Speaker: Sergio Maldonado Villanueva

The most common approach to simulate morphodynamics is based on a coupled system of a hydrodynamic model, a bed-update equation and a sediment-transport empirical formula. However, empirical formulae are numerous and final morphological results following this approach have proven to be very sensitive to the selection of a particular formula. The present model is a physics-based alternative (free from empirical formulations for sediment-transport rates) where the shallow water-sediment-mixture flow is idealised as being divided into two layers with variable densities: the lower layer concerned with bed load transport, and the upper layer representing sediment in suspension. The model has been validated satisfactorily against widely used empirical expressions for bed load transport and then used to carry out insightful case studies. The present physics-based approach represents an alternative tool that can be potentially utilised to investigate sediment-transport phenomena that cannot be studied following the conventional approach; e.g. the influence of bed slope on the bed load transport.