A Simulation Of The Spatial Flow Of Soil Conservation Service On The Basis Of Service Path Attribute Networks Model

Using Landsat TM remote sensing data,rainfall data,soil type,land use type and socio-economic statistics,based on the ArcGIS platform,using Service Path Attribute Networks,using RUSLE model to simulate Su River Basin supply of soil conservation service,quantification soil conservation service demand based on economic loss of soil nutrient loss caused by soil erosion.Analyze the supply and demand balance of two ecosystem services,and use ArcGIS software to map the supply and demand balance map.Soil conservation service flow path is mainly determined by the terrain and river hydrology network,service flow is calculated based on river load by the SDR module of the InVEST model.Use ArcGIS software to map the soil conservation services flow levels,exploring the law of service flow change,providing theoretical support for ecological compensation policy,land use management and economic management decision-making.The main conclusions are as follows:?1?The supply of soil conservation services in the study area is mainly vegetation,mainly distributed in the east and south of the study area,of which Yongji city has the largest supply area.Compared with 2000,there was no significant change in the supply area of the study area in 2015,and the total supply decreased by 12.25%.In 2000,the soil supply service low supply area was mainly distributed in the west,north,southeast and southwest of the study area,including Linyi County,the north Wenxi County,the east of Wanrong County,the southwest and east of Xiaxian County,and the southwest of Yongji City,and the southwest of Yanhu District,low-coverage grassland is the main source,and the supply is small;the medium supply area,the higher supply area and the high supply area are mainly distributed in the south of the county,the south of Yanhu District and the south of Yongji City.The main areas are forest land,shrubs and high-coverage grassland,and the supply of soil conservation service is relatively high.In 2015,compared with 2000,the higher supply area shifted to the southwest of the Su River Basin?south of Yongji City?,while the medium supply area to the east?south and southwest of Jixian County?and the south?southern of Yanhu District?Transfer.?2?The soil conservation service demand area in the study area mainly includes farmland,residential areas?urban land and rural residential areas?,reservoirs and other construction land,of which the farmland area is large,accounting for 88.35%of the total area of the demand area.Linyi County has the largest demand area,and Yongji City has the smallest demand area.Compared with 2000,there was no significant change in the distribution and area of the demand area,but the demand for soil conservation service decreased by 28.42%,which was related to the decrease of rainfall erosion factor and the increase of vegetation coverage.In 2000,the level of soil conservation service demand gradually decreased from northeast to southwest.The high demand area was mainly distributed in the northeast of the Su River Basin,including the northern part of Wenxi County.The vegetation type was mainly low-coverage grassland,and the soil retention ability was weak.The soil erosion is serious,and the low demand area is located in the west of Su River Basin,mainly including Yongji City and Linyi County.In 2015,compared with 2000,the medium demand area expanded to the central part of the study area,the lower demand area expanded to the west of the study area,and the low demand area west of the middle area was replaced by the lower demand area.?3?The soil conservation service flow path in the study area is the river channel of the Su River,including Jiangxian section of Su River,Wulongyu River,Zijiayu River and Wenxi section of Su River.Compared with 2000,the total amount of river sediment transport in the study area decreased by 31.49%in 2015,which was related to the decline of rainfall erosivity and the increase of vegetation coverage.Wulongyu River and Zijiayu River with high vegetation coverage in 2000 and 2015 were high-grade service flows;in 2000 and 2015,the service flow grade of Jiangxian section of Su River section did not change,which was a low service flow;Compared with 2000,the service flow of Wenxi section of Su River has been upgraded from a low-level service flow to a lower-level service flow.There is a negative correlation between river sediment transport and vegetation cover.The regression equation is:y=8840.424*e^-2.731x?R²=0.307,F=19.455,sig.<0.001?and y=6332.635*e^-2.352x?R²=0.266,F=15.955,sig.<0.001?.The amount of sediment transport is positively correlated with soil erosion,the regression equation is:y=0.035*x^0.987?R²=0.832,F=217.513,sig.<0.001?and y=-42580.319+4170.084*lnx?R²=0.590,F=63.388,sig.<0.001?.