NUMERICAL MODELLING OF LONG-TERM MORPHOLOGY IN THE SURF ZONE OF THE BELGIAN COAST

Abstract

Longshore sediment transport in the surf zone plays a considerable role in the long-term morphological behaviour of the Belgian coast. In order to be able to analyse coastal protection measures in the future, a 2D morphology model is developed within the Delft3D software suit using a curvilinear grid which follows the coastline closely. A schematised tide and wave climate is used as boundary conditions for the model. In addition, a constant morphological acceleration factor (MorFac) and the MorMerge online-parallel approach are employed to achieve modelling of the long-term morphology within reasonable computation time. Qualitatively, most major morphological changes are well captured by the model. The modelled sedimentation/erosion is further quantitatively compared with beach erosion/deposition trends of the last 25 years presented in Houthuys (2012). The model still shows a reasonableagreement and its quality is discussed.