Coastal vulnerability differentiated according to geospatial quartiles method: Rasulpur to Subarnarekha estuary, east coast of India

The coastal stretch of Rasulpur to Subarnarekha estuary approx. length of 70.42 km is potentially exposed and vulnerable due to coastal erosion along Bay of Bengal. The research strives to assess the vulnerability degree using composite index by geospatial quartiles system. Six triggering parameters (elevation, distance to river estuaries, land use/land cover, coastal slope, distance to coastline and historical shoreline change rate) are combined for Coastal Vulnerability Index (CVI). The resulting values have been classified with 4 CVI classes (very high, high, moderate and low vulnerability) according to quartiles statistics. The research demarked that half of the shoreline fell under moderate (CVI rank 2) to very highly vulnerable class (CVI rank 4). The degree of vulnerability along study area varies between 0.57 and 33.54 by CVI calculation. The shoreline of Old Digha, Rasulpur estuary, Digha estuary, Mandarmani estuary and Mandarmani has been fallen under rank 4. Rank of 3 is identified Udaipur, New Digha, Beguran Jalpai, Junput, Bankiput and Talsari. A few important beaches are identified under moderate vulnerable rank (Chandpur and Subarnarekha estuary). Only in three shorelines are found as low vulnerable index i.e., Shankarpur, Tajpur and Dadanpatrabar. The outcomes of vulnerability also provide valuable insightful information to coastal planners and decision makers for formulating the new strategies that are suitable for the study area and that also helpful for sustainable coastal management.