Numerical model for flood routing with a Cartesian cut-cell domain

Abstract

Flood risk analysis requires adequate numerical modeling to estimate the inundation depth and velocity in a wide-ranging study area. Thus, accurate, simple, and efficient numerical models with adequate mesh systems are needed for large-scale flood simulations. A numerical model based on a finite volume approach with the Cartesian cut-cell method is adopted herein to solve the shallow-water equations. To improve the representation of the flow domain, a modified cut-cell technique is suggested. The modified cut-cell mesh can be generated by a mesh merging process which needs two or more cut-cell meshes for different flow characteristic domains such as a compound meandering channel with steps. The modified cut-cell mesh indicated a reasonable flow domain to represent complicated domains. To verify the accuracy and stability of the present numerical model, various tests were performed and the obtained predictions compared with available exact solutions and laboratory measurements. A very reasonable agreement was observed.