基于CADDIES-2D模型的城市内涝模拟与风险预警

he frequency of extreme rainfall disasters caused by global climate change has increased significantly, and the floods caused by this have caused serious casualties and economic losses to many cities in China. At present, China\'s waterlogging risk prediction stays in meteorological data forecasting, and the risk early warning system for meteorological characteristics is difficult to deal with heavy rainfall events with sudden and extreme characteristics, and the accuracy and accuracy of risk early warning are no longer suitable for refined urban disaster prevention management. The CADDIES-2D model is used to establish an early warning model of urban waterlogging disasters to quickly, timely and accurately identify urban waterlogging risk areas within the window period before the occurrence of waterlogging disasters, prevent and resolve major risks, and take the 2017 major flood disaster event in Changsha as an example to verify the model calculation accuracy. In order to improve the accuracy of emergency response to waterlogging disasters, the waterlogging risk situation of rainfall scenarios in different recurrence periods and different rainfall durations was analyzed. The results show that under the condition of short-duration heavy rainfall, rainfall in different recurrence periods has limited impact on the growth rate of waterlogging risk areas, while different rainfall durations have a greater impact on the temporal and spatial distribution of urban waterlogging risks, especially in high-risk (II.) and very high-risk areas (I.), most of the risk areas are distributed along roads, and their water depth and flow speed are large, which can easily cause casualties and need to be focused on prevention and control. Through the rapid waterlogging assessment of each catchment, the strategy of "time-sharing early warning, hierarchical early warning, and zonal control" is adopted for different warning levels, and a waterlogging early warning system is scientifically formulated and a rapid linkage mechanism is established, so that the emergency response to waterlogging is short, flat and fast.