不同绿化屋面对雨水调蓄能力的影响

目的]为了分析不同基质层厚度的绿化屋面对雨水的调蓄作用。方法]通过搭建绿化屋面装置,采用人工降雨模拟器开展试验,在不同基质层厚度和降雨条件下,对绿化屋面的降雨—径流过程、持蓄雨水和减滞洪峰能力进行了研究。结果]基质层厚度在一定的范围内时,绿化屋面出水的洪峰过程具有很高的相似性;绿化屋面基质层厚度与降雨持蓄率呈指数函数的关系;洪峰削减率与降雨强度无明显关系,主要由基质层厚度决定。结论]绿化屋面能在一定程度上降低雨水的径流峰值,减少总的径流量,延缓产流时间,且随着基质层厚度的增加,绿化屋面对雨水的调蓄能力越好。

Effects of Different Green Roof on Rainwater Retention and Reduction Capacity

Objective] To analyze the capacity of green roofs with different substrate layer thickness to hold rainwater and reduce the runoff.Methods] A series of green roof assemblies were constructed, and artificial rainfall experiments were carried out. Under the different condition of substrate layer thickness and simulated rainfall intensities, rainfall-runoff process and rainwater retention and reduction capacity were studied.Results] There is a relationship between runoff processes of green roofs and different substrate layer thickness; The thickness of substrate layer of green roofs has exponent relation with rainwater retention rate; Rainwater reduction rate has no obvious relation to rainfall intensity, and it mainly depend on the substrate layer thickness.Conclusion] Green roof can reasonably reduce the peak flow, total volume of runoff and delay the runoff generation, and the capacity increased with the increase of substrate layer thickness.