A phase-resolving beach evolution model based on fully nonlinear Boussinesq equations

A phase-resolving beach profile model is developed to simulate beach profile changes under different wave conditions. The model consists of three modules, i.e., wave module, mean flow module and sediment transport module. The wave module is based on the fully nonlinear Boussinesq equations developed by Zou and Fang (alternative forms of the higher-order Boussinesq equations: derivations and validations. Coastal Engineering, 2009, 55(6):506-521). It is able to capture accurately the location of breaking point which plays a key role in generating sandbars. The mean flow module considers undertow and the shear stress just on the top of the bottom, the former is described by a simple ad-hoc method (by Lynett, wave breaking velocity effects in depth-integrated models. Coastal Engineering, 2006, 53(4):325-333.) while the latter is considered by numerically solving Wave Bottom Boundary Layer (WBBL) equation. Finally, the beach updating model based on Weighted Essentially Non-Oscillatory (WENO) scheme (by Long et al., a numerical scheme for morphological bed level calculations. Coastal Engineering, 2008,55:167-180.) is adopted due to its efficiency. Other processes such as the new total sand transport rate formula which could take wave asymmetric and skewness into account is also incorporated into the model. The numerical results from the model are presented and compared with those from the other similar models