基于城市暴雨洪水模型的市政内涝防治设计

随着生态环境不断恶化,暴雨频率不断增加,暴雨洪水灾害对城市排水系统运行带来了极大挑战。城市既有排水系统难以满足排水需求,不仅造成下游地区防洪压力巨大,而且易引发严重内涝。开展城市暴雨内涝模拟研究能够为城市防灾减灾及排水规划设计提供重要理论依据。该文依托西安市某片区降雨、下垫面、管网数据进行暴雨管理模型(SWMM)构建,分析3、5、50年一遇常规降雨下3 h降雨过程,对片区相应重现期降雨下的管道超载及排水能力进行有效评估,并在此基础上进行低影响开发设施(LID)应用研究。结果表明,管道超载率随降雨量增大而增大,50年一遇降雨条件下为最高60%;片区管网排水能力不高,内涝风险随降雨量增大而增大,最大为44%;设计生物滞留池后,内涝风险降低幅度超40%。

With the continuous deterioration of the ecological environment and the increasing frequency of rainstorm,rainstorm and flood disasters pose a great challenge to the operation of urban drainage system.The existing drainage system in the city is unable to meet the drainage needs,which not only causes huge flood control pressure in downstream areas,but also easily leads to serious waterlogging.The research on urban rainstorm waterlogging simulation can provide an important theoretical basis for urban disaster prevention and mitigation and drainage planning and design.This paper builds a storm water management model(SWMM)based on the rainfall,underlying surface,and pipe network data of a certain area in Xi'an,analyzes the 3 h rainfall process under the 3,5,and 50 year return period conventional rainfall,effectively evaluates the pipeline overload and drainage capacity under the corresponding return period rainfall in the area,and on this basis,conducts the application research of low impact development(LID)facilities.The results show that the pipeline overload increases with the increase of rainfall,and the highest is 60%under the condition of 50-year rainfall;the drainage capacity of the pipe network in the area is not high,and the waterlogging risk increases with the increase of rainfall,the maximum is 44%;after the biological detention pool is designed,the waterlogging risk is reduced by more than 40%.