下凹式绿地对地表径流的调节作用研究

下凹式绿地是城市低影响开发建设的手段之一,为评价下凹式绿地对城市地表径流的调节作用,通过对不同暴雨重现期下的下凹式绿地雨水渗蓄率、临界下凹深度、临界面积比例进行计算,设计研究区下凹式绿地建设方案,并对各方案的径流拦蓄效果和减峰效果进行对比分析。结果表明:当暴雨重现期为3、5和10 a时,在研究区实施两种不同下凹深度(0. 15、0. 2 m)和不同下凹式绿地率(20%～45%)的下凹式绿地建设方案,其拦蓄效果和减峰效果均能达到99. 92%以上。下凹式绿地对城市地表径流调控具有显著的调节效果。

Regulating effect of concave green land on surface runoff

The concave green land is one of the measures of low impact development for urban construction. To evaluate the effects of the concave green land on regulating urban surface runoff, this paper calculates the rainwater infiltration rate, critical depth of depression, critical area ratio of the concave green lands under different rainstorm periods. The construction schemes of concave green land in the study area were designed, and the runoff interception effect and peak flow reduction effect of each scheme were compared and analyzed. The results showed that when the rainstorm return period was 3, 5 and 10 years, both the interception effect and the peak flow reduction effect of the two concave green space construction schemes with different concave depths (0.15m,0.2m) and different concave green land rates (20%~45%) in the study area can reach more than 99.92%. The concave green lands have significant effects on regulating urban surface runoff.