Abstract
Low-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 elevation 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 also strongly 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 revealed that short waves dominated bottom stresses on the forereef and near the reef crest; however, inside the lagoon, infragravity waves become increasingly dominant, accounting up to 50% of the combined bottom stresses.
Original language | English |
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Title of host publication | Proceedings of the 33rd International Conference on Coastal Engineering 2012 |
Editors | Patrick Lynett , Jane McKee Smith |
Place of Publication | United States |
Publisher | Coastal Engineering Research Council |
ISBN (Print) | 9780989661119 |
Publication status | Published - 2012 |
Event | 33rd International Conference on Coastal Engineering 2012, ICCE 2012 - Santander, Spain Duration: 1 Jul 2012 → 6 Jul 2012 |
Conference
Conference | 33rd International Conference on Coastal Engineering 2012, ICCE 2012 |
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Country/Territory | Spain |
City | Santander |
Period | 1/07/12 → 6/07/12 |