title: Modelling Belgian coastal zone and Scheldt mouth area: sub report 13. Scaldis-Coast model – Model setup and validation of the wave propagation model
Creators: name: Wang, L.
name: Kolokythas, Gerasimos
name: Fonias, S.
name: De Maerschalck, Bart
name: Vanlede, Joris
name: Mostaert, Frank
Publisher: name: Flanders Hydraulics Research
Year: 2021

description: With the increasing awareness of sea level rise, the Flemish Authorities initiated the Complex Project Kustvisie (CPKV) in order to start together with all involved stakeholders to define the overall long-term coastal defence strategy for the Belgian Coast. In order to analyze the impact of sea level rise on the morphology of the coast and to assess mitigation measures on their efficiency the need for a flexible coastal model for the Belgian coast and Scheldt mouth area was revealed.Therefore, in 2015 it was decided to build an integral coastal model within the TELEMAC-MASCARET model suite. The present report describes the setup and validation of the two-dimensional TOMAWAC wave propagation model. Together with the TELEMAC2D hydrodynamic model, the wave propagation model forms the basis of the final goal: the morphodynamic model. The hydrodynamic and the TOMAWAC spectral wave propagation model will be coupled to the SISYPHE sediment transport and bed update model. The wave model is driven at the boundaries by the wave direction, height- and wave period measurements at Meetnet Vlaamse Bank measurement station Westhinder. The modelled wave propagation was validated against the wave buoy measurements from the Broersbank project for a selected period including two storms, one from the South-West and one from the North. Two version of the model are available:• A stand-alone TOMAWAC wave propagation model. Only the vertical effect of the tide, i.e. the water level, is considered in a schematised way: the water level is only temporally varying and spatially uniform in the entire domain.• A coupled current-wave interaction version of the model. In this version both tidal currents as wave-induced currents are considered. Since the wave driven currents have a significant contribution of the sediment transport near-shore and onshore, this is the version that will be coupled to the sediment transport model.Before, it was only possible to couple TOMAWAC wave propagation models to TELEMAC tidal models and SISYPHE sediment transport models, when all models have the same domain outline and identical grids. However, due to the nature of the models, a shallow water solver often requires different grid properties than a wave model. Often, a lower resolution is sufficient for the wave transport model than for the hydrodynamics and sediment transport model. Also, parts of the model domain that are limited influenced by waves, like upstream the estuary and the Eastern Scheldt, it is not necessary to include them in the wave model. Since the wave propagation model often is the bottle neck with respect to computational cost for long term morphodynamic modelling, it was decided to develop a new routine, TEL2TOM, which allows to couple the wave and the hydrodynamic models in an efficient way running the models on different grids with a different resolution and different domain. For the fully coupled morphodynamic model, the implementation of TEL2TOM reduced the total computation time with a factor two without loss of accuracy.The wave propagation models are available at the Flanders Hydraulics Research model repository: https://wlsubversion. vlaanderen.be/!/#repoSpNumMod/view/head/TELEMAC/Scaldis- Kust/15_068%20Complex%20Model%20Kustvisie%202021/2_WAVEMODELS
description: Title : FHR reports. Flanders Hydraulics Research: Antwerp Volume : 15_068_13 Issue : Pagination : VII, 53 + 12 p. app.