Surface Waves and Coastal Dynamics

Abstract

This review covers theoretical advances made during the past decade for predicting or understanding wind-induced waves and associated coastal processes. First, the offshore propagation over many wavelengths is discussed. An effective approximation which permits practical calculations of both refraction and diffraction over a mildly sloping bottom is given. For still longer distances nonlinear effects accumulate to become important; recent progress in the parabolic approximation for the refraction and diffraction of short waves is also reviewed. The nearshore region is discussed and the infragravity waves which are caused by nonlinear interactions of short waves within a narrow frequency band are surveyed. The effects of a gradual or sudden change of depth or a steady current on the modulation of short waves and the generation of long infragravity waves is also discussed. A discussion of infragravity waves which resonate in harbours and the strong resonance of edge waves on beaches is made. The final topics are concerned with the causes and effects of bars and ripples on the seabed.