Determination of vulnerable zones along Brahmapur coast, Odisha using AHP and GIS with validation against multiple cyclones.

The Brahmapur is the southernmost sub-division of Ganjam district of the Odisha coast frequently prone to cyclones. This coastal stretch is one of the low-lying areas of Odisha with dense population. Recent severe cyclones such as Phailin and Titli crossed the considered coastal stretch in 2013 and 2018 respectively causing severe damages to life and property. Identification of the coastal vulnerability index of such low lying areas is vital to plan effective mitigation measures and better preparedness to hazards. In this view, the Coastal Vulnerability Index (CVI) of the coastal stretch was attempted in the present study using analytical hierarchical process (AHP). The Physical Vulnerability Index (PVI) and Social Vulnerability Index (SVI) were integrated to obtain the Coastal Vulnerability Index. The approach of the study included pair-wise ranking of parameters based on their relevance and importance to the objective of the study. The CVI assessment indicated 22.2% of the coastal stretch with very high risk, 44.5% with high and 24.4% with moderate risk stretches with discontinuous small stretches of 9% with low-risk areas. The outcome of the study was validated with the cyclone crossing tracks of Phailin and Titli which exhibited good correlation with the CVI zones identified from the study. The determined vulnerable zones are useful for mitigation measures and better preparedness during such cyclone hazards in future. Advance techniques of Remote Sensing and Geographic Information System (GIS) integrated spatially with AHP derived data were used in the present study.