Changes in the Sediment Transport Pattern after Breakwater Extension at Anmok Port, Korea

The breakwater extension at Anmok Port has resulted in erosional stresses along the shoreline immediately south of the port. In this study, the downdrift affects caused by the breakwater extension are investigated through both analytical and numerical model approaches. The analytical approach is accomplished through littoral drift vectors which are estimated in this study from measured volumetric changes by using an inverse matrix. The model has five components including a parabolic equation for wave transformation from the deep ocean to the coastal region, depth-integrated shallow water equations for calculating coastal current, diffusion-advection equations for sediment transport and a mass conservation equation of bottom-layered sediments for predicting depth changes. Analyses of sand transport processes in the vicinity of Anmok Port resulted in the conclusion that a heavy eddy generated in a sheltered zone is the predominant erosion mechanics at the site and therefore, the bypassing system is considered as a necessary device in order to basically solve the concurrent problem such as heavy accumulation of sediments in a port entrance and the closure of a stream mouth in the east coast as well as the eroding problem.