[Estimated nutrient export loads based on improved export coefficient model in Xitiaoxi watershed]

It is very important to estimate nutrient export loads from watershed, which is beneficial to water environmental management. The export coefficients for major land use types were evaluated by field surveying data, in addition the spatial distributions of precipitation and runoff were considered, to improve on export coefficient model (ECM), then integrated ECM into geographical information system to compose half-distribution model of export coefficients. Estimated nutrients export loads based on the ECM in Xitiaoxi watershed located upper of Taihu Lake area. Results show that the export load for TN and TP was 2 121.3 t and 49.3 t respectively, which provides important reference value for nonpoint source pollution management.