|Delft University of Technology
|Sand Motor; Ecosystem services; Delft3D; forecast
|Full text PDF:
The Sand Motor is a unique and dynamic solution for coastal erosion, aimed at distributing the nourished sand along the Delfland coast. Besides enhancing coastal protection, the Sand Motor has been designed to also provide opportunities for recreation and nature development. The contributions of ecosystems to human well-being, that arise from interaction between biotic and abiotic processes, are called ecosystem services. The Sand Motor provides several ecosystem services, such as recreation, coastal protection, a fresh water supply by dune filtration and it provides different types of habitats for species. Typically, ecosystem services are evaluated for one snapshot in time, usually at the initial state of the design. However, due to the dynamics of the Sand Motor, the ecosystem services are likely to change over time and space. To research the ecosystem service dynamics of the Sand Motor in the future, there is a need for an objective and concrete framework that is able to assess the services on a temporal and spatial scale. Predicting the response of a nourishment on the ecosystem services by means of a process-based model could improve the decision-making regarding integrated coastal zone management. The aim of this study is to assess the decadal development of the ecosystem services of the Sand Motor. This research focused on some of the services the mega-nourishment provides, namely coastal protection, recreation and habitat provision. Future morphological behavior of this intervention is being studied by process-based numerical models, which has resulted in morphological predictions, made with Delft3D, up to forty years ahead. There are many factors that are important to the actual use of ecosystem services that are difficult to incorporate into a long-term prediction. Therefore this research focused on the long-term potential of the ecosystem to contribute to human well-being, based on the physical capacity of the ecosystem to provide the service. The ecosystem service potential of the Sand Motor is evaluated on a yearly basis, forty years ahead and on a large spatial scale from Hoek van Holland to Scheveningen. The state-of-the-art Delft3D model was set up to make a long-term forecast of the morphology and, according to literature, has not been used previously in (dynamic) ecosystem service assessments. To verify the model performance regarding the prediction of ecosystem service dynamics, the computed ecosystem service potential was validated using the first four years of observations. The results indicate a robust enhancement regarding coastline maintenance that holds beyond the envisaged lifetime of twenty years. North of the Sand Motor, the coastline orientation is predicted to change, thereby decreasing the sediment transport gradients. Beach width available for recreation is expected to increase drastically along the entire Delfland coast. This may threaten the recreational potential at the beach of Scheveningen South, Kijkduin and Hoek van Holland. Regarding nature development, the diversity… Advisors/Committee Members: Stive, M. J. F., Luijendijk, A. P., Slinger, J. H., Van Wesenbeeck, B. K. ., De Vries, S., Van Oudenhoven, A. P. E..