城市道路雨水初期径流效应及适宜弃流量研究

Study on the initial flush effect and suitable abandoned flow of rainwater on a city road in Beijing

道路雨水径流是城市面源污染的主要来源之一,随着海绵城市的建设,初期径流弃流等源头减排技术成为控制城市面源污染的重要措施。为了提出适宜的城市道路雨水初期弃流量,削减城市面源污染,对北京温榆河公园来广营北路部分路段的雨水进行了监测采样,得到了2022年6—8月共计13场降雨的雨量、流量和水质等过程数据。采用基于污染物累积负荷M(累积径流量V)曲线初期冲刷效应的评价方法分析了来广营北路的初期径流效应,并探讨了适宜北京城市道路的初期径流弃流量及弃流效果。结果表明:城市道路各降雨类型初期径流效应存在较大差异,该道路初期径流弃流量宜采用6 mm径流深,该弃流量能控制大部分中小降雨的径流污染,其余场次降雨弃流后径流中总磷、总氮、氨氮、悬浮物和化学需氧量的平均负荷削减比例分别为31.85%、32.78%、32.30%、34.31%和30.95%。

Road storm water runoff is one of the main sources of urban non-point source pollution.With the construction of sponge city,the source emission reduction technology such as the initial flush discharge has become an important measure to control urban non-point source pollution.In order to propose the appropriate initial discharge of urban road rainwater and reduce urban non-point source pollution,the rainwater of some sections of Laiguangying North Road,Wenyuhe Park,Beijing,was monitored and sampled,and the process data of rainfall,discharge and water quality of a total of 13 rainfall events from June to August 2022 were obtained.The initial flush effect of storm water runoff in Laiguangying North Road was analyzed by using the evaluation method based on M(V)curve,and the initial discharge suitable for Beijing urban roads and initial flush effect were discussed.The results show that:there are significant differences in the initial flush effect of different urban road rainfall types;the depth of 6mm runoff should be adopted for the initial flush abandoned volume for this urban road,which can control the runoff pollution of most small and medium rainfall;after abandonment of the initial flush,the average load reduction ratio of TP,TN,NH3-N,SS,COD in subsequent runoff is 31.85%,32.78%,32.30%,34.31% and 30.95%,respectively.