A Study On Topographical Factors In Soil Erosion Prediction Model Based On DEM In Loess Plateau

China is one of the countries which suffer from serious soil erosion, in which the Loess Plateau is one of the most serious ones. The theoretical study of soil erosion on the regional scale provides a theoretical and technical support for comprehensive management of soil erosion. Soil erosion prediction models and topographical factors are two aspects of this study. Topographical factors are important hydrological variables in soil erosion prediction model, determining the loess erosion pattern and intensity of territorial distribution. In addition, soil erosion prediction models can predict the amount of soil erosion, which reflects the qualitative relationship between the amount of soil erosion and the impact factors such as soil, rainfall, vegetation, topography and preventive measures etc.Based on the previous research in this area, this study uses geographic information systems, geomorphology, soil and water conservation science and other basic theories and methods. This study uses a variety of landforms in Loess Plateau region with 1:10000 DEM. The RUSLE model's LS factor variation, the correlation between topography factors and LS factor, and LS factor's changes with the resolution of production-scale effects are discussed in the results. The main research findings are as follows:â‘ Selected 7 study areas in the Loess Plateau include Shenmu, Yulin, Suide Jiuyuangou, Yijun, Yanchuan, Ganquan and Chunhua. Calculated by AML language, LS factors are compared among different areas. The results show that the least erosions happens in Shenmu, followed by Chunhua, and the most serious one are Ganquan and Yanchuan, which is consistent with the actual situation.â‘¡This research also studies the correlation between the LS factor and topographic factors. Extracted from DEM, topographic factors include slope, slope length, curvature, surface roughness, topographic relief and erosion potential. The correlation between LS factor and each topographic factor is studied respectively. The results show that the degree of correlation from the highest to the lowest is that slope length, slope, topographic relief, erosion potential, surface roughness, surface curvature and profile curvature. â‘¢In the end, Discussed LS factor's changes with the resolution of scale effects with varying resolution are studied. LS factor's are extracted from, extracted LS factors through the 5m,10m,15m,20m,25m,30m,40m,50m,60m,70m,80m,90m and 100m resolution DEM., compared and analyzed the difference, finally found this rule. The results show that: the average trend is decreasing, but the changes of the average LS factor are uncertain with the lower resolution DEM. When DEM's resolution is higher, the average LS factor increases with a higher DEM's resolution, and L factor is the determinantcontrolling factor. However, when DEM's resolution is lower, the average LS factor is decreasing, and S factor is the determinantmaster factor.