Morphological modelling: A tool for optimisation of coastal structures

This paper discusses the problems of sedimentation in the entrance to a fishery harbour and its impact on the morphology of a sandy, very exposed coastline. An improved layout of the main breakwaters has been developed. The results obtained from testing the new layout in a morphological modelling complex are discussed. The new layout is expected to lead to improved bypass, decreased sedimentation and coastal impact, and a greater natural depth at the entrance, and to provide safer navigation conditions. The reliability of the modelling results was established through a comprehensive calibration process in which historical morphological development scenarios were successfully simulated. The recommended layout has been constructed and was inaugurated in December 2004. The performance of the new layout seems promising with respect to maintaining the required navigation depth in front of the entrance. However, because of the short operation time since the opening, sufficient quantitative data on maintenance dredging in the outer harbour is presently not available.