The Donghe basin is one of the typical regions with serious water and soil erosion in Kaixian county of Chongqing city.
In this study the spatial distribution variation of water and soil erosion in Donghe basin is analyzed based on a
comprehensive method that integrates SWAT model with a Geographic Information System and remote sensing
technology. SWAT is a physical based model that requires specific information about weather, soil properties,
topography, vegetation, and land management practices occurring within the watershed. Firstly, with the Donghe basin
as a study area, using the spatially distributed and mechanism-based SWAT model, the distributed hydrological and
sediment model are developed to simulate the runoff and sediment production of Donghe basin. Then the model is
calibrated and validated against observed runoff and sediment data from 2003 to 2004, the validated result shows a
deterministic coefficient of 0.93. Finally the spatial distribution of the water and soil erosion of Donghe is analyzed. The
results show that the mean sediment production of Donghe basin is 30.7 t/ha•a, the maximum sediment production of its
sub-watersheds is 212.7 t/ha•a, and the minimum is 0.3 t/ha•a. There is an obviously clustering feature of sub-watersheds distribution with different sediment production level. The area of the high erosion, strong erosion and violent erosion account for 30% of the whole basin area, the other soil erosion area occupy 70%.