Study On Regional Terrain Factors Of Soil Erosion

The research of regional dimension soil erosion was based on the slope surface and small basins of soil erosion. Different scales of soil erosion had different services. Therefore, it also urged the expansion of the county or more regional and national level. A lot of researches showed that slope and the terrain factors of little valley were no longer suitable for studying the regional dimension of soil erosion. So the study of regional dimension terrain factors were high valued and social.From the most serious regions with soil erosion of China, this paper had chosen four typical sample regions—Ansai County in the northwest loess plateau, Binxian County of the Heilongjiang Province in northeast black soil, Yanting County in Sichuan Province karsts purple soil and Xingguo County of Jiangxi Province in the south red earth rolling terrain. This study analyzed the theories and methods of extracting terrain factors selectively from the used macroscopic terrain factors of affecting the regional loss of soil and water, and compared their advantages and disadvantages in different landscape areas. On the basis of predecessors, this paper improved the terrain factor—Erosion Potential, and analyzed its applicability in different areas as a regional factor of soil erosion under the reference standard of high-accuracy LS factor. The concrete steps as follows:Firstly, the geomorphic feature of the regional terrain factors reflected was often be of the general effect in all some raster neighborhoods'elevation. So, before extracted and analyzed the regional terrain factor had to research the best analysis windows. The best analysis window was the key step to extract terrain factors. This paper used iterative method with two raster as iterative step length, and analyzed the relationship between topographic relief and the best windows to find out the best windows in different sample region's terrain factors.Secondly, improved the erosion potential energy terrain factor to increase its' applicability in different region. Lastly, with computing the related coefficient between the terrain factors and LS factor, analyzed their relativity. The result showed the improved erosion potential energy index had the highest relativity among those regional terrain factors, so it can be the key terrain factor of the regional scale loss of soil and water. And draw the map with 90 meters resolution of China erosion potential energy based on research.