WEST SUMATRA COASTLINE CHANGE DUE TO ABRASION PROTECTION STRUCTURES: PADANG BEACH

The abrasion disaster that has resulted in remarkable coastline changes is one of the national disasters that concern the Indonesian government. The West Sumatra Government which has a significant long beach has made many abrasion prevention structures to stop loosing of hundreds of meters of land due to abrasion. In fact, the abrasion prevention structures not only protect the beach but on the other hand they also change the shape of the beach. A field study has been conducted and found that beaches that have been protected with abrasion prevention structures are susceptible to changes in shape. On the one side, the change provides benefits but on the other hand, it causes a new problem. This paper explains the relationship between the dimensions of the coastal abrasion prevention structure and the properties of adjacent beach sediment related to the shoreline changes occurring in West Sumatra. This study is very important to provide a prediction of shoreline changes due to the prevention of abrasion related to the beach soil properties. The result can be used to determine the precise abrasion prevention structures in accordance with the conditions of sediment on the beach for a future expected change.