Risk assessment of rainstorm waterlogging disaster based on urban rainstorm waterlogging mathematical model in Fuzhou city

According to high-precision geographic information, drainage facilities and drainage operation model of urban Fuzhou, the urban rainstorm waterlogging simulation model in Fuzhou was established. The Urban Rainstorm Waterlogging Simulation Model in Fuzhou was used to simulate the waterlogging disaster caused by three typical rainstorm types in Fuzhou history and rainfall cases with different return periods. The simulated and actual values of ponding water depth in three rainfall types were evaluated. The results show that the percentages of water accumulation points with the absolute error between simulated and actual water accumulation depth less than 10 cm were 50%, 78% and 76%, respectively, for the three rainfall types. This model is more capable of simulating accumulated water for the rainfall type of long duration and uniform rainfall intensity than for that of short-term heavy rainfall. The simulated accumulated water was less than the real accumulated water in the rainfall type of short-term heavy rainfall. The model was used to evaluate the risk of waterlogging in Fuzhou city under different rainfall recurrence periods. The results show that the model can objectively reflect the risk distribution of waterlogging in the urban area in Fuzhou under the rainfall in different reappearing periods.