Coastal Vulnerability Index
CVI is an index that expresses the relative vulnerability of the coast to physical changes due to future sea-level rise. It highlights areas where the various effects of sea-level rise may be the greatest. Once each section of coastline is assigned a vulnerability value for each specific data variable, the coastal vulnerability index (CVI) is calculated as the square root of the product of the ranked variables divided by the total number of variables;
a = geomorphology
b = shoreline erosion/accretion rate
c = coastal slope
d =relative sea-level rise rate
e = mean wave height
f = mean tide range.
The calculated CVI value is divided into quartile ranges to highlight different vulnerabilities within the area of interest. The index high value means very high vulnerability is different for different areas.
In first half of 2012, the comprehensive ‘Coastal Vulnerability Index’ (CVI) Atlas has been brought out by the Indian National Centre for Ocean Information Services (INCOIS). Using data from satellites, simulated models, tide gauges and Shuttle Radar Topography Mission (SRTM) of the United States, INCOIS prepared this Atlas, which determines the relative risk to coastline due to future sea-level rise. This was for the first time, such an Atlas has been done at the national level. Based on seven physical and geological parameters, the Atlas has classified the areas along the coastline in terms of very high risk, high risk, medium and low risk to future sea-level rise. The seven parameters used are: tidal range, wave height, coastal slope, coastal elevation, shoreline change, geomorphology and historical rate of sea-level change.