77%, whereas it was just 2.73% in northern China. The hotspots of carbon storage declined year by year as a result of the effect of resource development and usage, with 11.95% of the excellent regions concentrated in the southern mountain forest, and certain places being vulnerable and needing to be conserved and optimized. [Conclusion] The study of carbon storage change and its influencing elements is critical for improving carbon sequestration capacity for carbon neutrality and urban sustainable development, as well as providing scientific references for arable land conservation and green agricultural development.
Abstract:
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:[Objective] Accurately and effectively monitor the effectiveness of soil and water conservation measures and their carbon sinks, and provide important support for the construction of carbon sink capacity evaluation index system and accounting methods under the dual carbon policy. [Methods] The carbon storage capacity of the vegetation carbon pool and soil carbon pool in the Luodihe small watershed was calculated through field sampling analysis and LiDAR collection of relevant parameters. The study evaluated the carbon sink capacity of comprehensive management of the small watershed. [Results] ①After 21 years of comprehensive management, the carbon sink role and capacity of all kinds of soil and water conservation measures were significantly improved, and the carbon storage of the small watershed increased by 3.97×104 t, with an average annual increase of 1.89×103 t/a, ②From the perspective of carbon pool, the carbon storage of soil and vegetation increased by 73.73% and 346.41% respectively during 2001~2022. The carbon sink of small watershed reached 3.05×104 t, including 1.66×104 t of soil carbon sink and 1.39×104 t of vegetation carbon sink.③There were differences in the ability of various measures to increase the increase of carbon sinks, among which chestnut forest land and fertilized Pinus massoniana forest land increased sink the most obviously, followed by coniferous and broad mixed forest, nursery and protection of Pinus massoniana, horizontal step land preparation of Pinus massoniana forest, and finally closed treatment and bayberry forest land. [Conclusion]The carbon sink capacity of various water and soil conservation measures in carbon retention, carbon sequestration and sink increase is obvious, while the carbon sink capacity of forest land such as chestnut forest and fertilized Pinus massoniana forest land with land preparation, afforestation, and fertilization and breeding measures is more significant, which is an effective means to improve the efficiency of soil and water retention and increase carbon sink.
Abstract:
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
[Objective] Seek slope fine groove erosion measurement technology with high efficiency and precision and strong adaptability, and overcome the problems of low efficiency, high cost and poor applicability of traditional measurement methods. [Methods] The UAV was used to obtain high-resolution images and models of slope trough development under six consecutive artificial simulations of rainfall through close photogrammetry, and verified by three aspects: positioning accuracy, model accuracy and erosion simulation, and the feasibility of slope fine groove erosion and morphological evolution process was quantitatively revealed, and the results are as follows: [Results] (1)The model errors: 〖RMSE〗_3D=1.5cm, 〖RMSE〗_H=0.42cm, and 〖RMSE〗_V=0.88cm. The model details and texture were clear, and the resolution reached the level of millimeter. (2) The multi-phase model can describe the five processes of rill development: raindrop spatter erosion, slice erosion, small drop water, intermittent rill and continuous rill. The rill’s average width, depth and plane density on slope surface developed from 1.25cm, 0.82cm and 0.05 to 3.27cm, 4.75cm and 0.23 cm, respectively. The maximum rill length was 236cm and the maximum rill depth was 14.23cm. (3) With the increase of rainfall duration, the simulated value of rill soil erosion is close to the real value and tends to be stable, with an average error of less than 10%. [Conclusion] This method can better reflect the development and evolution of rill, and has significant advantages over traditional measurement methods in operating efficiency and convenience. It provides new ideas and technical means for slope erosion monitoring practice and scientific research .
Abstract:
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract: [Objective] The main grain producing area have an important strategic position in achieving stable grain production and supply, and improving the cultivated land utilization efficiency in the main grain producing area is an institutional arrangement to guarantee grain security and achieve sustainable agricultural development. [Methods] The innovative two-stage dynamic network DEA model is used to measure the cultivated land utilization efficiency of 179 prefecture-level cities in the main grain producing area from 2010 to 2020, and its spatial and temporal evolution characteristics are analyzed by ArcGIS visualization technology and kernel density estimation, based on which a Tobit model is constructed to explore the factors influencing of cultivated land utilization efficiency. [Results] From 2010 to 2020, the overall efficiency level of the main grain producing area shows a trend of “small decline - rapid rise - fluctuating growth”, and the overall efficiency level is low and still has much room for improvement.By stage, the efficiency level of the production stage is always higher than that of the consumption stage, and the gap between the efficiency levels of the two stages has a tendency to further increase; the improvement of cultivated land utilization efficiency in the main grain producing area is influenced by the combined effect of the efficiency levels of the two stages, with the production stage being the main driver of efficiency improvement and the resistance coming from the efficiency of the consumption stage. By region, Northeast > Middle and Lower reaches of Yangtze River > Yellow and Huaihai regions in terms of cultivated land utilization efficiency, with significant regional imbalance. From the spatial point of view, the overall efficiency and production stage efficiency high value areas are spatially distributed from northeast to southwest, and gradually form a spatial pattern of “high-high” clustering and “low-low” clustering, while the consumption stage efficiency high value areas show a discrete distribution pattern and do not show the development trend of convergence in the direction of upgrading.The external influencing factors of the overall, production and consumption stages are different, involving the level of socio-economic development, urban and rural development, science and technology and agricultural infrastructures, and there are significant differences in the intensity and direction of different factors on the overall and sub-stages of arable land use efficiency in different regions. [Conclusion] Based on this, this paper proposes that in the future, the main grain producing area should not only explore regional differentiated arable land use paths and strengthen cooperation among prefectures, but also focus on the coordination between the convergence rate of the efficiency improvement in the consumption stage and the efficiency gap between the production stage and the consumption stage in each prefecture while improving the efficiency in the production stage.
Abstract:
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
[Objective] Vegetation restoration can effectively prevent and control soil and water losses at abandoned production sites and construction projects. Determining the soil and water conservation effects of various vegetation restoration methods in an abandoned dreg field can provide a theoretical basis for subsequent management and supervision of the area. [Methods] An artificial rainfall simulation experiment was set up to obtain the runoff and sediment production characteristics of a slope surface covered with selected waste slags under different planting methods (broadcast sowing, drill sowing, and hole sowing) and vegetation restoration stages (growth, maturity, and withering periods) from the production and construction projects in the Dabie Mountains of Western Anhui Province, and the patterns and differences were analyzed by methods such as cumulative average deviation. [Results] Compared with bare slope, vegetation restoration effectively delayed the initial runoff generation time. The most obvious effect was observed for broadcast sowing. Various planting methods exhibited varying degrees of effectiveness in reducing runoff and sediment, with the overall runoff and sediment output from a slope following the order of bare slope ＞ hole sowing ＞ drill sowing ＞ broadcast sowing, and withering period ＜ maturity period ＜ growth period. The production of sediment and runoff were characterized by distinct processes, and the effect of reducing runoff was weaker than that of reducing sediment. [Conclusion] The runoff and sediment reduction benefits of planting methods were shown to be greater for broadcast sowing than for drill sowing, with hole sowing being the worst. The efficacy of reducing runoff and sediment during the growth period surpassed that of the maturity period, while the withering period yielded the least benefits. Among the various sowing methods, broadcast sowing exhibited the highest efficiency in reducing runoff and sediment during the growth period, with rates of 49.6% and 95.5% respectively.
Abstract:
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
[Objective] The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light (LFoc) and heavy (HFoc) fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion. [Methods] This study was conducted on Lou soil from Yangling District of Xianyang City, Shannxi Province. An improved "three-zone" mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters, organic carbon compositions of each aggregate size in sediments, and their related δ13C values. Additionally, these results for Lou soil were verified based on the δ13C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil. [Results] ① When rainfall intensity and slope were low, both LFoc and HFoc were enriched in eroded sediments, and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates. ② The δ13C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFoc in SOC (λ), while the δ13C values of organic carbon in other size aggregates showed a significant positive correlation with λ values (p＜0.05). ③ Flow velocity was positively correlated withλ values of clay and silt particles (p＜0.05), while Reynolds number was negatively correlated with δ13C values of clay and silt particles, microaggregates, and macroaggregates (p＜0.01). Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon, while turbulence promoted the transport of organic carbon with low δ13C values in aggregates; ④ For clay and silt particles, the larger the flow velocity and Reynolds number, the smaller the δ13C value of organic carbon and the larger the λ were. For microaggregates and macroaggregates, the smaller of Reynolds number, the larger the δ13C values of organic carbon and λ values in microaggregates were. [Conclusion] The loss of LFoc and HFoc was closely related to flow velocity and Reynolds number during the sheet erosion process. The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
Abstract:
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
[Objective] Predicting changes in blue-green space land use and analyzing their impact on carbon storage in Daxing’an Mountains will provide scientific strategic guidance for realizing the "dual-carbon" goal. [Methods] Based on land utilization data for Daxing’an Mountains in 2015 and 2020, the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030. The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage. The main driving land types of blue-green space causing changes in carbon storage were quantified and verified. [Results] ① Blue-green space continued to grow from 2015 to 2030. Forest land increased over this time period, accounting for more than 60% of the blue-green space transfer, indicating that forest land held an absolute advantage. ② From 2015 to 2020, blue-green space accounted for 96.52% of the total area of carbon storage growth space. Carbon storage for the natural development, blue-green space protection, and rapid urban development scenarios in 2030 were 1.459 4×109 t, 1.483 1×109 t, and 1.464 7×109 t, respectively, mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland. Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③The degree of aggregation of forest land, grassland, and water areas in the blue-green space was significantly and positively correlated with carbon storage. Forest land and grassland were the first and second most dominant types of carbon storage changes. [Conclusion] Excellent ecological policies should be promoted in the future in order to protect the blue-green space and to improve the structural integrity of forest land and grassland in order to achieve the "dual-carbon" goal in the Daxing’an Mountains area.
Abstract:
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
[Objective] Soil erosion is a globally important environmental problem that seriously restricts human production and life. Quantitative study of soil conservation services is helpful for formulating regional soil and water conservation measures, and provides a scientific basis for the planning of water and soil conservation function zoning and control measures in Harbin. [Methods] Soil erosion and soil conservation in 2000, 2010, and 2020 in Harbin were analyzed based on the Sedimentary Delivery Ratio module of the InVEST model. Spatial autocorrelation was used to determine spatial aggregation types of soil conservation. An optimal geographic detector was used to determine the driving force of spatial heterogeneity. [Results] ① In 2000, 2010, and 2020, the soil conservation in Harbin was 2.18×109, 2.07×109, and 2.77×109 t, respectively, showing a trend of initially decreasing and then increasing. The overall spatial distribution pattern was characterized as "low in the west and high in the east". ② The soil conservation amount showed a strong spatial positive correlation，mainly "L-L aggregation" and "H-H aggregation" types， the “L-L aggregation” type area showed a downward trend, while the “H-H aggregation” type showed a decreasing first and then rising trend. ③ Elevation, precipitation, and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin, with average explanatory forces of 0.225 9, 0.198 9, and 0.180 4, respectively，and the interaction be- tween slope and precipitation and other factors was the strongest explanatory interaction factor in the study area. [Conclusion] Harbin should strengthen water and soil management in the western part of the city and along the Songhua River，while main- taining good water and soil conditions in the north and east parts of the city to avoid large-scale human disturbance activities.
Abstract:
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
[Objective] The ecological product values(EPV) were evaluated and the driving factors of their spatial change were also explored in Hebei Province, which is to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods] The EPV were computed for 168 counties in Hebei Province during 2010, 2015, and 2020 by use of the equivalent factor method. Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index, high/low clustering index, and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces. [Results] ① Between 2010 and 2020, Hebei Province's EPV surpassed 380 billion yuan, exhibiting notable overall improvement. EPV exhibited a pattern of gradual increase followed by rapid growth, exceeding 420 billion yuan by 2020. Forest land had the highest EPV, consistently dominating the ecological product types Water areas had the next highest EPV, and experienced the most substantial changes in both amount and rate. ② During 2010 to 2015, EPV's spatial distribution exhibited a north-south and west-east dichotomy, with high values concentrated in the northern Yanshan and Bashang Plateau regions, as well as in the western Taihang Mountain area, while lower values clustered in the southeastern Hebei Plain. During 2015 to 2020, the north-south divide persisted, with added east-west variation and central low values. ③ From 2010 to 2020, significant high-value clustering was observed spatially, mirroring the distribution pattern of cold and hot spots. ④ Single-factor analysis identified CO surface concentration, O3 concentration, and average annual temperature as primary influencers of EPV's spatial evolution. Per capita GDP emerged as the secondary vital factor, while the impact of social factors remained comparatively weak. Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP ∩ NO2 surface concentration, elevation ∩ O3 concentration, and per capita GDP ∩ CO surface concentration, with corresponding q values of 0.71, 0.73, and 0.66, respectively. [Conclusion] While forest land and water areas hold pivotal roles in augmenting EPV, significant spatial disparities exist. To drive more positive transformations, it is essential to not only consider robust ecological single-factor drivers, but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
Abstract:
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
[Objective] The spatial and temporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020 were systematically studied based on county area, and the spatial distribution, migration law, and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province. [Methods] Based on land use data for Fujian Province in 1980, 1990, 2000, 2010, and 2020, a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province. [Results] ① The cultivated land resources in Fujian Province were mainly distributed in a belt-shaped manner along the southeastern coast, and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences, and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province. The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land into mainly construction land, forest land, and grassland. ③ The center of gravity of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center, and its distribution was uneven. The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center, shifting first to the southwest, then to the southeast, and then to the northwest. The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province. The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part of the province to the northwestern part of the province. ④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering. The spatial changes of the "high-high" and "low-low" clusters played a dominant role in the evolution of the spatial autocorrelation of cultivated land non-agriculturalization in Fujian Province, with the "high-high" clusters shifting from the southeast to the northwest, and the "low-low" clusters shifting from the southeast to the northwest. The "high-high" clusters shifted from the southeastern region to the northwestern region, and the number of "low-low" clusters decreased. [Conclusion] The study results revealed the spatio-temporal evolution pattern of cultivated land non-agriculturalization in Fujian Province from 1980 to 2020, and provide a reference to guide the government in controlling the phenomenon of cultivated land non-agriculturalization in order to achieve the sustainable development of cultivated land resources.
Abstract:
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
［Objective］ Rainfall is an important factor inducing regional landslide disasters. In order to study the relationship between different durations of rainfall intensity and regional landslide disasters.［Methods］this article collected hourly rainfall data from 348 rainfall stations in the study area over the past 10 years, as well as the time and location of 231 disaster and dangerous landslide events that have occurred in the past 10 years. Based on the average rainfall intensity (I) - rainfall duration (D) model, it was divided into geomorphic units, Proposed critical rainfall warning thresholds and graded warning thresholds for different rainfall durations.［Results］ The research shows that the red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in the hilly terrain area of the study area are 29.774 mm, 18.579 mm, 14.416 mm, 11.186 mm, 8.679 mm, and 6.734 mm, respectively; The red warning thresholds for the average rainfall intensity at 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours under different early rainfall conditions in low mountain terrain areas are 28.849 mm, 15.542 mm, 10.520 mm, 7.121 mm, 4.820 mm, and 3.263 mm, respectively.［Conclusion］ Under the condition of rainfall in the early 24h period, the sensitivity of low mountainous area to rainfall is significantly higher than that of hilly area, and the critical warning thresholds of 1h, 3h, 6h, 12h and 24h in low mountainous area are significantly lower than those in hilly area. However, with the further extension of rainfall duration, the critical warning thresholds of low mountainous area and hilly area tend to be similar.
Abstract:
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
[Objective] The problem of water shortage has seriously restricted human production and life, and carrying out quantitative research on water yield services is not only conducive to the formulation of regional water resources protection planning, but also conducive to improving the comprehensive service function of regional ecosystems. However, at present, there is a lack of research on the temporal and spatial variation characteristics of water yield services in cold regions in China. [Methods]In this study, Harbin, a typical cold land city, was selected as the research area, and the spatiotemporal variation characteristics of water yield in 2000, 2010 and 2020 were analyzed based on the InVEST model water yield module, and the spatial and temporal evolution of water yield services in Harbin was revealed by using the parameter optimal geographic detector. [Results] The results show that: (1) The water output of Harbin from 2000 to 2020 showed a year-by-year growth trend, and the water output increased from 96.83×108m3 in 2000 to 223.08×108m3 in 2020. The spatial distribution pattern of water yield in different years is basically similar, and the overall distribution characteristics of high east and low west are manifested spatially. (2) There was a strong spatial positive correlation in the distribution of water yield in the study area, mainly low-low aggregation and high-high aggregation types, and the proportion of the two areas to the city''s area showed a downward trend from 2000 to 2020. (3) The influence of each driving factor on water yield has obvious spatial heterogeneity, actual evapotranspiration and land use type are the main driving factors of economic quality development zone. In the nature-dominated ecological barrier area, the comprehensive driving force of the two is far less than that of the economic quality development area. [Conclusion] Water yield assessment is the basis of water conservation research, which is closely related to the value of ecosystem services and ecological products, so the research results provide a basis for the establishment of ecological compensation mechanism and scientific and effective management of ecosystems in the research area.
Abstract:
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
[Objective] Reducing carbon emissions is important for Yunnan Province to actively serve and integrate into the national development strategy as it strives to become a vanguard in the construction of ecological civilization. {Methods] The spatio-temporal change and spatial correlation of eco-environmental quality in Yunnan Province were determined based on risk-screening environmental indicators (RSEI), and the priority of ecological restoration in Yunnan Province was identified by combining these results with regional ecosystem carbon reserves and an ecological protection red line in order to provide a scientific basis for low-carbon sustainable development of Yunnan Province. [Results] (1) The average value of RSEI in Yunnan Province showed an "S-shaped" trend over the past 22 years, with 2005 and 2011 being the inflection points of increasing and decreasing RSEI, respectively. (2) From 2000 to 2022, the spatial eco-environmental quality was characterized as "high in the west and low in the east". The ecological environmental quality in the western region was good, while the ecological environmental quality in the central urban agglomeration and the eastern karst region was poor. (3) From 2000 to 2005, the ecological environmental quality became better under the influence of the policy of returning farmland to forests. From 2005 to 2011, the ecological environmental quality decreased significantly due to drought and the drastic expansion of construction land. 2000–2016 was a period of recovery after drought. Except for the areas with rapid urbanization in central China, the ecological environmental quality in other areas gradually recovered. Due to the influence of national policies in 2016, the ecological environmental quality further improved. (4) The ecological environmental quality of Yunnan Province showed obvious spatial global and local autocorrelation; (5) The carbon reserves of Yunnan Province initially increased and then decreased from 2000 to 2022, and the total carbon reserves decreased by 2.38×107 t in 22 years. Carbon reserves showed a zonal distribution characterized as "high in the north and south, and low in the central region". (6) The high priority areas for ecological restoration in Yunnan Province were mainly located in the north and east, accounting for about 18.08% of the total area, while the medium priority areas for ecological restoration were more widely distributed, accounting for about 70.17% of the total area. The general priority areas for ecological restoration were mainly located in Pu′er City and other places, accounting for about 11.76% of the total area. [Conclusion] The ecological environmental quality of Yunnan Province exhibited distinct patterns in time and space from 2000 to 2022. Based on these results, the ecological restoration area should be divided, and the ecological environment should be controlled according to local conditions in order to promote ecological and sustainable low-carbon development in Yunnan Province.
Abstract:
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
[Objectve] Using remote sensing technology to objectively and timely dynamic monitor the urban ecological environment status and change information was of great significance for urban ecological planning, management and protection. [Methods] Nanning, the most critical core city of the China-Asean economic circle and the Beibu Gulf urban agglomeration, located in the transitional zone from karst mountain to non-karst basin in Guangxi. Here, this paper collected Landsat TM/ETM+/OLS historical images of the same season from 2000 to 2020 year, and removed images clouds, chromatic aberration on Google Earth Engine (GEE) platform at the pixel level. Meantime, the median value composite was adopted to calculate four remote sensing indicators including greenness, wetness, dryness and heat, and the remote sensing ecological index (RSEI) was constructed by principal component analysis (PCA) to evaluate the dynamic changes and spatial differentiation characteristics of urban ecological environment quality in Nanning city, under the help of parallel cloud computing ability in GEE. [Results] The average value of RSEI was 0.615 in Nanning city, and its ecological environment quality had shown a fluctuating upward trend of "down- rise- stable". The spatial heterogeneity of ecological environment quality in Nanning city was obvious. The areas with better ecological environment quality mainly concentrated on the nature reserves, forest land, grassland and water area, while the degraded areas of ecological environment quality were mainly distributed in the cities, urban-rural combination zone and farming areas. RSEI had a positive correlation with greenness and wetness indicators, while negatively correlated with dryness and heat. [Conclusion] RSEI could well characterize the ecological environment quality of Nanning city, and the overall ecological environment quality was at a good level from 2000 to 2020. This paper provided and demonstrated that GEE could effectively improve the remote sensing images quality efficiency and be used as a computing platform for monitoring and assessing the ecological environmental quality in the urban region and long-term sequence.
Abstract:
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
[Objective] In recent years, the non-point source pollution caused by agricultural intensification, especially the erosion of ditches, has become increasingly serious. Water pollution is exacerbated by ditch erosion and nutrient loss into the river, whereas the effect of plants on reducing ditch erosion and nutrient loss have not been quantified. Therefore, the influences of plants on reducing ditch erosion and C, N and P loss were studied to provide technical support for the prevention of ditch erosion and control of pollution. [Methods] In this study, the ditches of Nala watershed in the intensive sugarcane growing area of South subtropical China were taken as the research object. A kind of herbaceous plant named vetiver (Vetiveria zizanioides (L.) Nash) was planted with different vegetation coverage in the ditches. Regular field investigation and monitoring of planted ditches were conducted after rainfall from April to October ,and the characteristics of erosion and nutrient loss under different vegetation coverage were quantified.. [Results] ①From April to October, the width, erosion, nutrient loss of the ditches with different vegetation coverage gradually over time, and all the indices were in the same order: BG > SC > MC > CC; ②Compared with BG, the erosion amount of SC, MC and CC decreased by 37.01%, 71.60% and 75.04%,C loss decreased by 35.56%, 70.91% and 75.23%, N loss decreased by 35.89%, 71.01% and 74.39%, and P loss decreased by 34.22%,70.59% and 77.01%, respectively; ③The correlation analysis showed that the erosion amount of ditches was significantly negatively correlated with the coverage and plant root density (p < 0.01), which accounted for 91.94% and 89.23% of the erosion changes, respectively. [Conclusion] The results showed that with the increase of vegetation coverage, the ditch erosion and nutrient loss gradually decreased, and there was no significant difference when vegetation coverage was between MC and CC, which can provide reference for ameliorating the ditch erosion and reducing pollutants in other water sources areas.
YANG Cuihong, LI Yong, WANG Xu, CHEN Tingting, GUO Hao, YANG Yijiang, WU Zongmeng, ZHOU Xiaoqi, HUANG Zhigang
Abstract:
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
[Objective] Investigating the suitable configuration ratios contour planting and replanted configuration ratios of sugarcane, it can provide technical support for mitigating gully erosion and it-induced nutrient losses, improving cultivated farmland quality and rationally planting sugarcane in sugarcane growing area. [Methods] In this paper, three ratios of higher, medium and lower of contour and replanted sugarcane slopegully erosion and nutrient losses were determined by field measurement and laboratory experiment, with the stage of establishment growth (EG), vegetative growth (VG), grand growth (GG) and ripening growth (RG), and the influencing factors. [Results]①During the total growth (TG) of sugarcane, the total nitrogen (TN) and total phosphorus (TP) losses caused by gully erosion on sugarcane planting slope in Nala watershed were 31.3-66.3 t/hm2, 39.0-82.5 kg/hm2 and 18.0-38.4 kg/hm2, respectively. (2) EG was the main stage of gully erosion and nutrient losses in Nala watershed, and the contribution was 47.7%-57.7%. (3) In the stage of TG, gully erosion and associated nutrient losses of higher ratios of contour (Hc) were 33.03%-35.42% lower than those of lower ratios of contour (Lc) (P < 0.05), but the losses of medium ratios of contour (Mc) were not significant with those of Hc and Lc. Gully erosion and nutrient losses oflower ratios of replanted (LRp) were 27.41% to 32.98% Lower than those of Higher ratios (HRp), and 21.02% to 25.86% lower than those of medium ratios (MRp) (P < 0.05). The litter cover and root density were the important factors affecting gully erosion and nutrient losses. (4) During the stage of TG, TN and TP losses of slope accounted for 24.1%-39.5% and 107.0%-156.7% of the annual N and P application respectively. [Conclusion] Planting sugarcane with more than 60% contour planting ratio and less than 30% replanted ratio can effectively reduce soil and nutrients losses on slope.
Abstract:
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
[Objective] The influence of environmental factors on the plant community of a slope during the process of ecological restoration objective of this study was evaluated in order to provide a reference for the ecological restoration of disturbed areas in southeastern Tibet. [Methods] We studied an area of the newly constructed PAIMO Highway in southeastern Tibet. We determined the relationships between community cover, species diversity indexes (Shannon-Wiener index, Simpson diversity index, Margalef richness index, Pielou evenness index), community weighted trait values (specific leaf area, leaf dry matter content, leaf nitrogen content, and leaf phosphorus content), and environmental variables (elevation, restoration measures) based on an investigation of the plant community of an ecological restoration area along a slope. [Results] (1) Elevation significantly influenced the Margalef richness index and leaf dry matter content (p＜0.05); (2) High-intensity measures significantly increased community cover, specific leaf area, and leaf nitrogen content (p＜0.05), but significantly decreased leaf phosphorus content (p＜0.05); (3) the SJP technique with high human intervention could significantly increase the leaf dry matter content of high-elevation plants and showed an overall greater efficacy. [Conclusion] The difficulty associated with natural vegetation restoration increases as elevation increases, and artificial restoration measures need to be intensified to prevent ecological degradation in alpine regions.
Abstract:
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
[Objective] Three-River-Source National Park (TRSNP), which comprises the headwaters of the Yellow, Yangtze and Mekong Rivers, has been described as the ‘Water Tower of Asia’. It is of great importance to explore and analyze the spatial distribution characteristics of soil erosion in the TRSNP. [Methods] Water erosion of the park was assessed using the Chinese Soil Loss Equation (CSLE) integrating rainfall erosivity factor (R) acquired using the daily rainfall data of 5 counties including Zhiduo, QuMalai, Maduo, Zaduo and Tanggula county in Qinghai province during 1986-2015, soil erodibility factor (K) obtained from the First National Water Census for Soil and Water Conservation published by Ministry of Water Resources, P.R.China in 2013, slope length factor (L) and slope steepness factor (S) extracted from the 1:50,000 topographic map, biological control factor (B) estimated by vegetation coverage, and the values of engineering control factor (E) and tillage factor (T) assigned according to the related outcome of the First National Water Conservancy Census. Wind erosion of the TRSNP was evaluated by grass-shrub wind erosion model and sandy-land wind erosion model considering wind erosivity factors based on wind speed during 1991-2015, topsoil moisture factors calculated by AMSR-E level 2A brightness temperature, roughness factors and vegetation coverage. Takes phase transition water content, freeze-thaw cycle days, annual precipitation, slope, slope aspect, vegetation coverage as indexes to evaluate freeze-thaw erosion intensity. [Results] The results showed that the area of 2.64×104km2 suffered from soil erosion, accounting for 21.47% of land area in TRSNP. Among the three sub-parks, the Yellow-River-Source Park possessed with the most extensive soil erosion, in which soil erosion accounting for approximately 50% of the total land areas, twice than that of the TRSNP, whereas one-eighth of the Yangtze-River-Source Park area subject to extremely severe erosion. The elevation in the TRSNP along with the degree of slope, as well as depleted grassland cover were major factors in soil erosion. Water erosion occurred mainly in the area with elevations above an elevation of 4900 m, which occupied 70% of the land area, however, 85% of the wind erosion occurred in zones less than 4900m in elevation. The water erosion areas were mainly located in regions where the slope categories were 8°-25°, and a major part of the wind erosion were widely distributed in slopes between 0° and 5°, all of that needed urgent conservation measures. Grassland was the most important land cover in the TRSNP, which occupied about 80% of the area. Scenarios with different vegetation cover on soil erosion areas showed that low vegetation cover (<30%) and medium-low cover (30%-45%) can considerably caused the loss of soil erosion. Besides, it is worth noting that sandy land and bare land prone to high intensity soil erosion. [Conclusion] In general, Two-thirds of water erosion areas were mainly distributed in zones where the elevation was above 4900m, slope gradients between 8° and 35°, and grassland cover less than 45%. Wind erosion was particularly distributed in an elevation ranging from 4200m to 4900m, the degree of slope less than 5°, and grassland coverage less than 60%. The spatial distribution of soil erosion varied greatly among the sub-areas, demonstrating partition policy should be considered to reduce soil erosion. The present results provide a vital database necessary to control soil erosion in order to ensure sustainable ecological civilization construction in the TRSNP.
Display Method:
2023,43(4):238-247, DOI: 10.13961/j.cnki.stbctb.20230508.007
Abstract:
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
[Objective] The mechanism underlying the spatial and temporal variation characteristics of regional forest cover was studied by using the source-sink landscape principle in order to provide a basis for decision-making regarding forest resource conservation. [Methods] We collected datasets of land use/cover change (LUCC), digital elevation model (DEM), and road traffic in Fujian Province for 2010 and 2020, and identified landscapes (i.e., source landscapes and sink landscapes) that either promoted or prevented/delayed forest loss. The comprehensive location-weighted landscape contrast index (LCI') was calculated by integrating three landscape spatial elements (elevation, slope, and distance). The spatial pattern change of forest loss in Fujian Province was systematically determined at the provincial and city scales. [Results] At the provincial scale, LCI' was 0.117 and 0.152 in 2010 and 2020, respectively. The source landscape contributed more to forest loss, and the most influential of the spatial elements of the landscape was distance, followed by slope and elevation. There were differences in calculated LCI' at the city scale, with relatively small LCI' in Nanping, Sanming, and Longyan (＜0) and large LCI' in Fuzhou, Putian, Xiamen, Quanzhou, and Zhangzhou (＞0). The LCI' of all cities in Fujian Province in 2020 had increased slightly since 2010, with Fuzhou having the largest increase (0.070) and a more dramatic forest loss relative to other cities. [Conclusion] There have been different degrees of forest loss in various regions of Fujian Province during the last decade. The LCI' combined the landscape pattern with process, and effectively reflected changes in forest spatial patterns in Fujian Province from 2010 to 2020.
2023,43(4):154-161,210, DOI: 10.13961/j.cnki.stbctb.2023.04.019
Abstract:
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
[Objective] The changes in ecological environmental quality in the Taiyuan urban agglomeration from 2002 to 2021 were studied in order to provide scientific recommendations for sustainable urban development and green transformation. [Methods] We used the GEE platform, MODIS images, and principal component analysis to construct the ecological remote sensing index (RSEI) by coupling greenness, humidity, heat, and dryness. The spatial properties of ecological quality changes in the Taiyuan urban agglomeration were studied by using combining stability analysis and spatial autocorrelation analysis. The influence of various factors on RSEI was quantified by geographic detectors. [Results] The contribution rate of the first principal component was greater than 75% in all years, indicating that RSEI values extracted based on the first principal component could comprehensively characterize the ecological environmental quality in the study area. The ecological environmental quality of the Taiyuan urban agglomeration showed an overall upward trend from 2002 to 2021, increasing from 0.433 to 0.488, with a growth rate of about 0.0029/yr. The ecological improvement area accounted for 17.1%, mainly located in Lanxian County and Jingle County in the northwest. There was obvious spatial autocorrelation in the change of ecological environmental quality in the study area, and the Moran’s I index was 0.729. The high-high and low-low aggregation areas basically coincided with the ecological improvement and degradation areas, respectively. The ecological environmental quality of the Taiyuan urban agglomeration was significantly correlated with the climatic factors of relative humidity, air temperature, and potential evapotranspiration. [Conclusion] The ecological environmental quality of the Taiyuan urban agglomeration has improved from 2002 to 2021, and the vegetation coverage and urban expansion factors have had great impacts. RSEI can effectively monitor changes in the ecological environmental quality in the study area.
2012(5):8-12, DOI: 10.13961/j.cnki.stbctb.2012.05.011
Abstract:
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km2的有99个, 最大冰湖面积达到0.976km2。 (2)99个面积>0.01km2的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km2, 较1988年的7.03km2仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。
2023,43(4):220-228,326, DOI: 10.13961/j.cnki.stbctb.2023.04.027
Abstract:
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
[Objective] The construction method for an urban ecological network based on morphological spatial pattern analysis (MSPA) and ecological protection importance evaluation were studied in order to provide a scientific reference for the planning and construction of urban ecological network. [Methods] The importance of ecological protection at Mudanjiang City, Heilongjiang Province was evaluated using the topological superposition of MSPA analysis results, and the birth source area was comprehensively obtained. We used the minimum resistance model to extract potential ecological corridors in the study area, and combined them with gravity models for importance classification. We optimized the ecological network structure from three aspects: source supplement, corridor supplement, and stepping stone supplement. [Results] ① The MSPA analysis results showed that the core area of Mudanjiang City had the highest proportion of landscape types (accounting for 87.41%) and that forest land was the main landscape type. ② There were 10 main ecological sources and six secondary ecological sources at Mudanjiang City. ③ There were 16 potential important ecological corridors and 104 general ecological corridors at Mudanjiang City. ④ Ecological network closure (α index) before optimization was 0.53, and 0.66 after optimization. Number of network connections (γ index) was 0.69 before optimization, and 0.77 after optimization. Line point rate (β index) was 2.0 before optimization, and 2.26 after optimization. [Conclusion] The application of the comprehensive MSPA analysis method and the ecological protection importance evaluation method in ecological network construction can help improve the structure and functionality of the ecological network.
2022,42(2):264-274, DOI: 10.13961/j.cnki.stbctb.2022.02.036
Abstract:
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
[Objective] The response characteristics of vegetation NDVI to population density change were explored to reveal the migration track of vegetation NDVI and population density center of gravity in the Bohai Rim region, in order to provide a theoretical basis for vegetation monitoring and management and ecological environment protection in the region. [Methods] Based on the MOD13A3 NDVI and population density time series from 2000 to 2020, the methods of Theil-Sen Median analysis, Mann-Kendall significance test, Granger causality test, Getis-Ord Gi* analysis, and center of gravity transfer model were used to study the spatio-temporal variation of vegetation cover and the hotspot variation of population density. [Results] ① from 2000 to 2020, NDVI in the Bohai Rim region showed an upward trend, with an upward slope of 0.022/10 a, and the area of NDVI rising was much larger than that of falling area. The rising rate of NDVI from 2000 to 2010 was significantly higher than that from 2010 to 2020. ② From 2000 to 2020, the proportion of hot spots and cold spots in the change of population density in the Bohai Rim region was 11.26% and 46.84% respectively. The change of population density was mainly in the cold spot region, which mainly extended in strips from the northeast of the Bohai Rim region to the northwest and some areas in the southeast of Shandong Province. ③ There was a one-way Granger cause of population density on NDVI around the Bohai Sea. The change of population density was the Granger cause of the change of NDVI, while the change of NDVI was not the Granger cause of the change of population density. On the whole, the growth of population density mainly had a negative effect on regional NDVI. The higher the degree of population agglomeration, the more significant the decline of NDVI. ④ There was no obvious spatial pattern in the migration direction of NDVI center of gravity of vegetation from 2000 to 2020, but it generally migrated to the northwest, and the center of gravity of population density migrated from the southeast to the northwest. [Conclusion] From 2000 to 2020, the NDVI in the Bohai Rim region shows an upward trend. The increase of population density has a negative impact on the change of NDVI. Further study needs to be conducted considering the impact of population density change and climate change on NDVI change in the Bohai Rim region.
2006(3):1-5, DOI: 10.13961/j.cnki.stbctb.2006.03.002
Abstract:
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
降水入渗规律的研究可为流域水文过程的预测和评价提供重要的科学依据。通过野外人工模拟降雨的试验方法,研究了短历时暴雨条件下,不同降雨强度对林灌地、封禁草灌地以及裸露农地3种不同土地利用类型下土壤入渗的影响。试验结果表明:不同土地利用类型之间,林灌地和封禁草灌地的土壤入渗速率差异不明显,而与裸露农地之间的差异显著,且前者具有较大的入渗速率,后者入渗速率较小;在不同降雨强度下,林灌地和封禁草灌地的土壤水分入渗速率有随雨强增大而增大的趋势,对于坡耕裸地,随着雨强的增大,土壤水分入渗速率有降低的趋势;通过对试验数据的回归分析,建立了林灌地和封禁草灌地在短历时暴雨条件下的土壤水分入渗经验模型。
2009(1):62-65, DOI: 10.13961/j.cnki.stbctb.2009.01.027
Abstract:
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
采用固定点动态监测的方法,对黄土丘陵区吴起县合家沟流域阳坡和半阳坡各微地形土壤水分进行了对比研究。结果表明,微地形对土壤含水量具有显著影响,阳坡各微地形土壤水分顺序为:切沟>平缓坡>切沟沟头>陡坡>极陡坡;半阳坡各微地形土壤水分顺序为:平缓坡>浅沟>陡坡>极陡坡。0-20cm土层土壤水分变异系数最大的是切沟,最小的是切沟沟头。最后指出在植被恢复过程中,应根据不同微地形的土壤水分分布特征,结合"适地适树,适林适草"的植被恢复原则,合理配置乔、灌、草的营建模式。
2022,42(2):210-218, DOI: 10.13961/j.cnki.stbctb.20220124.001
Abstract:
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
[Objective] An urban ecological security pattern were constructd to identify the main ecological corridors in order to provide a scientific reference for optimizing the ecological pattern in urban land spatial planning. [Methods] Fuzhou City of Jiangxi Provicne was used as a research area. A minimum cumulative resistance (MCR) model was constructed by selecting various land use factors, soil and water conservation function importance, and ecological sensitivity. The importance of a biodiversity maintenance function, global hydrological analysis, ecological protection red line, and natural protection were used to identify ecological sources using the MCR model and spatial analysis tools in ArcGIS. [Results] ① The overall ecological environment of Fuzhou City was good. The proportion of areas with extremely important soil and water conservation function was 49.97%, mainly concentrated in the central area of Fuzhou City, mainly Lichuan County, Le’an County, Yihuang County, and Nanfeng County. The proportion of extremely important ecological sensitivity was 1.39%; ② The ecological source area was 3 302.34 km2, accounting for 17.57%, mainly in the east and southwest parts of Fuzhou City; ③ Based on the ecological elements and topography of the entire region, Fuzhou City presented an ecological security pattern of “one axis, two screens, multiple corridors, and multiple nodes”. [Conclusion] By combining ecological sources, ecological corridors, and ecological nodes, a complete and systematic ecological protection pattern and an open spatial network system can be formed to maintain the ecological security and biodiversity of Fuzhou City.
2002(4):50-53, DOI: 10.13961/j.cnki.stbctb.2002.04.013
Abstract:
对青藏铁路格尔木—拉萨段的生态环境本底状况作了全面地分析,指出建于世界上最高、最大的高原面上的青藏铁路沿线的生态环境具有无以比拟的特殊性、敏感性、脆弱性和生态景观的差异性,如果施工期间未能采取行之有效的环保措施,那么巨大的土石开挖量、堆积量和工程迹地量定会对青藏高原的生态环境造成严重的负面影响。提出了一系列的环保措施,以期对铁路建设单位有所帮助,将对青藏高原生态环境造成的负面影响减少到最小,使生态环境恢复到最好
对青藏铁路格尔木—拉萨段的生态环境本底状况作了全面地分析,指出建于世界上最高、最大的高原面上的青藏铁路沿线的生态环境具有无以比拟的特殊性、敏感性、脆弱性和生态景观的差异性,如果施工期间未能采取行之有效的环保措施,那么巨大的土石开挖量、堆积量和工程迹地量定会对青藏高原的生态环境造成严重的负面影响。提出了一系列的环保措施,以期对铁路建设单位有所帮助,将对青藏高原生态环境造成的负面影响减少到最小,使生态环境恢复到最好
2019,39(5):194-203, DOI: 10.13961/j.cnki.stbctb.2019.05.027
Abstract:
[Objective] This study aims to explore the regional water stress state and their causes and provides a theoretical basis for the development and allocation of rational water resources.[Methods] A three-dimensional water footprint model was built to analyze the sustainability of water resources by using the sustainability index of water resource. The logarithmic mean divisia index (LMDI) factor decomposition model was also applied to quantitatively analyze the structural, technological, economic, and population effects on water resources in Anhui Province from 2007 to 2016.[Results] ① From 2007 to 2016, the water footprint of Anhui Province, in which the internal water footprints accounted for 97.88% to 98.73%, at first increased and then decreased. The consumption of water by agriculture among the internal water footprints was the highest and showed the same variation as the overall water footprint. In 2016, the per capita agricultural water use in Anhui Province decreased from north to south, meanwhile, the Yangtze River basin accounted for the highest proportion in the other types of water footprint. ② During 2007-2016, the footprint depth of the Anhui Province fluctuated within 2~4 and eventually declined from north to south. The results indicated that the overall sustainable use of water resources in Anhui Province increased from 2007 to 2016. ③ The driving factors of the water footprint in Anhui Province showed that the technical effect was a reverse driving, and the economic effect contributed the most to the positive driving.[Conclusion] The three-dimensional water footprint model used in this study can be a helpful tool to better reflect the actual situation of the water footprint in Anhui Province. Although of the use of water resources generally increased, optimizing the structure of the water resources utilization and accelerating improvements in the efficiency of water resource usage is necessary to alleviate the pressure on water resources resulting from economic development and population growth.
[Objective] This study aims to explore the regional water stress state and their causes and provides a theoretical basis for the development and allocation of rational water resources.[Methods] A three-dimensional water footprint model was built to analyze the sustainability of water resources by using the sustainability index of water resource. The logarithmic mean divisia index (LMDI) factor decomposition model was also applied to quantitatively analyze the structural, technological, economic, and population effects on water resources in Anhui Province from 2007 to 2016.[Results] ① From 2007 to 2016, the water footprint of Anhui Province, in which the internal water footprints accounted for 97.88% to 98.73%, at first increased and then decreased. The consumption of water by agriculture among the internal water footprints was the highest and showed the same variation as the overall water footprint. In 2016, the per capita agricultural water use in Anhui Province decreased from north to south, meanwhile, the Yangtze River basin accounted for the highest proportion in the other types of water footprint. ② During 2007-2016, the footprint depth of the Anhui Province fluctuated within 2~4 and eventually declined from north to south. The results indicated that the overall sustainable use of water resources in Anhui Province increased from 2007 to 2016. ③ The driving factors of the water footprint in Anhui Province showed that the technical effect was a reverse driving, and the economic effect contributed the most to the positive driving.[Conclusion] The three-dimensional water footprint model used in this study can be a helpful tool to better reflect the actual situation of the water footprint in Anhui Province. Although of the use of water resources generally increased, optimizing the structure of the water resources utilization and accelerating improvements in the efficiency of water resource usage is necessary to alleviate the pressure on water resources resulting from economic development and population growth.
2002(3):58-58, DOI: 10.13961/j.cnki.stbctb.2002.03.017
Abstract:
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。
2023,43(2):43-49,59, DOI: 10.13961/j.cnki.stbctb.20230423.001
Abstract:
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
[Objective] The reinforcing effects of Sophora japonica roots on soil at different water contents and different thawing times were studied in order to provide a design basis for the soil consolidation effect of Sophora japonica in the monsoon freeze zone. [Methods] The stress-strain and strength characteristics of the root-soil composite of the Sophora japonica root system were determined using the indoor triaxial test method. The shear strength index of the Sophora japonica root-soil composite was determined under different thawing times and different moisture contents. [Results] The reinforcing effect of the Sophora japonica root system at different water contents was most obvious at low and high water contents. The reinforcing effect of the Sophora japonica root system before and after freezing and thawing was reflected in the fact that the Sophora japonica root system bound the movement between soil particles when the soil received a load, increased the occlusion between soil particles, and increased the contact surface between the roots and soil particles, thus increasing the angle of internal friction. The electron microscope scanning test showed that the Sophora japonica root system inhibited the generation and development of cracks in the soil, thus increasing the integrity of the soil. [Conclusion] The Sophora japonica root system can result in a reinforcing effect in all areas. There are different optimal root contents for different water contents. The solidification effect of the Sophora japonica root system is reflected by the increase in internal friction angle of the soil body, increasing the structural integrity of the soil.
2001(1):30-34, DOI: 10.13961/j.cnki.stbctb.2001.01.008
Abstract:
水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.
水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.
2014(5):153-157, DOI: 10.13961/j.cnki.stbctb.20140928.002
Abstract:
北京市水资源短缺的问题已成为制约社会经济发展和影响社会稳定的重要因素之一,因此,如何协调北京市城市绿化与水资源的合理有效利用问题亟需得到解决。基于北京市城市绿化现状及水资源利用现状,采用尺度扩展法,计算了2012年北京市城市绿化的生态需水量,并结合北京市有效降雨利用量和实地调查数据,求得2012年北京市城市绿化的理论供水量和实际供水量。在此基础上,利用灰色马尔科夫链模型与熵值法对北京市城市绿化供水的3种来源(地表水、地下水、再生水)做出评估,得出2014年实际供水量预测值区间。2012年北京市理论供水量为5.07×108 m3,实际供水量为6.86×108 m3。2014年预测实际供水量区间为7.29×108~7.93×108 m3。评估结果表明,北京市仍存在城市绿化用水供需风险问题,并据此提出相关节水措施和建议,为保障北京城市供水安全与水资源可持续利用相关研究提供参考和借鉴。
北京市水资源短缺的问题已成为制约社会经济发展和影响社会稳定的重要因素之一,因此,如何协调北京市城市绿化与水资源的合理有效利用问题亟需得到解决。基于北京市城市绿化现状及水资源利用现状,采用尺度扩展法,计算了2012年北京市城市绿化的生态需水量,并结合北京市有效降雨利用量和实地调查数据,求得2012年北京市城市绿化的理论供水量和实际供水量。在此基础上,利用灰色马尔科夫链模型与熵值法对北京市城市绿化供水的3种来源(地表水、地下水、再生水)做出评估,得出2014年实际供水量预测值区间。2012年北京市理论供水量为5.07×108 m3,实际供水量为6.86×108 m3。2014年预测实际供水量区间为7.29×108~7.93×108 m3。评估结果表明,北京市仍存在城市绿化用水供需风险问题,并据此提出相关节水措施和建议,为保障北京城市供水安全与水资源可持续利用相关研究提供参考和借鉴。
2001(3):59-62, DOI: 10.13961/j.cnki.stbctb.2001.03.020
Abstract:
分析了田间同深度土壤含水量的半方差和不同深度土壤含水量的交互半方差特征，探讨了土壤含水量的Kriging和Cokriging估值方法。研究表明，同深度土壤含水量与不同深度的土壤含水量之间均具有显着的空间相关性，用Kriging方法进行土壤含水量的估值精度较传统方法高。加入浅层土壤含水量用Cokriging方法来估测深层土壤含水量，可进一步提高估值精度。
分析了田间同深度土壤含水量的半方差和不同深度土壤含水量的交互半方差特征，探讨了土壤含水量的Kriging和Cokriging估值方法。研究表明，同深度土壤含水量与不同深度的土壤含水量之间均具有显着的空间相关性，用Kriging方法进行土壤含水量的估值精度较传统方法高。加入浅层土壤含水量用Cokriging方法来估测深层土壤含水量，可进一步提高估值精度。
2020,40(2):85-91,99, DOI: 10.13961/j.cnki.stbctb.2020.02.012
Abstract:
[Objective] The evolution and driving forces of the sea reclamation in the Bohai Rim from 1985 to 2017 were analyzed, in order to provide support for the comprehensive management of the sea reclamation and promote the sustainable development of the region.[Methods] Using the remote sensing data, ENVI and ArcGIS were used to process and extract the sea reclamation coastline and land use types in each period, and the characteristics of reclamation evolution were analyzed by fractal dimension, coastal reclamation index, development intensity index and transfer matrix. The driving mechanism of reclamation activity was discussed by grey correlation degree method.[Results] ①From 1985 to 2017, the total area of reclamation around Bohai Sea increased by 4.25×105 hm2, with an average annual development intensity index of 2.6%. The reclamation coastline increased by 1 734 km, with an increase rate of 62%. In terms of time, the average annual development intesity index and coastal reclamation index changed in a similar way, showing a trend of decreasing, increasing and decreasing. In terms of space, the development intensity in the south was much higher than that in the north and the west was much higher than that in the East. ② There are two reclamation peaks in the study period, the first one was mainly for aquaculture, occupying a large number of vegetation land and unused land, and the second one was mainly for construction, taking up lots of natural sea areas. ③ The main driving forces of sea reclamation activities were social and economic development, among which aquatic product production, regional population and fishery industry development were the main driving forces. In addition, national policies and natural factors were of great significance to the sea reclamation activities.[Conclusion] The effective ways to restore the coastal ecological environment are to reasonably plan the aquaculture water area and increase the production capacity of unit area. Balancing the intensity of regional development and regulating the growth of regional population are of great significance to the realization of regional sustainable development.
[Objective] The evolution and driving forces of the sea reclamation in the Bohai Rim from 1985 to 2017 were analyzed, in order to provide support for the comprehensive management of the sea reclamation and promote the sustainable development of the region.[Methods] Using the remote sensing data, ENVI and ArcGIS were used to process and extract the sea reclamation coastline and land use types in each period, and the characteristics of reclamation evolution were analyzed by fractal dimension, coastal reclamation index, development intensity index and transfer matrix. The driving mechanism of reclamation activity was discussed by grey correlation degree method.[Results] ①From 1985 to 2017, the total area of reclamation around Bohai Sea increased by 4.25×105 hm2, with an average annual development intensity index of 2.6%. The reclamation coastline increased by 1 734 km, with an increase rate of 62%. In terms of time, the average annual development intesity index and coastal reclamation index changed in a similar way, showing a trend of decreasing, increasing and decreasing. In terms of space, the development intensity in the south was much higher than that in the north and the west was much higher than that in the East. ② There are two reclamation peaks in the study period, the first one was mainly for aquaculture, occupying a large number of vegetation land and unused land, and the second one was mainly for construction, taking up lots of natural sea areas. ③ The main driving forces of sea reclamation activities were social and economic development, among which aquatic product production, regional population and fishery industry development were the main driving forces. In addition, national policies and natural factors were of great significance to the sea reclamation activities.[Conclusion] The effective ways to restore the coastal ecological environment are to reasonably plan the aquaculture water area and increase the production capacity of unit area. Balancing the intensity of regional development and regulating the growth of regional population are of great significance to the realization of regional sustainable development.
2017,37(5):128-134, DOI: 10.13961/j.cnki.stbctb.2017.05.022
Abstract:
[Objective] This paper illustrated the influencing factors of water resource security and its evolution trend aimed to put forward some suggestions about the water resource security in Karst area.[Methods] Based on the data of Guizhou Province in the past ten years, this paper established a BP network model and applied the mean impact value(MIV) algorithm method to analyze the influencing factors of the water resource security in Karst area.[Results] The groundwater supply ratio, the industrial water use proportion, water use efficiency, per capital grain yield and water yield modulus were the obstacles to the development of water resources system. The influencing degree of water yield modulus was decreasing year by year, while the other four factors showed increasing trends. Comprehensive utilization rate of industrial solid waste, the attainment rate of the industrial waste water, the ratio of moderate rocky desertification area, water requirement per-unit GDP and exploitation degree of groundwater were the driving factors. In chronological order, the influence of water requirement of per-unit GDP and exploitation degree of groundwater were stable, while the ratio of moderate rocky desertification area was more and more pronounced. The impact of the attainment rate of the industrial waste water decreased year by year, while comprehensive utilization rate of industrial solid waste fluctuated greatly.[Conclusion] The MIV-BP model is feasible in studying influencing factors of water resource security in karst area.
[Objective] This paper illustrated the influencing factors of water resource security and its evolution trend aimed to put forward some suggestions about the water resource security in Karst area.[Methods] Based on the data of Guizhou Province in the past ten years, this paper established a BP network model and applied the mean impact value(MIV) algorithm method to analyze the influencing factors of the water resource security in Karst area.[Results] The groundwater supply ratio, the industrial water use proportion, water use efficiency, per capital grain yield and water yield modulus were the obstacles to the development of water resources system. The influencing degree of water yield modulus was decreasing year by year, while the other four factors showed increasing trends. Comprehensive utilization rate of industrial solid waste, the attainment rate of the industrial waste water, the ratio of moderate rocky desertification area, water requirement per-unit GDP and exploitation degree of groundwater were the driving factors. In chronological order, the influence of water requirement of per-unit GDP and exploitation degree of groundwater were stable, while the ratio of moderate rocky desertification area was more and more pronounced. The impact of the attainment rate of the industrial waste water decreased year by year, while comprehensive utilization rate of industrial solid waste fluctuated greatly.[Conclusion] The MIV-BP model is feasible in studying influencing factors of water resource security in karst area.
2008(4):121-125, DOI: 10.13961/j.cnki.stbctb.2008.04.023
Abstract:
公路建设过程中产生的水土流失非常严重。在标定人工降雨器降雨参数的基础上,研究了华北地区公路土质边坡水土流失规律。结果表明,土体硬度、前期土壤含水量、降雨强度相同条件下,土壤侵蚀量随坡度的增大而增加,在25°附近达最大值,之后随坡度的增加侵蚀量略有下降并渐趋稳定;土壤侵蚀量随土体硬度的加大而减小,且降雨强度越大这种影响愈显著;前期土体含水量愈大,土壤侵蚀量呈增大趋势。本研究可为科学评价工程土质边坡的水土流失提供依据。
公路建设过程中产生的水土流失非常严重。在标定人工降雨器降雨参数的基础上,研究了华北地区公路土质边坡水土流失规律。结果表明,土体硬度、前期土壤含水量、降雨强度相同条件下,土壤侵蚀量随坡度的增大而增加,在25°附近达最大值,之后随坡度的增加侵蚀量略有下降并渐趋稳定;土壤侵蚀量随土体硬度的加大而减小,且降雨强度越大这种影响愈显著;前期土体含水量愈大,土壤侵蚀量呈增大趋势。本研究可为科学评价工程土质边坡的水土流失提供依据。
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- Founded in 1981, bimonthly
- CN：
61-1094/X
- ISSN：
1000-288X
- Administrted by：
Chinese Academy of Sciences
- Sponsored by：
Institute of Soil and Water Conservation, CAS & MWR;
Monitoring Center of Soil and Water Conservation, Ministry of Water Resources - Published by：
Science Press
- Editor-in-Chief：
FENG Hao
- Deputy Editor-in-chief：
Qiao Dianxin
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