Print Email Facebook Twitter Improvements in spectral wave modelling in tidal inlet seas - Overview of results of the SBW-Waddenzee project 2006-2010 Title Improvements in spectral wave modelling in tidal inlet seas - Overview of results of the SBW-Waddenzee project 2006-2010 Author Van der Westhuysen, A. Van Dongeren, A. Van Nieuwkoop, J. Groeneweg, J. Eslami Arab, S. Corporate name Rijkswaterstaat Project SBW Date 2011-05-01 Abstract Over the last five years a research program has been carried out to assess the performance of the spectral wave model SWAN in the Wadden Sea so that it may be used for the transformation of offshore wave conditions to wave boundary conditions near the sea defenses (dikes and dunes). The assessment was done on the basis of extensive wave measurements conducted in the Ameland inlet and the Dutch Eastern Wadden Sea, as well as relevant data from other inlets, lakes and estuaries. We found that the 2006 default version of SWAN (version 40.51) performed reasonably well for storm conditions, but three aspects required further attention. First, over the tidal flats, the computed ratio of integral wave height over water depth showed an apparent upper limit using the conventional Battjes and Janssen (1978) depth-limited wave breaking formulation with default breaking parameter. Using the default settings, the wave height for a given water depth would be underpredicted near the sea defenses adjacent to nearly-horizontal flats. The problem has been largely solved using a new breaker formulation. The second area of model improvement concerns two processes related to wave-current interaction, namely the so-called wave age effect on waves generated in ambient current, and enhanced dissipation due to wave steepening in negative current gradients. Third, the variance density of lower-frequency wind waves from the North Sea penetrating into the inlet was underpredicted. Best results were obtained when the bottom friction coefficient was set at a lower value than the current default for wind seas. All these improvements have lead to a wave transformation model with which reliable wave conditions in the Wadden Sea and related complex areas can be determined. Subject wave modelingtidal inletSWANWaddenzeewave current interaction Classification TLJ6000TLJ300200 To reference this document use: http://resolver.tudelft.nl/uuid:205d0ba2-2fbf-4ff3-b007-90e30c07e47d Publisher Deltares Source Deltares report 1202119-006-HYE-0003 for Rijkswaterstaat, Waterdienst Part of collection Hydraulic Engineering Reports Document type report Rights © 2011 Deltares Files PDF 1202119-006-HYE-0003-v6_0 ... mpleet.pdf 5.31 MB Close viewer /islandora/object/uuid:205d0ba2-2fbf-4ff3-b007-90e30c07e47d/datastream/OBJ/view