A Study on Submerged Breakwater Length, Offshore Distance and Crest Width Affecting the Shoreline Response

Submerged breakwater widely perceived to be able to protect shoreline from erosion by leaving no aesthetic issue to the beach comparing to conventional design such as groynes and revetments. There are also multi-functional submerged breakwaters which are excellent in enhancing surfing condition in local beach. However, several literature reviews revealed submerged breakwater built are most likely have erosion than accretion in the lee of the structure. The rare adoption of submerged breakwater often related to its inconsistency in combating erosion problem as the shoreline response to these structures are not well understood at present. Therefore, this study is aimed to identify the shoreline response behind SBW in Kerteh and Niigata. The geometrical ratio of crest width, breakwater length and offshore distance of SBW is then investigated by taking shoreline movement into account. The images are first extracted with Landsat Toolbox and corrected with tidal correction model. Then, DSAS is used to compute the shoreline changes from early 1980s – 2009. The shoreline changes are discussed and the geometrical ratio of submerged breakwater is investigated by relating it to the shoreline response in the leeside of the structure. Result showed that shoreline of Kerteh are generally eroded while accretion is seen behind the Niigata shoreline.