A Two-Phase Model for Fast Geomorphic Shallow Flows

The paper introduces a 2D depth averaged model for the analysis of river morphodynamics, based on a two-phase formulation. Mass and momentum conservation principles are separately imposed for both phases. The model naturally accounts for unsteady non-equilibrium solid transport, since neither instantaneous adaptation hypothesis nor any ad hoc differential equation is employed to represent sediment dynamics. The hyperbolic character of the proposed model is shown to be preserved independently on the flow conditions. Results from numerical simulations for both 1D and 2D test-cases are compared with literature experimental data and with available numerical solutions.