The study on risk assessment of urban waterlogging and determination of rainfall thresholds for waterlogged points in Hefei city

In the case of Hefei city, four levels of waterlogging risk were designed, and the "FloodArea" model is used to determine the threshold of typical waterlogging point under two kinds of drainage conditions, and the dynamic flooding simulation of urban waterlogging is carried out to assess the possible loss of the disaster under different risks. The results indicate that the thresholds of New Yuexi community are 56.9 mm·h^-1 for level 4, 65.9 mm·h^-1 for level 3, 100.8 mm·h^-1 for level 2, and 162.3 mm·h^-1 for level 1. The waterlogging occurs frequently in area of northeast Yuexi residential area, and potential property loss increases with increasing rainfall. The 49.0 mm·h^-1 (level 4), 53.0 mm·h^-1 (level 3), 78.0 mm·h^-1 (level 2) and 108.0 mm·h^-1 (level 1) represents thresholds of waterlogging risk in Changjiang eastern street bridge, respectively. Above the level 2, the loss of vehicle would be increasing dramatically.