Wave concentration by a navigation channel

Navigation channels are often dredged in harbours to cater for increasing ship sizes. These abrupt changes in the topography affect the wave propagation to a large extent. Because of the wave refraction by the side slopes of a channel, wave concentration at the sides of the channel occurs. This may be critical to the design of the channel. On the other hand, sea waves are random and multi-directional, and the wave propagation in coastal regions is a non-linear process. Recent efforts have extended the range of application of the classical Boussinesq equations to greater depths. The improved equations give a better description of wave propagation in shallow water. In this paper, a numerical model based on the modified Boussinesq equations is used to simulate the wave propagation over a topography with a navigation channel. The effects of the channel on the wave propagation and the wave distribution in a harbour are numerically investigated. The abrupt changes in topography can dramatically change the wave distribution and cause wave concentration at some locations. These phenomena should be given special attention in harbour design.