|Using numerical simulations to improve insight on the historical evolution of tides and morphology in the Scheldt estuary|
Stark, J.; Smolders, S.; Vandenbruwaene, W. (2019). Using numerical simulations to improve insight on the historical evolution of tides and morphology in the Scheldt estuary, in: 38th IAHR World Congress September 1-6, 2019, Panama City, Panama: E-proceedings. pp. 1741-1751
Topographic features > Banks (topography) > Embankments
ANE, Schelde-estuarium [Marine Regions]
Hydrodynamic modelling; Tidal propagation; Channel enlargement
Five historical models of the Scheldt estuary are set up for 1930, 1960, 1980, 2001 and 2013, making use of an available TELEMAC-3D model of the estuary and the Belgian coastal zone. These historical models are simultaneously calibrated through adjustments of the bottom friction coefficients in order to obtain the best overall model performance. Historical tidal characteristics, such as high and low water levels, tidal range, tidal prisms and tidal asymmetry, are then extracted from the model results. The historical models confirm findings from historical data analysis that the pre-1970 morphological development, in which embankments were dominant, led to a decrease in tidal prism and a more flood-dominant asymmetry. Conversely, the post-1970 morphological trend of channel enlargement enhanced flood-dominance and led to an increase in tidal prism and tidal range. In addition, morphological scenarios are simulated to assess the impact of specific geometrical and morphological changes on tidal hydrodynamics. In particular, scenarios are set up in which the 2013 bathymetry is implemented in a specific area of the 1930 model. A distinction is made between subtidal changes (i.e., channel enlargement) and intertidal changes (i.e., intertidal area loss). The scenarios show that intertidal changes mainly influenced tidal asymmetry and had limited impact on the tidal range, whereas subtidal changes also altered the tidal range. In addition, the scenarios also allow to identify the estuarine sections in which morphological changes had the largest impact on tidal hydrodynamics.