Coastal vulnerability assessment: a case study on erosion and coastal change along Tuticorin, Gulf of Mannar

Abstract

Assessment of vulnerability is essential for identifying and recognizing the coastal livelihood, socio-economic and ecological security status. However, coastal vulnerability assessments require a complex dataset including human and socio-economic factors. In this study, we investigated coastal vulnerability index (CVI) to map the vulnerability of Tuticorin coast toward coastal erosion using remote sensing data and geographical information techniques based on a multi-indicator approach. Gulf of Mannar located along the southeast coast of India and declared as a marine national park with high ecological diversity faces threat due to anthropogenic interventions as a result of industrialization, sand and coral mining, etc. CVI highlights the vicinity where the physical effects may be the greatest. Beach width was considered as an additional parameter, since a large number of coastal habitations were present adjacent to the beach along the study area. Coastal erosion, slope and relative sea level rise are the major factors affecting the coastal vulnerability in Tuticorin. CVI scores were categorized into four classes, viz., low, moderate, high and very high risk. Out of 84-km coastal stretch, 15 % falls under high risk, 12 % moderate vulnerability and 73 % the low vulnerable category. This approach provides an insight to assess the vulnerability and the degree of potential threat to the coastal system in order to prioritize actions and to develop adaptation measures.