基于暴雨洪水管理模型的低影响开发设施应用研究

海绵城市是针对解决我国水危机提出的新理念,而低影响开发(LID)设施是构建海绵城市的关键。为了分析不同降雨重现期、不同降雨历时、占地面积对单项LID设施径流控制能力的影响,以亦庄调节池一期工程为研究区域,利用暴雨洪水管理模型(SWMM)进行模拟计算,研究了不同占地面积下各LID设施对不同降雨过程的径流削减效果,分析了降雨重现期及降雨历时与占地面积影响作用的相关性。结果表明:随着降雨重现期由1年增加至10年,透水铺装径流削减率下降了13%～35%;随占地面积占比由25%增至100%时,其径流削减率增大了4. 8%～23%,且占地面积变化对低重现期降雨径流削减效果影响明显,生物滞留槽和植草沟呈相同规律。相反,下凹绿地占地面积变化对高重现期径流削减效果影响较大。绿色屋顶的径流削减率与土壤层厚度成正比,与降雨重现期成反比,且绿色屋顶厚度对低降雨重现期削减效率影响稍大; LID设施的径流削减率随降雨历时增加而增大(削减率增长区间为1. 7%～7. 7%),且占地面积越大,降雨历时变化对径流削减率的影响就越明显。各LID设施的性价比和适用情况对比计算表明,下凹绿地和透水铺装性价比较高,适于作为主控设施大面积应用,而植草沟、生物滞留池及绿色屋顶适于作为辅助设施部分应用。研究成果为选择效益最优的海绵城市建设模式提供科学参考。

Storm water management model-based study on application of low impact development facilities

The sponge city is a new idea proposed for solving the water crisis in China，while the low impact development ( LID) facilities facilities are the key-links for constructing the sponge city. In order to analyze the impacts of various rainfall recurrence periods， various rainfall durations and land occupancy areas on the runoff control capacity of a single LID facility， a simulation calculationis made with the storm water management model ( SWMM) by taking the Phase-I project of Yizhuang Ｒegulation Pool as the studyarea， in which the runoff reduction effects of all the LID facilities during various rainfall processes under conditions of variousland occupancy areas are studied， furthermore， the correlations of the rainfall recurrence period and the rainfall duration with theimpact from land occupancy area are analyzed as well. The result shows that along with the increase of rainfall recurrence periodfrom 1 year to 10 years， the runoff reduction rate of thepermeable pavement is decreased by 13% ～ 35% . Following with the in-crease of the proportion of the land occupancy area from 25% to 100% ， its runoff reduction rate is increased by 4. 8% ～ 23% ， while the impact from the variation of land occupancy on the rainfall reduction effect of the low rainfall recurrence is significantand the same laws are presented by both the bio-retention trough and the grassed swale. Contrarily， the impact from the variationof the land occupancy of the concave greenland on the runoff reduction effect of the high rainfall recurrence period is relativelylarge. The runoff reduction rate of the green roof is proportional to the thickness of the soil layer and is inversely proportional tothe rainfall recurrence period， while the impact from the soil layer thickness of the green roof on the reduction efficiency of thelow rainfall recurrence period is a little bit large. The runoff reduction rate of LID facility is increased along with the increase ofthe rainfall duration ( the interval of the increase of the reduction rate is 1. 7% ～ 7. 7% ) ， while the larger the land occupancy is， the obvious the impact from the variation of the rainfall duration on the runoff reduction rate is to be. It is indicated from the com-parative calculation of the cost-performance ratio and applicable status of all the LID facilities that the cost-performance ratios ofconcave greenland and permeable pavement are higher and then applicable to be applied as the main control facility in large area， while the grassed swale， bio-retention trough and green roof are applicable to be partly applied as the auxiliary facilities. Thestudy result provides a scientific reference for selecting the construction mode of sponge city with optimal benefit.