Wave structure interaction and wave run-up on beaches and/or dunes require complex models capable to deal with steep and emerged slopes such as 3D RANS-VOF models . To limit the computational effort while modeling a number of scenarios, the approach adopted here combines an original procedure developed for propagating waves from off-shore to the sea ban with the MIKE 21 Flexible Mesh modeling suite developed by DHI for propagating the flood starting from the shoreline.
Waves are transferred for a given tidal range from offshore to the shore, following the method by Goda and including wave reduction due to structures where applicable . The 2% wave run-up on the beach is then estimated from the formula by Stockdon, Holman, Howd, and Sallenger , where the original formulation is modified to include the transmitted wave height inshore the mitigations and the local wavelength. A random-phase Gaussian process is finally generated having 2% characteristic value consistent with the value of the 2% run-up derived from this formula. This process is combined with the constant tidal and storm surge level to produce the varying water level in time that is provided as input to the flooding model.
