Thursday, June 26, 2008

Manmade flooding on the Mississippi?



I'm back at work, alive, but only barely because I have to give up caffeine for a while.

Our SIUC colleague Nicholas Pinter was quoted in an excellent article by Micheal Grunwald in TIME magazine today. Grunwald takes the US Army Corps of Engineers to task for its management of the Mississippi River:

Professors Nicholas Pinter of Southern Illinois University, Robert Criss of Washington University and Timothy Kusky of Saint Louis University have calculated that Corps structures are stacking up water during floods — as much as two meters around Winfield, Mo., and nearly six meters around Grand Tower, Ill. "River engineering is the 800-pound gorilla driving these flood levels higher," says Pinter, who oversees the database and wrote the March 4 letter. "We're not talking inches higher; we're talking meters higher."

Pinter and others argue that levees and navigation structures on the Mississippi have substantially raised flood elevations--that a given discharge results in a higher elevation and more flooding because of these structures.

Much of the criticism centers on the modeling methods the Corps uses, especially studies like this one using what they call Micromodeling. The Corps micromodels are little different from our Emriver models, and many scientists, including the author of this 2006 Journal of Hydraulic Engineering article, believe that they are not at all appropriate to use for modeling flood elevations on rivers of any size, let alone the Middle Mississippi.

Having much experience with the plastic media used in these models, I strongly agree. The models are wonderful simulators, and can do some predictive modeling, but not of flood stages on the Mississippi River.

All in all, if Pinter and others are right, the Corps structures, along with likely increases in frequency and magnitude of flood flows from climate change, are bad news for Mississippi River floodplain dwellers.

Quite a few good links with this Google search.

The illustration is from Fisk's monumental 1944 study of the Mississippi River. Downloads of the report and its beautiful maps here.

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