强降雨事件对宋庄蓄滞洪区二期水质影响OA

Extreme rainfall events can lead to an increase in pollutant concentrations in semi-closed water bodies,thereby increasing the risk of eutrophication.This paper selected three intense rainfall events in the Phase Ⅱ of the Songzhuang Flood Retention Area in Beijing,where the rainfall intensity exceeded 120 mm/h during the summer of 2023-2025.The trends of water quality indicators such as ammonia nitrogen,total phosphorus,chemical oxygen demand,electrical conductivity,and turbidity were analyzed based on monitoring data.The results show that various water quality parameters changed to different extents before and after the intense rainfall events.Compared to the median values before the rainfall,the peak median values of water quality parameters during the three intense rainfall events showed the following changes:ammonia nitrogen concentration increased by 40％,total phosphorus concentration increased by 21％,chemical oxygen demand increased by 11％,electrical conductivity decreased by 10％,and turbidity increased by 452％.The study results indicate that intense rainfall has a significant impact on the water quality of semi-closed water bodies,providing valuable reference for pollution prevention and water quality management in semi-closed water bodies under extreme weather conditions.