MOZES – Research on the Morphological Interaction between the Sea bottom and the Belgian Coastline: Working year 3
Dujardin, A.; Houthuys, R.; Nnafie, A.; Röbke, B.; Nguyen, D.; de Bakker, A.; de Swart, H.E.; van der Werf, J.; Huisman, B.; De Maerschalck, B.; Dan, S.; Verwaest, T. (2025). MOZES – Research on the Morphological Interaction between the Sea bottom and the Belgian Coastline: Working year 3. Version 4.0. FH reports, 20_079_3. Flanders Hydraulics: Antwerp. XI, 131 + 23 p. app. pp. https://dx.doi.org/10.48607/355
Part of: FH reports. Flanders Hydraulics: Antwerp. , more
|
|
| Available in | Authors |
|
Document type: Project report
|
| Keywords |
Earth sciences > Geology > Geomorphology > Coastal morphology
Hydraulics and sediment > Morphology > Erosion / sedimentation
Literature and desktop study
Numerical modelling
Transport > Sediment transport
|
| Project | Top | Authors |
- MOZES: onderzoek van de morfologische interactie tussen de kustnabije banken en geulen en de strandzone, more
|
Contact detailsProposer: Vlaamse overheid; Beleidsdomein Mobiliteit en Openbare Werken; Vlaams Ministerie van Mobiliteit en Openbare Werken; Agentschap voor Maritieme Dienstverlening en Kust; Afdeling Kust , more
| Authors | | Top |
- Dujardin, A., more
- Houthuys, R., more
- Nnafie, A., more
- Röbke, B.
|
- Nguyen, D.
- de Bakker, A.
- de Swart, H.E.
- van der Werf, J.
|
- Huisman, B.
- De Maerschalck, B., more
- Dan, S., more
- Verwaest, T., more
|
| Abstract |
The MOZES‐project (MOrfolgische interactie kustnabije ZEebodem en Strand) investigates the morphodynamic interaction between the Belgian offshore seabed (shelf and nearshore) and adjacent shoreline across varying time scales (days to centuries), aiming to improve regional morphodynamic understanding needed for effective coastal management.
This report outlines progress during the third year across four Work Packages (WP1, WP2, WP3 and WP4). WP1 analysed field data, WP2 further developed the idealized models (coupled shelf-shoreline model and morphodynamic model) established in the first two years, WP3 validated the Scaldis-Coast and FlemCo models by simulating nearshore wave directions, while WP4 began hindcasting shoreline and seabed changes near Knokke-Heist from 1999-2003. Key findings and highlights from each Work Package are listed below.
WP1:
• Vectorisation of historical topo-bathymetric maps continued in the third year, focusing on selected areas surveyed in the 1970s and around 1990.
• Over the past two centuries, shoreface-connected sand ridges (sfcr) migrated by up to 5 km eastwards, and several hundred metres landwards. The underlying driving forces are believed to be mainly the residual sediment transport and sea-level rise. While the area of tidal sand ridges (tsr) lost sediment, the area of sfcr accreted, although vertical change remained within depth uncertainty. The relative height of all sand ridges did not change.
• Dredging of navigation channels deprives the downdrift sandbanks and the point where they attach to the shore of sediment. A morphological analysis for Stroombank yields a longshore sediment transport estimate of about 300 m³/m/year.
WP2:
• The coupled shelf-shoreline model, featuring synthetic sfcr and tsr resembling the Belgian shelf, successfully reproduces observed shoreline progradation near sfcr crests, retreat near channels, with tsr having smaller but non-negligible impact. These results are published in the Journal of Geophysical Research.
• The morphodynamic shelf model, for the first time, simulates the simultaneous development of sfcr and tsr under waves, wind, and tides. While the simulated ridges resemble those on the Belgian shelf, key differences exist: sfcr are less oblique and migrate faster in the model, while tsr are located more shoreward than in observations.
• The morphodynamic shelf model, for the first time, successfully simulates sfcr using sediment formulations other than those traditionally used, showing sfcr formation is not constrained by a specific sediment transport formulation.
WP3:
• Overall, the wave heights and directions as simulated with the Scaldis-Coast and FlemCo models agree with the observed wave heights and directions at the Flemish coast but the interaction between tides and waves in the Appelzak gully near the coast is not fully reproduced by both models.
• FlemCo slightly overestimates the wave directional spreading offshore, while Scaldis underestimates the spreading nearshore, leading to an exaggerated peak for waves from the northwest.
WP4:
• Overall, FlemCo produces the observed morphodynamics at the beach and shoreface of Knokke-Heist, though discrepancies increase seaward of the shoreface.
• The Scaldis-Coast model generally captures the main morphological changes during the period 1999-2002/2003: erosion in the nourishment area. However, deviations remain in the magnitude and spatial distribution of bed level changes in the broader area.
• Both models require further calibration and validation before being use to study erosion of nourishments of the coastline of Knokke-Heist coast in more detail.
|
|
