Depth-resolved Modelling of Suspended Sediment in the Surf and Swash Zones

Abstract

We present a depth-resolving model that is capable of resolving the vertical flow and suspended sediment structures in the surf and in the swash zones. The model uses the RANS equations to simulate hydrodynamics, and includes sediment transport using an advection diffusion approach. The model is first validated hydrodynamically using measured surface elevations. The results from the model show a strong vertical dependence in the suspended sediment flux, and that at certain cross-shore locations the waveaveraged sediment transport moves onshore where the average flow velocity is offshore-directed. These physical processes are important to consider when designing more practical, long-term depth-averaged models for simulating coastal morphodynamics.