The Beijing mountain area
soil erosion model was developed on the basis of the new technology and new research considered
soil erosion on steep slope. The BESEM is a computer program which uses distributed parameters and is event oriented. The model was developed to predict erosion from support practices and to accommodate spatial variability in topographies, soil properties, and land use conditions within small watersheds. The model contains three primary components: hillslope, channel and impounds such as check dam. Each component calculates rainfall excess by a Green Ampt Min Larson infiltration equation or SCS curve number method,according to the data of continuous record of rainfall; peak flow rate by simplified regression equation;
soil erosion by CSLE; and deposition soil as a function of sediment detachment, sediment transport capacity, and existing sediment load in the flow. The test results show that the model can precisely assess the runoff, peak flow rate and sediment yield. The model can also predict the distribution of runoff and soil loss. So the model can be used to evaluate the effect of variation of land use and support practice on runoff, peak flow rates and soil loss. The model can also be served as the soil and loss evaluation, management and the design of the support practice.