Vulnerability assessment of mangrove areas in coastal West Bengal, India

Abstract

In the era of climate change, coastal areas are more susceptible to global warming-related problems like increasing atmospheric and sea surface temperature, increasing frequencies of cyclones, sea-level rise, etc. In these circumstances, vulnerability analysis in coastal regions is of utmost importance to mitigate the impact of multiple hazards and protect coastal resources. Mangroves act effectively as a bio-shield to protect the coast and its hinterland. However, mangroves are themselves under threat due to natural and anthropogenic causes. The study is an attempt to analyze vulnerability along the coastal region of West Bengal, where eight dynamic parameters, viz., geomorphology, rate of shoreline change, sea level rise, regional elevation, coastal slope, bathymetry, mean tidal range, and mangrove density were classified and ranked to calculate grid-wise coastal vulnerability index (CVI) and mangrove vulnerability index (MVI) using geospatial techniques. Based on the index scores, the entire coastal area was divided into five vulnerable zones. The result shows 32.94% of coastal grids and 41.33% of mangrove grids along the coast are under high to very highly vulnerable zone. The result also highlights that mangrove-dominated islands, viz. Thakuran Reserve Forest (RF), Bulchery Island, Dulibhasani RF, Dalhousie Island, Bhangaduni, and Gosaba RF are under severe threat. The vulnerability maps created in this study would be a valuable guide to coastal planners for the sustainable management of the coastal mangrove ecosystem.