Abstract:

It’s essential to determine the areal precipitation thresholds of rainstorm-flood disaster, flood inundation scope and water depth for rainstorm-induced mountain flood disaster risk zoning. A case was performed for Pihe River Valley, which lies in Anhui province. Relationship between hydrological elements and rainstorm during typical flood process was analyzed in order to explore the relationship between rainstorm and floods by using statistical methods and hydrological model. With water level records of historical floods, the areal precipitation thresholds of rainstorm-flood disaster were obtained further. The flood inundation simulations were carried out by using the FloodArea model. Furthermore, the maps of rainstorm-induced mountain flood disaster risk assessment and zoning were estimated based on different recurrence periods by overlapping the information of disaster-bearing body. The inundation induced by Soudelor, which was the most serious typhoon in recent years, was simulated dynamically. The inundation risk assessment and zoning were proved to be reasonable by contrasting the simulated results with the actual disaster investigative records about the flooding scope and maximum water depth. The results show that the operational procedure of the rainstorm and flood disaster loss evaluation based on rainstorm and flood inundation model has a clear physical basis, the FloodArea model could be employed in the risk evaluation and early-warning of rainstorm and flood disasters.

Key words: rainstorm-induced mountain flood, FloodArea, disaster risk zoning, flooding simulation, Pihe River Valley