基于海绵城市子汇水分区LID设施的峰值径流控制效应

Study on Peak Runoff Control Effect of LID Facilities Based on Sponge City Sub-catchment Area

为探索海绵城市设计中子汇水分区的积水内涝风险的解决途径,采用SWMM建模针对不同重现期下LID设施及组合的峰控特性、容积型LID设施增量规模的峰控规律进行研究。结果表明,容积型LID设施主要通过延时达到峰控效果,渗透型LID设施主要通过整体产流削减达到峰控效果,容积型LID设施峰控效果更为明显;仅渗透型LID设施组合对5年及以上重现期降雨无明显的峰控效果,搭配容积型LID设施后能够对重现期为10年以内的降雨达到20%以上的削峰率;渗透型LID设施规模增加60%及以上时,对重现期50年及以内的降雨削峰效果较为明显;其规模增加80%及以上时,基本能够保证重现期50年及以内开发后径流总量不超过开发前。研究结果旨在探索局部区域的积水内涝风险的解决途径,为实际海绵城市子分区峰值径流控制设计提供理论参考。

In order to explore the solution to the risk of ponding and waterlogging in the sub-catchment area during sponge city design,SWMM modeling was used to study the peak runoff control characteristics of LID facilities and their combinations under different recurrence interval,as well as the peak runoff control laws of the incremental scale of volumetric LID facilities.The study shows that the peak runoff control effect of volumetric LID facilities is mainly achieved through peak time delay,while the peak runoff control effect of permeable LID facilities is mainly achieved through overall runoff reduction,and the peak runoff control effect of volumetric LID facilities is more significant;Only the combination of permeable LID facilities cannot significantly reduce peak runoff and delay peak time on a rainfall event with a recurrence interval of 5 years or more.When combined with volumetric LID facilities,it can achieve a peak runoff reduction rate of over 20%for rainfall with a recurrence interval of less than 10 years;When the scale of permeable LID facilities increases by 60%or more,the peak runoff reduction effect is more obvious for rainfall with a recurrence interval of 50 years or less;When its scale increases by 80%or more,it can basically ensure that the total runoff volume of post-development does not exceed which of pre-development with a recurrence interval of 50 years or less.The research results are aimed at exploring solutions to the risk of ponding and waterlogging in local areas,which provides theoretical reference for the design of peak runoff control in actual sponge city sub-catchments.