A MacCormack Method for Complete Shallow Water Equations with Source Terms
For hydrologists and engineers modeling overland flow, this provides a stable and accurate numerical scheme for shallow water equations with source terms, though it is an incremental extension of existing methods.
This paper extends the MacCormack method to solve 1D complete shallow water equations with source terms, analyzing stability and convergence. Numerical tests show the method achieves second-order convergence and matches analytical solutions.
In the last decades, more or less complex physically-based hydrological models, have been developed to solve the shallow water equations or their approximations using various numerical methods. The MacCormack method was developed for simulating overland flow with spatially variable infiltration and microtopography using the hydrodynamic flow equations. The basic MacCormack scheme is enhanced when it uses the method of fractional steps to treat the friction slope or a stiff source term and to upwind the convection term in order to control the numerical oscillations and stability. In this paper we describe, the MacCormack scheme for 1D complete shallow water equations with source terms, analyze the stability condition of the method and we provide the convergence rate of the algorithm. This work improves some well known results deeply studied in the literature which concern the Saint-Venant problem and it represents an extension of the time dependent shallow water equations without source terms. The numerical evidences consider the rate of convergence of the method and compares the numerical solution respect to the analytical one.