To assist in this planning process an index of socioeconomic development was combined with a coastal vulnerability index (CVI) to produce a new economic vulnerability index (EVI) for the U.S. coastal zone. The EVI considers both physical (e.g. mean wave height, elevation) and socio-economic variables (e.g., population density, housing values) in determining the relative economic impact of inundation or coastal erosion (Table 1). This is the first such index to consider the U.S. East, Gulf, and West Coast as an integrated unit.
The EVI answers two questions, what coastal areas are at risk and what would be the relative (to all coastal counties) economic and social impact of their loss. Thus, the EVI may be used to target limited research, planning, and construction funds to areas where the economic cost of abandoning the shore may approach or exceed the cost of holding the coast in place.
Very Very Coast Low Low Moderate High High
EVI East 15.2 24.5 18.0 20.7 21.7 Gulf 21.5 19.0 25.9 25.9 7.8 West 26.8 15.3 14.8 11.5 31.7 CVI East 20.1 25.1 17.6 29.4 7.7 Gulf 1.5 5.9 7.8 22.4 62.4 West 32.2 27.9 21.9 15.8 2.2
The decision to abandon any coastal area to the sea is complicated by many conflicting interests. For example, local property owners have a vested interest in protecting their land, as do city and county governments who may lose tourism dollars if their beaches and historical coastal sites are inundated or washed away. State governments and federal agencies, on the other hand, could be expected to attempt to take the least-cost path. Unfortunately, individuals and local governments often do not have the resources needed to take proactive measures (relatively low cost) to prevent the loss of their high value assets. As a result, state governments and federal agencies are lobbied to assist in rebuilding the beach, building the seawall, or moving the building (high cost) before their catastrophic loss.
The EVI provides some of the information needed to make these recommendations in advance. Other information needed for the decision-making process includes an estimate of the costs associated with implementing the most appropriate mitigation measure (e.g., beach nourishment). With such information policy-makers will have the information necessary to make defensible least-cost decisions years or decades prior to the actual loss.
Carbon Dioxide Information Analysis Center
Environmental Sciences Division
Oak Ridge National Laboratory
Oak Ridge, Tennessee 37831-6335
Phone: (423) 574-0390 or 241-4846
Gornitz, V.M., Daniels, R.C., White, T.W., and K.R. Birdwell. 1994. The development of a coastal risk assessment database: Vulnerability to sea-level rise in the U.S. Southeast, pp. 327-338. In Coastal Hazards: Perception, Susceptibility and Mitigation, Finkle, C.W. Jr. (ed). Special Issue No. 12, The Coastal Education and Research Foundation, Fort Lauderdale, Florida.