平原城市高度建成区暴雨内涝模拟及防治研究

Simulation and prevention of urban waterlogging in highly built-upareas of a plain city during torrential rain

针对平原城市高度建成区暴雨引发的城市内涝问题,以珠三角城市东莞市为例,基于MIKE FLOOD平台,利用MIKE URBAN、 MIKE 11和MIKE 21构建了城市内涝耦合模型。同时,结合历史暴雨事件提出一种长历时暴雨设计雨型,分析50 a一遇设计降雨重现期下东莞市中心城区暴雨内涝过程和积水特征,提出改善“大排水系统”排水能力的内涝治理措施并评估其实施效果。结果表明:东莞市中心城区内涝的主要原因为河道水流顶托及道路排水不畅,河道拓宽整治结合道路竖向调整可使管网溢流程度降低45%,内涝淹没面积减小73%。提高研究区内河、道路排水通道等“大排水系统”的排水能力对改善研究区域的内涝现状效果显著。研究成果可为平原城市高度建成区的内涝治理提供技术支撑。

For urban waterlogging caused by torrential rain in highly built-up areas of plain cities,a coupling model of urban waterlogging was constructed by using MIKE URBAN,MIKE 11 and MIKE 21 based on the MIKE FLOOD platform.Taking Dongguan City in Pearl River Delta as an example,a new long-duration designed storm was proposed based on historical rainstorm events to analyze the process of urban waterlogging and characteristics of flood inundation in the central urban area of Dongguan City under 50-year designed storm scenarios.Measures to improve the drainage capacity of"major drainage system"were suggested,and its effectiveness was evaluated.The results showed that the main causes of urban waterlogging in the central urban area of Dongguan City were river water jacking and poor road drainage.Combining river channel widening and road vertical adjustment could reduce the overflow volume of the pipe network by 45%and decrease waterlogging area by 73%.Improving the drainage capacity of"major drainage systems"such as rivers and road drainage channels has a significant effect on improving the waterlogging situation.The research results can provide technical support for the management of waterlogging in highly built-up areas of plain cities.