Effects of breaking-induced currents on refraction-diffraction of irregular waves over submerged shoal

Abstract

To investigate the accuracy degeneration of conventional wave models for the case of breaking waves over a shoal, a system of numerical models is constructed by combining wave and flow models. The wave model employs the parabolic equation considering wave and current interaction. The flow model employs the shallow water equations including radiation stresses of waves. Numerical tests show that the breaking waves induce jet-like strong currents behind the shoal, and the currents, in turn, defocus the waves. As a result, the calculated wave height distribution agrees much closer to the measured data than that obtained using conventional wave models. Thus the effect of breaking-induced currents on the refraction-diffraction of waves over a shoal is clearly understood. (C) 2003 Published by Elsevier Ltd.