According to the variation of the components in the ground water of Streamflow within a year, the nonpoint pollutant load in a basin can be computed.

• 用水文学方法找出典型年河水中地下径流成分，然后分割出壤中流和地面径流。再根据实测的水质和流量资料计算出流域非点源污染负荷。