Characterizing the multi-risk with respect to plausible natural hazards in the Balasore coast, Odisha, India: a multi-criteria analysis (MCA) appraisal

Coastal zones are often prone to several natural hazards, and where the coastal zone has high population density and infrastructural assets, these hazards can render severe loss to both life and properties. The present paper reports a comprehensive assessment of the multi-hazard and multi-risk (keeping in view the population and assets exposed to multi-hazards) in the Balasore coast, situated in the state of Odisha, India, facing the Bay of Bengal immediately to its east. In most of the multi-hazard and multi-risk assessments, the importance of any one hazard in relation to others is often determined arbitrarily. To overcome this limitation, this work presents a multi-criteria analysis implemented on six hazards, namely coastal erosion, storm surge, sea level rise, coastal flooding, tsunami, and earthquake. The respective hazards were ranked according to their relative weight computed by pair-wise comparison, and the overall multi-hazard map of the coast was prepared using weighted overlay technique in GIS environment. In order to assess the exposure, population density and urban assets of the study area were also mapped. Finally, the population and urban density data were overlain on the multi-hazard map in order to derive the final map portraying the multi-risk of the Balasore coast. Coastal erosion and storm surge inundation are the two most substantial natural hazards that regularly affect this coast. It is also observed that hazard from the perspective of coastal erosion is spatially concentrated along the central part of the coast, while in the southern part, the effect of storm surge is higher. The area in and around Chandipur, which is situated in the central portion of the Balasore coast, has been found to have the highest multi-risk, which also happens to be a popular tourist destination.