Abstract
The effect of the longshore dimension on dune erosion is examined numerically with a 2DH process-based model XBeach. Exploratory simulations are presented to examine longshore effects due to directionally spread waves, longshore variation in topography and longshore variation in bathymetry. The simulations reveal that alongshore sediment exchange during a storm surge affects the cross-shore development of the foreshore and can locally increase or decrease storm impact on dunes substantially. This finding illustrates that dune erosion on natural coasts (which are never cylindrical or subject to longcrested waves) is an inherent 2D process for which 1D cross-shore models do not suffice without further assumptions.References
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