基于SWMM的住宅区多LID措施雨水系统径流控制

为分析不同的LID措施对雨水径流的控制效果,以江西省南昌市某住宅小区为例,利用SWMM模型模拟了多LID措施串联的不同方案在不同重现期降雨条件下的削峰减排效果。结果表明,采用下凹式绿地、渗透铺装、植被浅沟的小区雨水系统,在降雨重现期为1、2、5、10、20年时总径流量、洪峰流量分别减少13.9%~25.1%、31.6%~47.9%;在此基础上分别串联屋面雨水桶、绿色屋顶、绿色屋顶+雨水桶的设计方案均能得到更好的径流控制效果;雨水桶相比绿色屋顶对总径流量有更强的削减作用,而绿色屋顶比雨水桶有更好的洪峰控制效果,尤其是在高强度降雨条件下单用雨水桶不能发挥削峰效果;绿色屋顶与雨水桶串联相比单独使用能发挥更强的削峰减排效能,且在高降雨强度下串联优势更明显。研究成果可为住宅区雨水系统的径流控制提供参考。

Runoff Control of Multiple LID Facilities Rainwater Drainage System in Residential Area Based on SWMM

To analyze the effect of different LID facilities on the control of rainwater runoff, the effect of peak flow reduction and runoff retention of multiple-LID-facilities rainwater drainage systems was simulated by SWMM under different rainfall intensities. The study area was a built resident quarter in Nanchang city, Jiangxi province. The results indicate that when the rainfall intensities were 1,2,5,10,20-years storms, runoff control rates of 13.9%-25.1% and the flood peak reduction rates of 31.6%-47.9% could be achieved by applying multiple LID facilities including sunken lawn, porous pavement and vegetative swale. Higher control rates could be achieved by applying rain barrel, green roof or both of them in addition to these facilities. The outlet runoff reduction effect of rain barrel was more remarkable than that of green roof, while green roof could have higher peak flow reduction rate than rain barrel, especially under the condition of rainfall with high intensity when rain barrel could hardly achieve peak flow reduction effect. The results also show that the effect of peak flow reduction and runoff retention were more significant when the green roof and the rain barrel were connected in series, and the series advantage was more obvious with the increase of rainfall intensity. The research results can provide reference for the runoff control of rainwater system in the residential area.