On the Assessment of a Modified Diffusion-Wave Approximation Model in the Framework of Overland Flow

摘要

In Hydrology, the Saint-Venant equations are often reduced to various wave approximations, one of them being the diffusion-wave. This model, by neglecting the convective term, reduces the initial full Partial Differential Equation (PDE) system into a single parabolic PDE. Therefore, it is from great interest regarding both the computing time and possibilities. Meanwhile, on large scale basins, its limitations can cause the local requirement of the full system, leading to boundary coupling. In this paper, the authors propose a modified diffusive-wave approximation, where the time-dependent term of inertia is not neglected, keeping therefore a system of hyperbolic PDE. Beside its ability of suiting to all types of topography, it also has the advantage of a lower celerity. This model is compared with the SWE model, in order to assess the reliability of the proposition in the framework of overland flows and discuss both the required computing time and the necessary computing resources.