不透水表面坡度对溶解态污染物传输过程的影响研究  

Influence of slope on the dissolved pollutant transport process over impervious surface

作　　者：肖洋 王磊[2] 张涛涛 冯雯 XIAO Yang;WANG Lei;ZHANG Taotao;FENG Wen(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,南京210098 [2]河海大学水利水电学院,南京210098

出　　处：《南水北调与水利科技》2018年第6期74-79,共6页South-to-North Water Transfers and Water Science & Technology

基　　金：国家重点研发计划(2016YFC0402605);国家自然科学基金项目(51239003;41323001);江苏省第五期"333工程"培养资金资助项目(BRA2017371)~~

摘　　要：溶解态污染物是城市降雨径流污染的一个重要组成部分,揭示其在降雨径流阶段的传输过程对于城市污水治理具有重要意义。采用人工模拟降雨实验研究了不透水表面不同坡度(0.5°、1°、2°、3°、4°、5°)情况下降雨径流及溶解态污染物传输过程。结果表明:坡度越大,坡面产汇流时间越短,径流量越快达到稳定;污染物浓度随降雨径流深度增加呈逐渐减小趋势,坡度越大,初始浓度越高,衰减越快;污染物传输速率呈先增大后减小的变化规律,坡度越大,污染物传输速率峰值越大,峰值出现在径流深度为0.3~0.5mm之间;溶解态污染物传输过程符合指数冲刷模型,随着坡度的增大,冲刷系数k先线性增加,坡度大于3°基本保持稳定。相对于颗粒态污染物,溶解态污染物冲刷系数大,易被冲刷,冲刷集中发生在径流初期。Dissolved pollutants are an important part of urban rainfall runoff pollution.To reveal their transport process during the rainfall runoff stage is of great significance to urban wastewater treatment.In this study,we conducted a series of experiments to study the processes of rainfall-runoff and dissolved pollutant transport over impervious surface at different slopes(0.5°,1°,2°,3°,4°,5°).The results showed that the higher the surface slope,the shorter the time of runoff yield and concentration,and the faster it took for the runoff volume to reach stability.The pollutant concentration would decrease as the rainfall runoff depth increased;the higher the slope,the higher the initial concentration,and the faster the attenuation.The pollutant transport rate would increase first and then decrease with time;the higher the slope,the larger the peak of pollutant transport rate.The peak of pollutant transport rate appeared when the cumulative runoff depth was 0.3 to 0.5 mm.The pollutant transport process conformed to the exponential wash-off model.The wash-off coefficient k would increase linearly first and then remain basically stable when the slope was above 3°.Compared with particulate pollutants,the dissolved pollutants had a larger was-off coefficient and were more likely to be washed off,especially in the initial runoff stage.

关 键 词：不透水表面 降雨径流 污染物传输 溶解态污染物 

分 类 号：TV131[水利工程—水力学及河流动力学]