城市化地区内涝风险模拟与分析

以青岛市黄岛区为例,构建SWMM城市雨洪模型,划分11个排水子区,模拟分析现状管网在不同重现期暴雨(1、5、10、20、30年一遇)下的排水过程,以积水时长、体积等为指标评估城市化地区内涝风险空间分布。结果表明,随着暴雨加剧,下垫面下渗截留对地表直接径流影响越来越小,管网排水负荷明显增加且显著影响排水效率,管网超载率越来越大;1年一遇暴雨时内涝风险相对较小,仅灵山卫、峄山排水区小范围积水;5年一遇时大量节点溢流,灵山卫、峄山、铁山、长安河、大卢河排水区为相对高危险区;10、20、30年一遇时约1/2节点溢流,以灵山卫、峄山、铁山、长安河、大卢河、豆金河排水区最严重,整体管网不能满足城市排涝。

Simulation and Analysis of Waterlogging Risk in Urbanized Areas

The Huangdao District of Qingdao City was selected as the research area to construct the SWMM urban stormwater model.A total of 11 drainage sub-areas were divided to simulate the drainage of the current status of the pipeline network under different heavy rains recurrence period(1 a,5 a,10 a,20 a,30 a).In the process,the spatial distribution of waterlogging risk within the urbanized area was assessed by using the duration and volume of the accumulated water as indicators.The results show that with the increase of heavy rain,the impact of the infiltration of the underlying surface on the direct runoff of the surface is getting smaller and smaller,the drainage load of the pipe network is significantly increased and the drainage efficiency is significantly affected,and the overload rate of the pipe network is increasing;The waterlogging risk is relatively small for 1 aencountering rainstorm,only Lingshanwei and Lushan drainage area appear water-logged in a small area;For 5 aencountering a large number of nodes overflow,Lingshanwei,Lushan,Tieshan,the Chang’an River and Dalu River drainage areas are relatively high-risk areas;For 10 a,20 a,30 aencountering about half of the nodes overflow,Lingshanwei,Lushan,Tieshan,Chang’an,Dalu,and Bean River drainage areas are the most serious.The overall pipe network can not meet the urban drainage.