High-Resolution Analysis of Sea Level Rise

Challenge: EPA Office of Climate Change needed help to communicate the gravity of potential sea level rise predicted to accompany global warming. Choosing to apply GIS – a relatively new technology approach - to sea level rise improves the EPA’s ability to (a) identify impact areas, (2) target limited resources to vulnerable areas, (3) prepare adaptation plans, and (4) raise awareness and communicate the need to adapt, in a clear manner to the public

Solution: ICF GIS Lab staff combined current wetland, shoreline digital elevation and stream information, projected state-level shoreline protection data, and ocean height models from tidal station information to develop models and maps of future shorelines as well as estimates of the projected land use and population impacts.

Initially, ICF Consulting seamed together U.S. Geological Survey prefabricated, digital elevation models to determine which lands were most likely to be inundated. While the raw base data did contain obvious errors, it was a first in doing sea level rise modeling. ICF developed this model initially for the entire East Coast and Gulf Coast, and then applied it to West Coast.

The resulting 1:250,000 scale map series showed with great clarity where sea level rise impacts may occur. These maps of sea level rise scenarios were developed for optimal Internet display, as well as for color and for black and white hardcopy production. In addition, the ICF staff developed statistics detailing the amount of people, urban areas, and land use types to be impacted with the given sea level rise scenarios. In a follow-up to the above study, the ICF GIS Lab has developed a new, higher resolution model based on 1:24,000 scale maps. Statistics were also developed here to tabulate the area of wetland gained, lost, and sustained.

Benefits: ICF Consulting’s maps have appeared in the New York Times January 1, 2000 issue, and were featured in a cover story for Time magazine on global climate change. These maps are compelling because they show that inundation will likely occur in areas that we care about – such as in the Florida Everglades and nearby beach resort areas. Future rounds of analysis will include more factors such as storm surge and erosion on the impact of sea level rise. Check out EPA’s Global Climate Change Web site to see the coarse scale 1:250,000 maps from the initial study at http://www.epa.gov/globalwarming/publications/impacts/sealevel/maps