基于海绵城市的生物滞留池水文效应分析

Hydrological Effect Analysis of Bio-retention Ponds Based on Sponge City

由城市化带来的水问题说明城市雨洪调控和建设海绵城市的重要性。运用暴雨洪水管理模型(SWMM)构建模型,模拟分析研究区天然状态、城市化后无调控措施和添加生物滞留池调控三种情景下水文指标的变化情况和相应的水文效应,并通过改变生物滞留池的表层厚度模拟径流参数的变化。结果表明,生物滞留池能有效减小径流、削减洪峰、延迟出口流量过程出现的时间,且对小降雨事件的调控性能显著;改变生物滞留池的表层厚度对下渗几乎无影响,随着表层厚度的增大表面出流和径流系数都减小,而对出口流量过程影响不大,因此可以提高生物滞留池的面积比例或其他措施共同调控城市的径流。

The water problems brought by urbanization are analyzed,and the importance of the urban storm water control and the construction of the sponge city are explained.By using SWMM,the changes of hydrological indicators and the corresponding hydrological effects in the three scenarios are simulated and analyzed,which are the natural state of the study area,no control measures of urbanization and the regulation of the bio-retention ponds.By changing the surface depth,the change of runoff parameters is simulated.The results show that the bio-retention ponds can effectively reduce the runoff and peak flow,and delay the process of outlet flow,and the performance of small rainfall events regulation is more significant;changing the bio-retention ponds surface depth has almost no impact on the infiltration,with the increase of surface depth,the surface flow and runoff coefficient decreases,but it has little impact on the flow process of the outlet.So,it can raise the proportion of bio-retention ponds area or through other measures together to control the urban runoff.