Model measurements
The model measurements were performed at WL|Delft Hydraulics. Among other facilities, the Delta flume (225 m length, see Fig. 113, Fig. 114 and Fig. 115) was used for the measurements. Waves, generated at one end of the flume, attacked a model dune at the other end. During the tests, measurements were taken of the wave heights, the water velocities, the sediment concentrations and the erosion of the dune profile.

The main result of the model tests was that, in the case of intensively breaking waves, the cross-shore transport calculated simply as the product of the time-averaged values of the fluctuating water velocity and the sediment concentration gives a fair estimate of the total measured transport rates. This greatly simplifies the calculations of the cross-shore sediment transport since the complicated fluctuating velocity and concentration components can be neglected.

The calculation model
The calculation model has been based on the results of the model measurements. The distribution of the cross-shore sediment transport over the coastal profile is calculated using the time-averaged values. Starting from the initial coastal profile, the new profile after each time step is estimated using the local erosion and accretion resulting from the calculated transport rates. The effects of a complete storm surge are simulated in this way. Comparison of model calculations with measurements gives good results in most situations (see Fig. 116). The model is expected to playa key role in future decisions on coastal management in the Netherlands.