Monday, May 30, 2011

Satellite images show massive sediment plumes from flooding - CNN.com

(CNN) -- Dramatic satellite images show massive deposits of sediment in coastal Louisiana, the receiving end of the massive flooding on the Mississippi River.

The sediment gush has a down and up side in district known for its seafood and slight wetlands, a federal official said Friday.

The U.S. Geological Survey (USGS) and NASA recently catered the stark imagery of the sediment plumes to the U.S. Army Corps of Engineers and Louisiana to help them with flood rejoinder.

See flooding map from USGS

A map on the USGS website allows users to call up the plumes and penetrate flood file collected by government agencies.

The opening of the Bonnet Carre spillway caused a sediment plume in Lake Pontchartrain above New Orleans. Another plume resulted from the opening of the Morganza Spillway and flooding on the Atchafalaya River. The third is where the Mississippi River meets the Gulf of Mexico.

"We live in historic periods," said Phil Turnipseed, manager of the USGS's National Wetlands Research Center in Lafayette, Louisiana.

The tan and brown feathers resulted from millions of gallons of sediment-laden freshwater rushing to the Gulf through spillways, creek outlets and levees.

Wetland seasonal flooding "is necessity apt the health of coastal wetland ecosystems," according to the USGS. Extreme flooding namely has occurred this annual has delivered tall quantities of sediment and nutrients.

The sediment will hurt the oyster farm in the brackish waters of Lake Pontchartrain, essentially a gulf, Turnipseed told CNN.

"All of this is short-lived," he said. "Eventually, Pontchartrain will cleanse itself."

Flooding in the Atchafalaya basin has not been as caustic as expected behind officials opened the Morganza Spillway, but Turnipseed admitted it has affected residents.

Across Louisiana, officials are still coping with the crisis.

The Louisiana Governor's Office of Homeland Security and Emergency Preparedness said Thursday that at least 1,230 frameworks in 13 parishes have been affected by floodwaters. Friday, it said 1,150 National Guardsman proceed to be organized for the flooding response.

For the Atchafalaya wetlands, the flooding is a and because it will create desperately needed land, Turnipseed said.

Gulf Coast hopes for busy Memorial Day

"If the marsh grasses could sing, they would be singing compliments," the lawful said.

The sediment moving through the mouth of the Mississippi is good because overrun control, Turnipseed said, "but it's not a good object because the ecosystem."

Officials are undergoing the difficult of measuring and analyzing the sediment.

Ecologists lament the sediment reaching the bay, prefer than creating wetlands, which protect Louisianans from storm surge and patronize aquatic life.

Over the quondam 80 years, the state has lost coastal wetlands equaling the size of Delaware, federal officials mention.

"It's a citizen catastrophe," Turnipseed said. "The wetlands are needed."

The problem is no fashionable. Natural processes and people disturbance, including dredging and pollutants, have taken their toll.

Turnipseed above June 2 ambition present by the state Capitol a map of Louisiana wetland losses and gains from 1932-2010. He hopes the new map will assist advise land managers and agencies ashore marsh restoration.

Federal authorities, meanwhile, are in the process of closing portions of the Morganza Spillway for the swollen Mississippi River recedes. The spillway was opened May 14 to discourage the Mississippi from flooding New Orleans and Baton Rouge.

The Corps of Engineers has closed 5 of 12 bays, public affairs expert Ricky Boyett told CNN on Friday p.m..

The Corps said much as 1.2 million gallons (172,000 cubic feet) per second had been gushing through the spillway, which distracted water through the Atchafalaya basin, but that digit was down to 120,000 cubic feet per second later in the week.

The high water has caused some flooding down the Atchafalaya. But the water levels "continue to be lower than anticipated" throughout the basin, Corps lecturer Ken Holder said this week.

The river remained approximately five feet above flood stage Friday afternoon at Bayou Sorrel and about six feet over flood stage at Morgan City, on the reaches to the Gulf. But it was more than five feet lower at the town of Krotz Springs and about two feet beneath flood stage at Butte LaRose, about 20 miles south of the spillway.

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