The Mississippi delta and hurricanes: implications of global climate change, energy scarcity, and societal change.
Day, John*,1, 1 Louisiana State University, Baton Rouge, LA
ABSTRACT- The passage of Katrina resulted in winds in excess of 150 mph and a tidal surge southeast of New Orleans of nearly 20 feet. Levees in the eastern part of the city were overtopped and some levees protecting the city from Lake Pontchartrain failed. Eighty percent of the metropolitan area was flooded and an estimated 90% of homes were destroyed or damaged. In addition to damage to developed areas, the hurricane affected coastal ecosystems. Over 100 km2 of wetlands were altered or destroyed in the Breton Sound coastal basin southeast of New Orleans. These impacts were not just a natural disaster, but were strongly exacerbated by the effects of human activities. Not only is the City of New Orleans built on reclaimed wetlands that have subsided by up to 5 m, but also over 25% of coastal wetlands disappeared in the 20th century. This reduced the storm buffer capacity of coastal wetlands. The loss of coastal wetlands is due to a combination of isolation of the river from the delta plain and pervasive hydrologic alteration. Numerous scientists and managers have concluded that effective storm protection is not possible without effective coastal restoration. This restoration will include reconnecting the river to the delta plain and hydrologic restoration. An important part of this restoration is closing or restricting canals such as the Mississippi River Gulf Outlet that contributed to the flooding. Two factors that must be considered in restoring the coast are global climate change and energy cost and availability.
Key words: Hurricane Katrina, ecosystem restoration, coastal wetlands
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