As the Mississippi River enters the Gulf of Mexico, it deposits its load of sediment in a delta.
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Changing the Mississippi River Could Lead to New Land near New Orleans
News story originally written on October 20, 2009
Around the city of New Orleans, the land has been sinking and the level of the sea has been rising. These changes mean that large areas of land have disappeared.
The concrete levees on either side of the Mississippi River keep water from flooding the land. That’s a good thing but they also cause the river water to move too fast to drop the sand mud, and gravel sediments that it carries. Those sediments carried by the river build up the land when they drop out. When the river doesn’t drop them, the land disappears even faster.
Scientists were looking for a way to get the river to drop the sediments making more land. Using a computer model, they discovered how to build-up new land by allowing water to flow beyond the levees of the Mississippi River. They studied how the river carries sediment and deposits it areas where the flowing water slows. The build up of these sediments creates land.
The scientists’ model looks at how allowing water to spill out of the levees through two openings would affect the land. The model shows that the water would slow down as it gets beyond the levees, depositing sediment and helping to build up the land.
The changes to the river's path would not solve the problem of disappearing land in the New Orleans area, but they would help slow the loss of land.
Last modified January 21, 2010 by Lisa Gardiner.
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