CHAMPAIGN, Ill. Researchers could have a new method to rebuild wetlands of the Louisiana delta, thanks to a chance finding while monitoring severe flooding of the Mississippi River.
A team of civil engineers and geologists from the University of Illinois, in collaboration with the U.S. Army Corps of Engineers, published their findings in the journal Nature Geoscience.
In the spring and summer of 2011, high floodwaters on the Mississippi prompted the corps to open the Bonnet Carre spillway. The spillway had been built to divert water from urban New Orleans after flooding in 1927. The Illinois team saw in the spillway opening a chance to study how much sand flowed from the river into the spillway wetlands.
"Whenever we have such natural disasters, it stresses the human system quite a bit," said Praveen Kumar, a professor of civil and environmental engineering at the U. of I. "But it also offers an opportune time to look at some scientific questions that we might otherwise not be able to explore."
Armed with funds from the National Science Foundation, the researchers went to the spillway site to monitor the sand diverted from the river to the delta wetlands. They discovered a surprising dichotomy: a mere 10 to 15 percent of water from the top of the river sloshed into the spillway, but an estimated 36 to 41 percent of the river's sand load deposited into the Bonnet Carre.
"That was a completely unexpected finding in this particular study," said postdoctoral researcher Jeffrey Nittrouer. "I think one of the real strong outcomes that came from this particular study is that we happened to be lucky about where the site was placed. Back when the structure was built, the Army Corps of Engineers just wanted to get water out of the river. But it turns out that where they decided to place the spillway was a fantastic location for getting sand out as well."
The findings were exciting to the team, because divert
|Contact: Liz Ahlberg|
University of Illinois at Urbana-Champaign