Many low-lying densely populated areas and important economical regions in Europe are threatened by sea level rise. \cite{groeskamp2020need} suggest an international cooperation to be able to protect these areas if climate change mitigation fails: the construction of the Northern European Enclosure Dam (NEED). In this research first order calculations are used to show the effects the construction of the NEED has inside the enclosed North Sea basin. The topics covered are: monthly water level variations; hydrodynamics (tides, waves and currents); salinity; temperature and lastly sediment transport. At first these topics are treated independently, after which a first step is made with studying their dependencies. Besides the dependencies, the implications of the NEED on the environment, economy and society are explored. The implications are also shown in a case study looking into the Wadden Sea, which is Natural UNESCO World Heritage.

It is found that, with constant pumping, the water level variability stays within a range that is an order of magnitude smaller than the tidal amplitudes that prevail nowadays. The salinity of the top layer drops with an order of magnitude as well, from 35 PSU to 3.5 PSU in 50 years, while the deep, stratified part of the basin stays salt. The surface temperature only changes slightly with a drop of 0.3 $^{\circ}$C.
The hydrodynamic processes in the enclosed North Sea basin together generate a weak anti-clockwise circulation that replaces the stronger anti-clockwise circulation imposed by the tides that prevailed before the enclosure of the basin. Due to a drop in average flow velocities, the sediment transport in the basin decreases and transforms from tide-dominated to a system where tides and wind are equally important. It is found that all of the above described changes have major implications on environment, economy and society and that much more research is needed to fully understand the changing processes and their effects.

Burrard Inlet (Vancouver, Canada) has been the home of the Tsleil-Waututh Nation (TWN) for thousands of years. Over the past decades, ongoing erosion has been observed along the shores of Burrard Inlet and the TWN reserve specifically. This leads to loss of land for the TWN community, damage to infrastructure, and exposure of historic sites with cultural value. Currently, there is insufficient knowledge concerning both the governing processes for sediment transport and transport pathways into, within, and out of Burrard Inlet. This knowledge is needed to propose and evaluate effective measures to prevent further erosion. This study aims to investigate the transport pathways in Burrard Inlet and give more insight into the mechanisms governing sediment transport in this inlet.

For this purpose, a Delft3D FM model of the area is set up and calibrated. This model is used to analyze sediment transport in the inlet under various forcing conditions. Transport pathways are visualized using SedTRAILS.

The model shows that flows and sediment transport in Burrard Inlet are tide-dominated and governed by the topography. Flows are strongly accelerated in constricted areas (First Narrows and Second Narrows), which leads to large velocity differences. Following the velocity field, sediment transport patterns are correspondingly dominated by these topographical restrictions. In the wider basins, flows slow down and form eddies. The model results suggest that these eddies act as sediment sinks. Additionally, sediment is lost into Indian Arm, a deep fjord with low flow velocities at the eastern end of Burrard Inlet. The possible pathways for sediment originating from the eroding shorelines at the TWN reserve are visualized. As soon as sediment from these banks is mobilized, it tends to move away from the shore with a final destination either in one of the eddies or in Indian Arm. The impact of wind and waves on the sediment transport patterns is limited.

Since first European contact in 1792, the shoreline of Burrard Inlet has changed significantly due to dredging activities, land developments, and industrial development as the city of Vancouver was built. Reconstructed historic shorelines are implemented in the model to assess the consequences of these shoreline changes on the sediment transport. Model results show that the tidal prism and the velocities in the Narrows have decreased since 1792, while the tidal range has increased. Moreover, sediment mobilized along the eroding shorelines showed greater potential for deposition along these same shores in 1792, compared to the present-day situation.