Precipitation variation profoundly affects agricultural development and increases the diffuse pollution risk, which may weaken the positive effects of pesticide reduction policy. This study aimed to analyze the response of pesticide discharge loads in the large vulnerable watershed to pesticide application intensity and precipitation variance before and after implementing the pesticide reduction policy. We integrated empirical models, field observation and statistics to explore the sensitive factors of the typical pesticide atrazine before and after the pesticide reduction policy in the Yellow River Watershed. The results showed that the implementation of pesticide reduction policy effectively decreased the annual discharge load of atrazine within the watershed. In addition, the most sensitive factor of atrazine discharge loads shifted from precipitation to the atrazine application intensity after implementing the pesticide reduction policy. However, the discharge loads of atrazine significantly increased in an unusual high precipitation year in the context of increasing precipitation variability.

降水变化深刻影响农业发展，增加扩散污染风险，可能削弱农药减量政策的积极效果。本研究旨在分析农药减量政策实施前后大脆弱流域农药排放负荷对农药施用强度和降水量变化的响应。结合实证模型、现场观察和统计，探讨了黄河流域农药减量政策前后典型农药莠去津的敏感因素。结果表明，农药减量政策的实施有效降低了流域内莠去津的年排放负荷。此外，农药减量政策实施后，莠去津排放负荷最敏感的因素从降水量转向了莠去津的施用强度。然而，在异常高降水年，在降水变率增加的背景下，莠去津的排放负荷显着增加。