前池雨水花园系统径流水量控制性能试验研究

Experiment on Runoff Volume Control Effects of Front Pond Rain Garden System

针对现有城市工业区建筑物屋面雨水径流的特点,在原有雨水花园基础上增设蓄存功能,提出了一种前池雨水花园系统,并模拟了降雨量下(降雨条件为重现期0.5、1、2年,降雨历时为30、60、120 min)的径流水量控制试验。结果表明,前池雨水花园系统对径流的削减可达到1/2以上,甚至可全部削减,且蓄水高度、各部分水量分配及流量曲线等均与重现期和降雨历时相关。与常规雨水花园系统进行对比试验发现,前池雨水花园系统的径流总量削减率更高,且其溢流时间点和出流时间点均延迟约34 min,而溢流峰值与出流持续时间却分别缩短了24、40 min。因此,在雨水花园系统中增设前池能显著提高其对雨水的管控能力。

According to the roof rainfall runoff of the existing urban industrial area, the front pond rain garden system was proposed to carried out runoff volume control experiment under the simulating rainfall conditions of rainfall recurrence period of 0.5, 1 and 2 years, and rainfall duration of 30, 60 and 120 minutes. The results show that the runoff can be reduced more than a half or even completely by the front pond rain garden system. The water storage height, water distribution in each part and the flow curves are all related to rainfall recurrence period and duration. Compared with the conventional rain garden system, it is found that the total runoff reduction rate of the front pond rain garden system is higher, and both the overflow and outflow time are delayed by about 34 minutes, while the peak overflow time and outflow state are shortened by 24 minutes and 40 minutes, respectively. Therefore, adding a front pond in a rain garden system can significantly improve its rainwater management and control ability.