低影响开发措施的城市雨洪控制效果模拟

以广州市某小区为研究对象,根据实测降雨径流资料,结合现状排水管网,建立暴雨雨水管理模型(storm water management model,SWMM),模拟不同降雨条件下的产流与排水状况。基于SWMM的低影响开发(low impact development,LID)模块,模拟分析采用渗透铺装、下凹式绿地、雨水花园和LID组合方案对城市雨洪的控制作用。结果表明,采用渗透铺装、下凹式绿地和雨水花园等LID措施,洪峰流量和径流系数均明显降低,可有效缓解市政管网的排水压力,各种LID措施的雨洪控制效果在低重现期降雨时更为显著。其中雨水花园对径流系数和洪峰流量的削减效果最显著;LID组合措施对洪峰的削减和滞后作用较好;下凹式绿地和渗透铺装单独布设的雨洪控制效果一般。

Simulation of control efficiency of low impact development measures for urban stormwater

A storm water management model(SWMM)was set up in this study to simulate runoff generation and drainage with different types of precipitation in a residential area in Guangzhou City, based on real-time observed rainfall-runoff data and the current drainage network. Combined with the low impact development(LID)module, the influences of permeable pavement, sunken lawns, rain gardens, and combined LID appliances on urban storm water were simulated and analyzed. The results show that both peak flow and the runoff coefficient decreased significantly through application of permeable pavement, sunken lawns, rain gardens, and LID appliances, which was conducive to the drainage of municipal pipe network. The effect of storm water control and utilization was more significant during low-return periods. The decreases of peak flow and the runoff coefficient were more significant when rain gardens were used. The combined LID appliances had more significant effects in reducing peak flow and postponing the time of peak flow. The effect of storm water control and utilization was not significant when permeable pavement and sunken lawns were used.