The present work is devoted to the application of a complete 2D shallow water model in finite volumes to the simulation of overland flow in urban flooding problems. The numerical model is well fit for unsteady flow simulations over dry surfaces of irregular shape. It was previously developed and validated in other contexts and is proposed here as a useful tool to handle very complex situations in urban context where high water velocities can be encountered in presence of sharp vertical gradients in bed elevation and important variations in the cross section due to sudden expansions and contractions. The ability of the model to calculate flow transients over dry beds relying simply on a Manning friction model and a detailed topography data without any additional tuning parameters is especially emphasized. The possibility to simulate a situation of building overtopping is included in this model. The results are useful to establish the suitability of the mathematical formulation for this kind of application, the necessity of a correct discretization of the flood advance over the inundation area in presence of sharp bed level variations such as those induced by the city buildings and show that a compromise between grid refinement and accuracy in the computational results can be found.
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