基于SWMM的海绵城市LID设施规划与布局——以萍乡市为例

Research on Planning and Layout of LID Facilities in Sponge Cities Based on SWMM:A Case Study in Pingxiang City

【目的】萍乡市是我国第一批海绵城市的试点城市,大尺度范围的雨水设施格局规划或布控研究需要进一步研究,旨在为萍乡市和其他南方多雨型城市的海绵城市建设提供技术参考与案例借鉴。【方法】以萍乡市主城区的年径流总量控制率为海绵城市建设目标,借助GIS技术,利用排水管网、降雨量、用地现状等基础资料,建立研究区域的SWMM模型,再利用AHP法和容积法计算得出LID设施布设方案,并通过不同降雨事件模拟其径流控制效果。【结果】在该目标下绿色屋顶率、渗透铺装率和生物滞留设施率分别需要达到44.51%,22.80%和14.10%;该方案对重现期p=1a、p=2a、p=5a、p=10a、p=20a的降雨径流削减比例分别为47.25%,44.23%,42.51%,40.67%和37.76%。【结论】海绵城市LID设施布设后能够满足要求并有效缓解城市内涝现象,但面对大雨、暴雨仍需要结合传统排水系统共同发挥作用。

[Purposes]Pingxiang City is one of pilot cities for the first batch of sponge cities in China.The large-scaled pattern planning or distribution control research of rain water facilities needs further study,aiming to provide technical references and case studies for the construction of a sponge city in Pingxiang City and other southern China’s rainy cities.[Methods]Taking the annual runoff control rates of a sponge city in the urban areas of Pingxiang City as the target,based on GIS technology,using the basic data of pipe networks,rainfalls and status quo of land use,etc.,SWMM model of the study area was established.The planning of green stormwater infrastructures was calculated by AHP and volumetric method.The runoff control effect was then simulated by different rainfall events.[Result]The results showed:under this respective target,the green roof rate,osmotic pavement rate and bioretention facility rate need to reach 44.51%,22.80%and 14.10%,respectively;For the return periods,p=1a,p=2a,p=5a,p=10a,and p=20a,the rainfall runoff reduction ratios were 47.25%,44.23%,42.51%,40.67%,and 37.76%,respectively.[Conclusion]LID facilities in sponge cities could meet the requirements and effectively alleviate the urban waterlogging,but in face of heavy rains,the combination with the traditional drainage system still needed.