Author(s): Y. Plancke; G. Vos
Keywords: No keywords
Abstract: The Schelde-estuary serves different estuarine functions and therefore faces managers with multiple challenges: increasing tidal propagation vs. safety against flooding; sedimentation in the navigation channel vs. port accessibility; changing dynamics vs. ecology. Within the Flemish-Dutch Long Term Vision for the Schelde-estuary, a 4 year (2014–2017) research programme was defined, in which 8 topics will be dealt with (e.g. tidal penetration, risk for regime shift, sediment strategies, valuing ecology). Two fundamental tools are crucial in answering the different questions towards the future management of the estuary: expertise/system understanding and numerical models. Where the numerical models reproduce the hydrodynamics reasonably well, sediment transport and the resulting morphological changes is still a big challenge. Therefore an extensive monitoring campaign was performed in 2014, during which both hydrodynamic and sediment transport measurements were performed in the Schelde-estuary. The data allows to validate the existing numerical models, allowing a better assessment of the possibilities and limitations of the present numerical models. This paper describes the validation of a 2D numerical model, that is used to optimize the relocation strategy of non-cohesive sediments in the Beneden-Zeeschelde. The comparison of sediment transport of field data and numerical model results show a rather promising agreement (i.e. differences of factor 2 to 3) for the Beneden-Zeeschelde. However, important differences (both in patterns, intensities and between different formula) were found when comparing topo-bathymetric changes predicted by the morphological numerical model and observed bathymetric changes.