Development of a regional-scale erosion vulnerability assessment approach along a human-intervened coast–a case study from the southern part of Kerala, India

Abstract

The coastal district of Thiruvananthapuram, situated in the southern part of the state of Kerala, is endowed with sandy beaches, majestic cliffs, scenic backwaters and rocky promontories, aside from hosting a sizeable coastal population, well-known tourist attractions, unique biodiversity, and numerous developmental activities. However, erosion is one hazard that gravely impacts these zones, disturbing the coastal environment and affecting the lives of thousands residing in these regions. The present study attempts to identify the critical vulnerable areas to erosion, considering the combined influence of hazard parameters, i.e. drivers of erosion and risk parameters, i.e. the assets at stake. A multi-criteria decision-making approach, integrated with expert ranking, is adopted in the present study to identify and classify the vulnerable stretches, demanding urgent intervention to prevent further erosion and safeguard vital resources. The results indicate that approximately 10% of the coast falls under low vulnerability, 77% under medium vulnerability, 12 % under high vulnerability, and 1% under very high vulnerability. The coastal reaches of Shangumugham and Anchuthengu are identified as highly vulnerable and in urgent need of intervention. The spatial distribution of vulnerability necessitates a focused and site-specific management plan to tackle the present and possible erosion issues and protect critical resources. © 2025 Indian Society for Hydraulics.