The Wadden Sea serves multiple roles: it acts as a protective barrier against severe wave conditions, is a natural habitat for diverse flora and fauna and has recreational purposes. This research provides a comprehensive analysis of the intricate morphological dynamics of the Wadden Sea. By implementing various model schematizations, the study aims to enhance understanding of complex interactions between tidal inlets and basins, sediment transport dynamics, the influence of forcing actors and the importance of grid resolution. The ultimate goal is to improve the process-based models that are used to perform morphological forecasts, serving as a valuable tool for efficient coastal management and ensuring the preservation of this unique tidal ecosystem.

The study incorporates several schematizations, including the spatial extent of the modelling grid (domain schematization), grid resolution and various forcing components applied to the model boundaries and grid. Analysing water and sediment exchange between basins and through the Ameland tidal inlet has revealed distinct differences in hydrodynamics and morphodynamics across the model schematizations.

The single-inlet domain schematization encompassed only the Ameland tidal inlet region, while the more expansive multi-inlet schematization captured the entire Wadden Sea area. The single-inlet schematization does not account for hydrodynamic interactions between the Ameland basin and neighboring basins. This impacts sediment transport and morphological development in the Ameland inlet. A multi-inlet approach, encompassing the entire Wadden Sea, grants a more comprehensive model. The model with Wadden Sea domain schematization is essential for obtaining accurate results, as it showed significant differences in sediment transport compared to the single-inlet model. Modeling practices that exclude transport dynamics between tidal basins risk misrepresenting the natural processes in play.

Around the Ameland inlet, ebb dominance is observed in most regions, but there are exceptions in the marginal flood channel and at the outer side of the ebb-tidal delta. The Ameland model shows more ebb-dominance than the Wadden Sea model. Sediment transport during ebb periods exceed than during flood periods and differences in sediment transport between model schematizations are more pronounced during ebb than during flood.

Regarding the drivers of change, the spring-neap tidal cycle is particularly indicative of periods with meaningful residual sediment transport. Wind, especially from southwesterly directions, has a significant impact on water transport dynamics and a limited impact on sediment transport through the inlet.

Two grid schematizations are used, one with a base resolution of 60 by 60 meter and another with a high-resolution grid of 30 by 30 meter near the inlet. An enhanced grid resolution results in marginal changes in simulation outcomes, offering limited advantages for the conducted short-term morphological forecasts.

Overall, enhanced model schematizations can significantly improve short-term morphological forecasts of the Ameland tidal inlet, providing a more accurate and comprehensive representation of the complex hydrodynamic and sediment transport processes. Leveraging high-performance computing (HPC) for executing Delft3D-FM models has been central in this research, offering possibilities to enhance model resolution and reduce computational time.

The benefits of HPC come with the added challenge of mastering new software, handling larger models and interpreting more extensive data sets. A deep understanding of the physical processes and careful cost-benefit consideration is crucial, as increased computational power does not automatically resolve all modeling limitations. As such, the effective use of HPC in coastal modeling requires a balance between its sophisticated capabilities and the complexity it introduces.