Factors regulating sediment fluxes over an engineered foredune and adjacent dune slack

This study aims to identify and understand the annual scale sediment transport patterns in a fully engineered dune-dune slack system that was created from seabed sediments for grey dune and moist dune slack habitat creation at the Delfland coast (the Netherlands). The annual morphological development was analysed using LiDAR elevation data. Daily aeolian sediment transport was simulated across the foredune and in the adjacent dune slack, using the numerical aeolian sediment transport model AeoLiS. All simulated transport events were combined to reveal how aeolian sediment transport behaves on an annual scale. Planting two continuous strips of marram grass along the top of the foredune induced rapid growth of the foredune, while limiting sediment supply to the dune slack. The armouring layer of shells that formed at the surface of the engineered topography, functioned as a supply-limiting factor and restricted the sediment entrainment and deflation of the dune slack. Therefore, the formation of a moist dune slack habitat may take longer for this engineered case than in a natural case with similar boundary conditions