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MODELLING INFRAGRAVITY WAVES AND CURRENTS ACROSS A FRINGING CORAL REEF


Posted on 13 March 2013

TitleMODELLING INFRAGRAVITY WAVES AND CURRENTS ACROSS A FRINGING CORAL REEF
Publication TypeJournal Article
Year of Publication2012
AuthorsVan Dongeren, A, Lowe R, Pomeroy A, Duong TM, Roelvink D, Symonds G, Ranasinghe R
JournalCoastal Engineering Proceedings
Volume1
Issue33
Date Published12/2012
ISSN0589-087X
Keywordsfringing coral reefs, hydrodynamics, infragravity waves, low frequency waves, surfbeat, wave breaking, XBeach
AbstractLow-frequency (infragravity) wave dynamics on a fringing coral reef were investigated using the numerical model XBeach (Roelvink et al, 2009). First, the skill of the one-dimensional model was evaluated based on its predictions of short waves (0.04-0.2 Hz), infragravity waves (0.004-0.04 Hz) and water level measurements (tidal and wave setup) obtained during a 2009 field study at Ningaloo Reef in Western Australia. The model calibration was sensitive to friction coefficients for short waves and current / infragravity bed friction, which were assumed independent in this model study. The infragravity waves were found to be generated primarily in the surf zone through the breakpoint generation mechanism rather than through offshore forcing. The infragravity waves were strongly also modulated over the reef by tidal depth variations, primarily due to the variability in frictional dissipation rates when the total water depth over the reef varied. The results reveal that short waves dominated bottom stresses on the fore reef and near the reef crest; however, inside the lagoon, infragravity waves become increasingly dominant, accounting up to 50% of the combined bottom stresses
URLhttp://journals.tdl.org/icce/index.php/icce/article/view/6882
DOI10.9753/icce.v33.currents.29
Short TitleInt. Conf. Coastal. Eng.