Preliminary assessment of coastal erosion in Marawila, Sri Lanka

Abstract

Marawila is one of the main coastal areas located in the Puttalam district of Sri Lanka, an island bounded by a coastline. Coastal erosion in Marawila became a noteworthy environmental concern in Sri Lanka. The study was conducted to map the coastal shoreline and to assess the pattern of changes and the rate of changes in the shoreline of the study area, to contemplate conservation measures. Land Remote-Sensing Satellite data and ArcGIS have been used to create thematic maps of coastal erosion. The annual average coastal area erosion rate of the Marawila is +0.05 km2/yr, and it has been estimated that 1.05 km2 of the area changed from 2000 to 2019. Sand mining in Maha Oya and Deduru Oya has increased the erosion vulnerability in Marawila. Although not practiced, ‘rock structure’ assumed to be effective in preventing further erosion. Alternatively, establishing a mangrove belt in the coastal area could dissipate wave action that prevents further erosion. And also, sand nourishment is a promising method to protect coastal areas.