南方平原城市生态滞蓄设施运行效果的模拟评估

Simulation and Evaluation of Operation Effect of Ecological Retention Facilities in Southern Plain Cities

《海绵城市建设技术指南——低影响开发雨水系统构建(试行)》(简称《指南》)对不同地区低影响开发(LID)系统的年径流总量控制率提出了具体要求,但《指南》中同一类型地区的LID达标却面临不同的问题。以上海市为研究对象,探讨在南方平原城市地下水位高、土壤渗透性差、建筑密度高等限制条件下,适用的生态滞蓄型LID设施的选择问题;利用SWMM模型评估下渗作用受限制的应用条件下,设施的年水量控制效果。结果显示,在接近最大可能条件下进行低影响开发,上海典型城区LID系统的年径流总量控制率低于55%,难以达到《指南》的要求。因此建议,在南方平原地区将滞蓄型LID设施排水管道的出流水量计入受到控制的水量范围,以体现不同区域雨水管理目标的差别。

Sponge City Development Technical Guide ： Low Impact Development imposed the specific requirements for volume capture ratio of annual rainfall of low impact development systems in different regions, while different problems arose to meet the LID standards in the same type of regions. Taking Shanghai as the research object, the choices of suitable ecological retention LID facilities were discussed under the limiting conditions of high underground water level, poor soil permeability and high building density in southern plain cities. The control effects of annual runoff volume of LID facilities with restricted infiltration were evaluated by using the SWMM model. The results showed that with the low impact development at close to the maximum possible conditions, the volume capture ratio of annual rainfall of the LID system was lower than 55 % in typical urban area of Shanghai, which is difficult to meet the standard of the guide. Therefore, it is suggested that the effluent volume from retention LID facilities should be incorporated into the controlled range in the southern plains region in order to reflect the difference in rainwater management goals in different regions.