Physical and social vulnerability to coastal erosion: An assessment of Kalutara Coastal Belt, Sri Lanka

Abstract

The shoreline of Kalutara, Sri Lanka has become more prone to erosion because of environmental changes caused by natural and anthropogenic factors including climate change. The study aimed to assess and map the physical and social vulnerability to coastal erosion in the shoreline between the Kalu and Bolgoda River mouths in Southwest Sri Lanka. This study relied on secondary data sources such as topographic, digitized, and satellite maps obtained from the Survey Department and the website of the United States Geological Survey (USGS). The Coastal Vulnerability Index (CVI) was calculated using only five variables namely coastal slope, geology, soil, shoreline change (End Point Rate), and Land Use and Land Cover (LULC). On the other hand, for the Social Coastal Vulnerable Index (SVI), several socioeconomic variables were examined. Kalutara North and Thotupala have been identified as having a higher risk of Physical and Social Coastal Vulnerability. This research, therefore, revealed that the coastal zone along Kalutara – Panadura in Sri Lanka is vulnerable both physically and socially due to the accelerating rate of coastal erosion. Because of the potential effects of climate change and rising sea levels, this scenario would pose a serious threat to the environment and communities in the foreseeable future.