Author(s): Xinhua Zhang; Kuniyoshi Takeuchi; Hiroshi Ishidaira; Satoru Oishi
Linked Author(s): Satoru Oishi
Keywords: Flood inundation; Shallow water equation; Flood damage potential; Flooded area; Inundated water-depth
Abstract: In flood inundation simulation, the 2-dimansional (2D) shallow water equations (SWE) are often used as the basic governing equations, in which Manning coefficient n is the main source of simulation errors. Its spatial characteristics and effects have not yet been thoroughly investigated. Once flood inundation occurs over a floodplain due to a dike breakage, drainage modes have to be considered in the finite differential method (FDM) of simulating 2D SWE. Pumping strategy is an effective measure to relieve flood damages for catchments where the elevation in the flooded area is much lower than that of the river. However, the simulation for pumping drainage is not an easy task, because denser meshes must be applied to the areas neighboring a pump station. These two subjects are investigated in this paper. A case study was conducted in Fuefuki watershed with a basin area of1039.7 km 2, bounded by the Ara River and the Fuefuki River with continuous levees.