2D Modelling of Unsteady Morphodynamical Processes

Morphodynamical processes are usually strongly unsteady and characterized by a behaviour not explainable using the hypothesis of immediate adaption of solid transport to flow condition. Such consideration stimulated in the last two decades the formulation of many models these not assume the instantaneous adaption hypothesis. The models are based both on two-layers and two-phases approach; moreover recently some of the Authors proposed a depth-integrated two-phase morphodynamical model and demonstrated its unconditionally hyperbolicity. This property, not shared by two-layers models, permits more soundly numerical integration of the model. In the paper capabilities of the proposed model in reproducing transients phenomena is investigated. Comparisons of numerical results against experimental literature data of a dam removal process by overtopping is presented. The model results appear satisfactory; in fact principal qualitative and quantitative agreement between numerical results and experimental data are observed. Moreover it is demonstrate that using an immediate adaption model such agreement cannot been obtained.