城市典型LID措施水文效应及雨洪控制效果分析

Hydrological responses and stormwater control effects of typical urban LID measures

城市化的快速发展加剧了城市内涝灾害及水污染问题。以天津市蓟州区某小区为研究区域,根据其规划方案,在透水铺装物理实验基础上,建立SWMM模型,模拟不同降雨事件中7种规划方案的径流控制效果,分析在一定区域内采用自然排水系统代替雨水管网的可行性,以及单独布设透水铺装、下凹绿地、植草沟、生物滞留区和组合LID方案对径流的控制作用。结果表明:通过植草沟等完成汇流是可行的,并且能达到更好的控制效果。LID措施能够削减径流总量、洪峰流量、积水量,延迟峰现时间,且控制效果在低重现期、短历时降雨时更为显著。其中,组合LID方案的控制效果最优;透水铺装和生物滞留区对洪峰流量的削减效果最显著;植草沟单独铺设时,雨洪控制效果较差。

Rapid development of urbanization has aggravated the problem of urban waterlogging and water pollution.In the present study of a residential area in Jizhou District of Tianjin,a SWMM model is developed on the basis of its planning scheme and a physical experiment of permeable pavement,and the stormwater control effects of seven planning schemes for different rainfall events are simulated.We explore the feasibility of adopting a natural drainage system in replacement of a rainwater pipe network in a certain area,and examine the control of different schemes-separate permeable pavement,depressed green,vegetative swale,bio-retention facility,and combined low impact development(LID)measures.The results indicate that it is feasible for the natural drainage system to complete the flow convergence through permeable pavement,etc.and these measures can achieve a better control effect.Combined LID measures can reduce total runoff,flood peak flow and water accumulation,and delay peak time,thereby producing a more effective stormwater control for the rainfalls with a short return period and short duration.Among all the measures examined,the scheme of combined LID measures is best in stormwater control,the combination of permeable pavement and bio-retention facility is best in reduction of peak flow,and vegetative swale has a poor stormwater control effect.