A study on estimation of the amount of soil erosion in small watershed based on GIS: a case study in the Three Gorge Area of China

Soil erosion is a serious environmental and production problem in the Three Gorge Areas (TGA) of China. The objectives of the study were to develop and validate a soil erosion-predicting model based on the revised Universal Soil Loss Equation (RUSLE) in a geographic information systems (GIS) environment. The use of GIS to develop conservation-oriented watershed management strategies in the Taipingxi watershed is presented. The study showed that the serious eroded area (sediment is higher than 50 t/ha) is 10.629/c but contributes 61.55% sediments of all watershed, while no or slightly eroded area (sediment is lower than 10t/ha) is 62.18%, only contributes 3.49% sediments in the watershed. In the watershed, the annual average soil loss rate from relatively flat agricultural land was approximately 21 t/ha, whereas 48 t/ha was found on the cultivated sloping lands, which constitutes a large proportion of soil loss.