Two-Dimensional Flood Simulation on Unstructured Grids

Abstract

A two-dimensional flood simulation model using unstructured grids has been developed to study the hydrodynamics of flooding processes. The model employs the finite volume method to solve the conservative form of the shallow water equations. The HLL approximate Riemann solver is used for computing the intercell fluxes because of its robustness and easiness to implement. The momentum equation used in the model has only one source term representing the driving forces, so that numerical imbalance between source and flux terms can be easily eliminated. In addition to the model formulation, this paper presents the model verifications and validations against analytical solutions and experimental data for a partial dam-break problem and an oblique hydraulic jump test case, respectively. The results show that the model can correctly account for the two-dimensional shallow water flows which may have mixed flow regimes and dry bed problems. These features can allow the model to simulate complicated real-life flooding problems.