Vulnerability assessment through index modeling: a case study in Muriganga–Saptamukhi estuarine interfluve, Sundarban, India

Abstract

The coastal regions, deltas, and estuaries are severely affected by the sea level rise and cyclonic activities and climate changes. Sundarban delta is one of the most mysterious landscapes in the world, which has successively evolved due to sediment accumulation by the great Ganga and Brahmaputra river system. The area is characterized by low-lying islands and a flat topography coupled with macro-tidal activities, powerful surges, and seasonal cyclonic events. All these conditions put together this landscape defenseless to frequent flood and erosion. Since the last hundred years, the face of Sundarban has been changed remarkably from wildest to human-occupied territory by protecting this low-lying flat plain from tidal inundation through artificial embankment. In this background, the current study attempts to highlight the spatial extent and magnitudes of internal risk factors of the region using the composite vulnerability index. Coastal vulnerability defines a system’s openness to flood and erosion risk due to hydrogeomorphic exposures and socio-economic susceptibility in conjunction with its capacity/incapacity to be resilient and to cope, recover, or adapt to an extent. Coastal vulnerability assesses the potential risk from erosion and flooding of any low-lying coastal region due to its physiographical and hydrological exposures, socio-economic and political susceptibility, and resilience capacity. A natural system affects the socio-economic scenario of any region. Hence, multidimensional databases can be more effective to understand the extent of exposure, susceptibility, and resilience of any system. To throw some light on the situation of vulnerability of western estuarine Sundarban, between Muriganga and Saptamukhi interfluve, the composite vulnerability index has been carried out to delineate the magnitude and spatial extent of vulnerability with the help of quantitative techniques and geospatial tools. The estuarine tracts and coastal parts of the Ganga delta are two of the most densely populated areas in the world. The study highlights the critical situation of the population under different potential risk classes residing in the study area with the intention of suggesting some proper course of action of planning and management to conserve coastal communities in their original habitat.