COASTAL VULNERABILITY INDEX

The coastal vulnerability index (CVI) presented here is the same as that used in Thieler and Hammar-Klose (1999) and is similar to that used in Gornitz et al. (1994), as well as to the sensitivity index employed by Shaw et al. (1998). The CVI allows the six physical variables to be related in a quantifiable manner that expresses the relative vulnerability of the coast to physical changes due to future sea-level rise. This method yields numerical data that cannot be equated directly with particular physical effects. It does, however, highlight areas where the various effects of sea-level rise may be the greatest. Once each section of coastline is assigned a risk 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;



where, a = geomorphology, b = shoreline erosion/accretion rate, c = coastal slope, d =relative sea-level rise rate, e = mean wave height, and f = mean tide range.
The CVI values reported here apply specifically to Cape Cod National Seashore. Thus, absolute CVI values given for other coasts and parks are not directly comparable to the data presented here. To compare different coastal parks, the national-scale studies should be used (Thieler and Hammar-Klose, 1999, 2000a, 2000b). In addition to the CVI values, the data ranges are also subdivided using values different from other studies so that the values used here reflect only the relative vulnerability along this coast. We feel this approach best describes and highlights the vulnerability specific to each park.