Storm surge vulnerability assessment of Saurashtra coast, Gujarat, using GIS techniques

The coastal stretch of Saurashtra, Gujarat, is seriously threatened by storm surges. Hence, assessing the preparedness to storm surge impacts is a major task in coastal disaster management where identification of relative vulnerability of coastal stretches is a prime concern. The aim of this study is to assess coastal vulnerability related to storm surge events along the coastal talukas of Saurashtra coast, by analyzing physical features and demographic variables using Geographical Information System (GIS) techniques. Vulnerability of a taluka is defined in terms of its exposure, sensitivity, and adaptive capacity. We calculated vulnerability of Exposure Index, Sensitivity Index, and Adaptive Capacity Index separately in ArcMap s/w, and the vulnerability map of different indices in the study region was drawn. The Total Vulnerability Index (TVI) is prepared by integrating the above index. The TVI map shows that Kalyanpur, Porbandar, and Talaja talukas are highly vulnerable in comparison with other talukas as they have large area under low-lying, high sensitivity value, and low adaptive capacity value. On the other hand, Diu and Maliya are lower vulnerable due to the presence of rocky/cliffy coast, sand dune, small coastal length and located in elevated region although there exists high population density and built-up area. Our research finding will assist coastal disaster managers and decision makers to plan appropriate measures to minimize the losses due to storm surge impacts.