Breaking Waves Propagating Over a Shoal

Abstract

Spectral evolution of breaking and nearly breaking waves propagating over a submerged trapezoidal bar has been investigated in laboratory experiments. It is found that wave breaking itself does not play a crucial role in the evolution of the spectral shape, but contributes simply by extracting energy roughly in proportion to the local spectral density. For nonbreaking waves, a Boussinesq model with improved dispersion characteristics is found to simulate the wave evolution very well. On the basis of these findings, it is suggested to combine a semi-empirical model for the overall energy dissipation with a nondissipative Boussinesq model so as to obtain a model for simulation of spectral evolution of breaking waves.