EFFECTS OF DREDGE HOLES ON THE SHORELINE CHANGEIN THE BLACK SEA

摘要

Marine dredging, whether for terrestrial construction or beach nourishment, canrnalter sediment transport patterns and lead to local beach erosion. The resulting dredge holernalters sediment transport both through direct and indirect effects. The direct effect isrnassociated with infilling of the pit from beach sediments, and represents a net loss from thernbeach, whereas the indirect effect arises from project-induced wave transformation that altersrnlongshore sediment transport patterns and results in a redistribution of sand along the beach. Arnmethodology is presented for assessment of both effects, based on long-term, hindcast waverndata. By systematically adjusting parameters of the dredge pit (length, width, depth), it isrnshown that a long (in the longshore direction), thin pit, with tapered sides, minimizes thernindirect effects, whereas increasing the project relative depth (a function of the incident wavernclimate) is the best way to minimize the direct effects. A site at Kilyos, on the Turkish BlackrnSea coast west of the Bosphorus Strait, is considered as a case study.