Influence Of DEM Resolution On Soil And Water Loss Evaluation In Daxing'an Mountains

70%of the country suffers from water loss and soil erosion all over the world.Almost all provinces in China is suffering from different degree of water loss and soil erosion.Water loss and soil erosion has seriously affected human living environment,and it will stunt the sustaina ble development of economy and society,it has been in the forefront of global environmental p roblems.In this paper,we take Greater Khingan Mountains as the research area,based on the RUS LE model,supporting by Geographic Information System(GIS)and Remote Sensing(RS)techn ology,using DEM in different resolution(10,20,30,40,50,60,70,80,90,100m),we extract s lope factor(S),slope length factor(L),and combined these two factors into terrain factor(LS),a nd then we introduced 5 main factors affecting water loss and soil erosion into the modified ge neralized soil loss equation(RUSLE)to get soil and water loss under different DEM resolution s.The 5 main factors are LS factor,rainfall erosivity factor(R),soil erodibility factor(K),veget ate on cover and management factor(C)and soil and water conservation measures factors(P),a mong them,the most feasible R is obtained by comparing 3 different interpolation method,Inv erse Distance Weighting(IDW),Spline Function(Spline)and Ordinary Kriging(OK),and fina 1ly,we choose OK method for spatial interpolation of R.The results show that soil loss is the most sensitive to DEM resolution change,and the sen sitivity of LS factor to DEM is greater than that of S factor and L factor in our study area.Whe n the DEM resolution is lower than 40m,the change of soil and water loss amount is small,wh en the DEM resolution is 50m,the amount changes rapidly,when the DEM resolution is higher than 60m,the amplitude of change tends to be stable.With decrease of DEM resolution,the impact of DEM to soil and water loss results is getting smaller.Therefore,50?60m should be t he most suitable DEM resolution for evaluating soil and water loss.Soil erosion in the study ar ea using the 50m resolution DEM is mainly dominated by slight and mild erosion.,which over take 90%of the total area.The serious soil and water loss is mainly occurs on ridges and the re gion of intense human interference.