Impact of Land-Use Changes on Intensity of Soil Erosion in the Mountainous Area in the Upper Reach of Shiyang River in Arid Northwest China

In arid and semi-arid areas, a large area of soil erosion in the upper reaches will not only aggravate drought of atmospheric and soil, but also induce deterioration of grasslands and desertification. In this paper, as the Shiyang River upper reaches a case, we analyzed how the changes of land use and land cover influence the soil erosion, based on remote sensing satellite date and DEM, using ArcGIS software and soil erosion formula (RUSLE). The results show that: (1) the soil erosion intensity of farmland was the most serious among the vegetation types. The ability of soil and water conservation of forest, shrub and high covered grassland was the best, and which can effectively prevent the soil loss caused by the increase of slope gradient. (2) Lapping the land use changes map, soil erosion changes map and the slope map, the result indicated that reclamation high covered grassland to farmland in the areas of slope gradient exceeding 15 was the most mainly cause.