Assessment of Soil Erosion Risk in Three Gorges Reservoir Area based on GIS and RUSLE

Assessment of soil erosion risk is necessary to effectively manage water and soil resources in the Three Gorges Area. In this paper, RUSLE factors algorithms were first improved based on environmental characteristics and data availability of the area. Improved algorithms were then used to evaluate soil erosion intensity using GIS. The results showed that the average annual soil erosion intensity in the Three Gorges Reservoir Area was 31.85 tha(-2)-a(-1). The area of slight and low erosion categories accounted for 33.03% and 30.90% of total area, respectively. Mostly situated in middle alpine gorge regions, about 11.06% of the area experienced very high and extreme erosion risk, contributing about 49.45% of total soil loss occurring in the area. The erosion intensity in grassland and barren land was higher than for other land use type. On the whole, erosion control in most areas has significantly improved. However, some areas still need attention from soil conservation management, especially in terms of improving the ecological restoration capacity of grassland and barren land.