Finite volume solution to integrated shallow surface-saturated groundwater flow

WOS: 000232680600004This paper describes development of an integrated shallow surface and saturated groundwater model (GSHAW5). The surface flow motion is described by the 2-D shallow water equations and groundwater movement is described by the 2-D groundwater equations. The numerical solution of these equations is based on the finite volume method where the surface water fluxes are estimated using the Roe shock-capturing scheme, and the groundwater fluxes are computed by application of Darcy's law. Use of a shock-capturing scheme ensures ability to simulate steady and unsteady, continuous and discontinuous, subcritical and supercritical surface water flow conditions. Ground and surface water interaction is achieved by the introduction of source-sink terms into the continuity equations. Two solutions are tightly coupled in a single code. The numerical solutions and coupling algorithms are explained. The model has been applied to 1-D and 2-D test scenarios. The results have shown that the model can produce very accurate results and can be used for simulation of situations involving interaction between shallow surface and saturated groundwater flows. Copyright (c) 2005 John Wiley & Sons, Ltd