Numerical modeling of sediment transport applied to coastal morphodynamics

A bed-load sediment transport model is used to describe realistic cases of the morphodynamics in coastal areas. The hydrodynamic equations are based on the well-known, two-dimensional depth-averaged non-linear shallow water equations, with bathymetry forces and friction, which are subsequently coupled to the Exner equation to describe the morphological evolution. Different forms of the bed-load transport flux are considered in the Exner equation and certain relations between them are established. The numerical model is expressed in a fully-coupled form where a single system of equations is solved by a high-resolution two-dimensional finite volume scheme of the relaxation type. The relaxation is performed by classical models where neither approximate Riemann solvers nor characteristic decompositions are needed. The overall numerical scheme is validated in benchmark problems, and for a realistic application of a coastal area on the northern side of the island of Crete. The validity of these results is established by comparisons made with the well-known MIKE Software by DHI Group.