Waterlogging Cause and Disaster Prevention and Control of “7·20” Torrential Rain in Zhengzhou
摘要
Recently, the global climate has sharply changed, which led to frequent floods. The specific high-intensity and extreme rainfall, and the consequent flood events occurred in the urban areas have seriously damaged the safety and property of residents.There was a torrential rainfall event happened in Zhengzhou on July 20th, 2021,which caused the most serious urban pluvial flood disaster since 1949 in China. Many studies have been done to explore the cause and mechanism of formation as well as the characteristics of the serious rainstorm，in order to improve the urban flood prevention and control. This paper analyzed the relevant studies of urban waterlogging systematically, especially focused on the Zhengzhou “7·20” Torrential Rain waterlogging disaster. Three contents were discussed, including: 1) the return period, spatial-temporal distribution and formation mechanism of the storm event 2) the shortcomings of drainage and waterlogging prevention infrastructure, as well as the weakest li＜x＞nk effect of emergency facilities 3) the main problems existing in urban flood emergency management 4) risk management and urban planning considering flood situation. The results show that the rainstorm in Zhengzhou has the characteristics of extreme and difficult to predict, and the single-day and cumulative precipitation both exceed the historical extreme values. Due to the coupling and comprehensive influence of typhoon, topography and "rain island effect", the heavy precipitation weather process was caused. Zhengzhou "7·20" pluvial disaster exposed the obvious shortcomings of drainage and waterlogging prevention infrastructure and construction in Zhengzhou city. There are bottlenecks in the river defense system. And inadequate emergency facilities and management capacity. ba＜x＞sed on the above problems, it is necessary to appropriately adjust the waterlogging prevention and control standards, strengthen the flood risk management and planning and construction control measures, bu