基于参数敏感性和径流调控的LID优化设计方法

LID optimal design method based on parameter sensitivity and runoff regulation

以上海中心城区某区域为研究对象,基于SWMM模型和Morris筛选法确定典型低强度降雨下LID(Low impact development)参数优化设计方法。研究结果表明,5种LID优化调控径流及污染的参数各不相同:透水铺装为调蓄层渗透率和厚度,调蓄层渗透率30mm/h时径流和SS负荷调控效果最优(削减率分别为91%和89%);生物滞留设施为调蓄层渗透率和可蓄水深度,且上层土壤渗透率是影响调控效果的关键因素;雨水桶为高度700mm时能够调控区域全部径流;绿色屋顶为厚度,但受屋顶承重限制当厚度较小时,对径流及SS负荷的调控效果不大;植草沟的植被覆盖率达到95%时,对径流峰值和SS负荷调控具有较好地促进作用。在实际工程中,应针对不同LID类型选择关键参数进行优化设计。

A storm drainage area in Shanghai central city was used as an example.The optimization design method of LID(Low impact development)parameters was determined based on SWMM model and Morris method under typical low intensity rainfall.The results showed that parameters of five LIDs for optimal regulation of runoff and pollution were different.For permeable pavement and bio-retention cell,the parameters were thickness and seepage rate of storage.The effects of runoff and SS load regulation were the optimum with 30 mm/h seepage rate(the reduction ratios were 91% and 89%,respectively)for permeable pavement,and the conductivity of upper soil was the key factor affecting the runoff and SS load control for bio-retention cell.The parameter was storage depth for rain barrel,and 700 mm could control all runoff from the area.For green roof,the parameter was berm height,however it was limited for weak bearing of roof,and the regulation effect for runoff and SS load was not significant.Vegetative swale with more than 95% vegetation coverage ratio could promote the regulation of peak runoff and SS load.In practical applications,optimizing the key parameters of LID is beneficial to achieve the better regulation effect of runoff.