北京“23·7”特大暴雨对密云水库上游河道水质影响研究

Influence of Beijing′s"23·7"heavy rainfall on water quality of upper reaches of Miyun Reservoir

2023年7月,台风“杜苏芮”导致北京市及周边地区出现灾害性天气,密云水库上游流域普降大到暴雨。针对密云水库上游河道水体,选取北京“23·7”特大暴雨前后6个监测断面、9项指标作为研究对象,分析北京“23·7”特大暴雨对密云水库上游水体水质的影响。结果表明:北京“23·7”特大暴雨过程中,密云水库上游水体水质变化趋势显著。水库上游河道水体水温呈先下降后上升趋势;暴雨中期,pH下降趋势显著,浊度上升幅度较大。暴雨期间,水体理化环境发生改变,营养盐及有机综合指标浓度呈先上涨后渐趋于平稳态势。

Due to the influence of typhoon"Dusuri",the upstream basin of Miyun Reservoir was affected by heavy rainfall.Aiming at the water body of the upstream channel of Miyun Reservoir,this paper selected 9 indicators,the physical and chemical indexes of 6 main monitoring sections and comprehensive indexes of nutrient salt and organic pollution before and after the Beijing"23·7"heavy rainstorm as research objects to analyze the influence of the"23·7"heavy rainstorm on the water quality of the upstream water body of Miyun Reservoir.The results showed that the water quality indexes of"23·7"main rivers had an obvious changing trend with the heavy rainstorm process.After the heavy rainstorm,the water temperature of the upstream channel of Miyun Reservoir decreased first and then rised slowly,and the pH decreased significantly and the turbidity increased greatly in the mid-period of the rainstorm.With the change of physical and chemical environment of water body,the concentration of nutrient salt and organic comprehensive index increased first and gradually stabilized during the whole rainstorm period.