Climate Change and Pesticide Loss in Watershed Systems: A Simulation Modeling Study

This paper aims at examining the impacts of climate change on pesticide loss to surface water through a modeling study. An integrated modeling system which combined a distributed pesticide loss model with geographic information system (GIS), database, and climate change scenarios was proposed. It can predict pesticide loss through runoff under climatic change conditions. A case study was used to calibrate and verify the proposed system. The atrazine loss in 2050 and 2100 was predicted under different climate change scenarios. With the global warming, the annual streamflow would augment by 3 to 5% and the total atrazine losses would also gradually increase by 1.4 to 1.7%. The maximum concentrations of atrazine in river would be raised by 2.5 to 23%. It was also found that the wet season would always take the biggest share of pesticide-loss contribution to the river. A sensitive analysis disclosed that both of streamflow and pesticide concentration are more sensitive to temperature increase than decrease. This study is the first one to quantify the relationship between pesticide loss and climate change through a mathematic modeling system. The results can help people more effectively assess climate-change impacts, manage pesticide practices, and control water pollution.