简单式绿色屋顶雨水径流滞留效果的影响因素

Influence Factors of Extensive Green Roof on Stormwater Runoff Retention Performance

绿色屋顶具有良好的环境、社会和经济效益,其在欧美等发达国家已得到广泛应用,但在国内雨水控制领域受到的关注度较低。为此,采用北方典型城市的设计降雨对绿色屋顶装置进行模拟降雨试验,分析简单式绿色屋顶的排水层材料、种植基质及降雨强度对其雨水径流滞留效果的影响。结果表明:凹凸排水板和陶粒两种排水层材料对绿色屋顶滞留雨水径流的效果无明显优劣;种植基质的初始湿度与绿色屋顶对雨水径流的削减率存在负相关关系;基质种类对绿色屋顶雨水径流滞留能力也有一定影响,与超轻量基质和田园土相比,改良土在雨水径流削减、产流延缓、峰值流量削减和延后等方面的效果更好;绿色屋顶对较低重现期的降雨事件具有更好的雨水径流滞留效果。

Green roof has a series of environmental, social and economical benefits, and it has been widely used in developed countries such as Europe and the United States. However, it attracted lit- tle attention in the field of stormwater control in China. Experiments on green roof were conducted using north typical rainfall to analyze the influence of the drainage layer material, growing media and rainfall in- tensity on the stormwater runoff retention performance. The results showed that the effect of stormwater runoff retention had no obvious differences between the concave-convex drain plate and ceramsite. The initial humidity of the growing media had a negative correlation with the rainwater runoff retention rate of green roof. The types of the growing media also had a certain influence on the rainwater runoff retention ability of green roof. Compared with ultra-low weight media and natural soil, the improved soil had ad- vantages in rainwater runoff retention, runoff delay, peak flow reduction and delay. Green roof had betterstormwater runoff retention effect for rainfall events with lower return period.