November 8, 2006

Predicting Coastal Vulnerability

Global mean sea level has been rising at an average rate of 1 to 2 mm/year over the past 100 years, a rate significantly larger than that averaged over the last several thousand years and severe weather patterns and tropical storm intensities are predicted to increase in conjunction with global climate change.

Exacerbated by recent disasters such as Hurricane Katrina, many organizations, businesses and media outlets are asking the question of what our coastlines and low-lying cities might look like when impacted by storms and rising sea levels.

ASA has become increasingly involved in mapping the impacts of storm surge flooding. The effort began in Boston, where the National Environmental Trust (NET) commissioned ASA to map the effects of a 100-year storm surge plus 100 years of sea level rise along the downtown coast.

These images were used i a recently released EPA report, "Climate's Long Term Impacts on Metro Boston". ASA then mapped the effects of a Category II hurricane storm surge plus 100-years of sea level rise for Miami, Washington DC, and Manhattan.

These images were released by NET in conjunction with the first Conference of the Parties of the Kyoto Protocol in December 2005. Vanity Fair also published artist renderings of the Washington DC and Manhattan model results in their May 2006 Green themed issue.

The mapping and visualization of the impacts of coastal storms is extremely effective for communicating the vulnerability and risk associated with many coastal areas. Of the 10 costliest hurricanes over the last 50 years, 8 have occurred in the last 5 years.

By mapping the flood zones of real storms, not just the 100-year FEMA design storm, property owners and officials alike can easily visualize the risks associated with actual events and determine how to reduce vulnerability.

To make these tools more available to users and the public, ASA is conceptualizing an inundation module within the COASTMAP framework. The COASTMAP Inundation Module is planned as a web based system that connects to various storm surge models using the COASTMAP Environmental Data Server (EDS).

The EDS imports real-time weather, oceanographic and other environmental data and will run inundation models to generate maps of areas at risk from predicted storm surges. These maps can easily be distributed to the public via a variety of websites, and also automatically emailed to interested parties, including local planners, emergency workers, and television networks.

These maps would allow planners to better allocate resources and to publicize the risk to vulnerable areas while allowing the public to be proactive in preparing for flooding.

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