Flanders Hydraulics Research was asked to apply a recently improved version of the cohesive sediment transport model in Delft3D-NeVla to analyze the impact of the bathymetric changes in the so-called Scenario 4 on the SSC distribution along the Scheldt estuary. In Scenario 4, developed by IMDC as part of the Interreg project IMMERSE’s Work Package 3.2, the bathymetry of the river banks in between Burcht and Rupelmonde just upstream of Antwerp (Lower Sea Scheldt) are raised to a maximum elevation of -1,0 m TAW. Based on the model results, the bathymetric changes in Scenario 4 lead to a SSC reduction of up to 10% in the Lower Sea Scheldt and a SSC increase of 10-40% in the Upper Sea Scheldt for a low discharge situation. This also corresponds to an upward movement of the ETM by about 10 km. The modelled impact during high discharge conditions is much smaller (i.e., relative change in SSC varies between -6% and +8%), as the spatial SSC variation hardly differs between Scenario 4 and the reference scenario for high discharge runs. Regarding the modelled influence on tidal hydrodynamics, Scenario 4 induces a tidal range reduction in the Upper Sea Scheldt, while the shape of the tidal wave becomes slightly more flood dominant upstream of the bathymetric changes and a bit less flood-dominant along and downstream of the altered section.
Juni 2022
Scheepvaart, waterwegen en zeewezen
J. Stark, S. SmolderS, Y. Plancke
WL rapporten 20_098_1