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MOZES – Research on the Morphological Interaction between the Sea bottom and the Belgian Coastline: Working year 2
Dujardin, A.; Houthuys, R.; Nnafie, A.; Röbke, B.; van der Werf, J.; de Swart, H.E.; Biernaux, V.; De Maerschalck, B.; Dan, S.; Verwaest, T. (2024). MOZES – Research on the Morphological Interaction between the Sea bottom and the Belgian Coastline: Working year 2. Version 4.0. FH reports, 20_079_2. Flanders Hydraulics: Antwerp. IX, 132 + 30 p. app. pp. https://dx.doi.org/10.48607/244
Part of: FH reports. Flanders Hydraulics: Antwerp. , more
MOZES – Research on the Morphological Interaction between the Sea bottom and the Belgian Coastline: Working year 2
Available in  Authors 
Document type: Project report
Keywords
    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 details

Proposer: Vlaamse overheid; Beleidsdomein Mobiliteit en Openbare Werken; Vlaams Ministerie Mobiliteit en Openbare Werken; Departement Mobiliteit en Openbare Werken; Waterbouwkundig Laboratorium (WL), more
Proposer: 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.
  • van der Werf, J.
  • de Swart, H.E.
  • Biernaux, V.
Abstract
    The MOZES-project (MOrfolgische interactie kustnabije ZEebodem en Strand) investigates the  morphodynamic interaction between the Belgian offshore seabed (inner shelf + nearshore) and adjacent  shoreline across varying time scales (months to centuries). The project aims to enhance the understanding  of the region's morphodynamics for effective coastal management.
    This report outlines progress in four Work Packages (WP1, WP2, WP3 and WP4) during the second project  year. WP1 addressed analysis of field data, WP2 involved the further development of the idealized models established in the first year, WP3 delved into investigating the hypothesis of natural beach feeding through  sediment transport over shoreface-connected sand ridges using the complex numerical models FlemCo and  Scaldis-Coast. Finally, using the latter two models, WP4 examined the effects of the observed deepening of  nearshore channels on beach erosion.
    WP1: Further digitization of bathymetric and beach topographic data and the collection of bed sediment  data. The depth uncertainty of bathymetric surveys was analyzed; yielding an empirical uncertainty of  ± 0.15 m. The produced data confirm that over the last four decades, the base of the shoreface suffers  structural erosion. In a case study of Pas van Stroombank, the routinely reported "Bagger Informatie  Systeem" (BIS) parameter "reduced volume" correlates well with the surveyed volume differences.  Longitudinal transport over Stroombank was estimated in 2014 to be about 100 m³/m. In Kleine Rede,  sediment transport was in 2010 about 4 times higher.
     WP2: Efforts were concentrated on further developing 1) the morphodynamic shelf model and 2) the coupled  morphostatic (i.e., bottom does not change) shelf-shoreline model established in the first year. The  development of the morphodynamic shelf model marked an important step forward, enabling the simulation  of self-developing shoreface-connected sand ridges by incorporating (for the first time!) wave-topography  feedbacks. The simulated ridges resemble those observed on the Belgian shelf, although some differences  are noted. Significant improvements were made to the coupled shelf-shoreline model, enabling the  reproduction of observed shoreline progradation (erosion) adjacent to the ridge crest (channel) and the  steeper bathymetry profile in the breaker zone near the channel compared to that near the crest. Simulations  with this model indicate that the observed onshore movement of ridges on the Belgian shelf is likely to  intensify shoreline retreat near the channels and progradation near the ridge crests. Finally, a new analytical  tide model showed that wave-induced sediment transport dominates in the breaker zone, while tide-induced  transport becomes significant further offshore. These findings qualitatively align with results from FlemCo  and Scaldis-coast models.
    WP3: Primary focus was to understand the observed differences between simulated longshore sediment  transport and sediment pathways over ridges by the Scaldis-Coast and FlemCo models. Results from  sensitivity runs revealed that these differences primarily stem from a larger wave-induced longshore  sediment transport in Scaldis-Coast compared to FlemCo. As was found by the idealized model (WP2),  these results confirm that wave-induced sediment transport dominates in the breaker zone, while