Saturday, May 26, 2007

New Orleans

The first of a long series of posts from last week's trip to the Gulf Coast for the Coastal Sediments Conference. The meeting kept me in the city until Thursday, but then I took a couple days on my own to explore the aftermath of Katrina and the shoreline between N.O. and the Florida Panhandle. There are more pictures and travellog on my hshipman blog.

I found a good view of the Mississippi from the 11th floor lobby of the Wyndham Hotel. New Orleans is about 100 miles above the Gulf of Mexico and the river has been effectively locked into a surprisingly narrow channel - the river is much wider farther upstream, although also much shallower. The river is the high point of the local landscape - a narrow canal following a meandering ridge of high ground through a low-lying delta and even lower-lying neighborhoods that are now below sea level and dry only by virtue of dikes and pumps.

The lower Mississippi does something called delta-switching every thousand years or so, when its existing path to the sea becomes too difficult and a better route presents itself. Had Europeans and industrial-age engineering not arrived on the scene, the Mississippi would probably have jumped to the Atchafalaya drainage (farther west) sometime in the past century or so. The forces driving this switch will continue to increase with time, and the only thing keeping the river in New Orleans is the Corps of Engineers, lots of money, and the inertia of human development. Too bad cities and petrochemical plants and oystermen aren't able to move as the landscape beneath their feet moves. In southern Louisiana, phrases like sustainability and adaptability and "out-of-equilibrium" kept nagging me.

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