Numerical Simulation of Flood Estimation for Gis-Based Local Inundation Map

Abstract

This study simulated the flood inundations of the Nakdong River catchment running through Yangsan, a small city located in the south eastern area of Korea by using the depth averaged two-dimensional hydrodynamic numerical model. The numerical model employs the staggered grid system including moving boundary and a finite different method to solve the Saint-Venant equations. A second order upwind scheme is used to discretize the nonlinear convection terms of the momentum equations, whereas linear terms are discretized by a second order Leap-frog scheme (Cho and Yoon, 1998). The numerical model was applied to a real topography to simulate the flood inundation of the Yangsan basin in Yangsan. The numerical result for urban district was reasonable in view of the urban flood damage when compared with field measurement and then it will be able to predict the inundation area efficiently for prospective flood events such as 100, 200 and 500 year flood events. These results can be essentially utilized to construct the inundation map after building the GIS-based database in local public organizations in order to protect the life and property safely.