Author(s): Jae Seok Bae; Junwoo Choi; Sung Bum Yoon
Linked Author(s):
Keywords: Tsunami inundation; Equivalent resistance coefficient; Imwon harbor; Numerical simulation; Nonlinear shallow water equation model
Abstract: For simulating large built-up area inundation by using the nonlinear shallow water equation model, the method using dense computational grids to represent all structures in the region of interest is inefficient and does not promise accurate results because of the depth-averaged approach adopted in the governing equation. Instead of the dense-grids method, the computational method using relatively larger grids and an equivalent resistance coefficient can be considered. The equivalent resistance coefficient, which represents flow resistance due to both bottom friction and drag caused by obstructions, is applied to the bottom friction term. In this study, an event of tsunami inundation was simulated by using the nonlinear shallow water equation model employing the equivalent resistance coefficient formula verified by the hydraulic and 3D numerical experiment. The formula depends on bottom friction, water depth and density of obstructions. The 1983 tsunami that attacked Imwon harbor city located at the east coast of Korea was chosen and simulated. The result was compared with the result using a constant value of Manning’s n value as well as reported inundation heights. From the comparisons, it was found that the result of the present method was more reasonable and agreed better with the reported inundation heights.
Year: 2010