Quantitative approach on erosion hazard, vulnerability and risk assessment: case study of Muriganga–Saptamukhi interfluve, Sundarban, India

The present research work determines the coastal erosion risk of Muriganga–Saptamukhi estuarine interfluve of western Sundarban. Risk assessment incorporates both hazard and vulnerability, which were assessed by construction of indices. The hazard index incorporates the extent and intensity of coastal and estuarine bank line erosion over time. Vulnerability index on the other hand is comprised of hydrogeomorphic exposures such as geology, relief, near-bank depth, mean tidal range, average surge height, socioeconomic susceptible elements including population growth rate, household density, proportion of agricultural land and structural and non-structural adaptive capacities like the literacy rate, availability of banking and credit facilities, embankment properties, presence or absence of marginal mangrove forest cover. The composite risk of each section can be determined by using the individual risk classes. The analysis concluded that southern coastal tracts and exposed marginal parts of the estuarine interfluve regions are more risk-prone. The composite risk assessment is thus a relevant and practical tool that can be utilized using large number of elements for coastal management.