Print Email Facebook Twitter Shoaling and shoreline dissipation of low?frequency waves Title Shoaling and shoreline dissipation of low?frequency waves Author Van Dongeren, A. Battjes, J.A. Janssen, T. Van Noorloos, J. Steenhauer, K. Steenbergen, G. Reniers, A. Faculty Civil Engineering and Geosciences Department Hydraulic Engineering Date 2007-02-13 Abstract The growth rate, shoreline reflection, and dissipation of low?frequency waves are investigated using data obtained from physical experiments in the Delft University of Technology research flume and by parameter variation using the numerical model Delft3D?SurfBeat. The growth rate of the shoaling incoming long wave varies with depth with an exponent between 0.25 and 2.5. The exponent depends on a dimensionless normalized bed slope parameter ?, which distinguishes between a mild?slope regime and a steep?slope regime. This dependency on ? alone is valid if the forcing short waves are not in shallow water; that is, the forcing is off?resonant. The ? parameter also controls the reflection coefficient at the shoreline because for small values of ?, long waves are shown to break. In this mild?slope regime the dissipation due to breaking of the long waves in the vicinity of the shoreline is much higher than the dissipation due to bottom friction, confirming the findings of Thomson et al. (2006) and Henderson et al. (2006). The energy transfer from low frequencies to higher frequencies is partly due to triad interactions between low? and high?frequency waves but with decreasing depth is increasingly dominated by long?wave self?self interactions, which cause the long?wave front to steepen up and eventually break. The role of the breaking process in the near?shore evolution of the long waves is experimentally confirmed by observations of monochromatic free long waves propagating on a plane sloping beach, which shows strikingly similar characteristics, including the steepening and breaking. Subject low-frequency wavessubharmonic gravity waveslong wavessurf beatwave generationlaboratory experiments To reference this document use: http://resolver.tudelft.nl/uuid:e5dea466-2037-4f2f-9c5e-a6275b7676f4 DOI https://doi.org/10.1029/2006JC003701 Publisher American Geophysical Union ISSN 0148-0227 Source http://europa.agu.org/?view=article&uri=/journals/jc/jc0702/2006JC003701/2006JC003701.xml Source Journal of Geophysical Research, 112, 2007 Part of collection Institutional Repository Document type journal article Rights (c) 2007 The Author(s); American Geophysical Union Files PDF Battjes_2007.pdf 701.66 KB Close viewer /islandora/object/uuid:e5dea466-2037-4f2f-9c5e-a6275b7676f4/datastream/OBJ/view