Modeling Grain Size Distribution Patterns in the Backbarrier Tidal Basins, East Frisian Wadden Sea (Southern North Sea)

Wang, Y., Gao, S., Hebbeln, D. and Winter, C., 2011. Modeling Grain Size Distribution Patterns in the Backbarrier Tidal Basins, East Frisian Wadden Sea (Southern North Sea). Journal of Coastal Research, SI 64 (Proceedings of the 11th International Coastal Symposium), 850 - 854. Szczecin, Poland, ISSN 0749-0208 Grain size distribution patterns in the back-barrier tidal basins of East Frisian coast (German Wadden Sea) have a landward fining trend from the back-barrier islands to the mainland shoreline. This cross-shore gradient of grain size is suggested to be empirically explained by the degradation of energy in the cross-shore direction within the tidal basins. To investigate the grain size distribution patterns in the back-barrier tidal basins, East Frisian Wadden Sea, a process-based model using shallow water equations with Delft3D system is built in the present study to simulate the morphological and grain size evolution. The model results show the grain size has a shoreward fining trend within the basin area, which is consistent with the observations, and proves this trend can be interpreted by the shoreward decreasing cross-shore maximum tidal current velocity magnitude, which is a proxy of energy. This study may have implications on an improved understanding of the impact of human interventions (e.g. land reclamation) on the morphodynamics and grain size evolution of the back-barrier tidal systems.