The effect of spatial–temporal characteristics of rainfall on urban inundation processes

Abstract

AbstractThe spatial–temporal characteristics of rainfall is one of the important elements affecting urban inundation. In this work, the effect of spatial–temporal characteristics of rainfall on urban inundation processes was investigated. To solve the problem that it is difficult to acquire the spatial–temporal characteristics of rainfall, the weather generator model was used to generate rainfall data in accordance with the climatic conditions of the study area. Then, precise rainfall data with 1 km2 spatial resolution and 5 min temporal resolution were obtained through the downscaling method. Finally, the GAST hydrodynamic model was used to simulate the urban inundation processes under different rainfall scenarios. The simulated results show that the inundation area and the inundation water volume increase with the rainfall spatial–temporal heterogeneity, and the inundation peak time lags behind. The impact of rainfall spatial–temporal heterogeneity on inundation weakens as the rainfall return period prolongs. When the rainfall spatial heterogeneity increases, the high‐risk inundation area enlarges, while the low‐risk inundation area shrinks. The temporal distribution of rainfall exerts the greatest impact on the inundation peak time. The research results can help researchers understand the key effects of the spatial–temporal characteristics of rainfall on urban inundation, and obtain relatively reliable simulated inundation results even without detailed information of the spatial–temporal characteristics of rainfall.