ABSTRACT Bengkalis island is the main island of Bengkalis Regency, Riau Province, where the district capital is located and is the border between Indonesia and Malaysia. Bengkalis islan. There is a reduction in shoreline(abrasion) in Bengkalis island which can reach 38.03 meter/year and the addition of the shoreline(sedimentation) which can reach 29.77 meter/year.The abrasion and sediment…