Samenvatting

The tidal area in the Eastern Scheldt is decreasing because of sand erosion and sea-level rise. Therefore, Rijkswaterstaat has investigated the possibilities to mitigate the consequences of erosion to maintain the intertidal areas. The height of the Galgeplaat tidal flat, the second-largest tidal flat in the Eastern Scheldt, has decreased substantially. This final thesis, commissioned by Rijkswaterstaat, describes the detailed changes of the Galgeplaat tidal flat.

Rijkswaterstaat provided three different types of data of the Galgeplaat tidal flat. Therefore, three different types of bed level height analyses are performed in this document. First, the satellite images of the Galgeplaat tidal flat are provided and the changes over time are described. Secondly, the data provided by ‘Vaklodingen’ has been analysed. These visualised interpolated maps gave a clearer indication of the morphological processes and trends at the centre of the Eastern Scheldt. And last, the profile analysis, which uses the most accurate and detailed data and provides a proper indication for the trend height of the Galgeplaat tidal flat.

To get a better understanding of the morphodynamic processes the hydraulic data has been analysed. Based on the literature review, wind and wave data are important parameters that influence sediment transport. The wind and wave data provided a better understanding of the trends, which were highlighted during the bed level height analysis.

The best solution for the Galgeplaat tidal flat erosion is sand nourishment. The trends are used to calculate the volume of the nourishment. The knowledge of the local hydraulic locations is used to obtain the best deposit location to design nourishment which a lifetime of 25 years.