A practical method for estimating non-point source pollution load for watershed

The non-point source pollution (NSP) is becoming the main pollution of environment since the controlling measurements of point source pollution (PSP) have been improved. Therefore, the estimation of NSP load is being increasingly important in water pollution controlling and planning in watershed Non-point source pollution (NSP) is a major cause of environmental pollution, and determining its load is a key step in watershed management and pollution prevention. Considering the shortage of monitoring data in China, a practical estimation method of non-point source pollution load-rainfall deduction method is established based on current available the rainfall and stream water quality data in China. Meanwhile, the principle and procedures of the model are introduced in the paper. Because it does not involve the physical process in pollutant transformation, the model is a very practical method with a simple structure. Comparing with the runoff division method, this rainfall deduction method is simpler in calculation with a reasonable result without additional NSP monitoring data.