Compared with runoff division method, the rainfall deduction method is characterized with simple calculation and a reasonable result but without additional NSP monitoring data.

• 与传统的径流分割法相比，降雨量差值法能利用现有水文水质资料而无需增加监测项目，即可对流域非点源污染负荷作出估算，计算过程简单，结果合理。