How does the model work?

The sediments, located at the bottom of the sea, consist either of coarse sand or of fine mud. Under the influence of the friction of the water with the sea bottom (bottom stress), the sediments will be eroded and brought in suspension, into the water column. This bottom stress is the consequence of the water currents, the tides and the waves. The amount of material that will be eroded depends on the bottom stress and of the type of sediments. The coarse sand, for instance, will be eroded less easily than the finer mud. The sediments, which are brought in suspension, can be transferred with the currents. When the bottom stress on the other hand will diminish again under a critical value, the material in suspension will be deposited on the bottom. This sedimentation is again function of the amount of sediments in the water and of the fall velocity. The heavier sand will be deposited faster than the light mud.

The two- and three-dimensional computer models calculate the transport of the different sediments under the influence of the currents and the waves. The currents are calculated with a hydrodynamic model, the waves a wave model. For each type of sediment, it is calculated how much material will be in suspension and how much on the bottom, how the material in suspension will be transported and how much material will be eroded or deposited.

 Hydrodynamic models with high resolution for the Belgian coastal zone

 Measurements of sediment transport at sea

 An animation of model results