WL|Delft Hydraulics; Royal Haskoning; J. Lansen ; M. Kluyver
Dikes and dunes are our protection against flooding by the sea. To guarantee the coastal safety a five yearly inspection of safety is prescribed in the Dutch Act on Water defences (in Dutch; Wet op de Waterkeringen). This periodic inspection is carried out by the responsible Water Boards based on legal regulations with prescribed methods and extreme conditions. The hydraulic conditions for the inspection are given in the Hydraulic Boundary Conditions (in Dutch: Hydraulische Randvoorwaarden).
It goes without saying that these Hydraulic Boundary Conditions (hereafter HBC) should be accurate and reliable. Unreliable HBC will result in an unreliable image of our safety. Too conservative conditions will result in high costs of needed strengthening of coastal defences. Most HBC consist, in addition to water level conditions, of wave conditions computed with numerical models like SWAN. In that case, the reliability of the HBC is strongly correlated with the reliability and performance of the SWAN model.
One of the most principal methods to determine the reliability of a model is to test it out in reality. For that case, we require representative measurements of storm conditions in the area of interest. Hindcasting is a method to simulate the measured condition with the model to validate the reliability of the model.
The data used for this hindcast has been provided to Royal Haskoning by RIKZ. However, the buoy data has been validated by the standard validation algorithms of the measuring network (SWAP), this data is not analysed in detail. This lies outside the scope of this hindcast.
Project name: Hindcast SWAN Waddenzee
Project number: 9S2639.A0