The current approach to protecting our coast from flooding from the sea is, where possible, to use soft seawall techniques. By means of beach, dune and foreshore replenishments, the aim is to provide protection against a 1000-year storm surge. The Coastal Division, however, continues to carry out research into innovative ideas and techniques that can be used to strengthen the soft seawall, taking into account the natural dynamics of the coastal system. This is where knowledge of the impact of shallow coastal zones and sandbanks on the coastal system is indispensable.

To examine the impact of sandbanks on the reduction of wave energy in detail, the Flemish Coast Monitoring Network was started in 2013. This monitoring network consists of seven buoys along our coast. Two of them, the Westhinder and the Trapegeer, are part of the already existing Flemish Banks Monitoring Network. The buoys are sited roughly in a line along the coast from Westhinder to Broersbank, and they cross several existing sandbanks.

Over 27 months, including three winter seasons, wave measurements were taken using the monitoring network. The Department of Engineering of KU Leuven processed all of these measurement series and built a unique database of waveform data. This data was used in the first instance to estimate the impact of shallow coastal zones and sandbanks on the propagation of waves approaching the coast. The next phase saw the database being used to build and optimise two model series. These model series can be used in a follow-up stage to assess the impact of storm surges on the coast. They will also be used as part of research into innovative sea defence techniques.

The results of the Flemish Coast Monitoring Network – project Broersbank – were presented to an academic audience on 21 September. The most important conclusion is that the project has managed to create a unique dataset and model instruments that will contribute to further research into a safe, rugged coast.

Presentations about the project can be downloaded in dutch below: