A Simulation of Extreme Rainfall Caused Torrential Flood Inundation

The utilization of FloodArea model in torrential flood dynamic simulation is examined in this paper using the instance of an extreme rainfall process in Chaping River Basin, An county, Sichuan province, July 9th, 2013. The differences of5 model simulations indicate DEM (Digital Elevation Model) accuracy is an important influence factor in FloodArea model simulates. The simulations with filled DEM data are more accurate, the roughness coefficient within a specified range has little influences on simulations. The model simulations of Chaping River Basin torrential flood process in this paper use the filled DEM data, IDW (Inverse Distance Weighted) rainfall raster data, Voronoi diagram of rainfall distribution and the watercourse added roughness coefficients. The simulation results meet the actual torrential flood dynamic process. Compare to the real process, the upstream and downstream inundated depth are 5. 8m and 3. 83 m, meets the actual case. Through the correlation between hourly inundated depth and 1-8h accumulated rainfall distribution get the early warning time indices of two experimental points are 2h and 6h.