CR 18:205-228 (2001)  -  doi:10.3354/cr018205

Maps of lands vulnerable to sea level rise: modeled elevations along the US Atlantic and Gulf coasts

James G. Titus*, Charlie Richman

Office of Atmospheric Programs, US EPA, Washington, DC 20460, USA
1Mercer (1978), Environmental Protection Agency (EPA) (1983, 1995), National Academy of Sciences (1983, 1985), and IPCC (1990, 1996a) 2See EPA (1995) at 145 (estimating that a 1 m rise has a 1% chance of occurring by the year 2100 and a 50% chance of occurring by the year 2200, along those coasts where sea level is currently rising 18 cm per year, which is the global average rate). See also IPCC (1996a) at 6 (reporting that greenhouse gases alone could raise sea level as much as 85 cm during the period 1990-2100)

ABSTRACT: Understanding the broad-scale ramifications of accelerated sea level rise requires maps of the land that could be inundated or eroded. Producing such maps requires a combination of elevation information and models of shoreline erosion, wetland accretion, and other coastal processes. Assessments of coastal areas in the United States that combine all of these factors have focused on relatively small areas, usually 25 to 30 km wide. In many cases, the results are as sensitive to uncertainty regarding geological processes as to the rate of sea level rise. This paper presents maps illustrating the elevations of lands close to sea level. Although elevation contours do not necessarily coincide with future shorelines, the former is more transparent and less dependent on subjective modeling. Several methods are available for inferring elevations given limited data. This paper uses the US Geological Survey (USGS) 1° digital elevation series and National Oceanic and Atmospheric Administration (NOAA) shoreline data to illustrate the land below the 1.5 and 3.5 m contours for areas the size of entire US states or larger. The maps imply that approximately 58000 km2 of land along the Atlantic and Gulf coasts lie below the 1.5 m contour. Louisiana, Florida, Texas, and North Carolina account for more than 80% of the low land. Outside of those 4 states, the largest vulnerable populated region is the land along the Eastern Shore of Chesapeake Bay stretching from Dorchester County, Maryland, to Accomac County, Virginia.


KEY WORDS: Sea level rise · Maps · Coastal erosion · Digital elevation model · Climate change · Global warming · Greenhouse effect


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