Relationship of Coastline and Mangrove Area in West Rangsang - Indonesia

Abstract

The coastal zone of West Rangsang is part of the Kepulauan Meranti regency, which directly faces Malacca Strait, which is one of the most crowded channels in the world. However, its shoreline is an open coast, which mostly undergoes local erosion as the defensive areas, encompassing coral rock and mangrove forest, are fragmented by nature and human exploitation. Therefore, this study aimed to investigate the relationship between the damaged coastline and the mangrove area changes in West Rangsang for the past 20 years. We propose a remote sensing method by satellite imagery to evaluate the coastline changes and the mangrove. Each year, the coastline positions were obtained using data processing involving geometric calibration, image cutting, and extraction. The changes were analyzed by inter-crossing the images of 1997 and 2017, further divided for four periods, i.e., 1997–2002, 2002–2007, 2007–2012, and 2012–2017. The results showed that varying erosion and accretion rates were due to shoreline exposure, strongly associated with the mangrove forests' devastation. However, this caused the physical function loss as an anchor against the coast's wear-out and as a breaker of waves and current approaching the island from the ocean. The stakeholder may use these research results to appropriate measures, such as replanting and creating mangrove-care societies, to conserve and maintain the coast.