Study of Applying USLE and Geographical Information System IDRISI to Predict Soil Erosion in Small Watershed

Based on the field survey in the typical small watershed, the method of geographical data base building was studied. Runoff and soil loss amount from experimental plots were used to generate K, C and P factors of USLE. By the support of IDRISI geographical information system and integration of the GIS and USLE, the soil erosion amount of the small watershed was predicted. Results showed that the serious eroded area (sediment is higher than 8 000 t/km 2) is 20%, but contributes 80% sediments of all watershed, while no or slightly eroded area (sediment is lower than 1 000 t/km 2) is 67%, only contributes 3% sediments.