USING A SUBMERGED ARTIFICIAL REEF AS COASTAL PROTECTION IN A BI- DIRECTIONAL WAVE CLIMATE

Sandy beaches are eroding all over the world. Methods to protect the beaches vary from soft methods, such as sand nourishments, and hard structures such as groins and detached breakwaters, which can be both emerged and submerged. Submerged breakwaters have been used at a variety of locations, but experiences relating to their performance are varying. Some locations have experienced accretion behind the breakwater as desired but in other locations the submerged breakwaters have contributed to erosion (Lamberti et al., 2005). Most research involving the effect of submerged breakwaters on the neighboring shorelines have involved waves coming perpendicular to the shoreline, which may cause accretion or erosion, or at an oblique dominant angle, where the shores will typically accrete behind the breakwater and upstream, but will erode downstream of the breakwater (Ranasinghe et al., 2010). Using a numerical model, it will be investigated whether a submerged artificial reef exposed to the wave climate at Samsoe could be beneficial for protecting the area threatened by erosion, while limiting erosion of the nearby shorelines by spreading the erosion of sand over a long stretch both north and south of the reef.