Abrasion at the Sipora island

Abrasion often strikes coastal areas, especially small islands. Coastal abrasion and damage are inseparable and also affect each other. Severe abrasion can cause coastal damage and vice versa, coastal damage can trigger abrasion. Abrasion is the process of beach erosion due to destructive waves and currents. Abrasion can be caused by various factors. Sipora Island is the outermost small island of Indonesia, part of the Mentawai Islands, which is in the western waters of West Sumatra Province. This island is prone to earthquake and tsunamis because it is located on the collision path of the active Eurasian and Australian Indian tectonic plates. Abrasion at The Sipora Island reduced coastal areas, caused tidal floods and damage to infrastructure roads and houses. However, Sipora Island is a world tourist destination because of its natural beauty, white sandy beaches, underwater scenery and surfing. To prevent more damage and prioritize coastal management, this research was carried out. This study aims to determine the level and area of the abrasion and coastal damage on The Sipora Island. The method is using the abrasion criteria of the Coastal Vulnerability Index and Indonesia regulation about Coastal Damage Assessment. The field survey was conducted in August and October 2020 using the purposive sampling at Kampung Dusun, Tua Pejat, The Sipora Island. The results shows that the area of abrasion is 1,608 m2, the abrasion rate is 3.73 m/year (year 2012-2018), which the level of coastal damage is heavily damaged and classified into priority rehabilitation action.