INVESTIGATION OF THE EFFECTS OF PLANT VARIETY AND SOIL SEDIMENT TO THE COASTAL ABRASION IN WEST SUMATRA

Indonesia has many islands that are suffering from beach abrasion. This phenomenon has been often happening and is categorized in one of the National Disasters. West Sumatra beaches with the total length of about 600 km stretch along the west side of Sumatra Island where directly opposite to the Indian Ocean. The waves from the Indian Ocean in any circumstance may cause abrasion to damage houses and public facilities. Factors that affect coastal abrasion include coastal geometry, wave parameters, soil sediment and beach plantations. An investigation on the plant species and soil sediment on the West Sumatra beach has been done. The effects of the last two factors on beach abrasion are then elaborated in this paper. It is found that some beach vegetations have shown remarkable role to reduce abrasion impact. Meanwhile, the type of soil sediments in which associated with physical properties showed also significant effect. From this study, it was found that vegetation roots will protect the beaches together with the soils. This investigation also concludes that coastal endemic plants in the West Sumatra need to be explored as a mitigation action to reduce the abrasion impact.