Integrated Physically Based Rainfall-Runoff Model Using FEM

The current study presents a physically based hydraulic model using derived watershed features to simulate rainfall-runoff response of a catchment. The finite-element concept is used to obtain the time-invariant weighting coefficients for estimation of the rainfall on the cascade planes. The overland flow is simulated using a kinematic wave model, and the finite-element formulation of variable width and variable slope is used to solve the resulting equations. The flow through the network of channels, which is fed with lateral overland inflows, is simulated by solving the full Saint-Venant equations, using the finite-element method (FEM). The model is applied on a hypothetical catchment, and the results are discussed on a qualitative basis. The results are encouraging and show the applicability of the formulations and concepts presented in this study.