基于SWMM模型的生物滞留单元对地表径流影响模拟分析

Simulation and analysis of impacts of biological retention units on surface runoff based on SWMM model

初期降雨径流作为城市面源污染的重要组成部分,处理不当则会严重污染区域内地表及地下水水质。生物滞留单元作为城市面源污染的重要治理手段,因此对不同暴雨强度下生物滞留单元对地表径流截留的模拟分析具有重要意义。本文利用SWMM 5.0软件对某研究区域内生物滞留单元对地表径流截流效率进行模拟,分析不同暴雨强度及生物滞留单元对地表径流截流的特征演化。研究结果表明:(1)本研究范围内,随着重现期增加,暴雨强度会逐渐增大并在降雨末期趋于缓和,且降雨重现期对雨型的影响较弱;(2)本研究范围内,生物滞留单元对地表径流截流具有良好的效果,但随着暴雨强度的提高,径流截流效率出现了明显的降低。研究结果对市政工程规划中不同暴雨强度下的生物滞留单元的设计及规划提供了重要的理论指导。

As an important part of urban non-point source pollution,the initial rainfall runoff will seriously pollute the regional surface and groundwater quality if it is not properly handled.As an important means to control urban non-point source pollution,biological retention units are of great significance for the simulation analysis of surface runoff interception by biological retention units under different rainstorm intensification.In this paper,SWMM 5.0 software was used to simulate the surface runoff interception efficiency of biological retention units in a study area,and analyze the characteristic evolution of different rainstorm intensification and biological retention units for surface runoff interception.The results showed that:(1)Within the scope of this study,with the increase of the return period,the intensity of the rainstorm will gradually increase and tend to moderate at the end of the rainfall,and the effect of rainfall return period on the rain pattern is weak;(2)Within the scope of this study,the biological retention units had a good effect on surface runoff interception,but with the increase of rainstorm intensity,the runoff interception efficiency decreased significantly.The research results provide important theoretical guidance for the design and planning of biological retention units under different rainstorm intensities in municipal engineering planning.