Morphology:
FINEL2D is capable of calculating morphological changes in different types of water systems. Experience has been gained in estuaries, seas, delta’s, rivers and coasts.Each type of water system has its own specific set of physical processes that need to be accounted for.
For example the morphology of coasts require wave input for a good morphological model (See Waves). In sheltered estuaries this is less important and the combination of both sand and mud is important for a good representation of morphological changes (See Sand-mud interaction).
Delta in time:
The animation above shows the formation of a delta in time.
The river (on the left) is transporting water and sediment into stagnant water (on the right) like a lake or sea.
The velocity is high in the river, but when the water reaches the lake the velocity decreases so the sediment will settle.
The resulting change in bed level and roughness results in continuous changes in velocity, channels and a progressing delta.
The animation above shows the bed level development in the Western Scheldt estuary over 750 years.
Initial the bathymetry is set at a constant level of -7m MSL.
The model then calculates the subsequent changes in bed level due to tidal flow only. A non-erodable layer is present in the model.
Ebb and flood channels develop, migrate and sometimes disappear again.
The computed bathymetry can be compared to the present day bathymetry: the location, number and size of the channels, shoals in the mouth (to the left) and in the Western Scheldt (to the right) are remarkably similar to the present day morphology.