Abstract:[Objective] The hydrologic regime change in typical watershed on Loess Plateau was studied, and its attribution analysis was carried out, in order to provide scientific support for soil and water conservation and efficient utilization of water resources in different regions of the Loess Plateau. [Methods] Sandu River (a tributary of Weihe River) and Dali River (a tributary of Wuding River) were selected as the study areas, and the traits in variations of streamflow and their driving factors from 1965 to 2018 were analyzed based on meteorological and hydrological data at Gangu and Suide hydrological stations by using the linear regression, Mann-Kendall test, accumulated anomaly, and double mass curve methods. The improved range of variability approach was employed to analyze the impact of the hydrological alterations in different river by soil and water conservation dominated by terracing and damming. [Results] The annual runoff showed significant decreasing trends(p<0.01) and the abrupt changes occurred in around 1990s in Sandu River and Dali River. The alteration degree of runoff in Sandu River was high (90.12%) and in Dali River was moderate (60.66%) calculated by the improved range of variability approach (RVA) method. Among 32 indicators of hydrologic alteration (IHA), the rise and fall rate of flow were affected most significantly. [Conclusion] In the Sandu River (dominated by terracing), both the magnitude of monthly median flow and the annual minimum flow decreased dramatically, timing of annual minimum flow delayed and duration of low pulses increased. In the Dali River (dominated by damming), the magnitude of monthly median flow depended on the seasonal alteration. The annual 1-day and 3-day minimum flow increased and frequency of low pulses declined.

Abstract:[Objective] The preferential flow morphology and characteristics of red soil in the arid and hot valley of the Honghe River was studied, in order to provide theoretical basis for regional water resources management and soil erosion prevention. [Methods] Taking typical vegetation—woodlands and wild grasslands in arid and hot valley regions as the research objects, the morphological distribution characteristics of preferential flow and its response to the characteristics of read soil were studied by using field dye tracing method and image processing technology. [Results] ① The average stained area of forest and grassland was 87.2% and 91.97% respectively. The stained area decreased with the increase of soil layer, and rebounded in local depths. The preferential flow length index of forest and grassland was 766.8% and 730.0% respectively. And the priority flow of the forest was more developed than wasteland. The maximum staining depth of forest and grassland was 40 cm and 35 cm respectively. ② The width of the dyeing path decreases with the increase of the soil layer. In the 0—20 cm soil layer, the main dyeing path was greater than 250 mm. The dyeing path within 20—40 cm was mainly in the layer between 20—250 mm, and the dyeing path was less than 20 mm in the soil layer below 40 cm. ③ There were significant correlations between the priority flow dyeing area, length index, dyeing path width and soil factors. The cumulative contribution rate of total porosity, organic matter, and moisture content to dyeing area ratio (D_A), length index (LI) and dyeing path width (SPW) was 97.8%, 86.95%, 87.45%, respectively. The factors such as moisture content, organic matter, bulk density, total porosity and Al³⁺ had the best linear relationship with dyeing area and dyeing path. [Conclusion] The combined effects of soil pore characteristics, base ions, and soil texture ultimately led to the difference in preferential flow between forest and grassland in the arid and hot valley of the Honghe River.

Abstract:[Objective] The relationship between vegetation cover change and environmental factors in the oasis in northern margin of Tarim Basin was studied in order to provide scientific reference for ecological management and restoration of the study area. [Methods] Based on MODIS/NDVI data from 2000 to 2018, combined with meteorological factors and human activities data in the same time series, the temporal and spatial variation of oasis in the northern fringe Tarim Basin were analyzed by using trend line analysis, correlation analysis, ArcGIS spatial overlay and through path analysis methods, to explore the influence of environmental factors on the NDVI changes of vegetation in the oasis area. [Results] ① From 2000 to 2018, each cover types of oasis in the Northern Tarim Basin was in a fluctuating upward trend, with a propagation rate of 0.033/10 a. The propagation rate of vegetation cover types from high to low were cultivated plants, shrubs, broad-leaved forest, meadow, desert, grassland, wetland, coniferous forest and alpine vegetation. ② Temperature change had a negative effect on NDVI of oasis vegetation in the northern margin of Tarim Basin, and the negative correlation area accounted for 72.15% of the oasis area. ③ Among the factors of human environment, the total output value of forestry and animal husbandry were the main controlling factors of NDVI. [Conclusion] Temperature had the strongest effect on NDVI, followed by gross output value of forestry and animal husbandry, and the effect of total output value of animal husbandry on NDVI is weak. In addition, the residual path coefficient is 0.26, which indicates that there are some other factors that have not been taken into account and need further study.

Abstract:[Objective] The development characteristics of preferential flow in slope farmland with different soil thicknesses were studied, in order to provide a basis for improving the irrigation efficiency and preventing and controlling the non-point source pollution. [Methods] The granite hilly slope cropland in Mengyin County, Shandong Province, which is located in the mountainous region of Northern China, was taken as an example. The samples with soil depth of 30 cm and 50 cm were selected, and the field staining tracer test method and indoor image processing technology were used to analyze the influence of soil thickness on the development characteristics of preferential flow. [Results] When the soil thickness was 30 cm and 50 cm, the average depth of substrate infiltration was 11.8 cm and 11.9 cm, respectively, and the average preferential flow ratio was 28.2% and 29.5%, respectively, there was no significant difference between the two depths. When the soil thickness was 30 cm, substrate flow was dominant in the soil layer above 9.9 cm, and the development depth of preferential flow ranged from 9.9 to 27.0 cm. When the soil thickness was 50 cm, matrix flow was dominant in the soil layer above 6.1 cm, and the development depth of preferential flow ranged from 6.1 cm to 39.5 cm. Under the condition of 50 cm soil thickness, the average maximum infiltration depth of preferential flow was 34.6 cm, the average length index was 192%, and the average coefficient of variation was 87.7%, which were significantly higher than those under the condition of 30 cm soil thickness. However, there was no significant difference in the non-uniformity coefficient of maximum infiltration depth between the two conditions. [Conclusion] The difference of soil layer thickness did not affect the substrate infiltration, but hindered the development of preferential flow to deep soil layer.

Abstract:[Objective] The compound soil of Feldpathic Sandstone and sand in Mu Us Sandy Land belongs to artificial reconstructed soil. The quality evolution of the compound soil after long-term crop planting was studied, in order to provide scientific basis for understanding the structure development and sustainable utilization of the compound soil. [Methods] Based on the field plot experiments of compound soil a with volume ratios of 1:1, 1:2 and 1:5 of Feldpathic Sandstone to sand during the period from 2010 to 2018, the dynamic change characteristics of water-stable aggregates, organic matter content and crop yield in the compound soils under different planting years were analyzed. [Results] With the development of the experiment, the content of water-stable aggregates with diameter>0.25 mm, average weight diameter (MWD) value and organic matter content in the three proportions of compound soils showed an overall increasing trend. After 9 years of planting, water-stable aggregates >0.25 mm in 1:1, 1:2 and 1:5 compound soil increased by 2.71, 3.31 and 4.24 times, respectively, and became the main component of aggregates. The soil organic matter content increased by 8.24, 10.62 and 13.76 times, respectively. In 2011, the potato yield order in different proportion of compound soil was showed as: 1:2 > 1:1 > 1:5, after 8 years of planting, the potato yield increased by 3.27, 4.25 and 6.96 times, respectively, and the yield order was 1:5 > 1:2 > 1:1. Among them, the potato yield in the 1:5 compound soil increased most significantly. The average yield for many years was as high as 53 850 kg/ha, which was equal to the yield of local high-yield fields. [Conclusion] With the increase of potato planting years, the physical and chemical properties of the three-proportion compound soil have been improved, and the compound soil structure has been increasingly optimized. In particular, it can effectively promote the formation of 1:5 compound soil organic and water stable aggregates, and the effect of potato yield increase is the best, so the ratio of 1:5 compound soil is suitable for potato growth.

Abstract:[Objective] The distribution characteristics of rainfall erosivity R value in the yellow soil area of karst mountainous region in Central Guizhou Province were studied, in order to provide scientific references for regional soil erosion quantitative prediction, soil conservation planning and soil and water loss control. [Methods] Based on the data source of the daily rainfall record from 2013 to 2019, and the extracted data of rainfall process at 5 min intervals from 10 soil and water conservation monitoring stations in the karst yellow soil distribution area of Guizhou Province, the individual distribution characteristics, monthly distribution characteristics, inter-annual variation characteristics of R value, rainfall and rainfall intensity distribution characteristics were analyzed. [Results] ① The maximum R values was several times to a dozen times of the average R value of each monitoring stations. The percentage of the maximum R values in the corresponding year was also significantly different, and at least accounted for about 22.28% of the annual value. The contribution rate of several heavy rainstorms in a year was very high. ② The R value of rainfall erosivity was mainly distributed from April to September, and particularly concentrated from June to August. The R value from April to September accounted for about 90.00% of the annual R value in the monitoring stations, among which some stations were more than 95.00%. From June to August, the lowest R value accounted for 55.98% of the annual value, and the highest was 85.25%. ③ The average annual R value decreased significantly from southeast to southwest. The inter-annual variation coefficient (C_v) of R values showed an opposite trend, and increased significantly from southeast to northwest. The variation range of the inter-annual variation coefficient (C_v) of R values was 0.20～0.44, with a large interannual variation. ④ Moderate rain, heavy rain, rainstorm, and heavy rainstorm were the main rainfall erosivity levels, with which most stations accounting for more than 60.00%. Heavy rain, due to its relatively high frequency and long duration, contributed the most to the total R value. Overall, the frequency of heavy rainstorm was not high, but the value of rainfall erosivity R value of a single heavy rainstorm could be very large, which could change the R value distribution by a single heavy rainstorm. The peak area of R value distribution was 15—30 mm/h, and the average proportion is 31.97%. The occurrence of high rainfall intensity was more random, and the spatial distribution difference of the R value proportion generated by rainfall intensity greater than 60 mm/h was also large. [Conclusion] The spatial and temporal variation of rainfall erosivity R value is obvious in the yellow soil area of karst mountainous region in Central Guizhou Province, so it is necessary to take measures to prevent and control soil erosion according to local conditions.

Abstract:[Objective] The characteristics and mechanism of Mn enrichment of dominant plants in two types of manganese residue disposal sites (manganese mine residue and electrolytic manganese residue) were analyzed, in order to provide useful theoretical information to benefit the ecological restoration of manganese residue disposal sites. [Methods] On the basis of field investigation, Mn content of dominant plants, total Mn content of growth matrix and low molecular weight organic acid extracted Mn content were detected. [Results] Mn content in dominant plants ranged from 34.47 mg/kg to 680.70 mg/kg. Mn content in individual plant tissues exceeded the normal range of general plants. The distribution of Mn in plant organs was as follows: root>leaf>stem or branch. The content of total Mn in the growth matrix of dominant plants ranged from 20 217.14 mg/kg to 75 115.58 mg/kg, and the rhizosphere matrix was less than that of non-rhizosphere. The extraction efficiency of Mn from matrix by low molecular weight organic acids ranged from 25.72% to 78.30%, and the overall performance was rhizosphere matrix>non-rhizosphere matrix. [Conclusion] Under the dual effects of plant absorption and rhizosphere effect, the dominant plants in manganese residue disposal sites have the potential to control Mn pollution.

Abstract:[Objective] The variation of runoff curve number after the gully land consolidation project (GLCP) was studied to explore the appropriate flow generation parameters, and to provide scientific support for the safety of GLCP and the consolidation of achievements in ecological construction. [Methods] Based on the physical scale model, the influence of GLCP on the runoff curve number under different vegetation cover conditions was investigated. [Results] Under the same vegetation coverage, the runoff curve number decreased with the increase of the land consolidation proportion. Compared with the unconsolidated basin, the runoff curve number decreased by 6.77 when the consolidation proportion was 20%. The decreasing rate of runoff curve number increased firstly and then decreased with the increase of land consolidation proportion, and the decrease rate reached the maximum when the consolidation proportion increased from 0.5% to 5%. Under different vegetation coverage, the runoff curve number decreased with the increase of consolidation proportion, and the decreasing rate of runoff curve number reached the maximum at the vegetation coverage of 50%. Vegetation coverage had great effects on the runoff curve number of the gully land consolidation area, and the runoff curve number decreased by 0.22 in the gully land consolidation area when the vegetation coverage increased by 1%. [Conclusion] The GLCP could change the hydrological characteristics of basin under layer and has significant effects on the runoff curve number.

Abstract:[Objective] The effects of different shrub planting patterns on slope stability with different slope degrees under rainstorm condition were studied to explore the critical slope degrees for shrubs to stabilize slopes, and to provide a scientific basis for scientific biological engineering to manage mountain disasters. [Methods] Indoor rainfall experiments were carried out by making shrub models to explore the impact of four shrub planting modes (sparse planting, moderate planting, dense planting, bare slope) on slope stability on slopes with different slope degrees (20°, 35°, 50°, 60°). The slope safety factor (F_s) was calculated by using a correction formula considering the influence of shrub weight and root traction. [Results] ① Gully erosion occurred on shrub slopes at 20° and 35°, which was independent of the planting mode; On bare slopes, 50° shrub slopes, and 60° sparsely and densely planted shrub slopes, the damage occurred progressively; Overall slipping failure occurred on moderately planted shrub slopes of 60°. ② Planting shrubs on gentle slopes of 20° and 35° could effectively enhance the stability of the slope during rainfall and reduce the amount of collapse by 4% to 70%; Planting shrubs on steep slopes of 50° and 60° could not only decrease the stability of the slope, but also increase the amount of collapse by 10% to 33%. [Conclusion] Slope stabilization by shrubs can not be simply attributed to effective or ineffective, it is closely related to the slope gradient, so attention should be paid to the choice of planting methods on different slopes.

Abstract:[Objective] The stability of soil aggregate in orchard with different planting years in granite eroded poor land was studied to provide scientific reference for comprehensive management of eroded poor land in granite hilly area of South China. [Methods] The composition and stability of soil aggregate in orchards with different planting years (0, 3, 7, 12, 16, 21 years) in eroded area were determined by using Le bissonnais (LB) method in granite hilly area of Southeast Guangxi Zhuang Autonomous Region, and to explore the variation trend of soil aggregate stability with planting years and its influencing factors. [Results] ① With the increase of planting years, soil permeability was improved, cation exchange content, organic carbon content and fine particulate matter content increased, and the soil texture gradually transformed from sandy soil to loam soil. ② Under three different LB methods, the soil aggregate mass percentage of >0.25 mm size increased with the prolongation of planting years, reached more than 65.68% at 21 years, which was 9.18% higher than that of control. ③ The mean weight diameter (WMD) of soil aggregate increased significantly with the prolongation of the planting years. And the RSI, RMI, and k values all decreased to different degrees, meaning that the aggregate stability was improved. ④ The MWD was extremely significantly positively related to soil organic carbon content and clay content. Cation exchange content was significantly positively related to MWD, and sand content was extremely significantly negatively correlated. This showed that the increase of organic carbon, clay and cation exchange content could significantly improved the soil aggregate stability. The content of organic carbon was the main factor affecting the stability of aggregates. [Conclusion] Cutting slope to form citrus orchard can effectively control eroded poor land, and with the prolongation of reclamation years, the soil structure tends to be stable, and then the aggregate stability and the soil quality are improved.

Abstract:[Objective] The effects of cyanobacteria-bacteria biological crusts on moisture and nutrient conservation and maize seedling growth were studied to provide a theoretical basis for soil treatment and improvement strategies. [Methods] Two species of bacteria (Sphingomonas sp. D3-1 and Massilia armeniaca sp. ZMN-3) and two species of cyanobacteria (Cladophora aegagrophila D3-a and Nostoc sphaeroides D3-25) isolated from the Wengniute Desert of Inner Mongolia Region, were used to prepare biological crusts. The relationships between the cyanobacteria-bacteria biological crusts and soil moisture and nutrient conservation, soil microbial quantity and soil enzyme activity were explored, and the effect of biological crusts on maize seedling growth was studied. [Results] Compared with the control, the soil surface cyanobacteria-bacteria crust significantly declined the rate of soil moisture loss, and reduced the average leaching efficiency of nitrogen, phosphorus and potassium by 76.9%, 64.4% and 47.8%, respectively, while increased the number of bacteria, fungi and actinomycetes in soil by 8.3 times, 1.8 times and 3.1 times, respectively, and decreased the number of bacillus by 12.4%. Besides, in the corn plants, the cyanobacteria-bacteria crust increased the aboveground fresh/dry weight, root fresh/dry weight, and above/lower length of corn seedlings by 45%/57.8%, 54.6%/32.8% and 19.7%/14.5%, respectively, and the chlorophyll content increased by 5.7%. [Conclusion] The mixed soil biological crust formed by cyanobacteria and extracellular polysaccharide producing bacteria significantly improved the soil microbial and fertilizer conservation effect, which could provide a reference for developing a new way of soil management.

Abstract:[Objective] The spatial correlation between the evolution of landscape pattern and surface runoff was explored, in order to propose a landscape pattern optimization strategy that could effectively alleviate urban waterlogging and provide suggestions for urban ecological safety. [Methods] Based on the remote sensing data sets from 2000 to 2019, the spatial distribution map of landscape patterns in the main urban area of Xi’an City was extracted, and validated with actual land use data. The methods of SCS model, landscape pattern index, ArcGIS and Pearson correlation analysis were employed to analyze the landscape pattern changes and its impacts on surface runoff. [Results] ① From 2000 to 2019, the landscape pattern showed a developing trend of high connectivity and high aggregation, regular patch shape, homogenization and stabilization, and the patch spread decreased. At the same period, the surface runoff depth increased year by year, however, the increase of runoff depth showed a downward trend with the time. In 2000—2005, 2005—2010, 2010—2015, 2015—2019, the increment of runoff depth was 4.99, 4.95, 3.55, and 3.33 mm respectively, indicating that retention effect of landscape pattern on surface runoff increased gradually. ② The correlation between the change rate of landscape pattern index and the annual growth rate of surface runoff was significant, and the artificial landscape index such as urban construction land had a significant positive correlation with the annual growth rate of surface runoff. On the contrary, there was a negative correlation of the annual growth rate of surface runoff and the change rate of natural landscape index such as cultivated land and water area. ③ With the help of urban ecological corridors and ecological nodes, the waterlogging prevention and control ecosystem was constructed, and the areas with high concentration of urban impervious surface were split, the urban green infrastructure was added, and the waterlogging prevention and control landscape pattern of source emission reduction was constructed. [Conclusion] Landscape pattern changes had a significant impact on the change of surface runoff, and the optimization of landscape pattern can effectively promote the urban benign water cycle and slow down the occurrence of waterlogging.

Abstract:[Objective] The accumulation and release of inorganic phosphorus in vegetable field soil under the condition of greenhouse cultivation was explored, in order to provide basis for the rational application of phosphorus fertilizer and the sustainable development of protected agriculture. [Methods] The greenhouse soil in Tieling County (2—28 years) and Haicheng City (2—33 years) of Liaoning Province with different planting years was collected. The change of total phosphorus, available phosphorus and inorganic phosphorus in soil and the curve of phosphorus release were taken as the breakthrough point, to analyze the variation of soil phosphorus with different planting years. [Results] ① The total phosphorus, inorganic phosphorus and available phosphorus in topsoil in both of Tieling County and Haicheng City protected vegetation fileds increased first and then decreased with the increase of planting years, and reached the peak at about 20 years after planting, with the highest contents of total phosphorus content reached 5.76±0.61 g/kg and 7.08±0.72 g/kg, respectively. ② Ca₈-P was the main content of inorganic phosphorus in surface greenhouse soil, and the highest content was 34.2% and 59.9% of the total inorganic phosphorus, followed by Fe-P and Al-P. Ca₈-P increased with the increase of planting years, while Fe-P decreased with the increase of planting years. ③ The release rate of phosphorus was relatively high in the early planting period (about 2—15 years), and the correlation between the release amount and Ca₂-P and Fe-P reached a significant level. [Conclusion] The main form of phosphorus accumulation in surface greenhouse soil was Ca₈-P, and Ca₂-P and Fe-P, were the main forms of phosphorus leaching.

Abstract:[Objective] The influencing factors and intensity of soil pH value in Southern Jiangxi Province were studied to provide a scientific basis for soil acidification prevention and control. [Methods] 8 167 surface soil samples in Nankang District, Ganzhou City were collected, and the distribution characteristics and influencing factors of soil pH value were analyzed by using Chi-square test and correlation coefficient methods. [Results] 83.1% of the soil in the study area was highly acidity (pH<5.0), and the proportion of neutral and alkaline soil was less than 17%. The soil pH value was mainly affected by natural factors such as soil parent material and geological background. The influence intensity was as follows: parent material > geological background > elevation > land type > landform. Acidic soil was distributed in Paleozoic igneous rocks and the element loss areas with higher terrain, the soil in Mesozoic sedimentary rocks and low-lying areas with rich elements was alkaline. At the same time, the contribution of human activities to soil acidification could not be ignored. [Conclusion] The soil pH value in Southern Jiangxi Province is mainly controlled by soil parent material and geological background, and human activities have caused a certain difference in soil pH value in different land use types.

Abstract:[Objective] The physical and chemical properties of swamp wetland in Yanchiwan National Nature Reserve of Gansu Province were evaluated to reveal the characteristics of wetland soil and the role of wetland soil in the wetland, in order to provide reference for wetland protection in the reserve. [Methods] Six typical marshes were selected in the reserve, and stratified soil samplings were collected by random method. According to the national standard, the soil porosity, soil moisture properties and soil nutrient characteristics of each marsh were measured. [Results] ① With the increase of soil depth, soil bulk density increased gradually, while soil porosity and soil aeration decreased gradually. The results of soil pore indexes in Yulin River Source Wetland and Daderji Wetland were better than those in other marshes. ② With the increase of soil depth, soil moisture properties decreased gradually. Soil moisture properties in Yulin River Source Wetland and Daderji Wetland were better than those in other marshes. ③ With the increase of soil depth, the soil nutrient contents of all marshes showed a decreasing trend. The soil nutrient contents of Yulin River Source Wetland were higher, the soil nutrient contents of Yema Daquan Wetland were the lowest, and there was no significant difference in the soil nutrient conditions of the other four marshes. [Conclusion] With the increase of soil depth, the soil of the marshes in the reserve gradually becomes compacted, the soil porosity, the water condition and the soil nutrient content decreases. The soil in Yulin River Source Wetland and Daderji Wetland are loose in quality, good in aeration, and have superior water conditions with strong ability of water storage and water conservation, while the Yema Daquan Wetland can quickly accommodate precipitation and infiltrate in time, which can effectively regulate runoff. The soil nutrient condition of Yulin River Source Wetland was the best, while that of Yema Daquan Wetland was the worst. The soil environment of the reserve marsh wetland is alkaline.

Abstract:[Objective] Experiments on strengthening the abrasion resistance of mitigation engineering by mixing nano silica, micro silica powder, polypropylene fiber and other materials with concrete were carried out to discuss the laws of the influence of the mixing material content on the abrasion resistance, in order to provide scientific reference for the mix design of abrasion resistance of concrete in the debris flow mitigation engineering. [Methods] The underwater abrasive test of concrete specimens was carried out by using the underwater steel ball method (SL352-2006) designed by orthogonal experimental design method, and the abrasive resistance strength of concrete mixed with nano silica, micro silica and polypropylene fiber was obtained. [Results] Within the range of selected content, the abrasion resistance strength of concrete specimens increased first and then decreased with the raise of Nano-SiO₂, and reached the maximum value when the content was 1.5%. With the increase of microsilica powder, the maximum value was reached when the content was 12%. With the increase of polypropylene fiber, it decreased at first, and then increased, and the maximum value was reached when the content was 1.8 kg/m³. With the increase of air entraining agent, it first decreased and then increased, and reached the maximum value when the dosage was 0.005%. [Conclusion] The most significant factor affecting the abrasion resistance strength of concrete is the content of nano silica, followed by polypropylene fiber, micro silica and air entraining agent.

Abstract:[Objective] The spatiotemporal characteristics of land use changes were studied to provide scientific reference for carrying out ecological and environmental monitoring in concentration area of open pit mine. [Methods] Based on Google Earth images in 2003, 2010, 2015 and 2019, the land use remote sensing classification was carried out in Changshangou open-pin mine concentration area in Tangshan City, Hebei Province. The land use transfer matrix was calculated by using ArcGIS software, and the spatio-temporal characteristics and causes of land use change in the open-pin mine concentration area were analyzed. [Results] ① From 2003 to 2015, the area of greenland in the study area decreased by 169.61 hm², accounting for 6.30% of the total area, and the area of bare land and industrial sites increased by 184.73 hm² and 60.46 hm², accounting for 6.86% and 2.25% of the total area, respectively; some arable land was occupied; spatially, greenland was mainly converted to bare land and industrial sites. ② From 2015 to 2019, the area of greenland in the study area decreased by 61.05 hm², accounting for 2.27% of the total area, and the area of industrial sites increased by 43.90 hm², accounting for 1.63% of the total area, with little changes in the area of other land use types; spatially greenland was transformed into bare land and industrial sites, with little change of the total area. [Conclusion] In the early stage of mining, a large amount of green land was occupied in the open pit mine, the vegetation destruction and land resource occupation was serious, and the ecological environment was seriously affected. At the late stage of mining, the ecological restoration and treatment of the mine were strengthened, and the effect of “management while mining” mode was initially achieved.

Abstract:[Objective] The advantages, disadvantages and applicability of various analysis methods of multi-year observation data of sediment transport modulus in small watersheds were studied, in order to provide references for selecting scientific methods to describe the characteristics of multi-year sediment transport modulus observation data. [Methods] Based on the observation data of sediment transport modulus in four small watersheds, through the comparative analysis of four methods and their combinations, including statistical eigenvalue, de-extremum arithmetic mean, frequency of erosion intensity grade, and box-whisker plot, the description methods with wide applicability and objectivity were explored. [Results] The statistical arithmetic mean and median could hardly represent the concentration and general level of multi-year sediment transport modulus. Although the de-extremum arithmetic mean had the tendency of reflecting the general level of data, it sacrificed the extreme value and its information for decision-making. The frequency of erosion intensity grade reflected the distribution of data in intensity classification. Box-whisker plot could show the concentration, dispersion and the number of abnormal data. [Conclusion] Various methods have their own advantages and disadvantages in characterizing the multi-year observation data. In order to describe their concentration and dispersion comprehensively and objectively, various methods can be used to make full use of their advantages and avoid their disadvantages. Box-whisker plot has good objectivity and applicability in displaying the multi-year data of small watershed.

Abstract:[Objective] The U-Net based land use/cover change detection method with high resolution image was introduced to provide theoretical support for the application of the model in remote sensing image change detection. [Methods] The U-type neural network was used to detect the change spots in Gaofen-1 image of Yuzhou City, He’nan Province and WHU building data, and compared with FCN and SegNet. [Results] The experimental results showed that the F₁ score of U-type neural network model were 0.699,0.66 and 0.673 respectively, which were better than the other two methods, and the missing rate was lower, which was closer to the change reference diagram. [Conclusion] It is feasible to use U-type neural network for change detection in high-resolution remote sensing images, and it could have high detection accuracy.

Abstract:[Objective] By constructing risk assessment model for dam break, the possibility of dam break was determined to provide technical support for check dam operation and management. [Methods] The risk assessment index system of check dam engineering was established through investigation and analysis of dam break risk problems. The weights of indexes were determined by analytic hierarchy process and the risk assessment model of dam break in Gansu Province was constructed. [Results] The model includes hydrological risk indexes (B₁), operation risk indexes (B₂), management risk indexes (B₃), and engineering risk indexes (B₄), a total of four risk types modules (with weights of 0.12, 0.13, 0.12, 0.63, respectively) and 16 specific evaluation indexes. Distance between water surface/mud surface and the height of dam(D₁), the available silting tank volume (D₄), the presence or absence of three management directors (D₇), and the dam deformation (D₁₂) are the maximum weight indexes of the four risk index modules. The scoring standard of each index was stipulated in the study, and the output risk level as well as early warning level were divided into 3 levels according to the comprehensive risk score. [Conclusion] The risk assessment model of check dam is composed of three modules: input, analysis, and output, which has clear hierarchy and structure. The construction of the assessment model can provide real-time warning data for risk assessment of check dam before rainfall events.

Abstract:[Objective] The construction model of the pastoral complex at check dam system in the loess hilly area was studied, in order to provide scientific support for the construction and utilization of the silt dam system in this area. [Methods] The construction mode and conditions of pastoral complex were studied through literature review, and the current situation, operation and utilization problems of check dams in loess hilly region were investigated. [Results] The management and constructing system of check dam system has been formed initially in Gansu Province. In the process of operation, there were problems such as hidden danger of dam failure, inadequate treatment of salinization soil, and insufficient utilization of water and soil. Taking Yulingou check dam system as an example, this study proposed suggestions of constructing the pastoral complex of dominant agricultural mode and building check dam pastoral complex with the consideration of modern agriculture, leisure tourism, pastoral community. [Conclusion] The construction of the check dam system pastorale complex is an exploration and innovation, it plays an important role in strengthening the ecological protection of the Yellow River basin, promoting high-quality development, and accelerating the strategy of rural revitalization.

Abstract:[Objective] The characteristics of soil and water loss of different types of power transmission line projects (PTLPs) in hilly and mountainous regions were explored to provide a theoretical reference for the design, monitoring, and prevention of soil and water loss. [Methods] PTLPs in hilly and mountainous regions (low-elevation mountains and hills of Northeastern China, hilly loess region of Northwestern China, hilly region of Southern China, the Qinghai-Tibet Plateau, and the Xinjiang hilly region) in China were taken as the study object. Based on literature review, field investigations and engineering examples, the sources, influencing factors, and controlling measure configurations of soil and water loss in PTLPs of hilly and mountainous regions were studied. [Results] The main sources of soil and water loss in PTLPs could be divided into station area, road area, temporary stacking area, tower area, stretch field area and slag stacking area. The soil and water loss of the PTLPs was spatially variable. The station area accounted for the highest proportion of soil and water loss, which was up to 48%～62% of the total soil and water loss, followed by the tower area. The main source period was the construction period. The influencing factors of soil and water loss and the key points of prevention in the hilly and mountainous regions were significantly different. [Conclusion] There are significant differences in influencing factors and key points of prevention and control of soil and water loss in different hilly areas. Different forms of soil erosion should be considered in the design of soil and water conservation, and the allocation of controlling measures should be adapted to the local conditions.

Abstract:[Objective] A comparative study of the fertility changes in six different slope ecological restoration types was conducted, in order to provide theoretical basis and technical support for the ecological environment restoration in the DG hydropower project disturbed area, Tibet, China. [Methods] Field measurement and laboratory tests were conducted to analyze the fertility change characteristics and vegetation growth status in different types of slope ecological restoration. The spatio-temporal changes of soil fertility and its correlation with vegetation growth were determined by the correlation analysis method, and the main control factors of the fertility in vegetation growth were discussed as well. [Results] The fluctuation of organic matter and nitrogen elements changed greatly in the six types of slope ecological restoration, which decreased first, then increased, and decreased finally with the seasonal change, while the change of pH value, available phosphorus and available potassium were relatively small. From the comparison of different slopes, the soil fertility from high to low showed as: spoil ground > soil slope > general construction site > earth rock mixed slope > rock slope > construction hardened surface. The vegetation restoration and growth status of different slopes showed the same order as the soil nutrient content. The ammonia nitrogen, nitrate nitrogen and available phosphorus had the highest correlation with vegetation growth, followed by available potassium and organic matter, while pH value had the lowest correlation, indicating that ammonia nitrogen, nitrate nitrogen and available phosphorus had the greatest impacts on slope vegetation growth. [Conclusion] Among the fertility conditions of different slopes, the performance of spoil ground is the best, while the restoration of rock slope and construction hardened surface is the poorest, and the contents of ammonia nitrogen, nitrate nitrogen and available phosphorus in fertility are closely related to vegetation growth.

Abstract:[Objective] The multi-functional intensity and coordination of cultivated land in Hu’nan Province were analyzed to provide a reference for improving the multi-functional management level of cultivated land. [Methods] The multi-functional intensity and coordination of cultivated land in each county of Hu’nan Province in 2018 were calculated by using the entire-array-polygon diagram method and the systematic clustering method. [Results] ① The multi-functional comprehensive intensity of cultivated land in each county of Hu’nan Province weakened from the northwest to the central, and to the southeast areas, while the multi-functional coordination increased first, and then weakened from the west to the centre, and to the east of Hu’nan Province. ② Based on the individual functional intensity of each unit, the multi-functional development mode of cultivated land in each county of Hu’nan Province showed five types of development mode: multi-functional weak coordination mode, multi-function coordination mode, multi-functional strong coordination mode, ecological priority development mode, and social-led development mode. Spatially, from the west to the central and east areas of Hu’nan Province, cultivated land multi-functional development model changed from ecological priority development model to multi-functional weak coordination, multi-functional coordination transformation, and finally into cultivated land multi-functional weak coordinated development mode. [Conclusion] The results of the study are in line with the agricultural strategic pattern of “one circle, one district, two zones” implemented in Hu’nan Province, and can reflect the multi-functional spatial condition of cultivated land in Hu’nan Province objectively.

Abstract:[Objective] The ecological source area was identified in Akesu area, Xinjiang Uygur Autonomous Region, in order to provide strategies and suggestions for the construction of the ecological security pattern of the region and the sustainable ecological restoration of the land and space. [Methods] Taking Aksu area in Xinjiang as an example, the ecological source area were identified by quantitative method (comprehensive evaluation method based on the InVEST model) and qualitative method (the ecological conservation redline was identified in the direct way). On this basis, the differences between the two results and their causes were compared to determine whether the ecological protection red line could reflect human demand for ecosystem services. [Results] ① The ecological source area identified based on the comprehensive evaluation method using the InVEST model was 11 433.6 km², accounting for 8.9% of the total area, mainly distributed in the rivers and surrounding areas. The ecological source area identified directly based on the ecological conservation redline was 22 746.8 km², accounting for 17.7% of the total study area, mainly distributed in the south of Tianshan Mountain and surrounding areas of rivers. ② There are great differences in the spatial distribution of the ecological source areas identified by the two methods. About 59.4% area of the ecological source identified by comprehensive evaluation was not in the ecological conservation redline, occupying 6 787.0 km². ③ The main reason for the difference between the two results was that the ecological conservation redline focused on the protection of ecological functions of the ecological land, while the concept of ecological source combined the requirements of human beings, and prefered the services that the ecological system provided to human production and living. [Conclusion] In the future, it is necessary to consider how to unify the concept of the ecological source areas that focus on meeting the social requirements with the ecological conservation redline that focus on the ecological environment conservation. We should define the ecological source in a comprehensive manner, based on the quantitively identified ecological source as the primary factor and the qualitatively identified ecological source as the secondary factor, and propose advices for potential plans and policies to realize the coordinated development of the social economy and natural environment.

Abstract:[Objective] The factors affecting water utilization in Jiangxi Province were analysed to provide theoretical evidence for sustainable utilization of water. [Methods] Based on the definition of water utilization, water utilization, social and economic development, and ecological environment were selected as latent variables. In addition, a structural equation model (SEM) was established to quantitatively analyse the factors affecting water utilization in Jiangxi Province. [Results] SEM could reflect the basic situation of water utilization in Jiangxi Province. Furthermore, in the model (SEM), economic development, social development and ecological environment all affected water utilization to varying degrees, and economic development (0.847) > social development (0.500) > ecological environment (0.177). Besides, the utilization of water was mainly reflected by the utilization rate of water development (0.891) and water resources per capita (0.803). [Conclusion] Since the utilization of water resources in Jiangxi Province was affected by many factors, the government should comprehensively consider the different conditions of water utilization in economically developed and under-developed areas. Moreover, the government ought to establish a good water-saving system, promote water-saving measures vigorously, increase the utilization rate of water gradually, and realize the sustainable utilization of water finally.

Abstract:[Objective] Rapid and accurate monitoring of farmland soil pH value were explored for large-scale soil improvement and achieving fine management of farmland. [Methods] The cotton fileds of the 12 th regiment at Alar City in the South of Xinjiang Uygur Autonomous Region were selected as the study area, in-situ hyperspectral data of 231 sample points were collected by grid sampling method, and soil samples at 116 sampling points were collected simultaneously. The correlation between in-situ hyperspectral reflectance data after different pretreatment modes and soil pH value was analyzed. Partial least squares regression, support vector machine regression and random forest were used to establish the hyperspectral inversion model of soil pH, respectively. According to the model evaluation indexes, the optimal model was selected and used for inversion and mapping of the pH value of the uncollected soil sample points. [Results] The reflectance after the differentia treatment could effectively improve its correlation with soil pH value. The random forest model with second-order derivative of reflectance was the optimal model among all models with R² of 0.87, RMSE of 0.04, and RPD of 2.53. The digital map interpolated by the pH value of optimal model inversion was highly consistent with the spatial distribution characteristics of the actual measurement pH value, which could objectively reflect the spatial distribution of soil alkalinization. [Conclusion] The random forest model is the optimal model for in-situ inversion of soil pH value in cotton fields in South Xinjiang Uygur Autonomous Region, and Kriging interpolation could objectively visualize the soil pH value distribution in the study area.

Abstract:[Objective] The applicability of the InVEST model in the evaluation of the importance of water conservation functions at the city and county level was assesssed, and the spatiotemporal characteristics and regional differences of water conservation services in Guangzhou City, Guangdong Province was analyzed, in order to provide a theoretical basis for regional socio-economic development and the formulation of ecological environmental protection and restoration policies. [Methods] Using comparative analysism, the accuracy of InVEST water conservation evaluation model and related guidelines (Technical Guide for Carrying Capacity of Resources and Environment and Suitability Evaluation of Land Spatial Development) recommended model in regional water conservation services was evaluated. And GIS spatial analysis method was used to analyze the spatial and temporal analysis of water conservation service in Guangzhou City from 2013 to 2017. [Results] ① The evaluation results of the water conservation evaluation model based on InVEST were highly accurate, and the evaluation results of the importance of water conservation functions also met the requirements. ② The total amount of water conservation in Guangzhou City increased first and then decreased, and maintained a certain growth trend. The high values were concentrated in the water area and the forested area in the northeast, while the low values were concentrated in the built-up area of the city center. ③ The overall water conservation function had been improved, but differences existed among different administrative divisions and land types. The administrative regions of Haizhu District, Panyu District and Liwan District had increased greatly, the cultivated land and construction land had been improved, forest land had remained unchanged basically, while grassland had been weakened. ④ The proportion of area of water conservation function importance zone was similar, but the proportion of different land types within each zone was different. [Conclusion] ① Compared with the guide model, the water conservation assessment model based on InVEST is more accurate and has a good application prospect in the field of planning. ② The spatial differentiation of water conservation in Guangzhou City is obvious, and the overall water conservation function has been improved from 2013 to 2017.

Abstract:[Objective] The conflicts of three space types in oasis counties in the northwest arid zone were analyzed and simulated, in order to provide scientific reference for the rational layout of land space and sustainable development of the region. [Methods] Taking the oasis county of northwest arid zone—Mageti County, Xinjiang Wei Autonomous Region as the study area, a spatial classification system was constructed based on the dominant land use function to divide the national land space into urban, agricultural and ecological space. A spatial conflict measurement model was constructed based on the landscape pattern index to explore the evolution characteristics of spatial conflict levels from 2009 to 2019. The CA-Markov model was used to predict the spatial layout in 2024 and analyze the characteristics of conflict intensity changes. [Results] The area of urban space increased from 1 537.74 hm² to 4 582.24 hm², and the area of agricultural space increased from 84 670.06 hm² to 107 447.66 hm², while the area of ecological space decreased by 25 822.69 hm². ② The intensity of spatial conflict increased significantly from 2009 to 2019, and the proportion of medium spatial conflict, relative high spatial conflict and high spatial conflict evaluation units increased by 50.41%, 13.45% and 0.53%, respectively. ③ In 2024, urban space and agricultural space would increase 2 981.19 and 4 285.96 hm², respectively, and ecological space decrease 7 267.16 hm². The conflict level would be dominated by medium spatial conflict, which account for 60.24%. [Conclusion] From 2009—2019, urban space and agricultural space increased year by year, while ecological space decreased, and the disordered change of all kinds of space led to the overall increase of spatial conflict intensity. Through the prediction, the change trend of the 3 types of space in 2024 would consistent with that in 2009—2019, and the medium spatial conflict was the main one.

Abstract:[Objective] The spatial downscaling and error correction of tropical rainfall measuring mission (TRMM) data at different time scales were researched in order to provide references for flood disaster monitoring in Central China. [Methods] This article mainly used geographically weighted regression (GWR) model to achieve spatial downscaling of TRMM data from 2001 to 2019 with the help of enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI), and compared and analyzed the annual, seasonal and monthly downscaled data through meteorological station data. Then combined with the geographic difference analysis (GDA) and geographic ratio analysis (GRA), the downscaling results of the year, quarter and month were corrected for error, and the data before and after the correction were compared and analyzed. [Results] ① The coefficient of determination (R²) of TRMM data and meteorological station data in year (0.630), season (0.710～0.865) and month (0.637～0.875) all showed that the TRMM data had better applicability in Central China. ② The spatial resolution of the TRMM data was downscaled from 0.25° to 1 km through the GWR model, and TRMM_EVI data had better accuracy than TRMM_NDVI data, indicating that TRMM data in Central China had a closer relationship with EVI than NDVI. ③ GDA and GRA corrections were performed on the optimized TRMM_EVI data. The GDA correction results were better than the GRA corrections, and the correction effect was better in months with more precipitation. [Conclusion] In Central China, EVI is more suitable for TRMM data downscaling research than NDVI, and downscaling data using GDA correction is more effective than GRA correction.

Abstract:[Objective] The dynamic changes of soil erosion in the mountain area of Southwestern Sichua Province were analyzed to support the comprehensive management of the regional ecological environment. [Methods] Based on the general soil loss equation, the study calculated the amount of soil erosion in the region from 2000 to 2018, and divided it into six levels including mild, light and moderate according to the national water erosion intensity grading standard. The spatial overlay analysis and linear regression equation methods were used to analyze its temporal and spatial changes. [Results] ① As a whole, soil erosion in the study area increased gradually from north to south. ② More than 50% of the region had obvious erosion. ③ In 2010, there was a obvious abrupt change in the intensity of regional soil erosion, but no significant change occurred in about 60% of the regional soil erosion intensity level over the whole period of time, and the overall stability of the soil erosion intensity levels was relatively high. ④ During the entire period, more than 95% of the areas in the region showed obvious improvement and no change in the degree of erosion state. [Conclusion] Soil erosion has been effectively controlled. The dynamic law of soil erosion in the study area is obvious, and rainfall erosion has an obvious driving effect on its change.

Abstract:[Objective] The ecological environmental changes in the headwaters of Dongjiang River in 2000—2019 were analyzed to provide scientific basis for the protection and utilization of the water source area. [Methods] Based on Landsat image data of 2000,2004,2009,2014 and 2019, four indexes including green degree (NDVI), humidity (WET), dryness (NDBSI) and heat (LST) were extracted. Principal component analysis and remote sensing ecological index (RSEI) were used. The ecological environment quality of the headwaters of Dongjiang River was evaluated and analyzed. [Results] From 2000 to 2019, the RSEI index in the study area was 0.356, 0.538, 0.332, 0.608 and 0.637, respectively. The ecological environment quality showed an upward trend, a downward trend and an upward trend. Overall, the ecological environment quality was significantly improved. The regions with better ecological environment were mainly distributed in the central and southeastern areas with higher vegetation coverage, while the regions with worse ecological environment were mainly distributed in the eastern and northwestern urban areas with close human activities. In the study area, the ecological environment quality of excellent level was dominant, and its area proportion had increased from 0.204 9% in 2000 to 92.346 4% in 2019, indicating that the ecological environment had significantly improved. The shift of gravity center of heat (LST) and dryness index (NDBSI) was 1.616 km and 1.482 km, while the shift of green density (NDVI) and moisture index (WET) was affected by population density and development degree. The distribution of green land and soil moisture began to scatter with the development of construction land, which increased the shift. [Conclusion] From 2000 to 2019, except for the deterioration of the surrounding environmental quality caused by urban transportation, the rest of the region had significant improvement compared with the previous period. The relationship between vegetation cover and urban land use was the main cause of ecological environment change in the headwaters of Dongjiang River.

Abstract:[Objective] The effects of production-ecological-living land use transformation on eco-environment quality in Guangdong Province were studied based upon grid cell in order to provide scientific basis for coordinated development of regional ecology and economic. [Methods] Based on the eight-phase Landsat TM image interpretation data of Guangdong Province and the dominant function classification system of land use in production-ecology-living space, and the characteristics of production-ecological-living land use transformation as well as its eco-environment quality were quantitatively analyzed. [Results] ① From 1980 to 2018, the agricultural productive land decreased greatly, with a total decrease of 5 369.61 km² and the mining productive land and urban living land increased greatly, with a total increase of 4 526.02 km² and 2 406.93 km². The conversion between agricultural production land and woodland ecological land was obvious. ② Spatial transformation of production-ecological-living land use in Guangdong Province was mainly manifested as the mean center of mining productive land and forest ecological land became closer to the geometric center of Guangdong Province, the mean center of agricultural productive land and urban living land moved away from geometric center. ③ The index of eco-environment quality in Guangdong Province was reduced from 0.648 1 in 1980 to 0.641 4 in 2018. The spatial differentiation of ecological environment quality was obvious, and the eco-environment quality in coastal cities was much lower than inland area. ④ The Getis-Ord G_i^* index proved that the hot region of the change of eco-environment quality was concentrated on the Eastern, Western and Northern regions of Guangdong Province, while the cold region was chiefly located in Pearl River Delta. ⑤ Guangdong Province had two trends which were ecological improvement and ecological deterioration. [Conclusion] Full consideration should be given to the regional natural considerations, the function positioning and the leading factors of ecological environment changes in order to formulate land policies and measures and promote the balanced development of Guangdong Province.

Abstract:[Objective] The desertification in Hebei Province was monitored by remote sensing and its driving factors was analyzed, in order to provide reliable theoretical basis and data support for desertification control. [Methods] Based on MODIS13 A3-NDVI and meteorological data from 2000 to 2017, taking the desertification index as the evaluation index, the temporal and spatial evolution of land desertification in Hebei Province and its driving factors were analyzed by trend analysis, future change analysis, and climate factors analysis. [Results] ① In 2000—2017, the desertification of study area decreased, with a decreasing rate of 0.009/18 a, of which the proportion of extremely significant decrease (p<0.01) was 11.13% and significant decrease (p<0.05) was 8.86%. ② The proportions of persistent and anti-persistent desertification in future in the study area were expected to be 41.29% and 58.71% respectively, of which, the weak persistence and weak anti-persistence was expected to be 37.43% and 51.35%, respectively. On the existing basis, the trend change in the future was basically unchanged, and the proportions of persistent and anti-persistent characteristics were 14.89% and 19.6% respectively. ③ The partial correlation coefficient of desertification index with precipitation and temperature in growing season was small and insignificant. [Conclusion] The overall desertification situation is improved during 2000—2017, but with obvious spatial heterogeneity. The desertification areas are mainly concentrated in the Bashang Plateau area and the Hurst index indicates that desertification might be reversed in local areas in the future. In terms of climate factors, the increase of temperature and the decrease of precipitation can promote desertification in the study area.

Abstract:[Objective] The sustainable development and the system coordinated development of the Yellow River basin was evaluated and analyzed, in order to provide theoretical reference for the sustainable development of the Yellow River basin. [Methods] According to 5 systems of resources, economy, society, ecological environment and science and technology, 37 indexes were selected to construct the sustainable development index system of the Yellow River basin. Nine provinces along the Yellow River basin from 2008 to 2018 were selected as the research objects. Entropy weight method and grey correlation analysis method were used to determine the index weight, and the coupling degree and coupling coordination degree of the five subsystems were calculated. Finally, the grey GM(1.1) model was used to predict the coupling coordination degree. [Results] The comprehensive evaluation index of sustainable development in the Yellow River basin was 0.214 5 and 0.410 2 in 2008 and 2018, respectively, showing an upward trend on the whole. From 2008 to 2018, the system coupling degree of the 9 provinces showed an upward trend. In 2008, the coupling degree of 4 provinces was in the running in stage, and the other 4 provinces was in the high running in stage, only the coupling degree of Gansu Province was in the antagonistic stage. In 2018, the coupling degree of all the 9 provinces was improved, and the coupling degree of the 9 provinces was at a high level of running in, but the coupling degree bettwen the provinces was different. The coupling coordination degree of the 9 provinces would be increased in the next 7 years. [Conclusion] The level of sustainable development in the Yellow River basin has been improved year by year, but there are differences in spatial coupling and coordination among provinces in the Yellow River basin.

Abstract:[Objective] The land use transformation structure, spatial characteristics and ecological environmental effects of the production-living-ecological space in the Yellow River basin were studied, in order to balance land resource development and ecological environmental protection, and provide decision-making for the ecological protection and high-quality development of the Yellow River basin. [Methods] Taking Yellow River basin as the study area, the land transformation was analyzed by using spatial analysis and mapping functions of ArcGIS platform, ecological environment quality index and the contribution index of land use transition to the ecological environment. [Results] ① From 2000 to 2020, the land use structure showed that production land area was decreasing, ecological land remains relatively stable and living land area was increasing. ② In 2000, 2010 and 2020, the eco-environmental quality index of the Yellow River basin was 0.450 2, 0.450 5 and 0.456 7 respectively and showed a stable upward trend. ③ There were obvious differences in the spatial distribution of the ecological environment quality index from 2000 to 2020, and the overall trend was increasing from the southeast to the north. ④ From 2000 to 2020, forage ecological land contributed the most to the ecological environment quality of the Yellow River basin. In last two decades, there existed two trends of deterioration and improvement of ecological environment, and the latter was more than the former. Consequently, ecological environment of Yellow River basin had been improved. [Conclusion] The occupation of agricultural production land by urban and rural living land, and industrial and mining production land is the main factor that caused eco-environmental deterioration in the Yellow River basin. The decision makers should rationally plan the production-living-ecological spaces and optimize the spatial allocation of land resources, so as to promote the major national strategy for ecological protection and high-quality development in the Yellow River basin.

Abstract:[Objective] The dynamics of water-related ecosystem services and its influences by south-to-north water diversion project were analyzed, in order to protect water resources and ecosystem balance of Miyun Reservoir. [Methods] The methods of market value, alternating engineering, alternative cost, carbon trading, willingness to pay, proportion apportionment and benefit transfer were used to evaluate the water-related ecosystem services of water resources supply, aquatic product provision, flood regulation and reservation, air humidity improvement, summer heat amelioration, water purification, water conservation, CO₂ sequestration, O₂ release, biodiversity protection, tourism and leisure and scientific research and education of Miyun Reservoir. [Results] The water-related ecosystem service values of Miyun Reservoir ranged from 70.996 to 100.360 billion during 2008—2019, which fluctuated slightly at first and then increased. As for components of water-related ecosystem services, the value of supporting services, especially biodiversity protection, played a dominant role (64%~80%). The value of regulating services was in the secondary position (18%~33%), which was mainly manifested in water conservation, humidity improvement, summer heat amelioration and flood regulation and reservation. The value of provisioning services and cultural services together accounted for less than 5%. Moreover, the south-to-north water diversion project significantly increased the values of air humidity improvement, summer heat amelioration, water conservation, water purification, tourism and leisure, scientific research and education and total ecosystem services (p<0.01), while significantly decreased the value of flood regulation and reservation (p<0.01). [Conclusion] The water ecological service function of Miyun Reservoir is affected not only by natural factors such as climate, but also by human factors such as south to north water diversion project and traffic convenience. The monitoring of water volume and quality and the development of cultural and ecological potential of Miyun Reservoir should be strengthened, so as to guarantee the security and reliability of drinking water reserves for Beijing City.

Abstract:[Objective] The ecological footprint and various types of land use was analyzed, in order to provide countermeasures and suggestions for the high-quality development of high efficiency eco-economic zone of Yellow River delta. [Methods] Taking 19 cities in the high efficiency eco-economic zone of Yellow River delta as the research objects, the ecological footprint model and factor detector were used to quantitatively analyze the spatio-temporal evolution and influencing factors of the ecological footprint in the high efficiency eco-economic zone of Yellow River delta from 2005 to 2019. [Results] ① The ecological footprint increased rapidly from 2010 to 2019, the ecological carrying capacity increased slowly, and the deficit expanded. ② The spatial distribution of ecological footprint in the high efficiency eco-economic zone of Yellow River delta was obviously different. The regional development could be divided into stable period, rising period and transition period. The ecological footprint in the middle and northwest was significantly higher than that in the east and southwest; ③ There were significant differences in the influencing factors, among which, cultivated land production and industrial development had the strongest influence on the ecological footprint of the high efficiency eco-economic zone of Yellow River delta, and the influence degree of other factors was in the order of population density > road density > urbanization rate > aquaculture. [Conclusion] ① The overall trend of per capita ecological footprint in the high efficiency eco-economic zone of Yellow River delta is stable, and the footprint of farmland and fossil energy land account for a large proportion of the regional ecological footprint. ② The regional ecological footprint increased from the east to the central and western regions, and the high value areas are mainly concentrated in the inland areas and the cities along the Yellow River. ③ Agricultural production and industrial production are the core development factors in the high efficiency eco-economic zone of Yellow River delta. Water development and utilization can promote regional ecological environment protection. Therefore, measures and stuafegies should be put forward from the viewpoints, such as farmland protection, industrial chain upgrading, digital empowerment and ecological restoration.

Abstract:[Objective] The effects of urban green space landscape pattern on air purification service were studied to provide theoretical guidance for the structural optimization and layout of urban green space landscape. [Methods] Based on the land use data of 2009 and 2019 in the urban area of Anyang City, He’nan Province, the purification efficiency of urban green landscape for SO₂, NO_x and PM₁₀ was measured, and the relationship between landscape configuration and airpurification services was explored from a spatial perspective. [Results] ① The landscape area of urban green space in Anyang City decreased by 3 492.18 hm, mainly for construction land. Shannon’s diversity index, landscape shape index and contagion index changed from 0.572 7, 44.272 1 and 78.98% to 0.875 8, 90.334 5 and 66.88%. ② The service value of air purification at the beginning and the end of the studied period was 565 million yuan and 2.67 billion yuan respectively. The proportion of dust retention function value increased from 97.19% to 99.07%, and the contribution of forestland landscape to the total value increased from 88.99% to 94.54%. ③ The high, medium and low value areas of green landscape air purification service presented a mosaic distribution state, and the low value areas of ecological value were more in the early stage, and the medium and high value areas increased significantly in the late stage. ④ The bivariate moran index of Shannon’s diversity index, landscape shape index, contagion index and air purification service value was 0.281, 0.458 and -0.305 in 2009, while the corresponding value was 0.403, 0.411 and -0.408 in 2019. [Conclusion] The increase of landscape diversity and the complexity of landscape shape could improve the air purification service, while the decreasing spread of green space landscape would inhibit the air purification service.

Abstract:[Objective] The interactive relationship between urban compactness and land use efficiency was explored, in order to provide a basis for promoting new urbanization and high-quality sustainable development in the region. [Methods] The index system was established based on the model of coupling urban compactness and land use efficiency, and the spatial and temporal characteristics of the relationship between them in Guangxi Zhuang Autonomous Region from 2003 to 2018 were analyzed by using the weighted summation method and the coupling coordination degree model. [Results] ① The urban compactness of Guangxi Zhuang Autonomous Region from 2003 to 2018 showed a fluctuated upward trend, and the compactness index increased from 0.301 to 0.433. The high compactness cities were mainly distributed in central and Northern Guangxi, the cities of low compactness were concentrated in Northwest Guangxi and Southeast Guangxi on both sides, and the cities of medium compactness were ringed around the cities of high compactness. ② The land use efficiency of cities in Guangxi had experienced the gradient improvement process of “steady optimization-accelerated growth”, and the scores had risen from 0.363 to 0.574. The land use efficiency showed the spatial pattern of high in the north and south, and low in the east and west. ③ The coordination degree of coupling between urban compactness and land use efficiency in Guangxi area increased from 0.408 to 0.504 at a low speed, the coordination type transitions from barely coordinated to primary coordination. Each city experienced the evolution process of “on the verge of disorder—barely coordinated—primary coordination”. In general, the coordination type showed the pattern of “point surface—cluster—linear belt”. [Conclusion] The mutual promotion role of urban compactness and land use efficiency in Guangxi area is weak, and their coordination relationship is not close. Promoting the coordinated development of them plays an important role in solving the negative problems in the process of urbanization.

Abstract:[Objective] Taking the urban agglomeration of Central Yunnan Province in the plateau karst area as an example, the terrain gradient was introduced to explore the impact of land use/cover change (LUCC) on ecosystem service value (ESV) in the process of rapid urbanization, in order to provide theoretical guidance for the improvement of ecosystem service value and land use planning of other similar areas. [Methods] Based on the land use data from 2000 to 2020, combined with the topographic index, modified ESV equivalent and hotspot analysis method, the spatial and temporal variation characteristics of LUCC and ESV on the terrain gradient the study area from 2000 to 2020 was quantitatively discussed, and the impact of LUCC on ESV was analyzed through the ESV profit and loss flow table. [Results] ① From 2000 to 2020, the cultivated land and forest land in the study area decreased by 1.21×10⁵ hm² and 1.19×10⁵ hm², respectively, while the construction land increased by 2.16×10⁵ hm². Cultivated land, water land and construction land were mainly concentrated on low terrain gradient, and forest land was mainly concentrated on high terrain gradient. ② The value of ESV decreased from 119.64 billion yuan to 113.75 billion yuan from 2000 to 2020, with a total decrease of 5.89 billion yuan. ESV had significant spatial differentiation characteristics on the terrain gradient. ESV high-value areas were mainly distributed in the western and northern regions with high altitudes and steep slopes, while ESV low-value areas were on the contrary. ③ The loss of forest land and water land and the occupation of construction land on cultivated land led to heavy loss of ESV. The loss areas were mainly distributed in urban areas in the central part of Kunming City and the northern part of Honghe Prefecture. From 2010 to 2020, due to the implementation of the policy of returning cultivated land to forest land, grassland, and water land, the area of forest land and water land in the northern part of Honghe Prefecture and the northern part of Qujing City increased, and the ESV value-added areas appeared. [Conclusion] During the study period, LUCC had a great impact on ESV and showed obvious spatial differences on the terrain gradient. Measures such as improving and protecting the existing forests, grasslands and lakeside wetlands, and strict control of ESV loss cold spots can effectively improve the ecosystem service value and promote regional sustainable land use of the study area.

Abstract:[Objective] The characteristics of territorial space in Fujian Province were explored, in order to solve the disorder of territorial space development caused by rapid urbanization and provide scientific basis for optimizing its layout. [Methods] Based on the perspective of production-living-ecological functions, taking Fujian Province as the research object, the comprehensive evaluation method, exploratory spatial data analysis, obstacle degree model and comparative advantage index analysis were used to evaluate the production-living-ecological functions, analyze its spatial distribution characteristics and obstacle factors, and figure out the superior function areas and put forward the optimizing countermeasures. [Results] ① The average values of production function, living function and ecological function of Fujian Province in 2018 were 0.061 8, 0.093 6 and 0.030 6, respectively. The spatial distribution characteristics of production-living-ecological functions in Fujian Province were higher in the east and lower in the west. ② The spatial distribution of the production-living-ecological functions were positively correlated. The spatial distribution characteristics of the hot spots and cold spots of the three were generally high in the east and low in the west, and there was a certain overlap in the region. ③ The main obstacles affecting production-living-ecological functions included economic density, total amount of ecological value service, traffic land density and urbanization rate. ④ The land space of Fujiang Province could be divided into four dominant functional areas. [Conclusion] There are great differences in production-living-ecological functions in Fujian Province, therefore, we should balance regional development and optimize the spatial layout of land.

Abstract:[Objective] The land use dynamics and the evolution of ecosystem service functions in Hulun Buir sandy land were studied to provide support for optimizing the land use structure and improving the ecological service function in this area. [Methods] Based on the remote sensing images of Hulun Buir sandy land in 2000, 2005, 2010, 2015 and 2020, and the supported by ENVI 5.3 and ArcGIS 10.2, the characteristics of land use change were analyzed by using the spatial analysis model of land dynamic attitude and the change intensity. The land use data of Hulun Buir sandy land were analyzed by using the calculation method of China’s sand ecological service value table and the ecological service value and sensitivity index of Hulunbuir sandy land were calculated. [Results] ① Desertification showed a reversal trend， the area of each desertified land decreased， the area of forest and grassland increased， the ecological environment of the area had been effectively improved. ② From the point of view of the rate of change，the change of forest and grassland was the largest, with the annual change rate of 9.3%. From the absolute value of change intensity, the change intensity of mild desertification was the largest, and the area decreased by 70% in 20 years. ③ The overall ecological service value of Hulun Buir sandy land showed an increasing trend, among which the ecological service value of forest and grass land was the highest, and the ecological service value of extremely severe desertification was the lowest. The sensitivity index of ecological service value are all less than 1, indicating that the ecological service value of sand was relatively stable and the results were credible. [Conclusion] The region should expand the area of forest grassland, manage the desert area reasonably, and enhance the value of regional ecosystem services.

Abstract:[Objective] The land use change and its driving factors in Shaanxi Province were studied to provide a scientific basis for promoting the comprehensive optimization of land resources and sustainable social and economic development. [Methods] Based on the remote sensing monitoring data of land use in Shaanxi Province in 2000, 2010, and 2018, the spatiotemporal evolution characteristics of land use in Shaanxi Province were quantitatively analyzed through methods such as land use dynamics, land use transfer matrix, and spatial autocorrelation, and principal component analysis method to explore the driving forces of the land use change. [Results] The area of each land use type changed in different degrees, among which, the area of cultivated land decreased the most, the area of industrial and mining construction land increased the fastest, and the area of water changed the least. Land use types were affected by natural conditions, and the spatial differences were significant. The spatial agglomeration of rural residential land, unused land, cultivated land, woodland, and grassland was strong, while the spatial agglomeration of water, urban residential land, and industrial and mining production land was relatively weak. Grassland and industrial and mining construction land form new agglomeration areas. The land use transfer in the Northern Shaanxi Plateau and Guanzhong Plain was relatively frequent, and the land use conversion change in the mountainous area of Southern Shaanxi Province was relatively small. The transfer of cultivated land to woodland and grassland, and the transfer of unused land and grassland to industrial and mining construction land were obvious in Yulin and Yan’an City, and the transfer of cultivated land and rural residential land to urban residential land was obvious in Xi’an City. The main factors of land use change were the development of social economy and the adjustment of industrial structure in the process of urbanization. [Conclusion] The regional differences of land use change in Shaanxi Province are great, and land use planning should be formulated according to local conditions, so as to promote the coordinated development of population-economy-ecology.

Abstract:[Objective] The comprehensive carrying capacity of resource and environment in Changzhou City of Jiangsu Province was studied, in order to clarify the direction of land space development and utilization, and to provide decision-making references for the spatial allocation optimization of land and population.[Methods] Based on multi-source land and space data from 2010 to 2019, a multi-index and multi-factor synthetic discriminant model was constructed. [Results] The comprehensive carrying capacity of resources and environment in Changzhou City presented significant spatial differences, such as high in the east and low in the west, high in the plain and low in the mountainous and hilly areas. Moreover, based on the food security guarantee level calculated with future land resources, the population carrying index of Changzhou City in 2030 would be as high as 1.27, which was significantly higher than the international alert level. [Conclusion] The spatial development degree, natural background and infrastructure conditions have significant constraints on the comprehensive carrying capacity of resources and environment in Changzhou City, and the population is in a state of overloading.

Abstract:[Objective] The existing issues in road erosion research and the research directions that need to be paid attention in the future were analyzed in order to provide important basis for soil erosion prevention and control, ecological environment safety and high-quality development of the watershed.[Methods] Through literature review, the definition of road erosion, the characteristics and influencing factors of road erosion were summarized and analyzed. [Results] The main problems existing in the study of road erosion are as follows: ① The research methods of road erosion were still immature. Simulated rainfall/scour test method were widely used, while field monitoring and model simulations were rarely used. ② Most of research contents were limited to the in-site erosion effect of road, and few involve the off-site erosion effect of road. ③ Most studies on road erosion control were focused on hardened roads, and only a few studies were focused on unhardened roads. [Conclusion] Future road erosion study should combine the characteristics of road erosion and its influencing factors, use the concept of connectivity to explore the “switch” effect of road on the transportation of runoff and sediment in the road area and the whole watershed, so as to reveal the influence of road on the mechanism of runoff and sediment transportation in the whole watershed. In future, the maintenance and management measures of hardened road and erosion control measures of soil road should be proposed according to local conditions.