Process-based Modeling of Coastal Dune Development

Abstract

This thesis presents the application of an aeolian transport model used in desert environments [Sauermann et al., 2001, Kroy et al., 2002] as a tool for the evolution of coastal nourishments. This study will try to investigate the driving processes in the model and adapt or extend the model application to the coastal system. If we want to apply the model, it has to be determined if the various model assumptions hold in a sandy coastal environment. This need becomes more urgent when dealing with a type of ‘mega’ nourishment like the sand engine, because of the considerable portion of surface area above the water line. To make the model suitable for the Dutch coastal zone, changes had to be made to several program components. From literature, several processes can be identified that have to be included in a proper model of coastal aeolian transport as opposed to a desert environment. This study identified several of these aspects that should be included in a correct model of aeolian sediment transport. The cases of the sand engine and Vlugtenburg put these modifications to the test and evaluated the results. With the sand engine case the emphasis lies on the evolution of the shape due to aeolian processes. The Vlugtenburg profile represents an arbitrary beach profile, but also contains interesting features like vegetated dunes and a sandy dune valley. Model results show that the processes of aeolian transport and morphologic feedback on the topography are captured. Combining this model with a hydraulic transport models like Delft3D or XBeach could provide more insight in the processes that act in the interface between the sea and the (high) beach.