A dynamic grid model for high resolutions of unsteady shallow water simulations

A two-dimensional shallow water simulation model based on adaptive quadtree mesh has been developed to study the process of flood inundation in this paper. The model employees the Godunov-type finite volume method to solve the two-dimensional shallow water equations. An adaptive criterion is applied according to local flow paten and the corresponding density of computational cells varies locally. HLLC Riemann approximate solver is adopted to evaluate convective fluxes across cell interfaces and non-negative reconstruction is implemented for second-order accuracy in space. The numerical model is validated against benchmark problems for oblique hydraulic jump case and circle dam break case. The results show that the model is robust and can simulate shallow water flows involving wet/dry front stably and accurately.