基于SWMM的建筑小区海绵改造水文效应评估

Evaluation of Hydrological Effect of Sponge Reconstruction in Building Community Based on SWMM

基于城市化前后水文特征,理论探讨海绵城市建设水文效应,确定特征因子;根据西安市暴雨公式,采用芝加哥雨型设计短历时暴雨;利用SWMM模拟重现期1、3、5、10、30、50 a条件下城市化前后、海绵改造前后雨洪过程;计算统计特征因子,分析海绵改造水文效应。研究区域海绵改造后径流总量控制率稳定达70%以上,洪峰削减率稳定达30%以上,区域下垫面自然渗透性得到有效恢复;针对湿陷性黄土下垫面特征,增加不渗透底部,在区域出口设置滞蓄装置,增大区域调蓄容积,控制峰现时间。

Based on the hydrological characteristics before and after urbanization,the hydrological effects of sponge city construction are discussed theoretically,and the characteristic factors are ascertained. According to the rainstorm formula of Xi’an,the rainfall pattern of Chicago is used to design a short-duration rainstorm;using SWMM to simulate the rain and flood process before and after urbanization as well as before and after the sponge transformation under the condition of recurrence period 1、3、5、10、30 and 50 a;the statistical characteristic factors were calculated and the hydrological effect of sponge transformation was analyzed. After the sponge transformation in the study area,the total runoff control rate is more than 70%,the flood peak reduction rate is more than 30%,and the natural permeability of the underlying surface is effectively restored. With respect to the underlying surface characteristics of collapsible loess,the impervious bottom is increased. A detention and storage facility is provided at the outlet of the area to increase the volume of the storage and to control the peak occurrence period..