CHANNEL CONCENTRATION AND ITS IMPACT ON NEARSHORE WAVE CONDITIONS

Abstract

Channel concentration is an important wave process in coastal regions. It occurs when a shallow water wave approaches a deep channel at a shallow angle, producing a localized region of increased wave height at the edge of the channel, and the early onset of wave breaking. Channel concentration can occur at dredge channels, so is of particular significance to port entrances and surrounding infrastructure, especially for breakwater heads. It also occurs at natural features such as submarine canyons, particularly where the canyon is perpendicular to the coastline. In contrast to refraction or channel reflection, channel concentration is not well documented in the available literature. While studies show wave concentration as a significant coastal process, there is insufficient information on the process to provide general design guidance for its consideration in harbour projects. As such, there is still the need to use design tools such as physical modelling to ensure the site specific wave conditions are characterised correctly.