Louisiana's Wetlands and Barrier Islands

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1870

Louisiana’s wetlands and barrier islands act as the initial shock absorbers from waves and currents that are magnified by hurricanes.

Incoming hurricane winds and storm surge can be significantly reduced by healthy marshland and fortified barrier islands.

These natural structures have historically served to keep hurricanes at arms length - protecting Louisiana cities and people.

1937

However, Louisiana's natural “buffers” are disappearing at a rate of up to 20 meters a year, according to recent USGS estimates.

Past hurricanes have added to the erosion along the coastline. Louisiana is also located along a natural fault, which causes the land to slowly subside, or sink.

But these changes are not only due to natural causes.

1973

Some sediments that are vital to the wetlands and barrier islands to “rebuild” themselves have been almost completely removed from the system by our construction of the levees.

Much of coastal Louisiana depends on a network of levees, canals and pumps for flood protection.

The levees confine the Mississippi River's flow, forcing the deposit of sediments far into the gulf.

2000

Other human activities such as dredging for navigation; cutting canals into the marsh for oil and natural gas extraction; and draining for expanded development also contribute to land loss.

As the wetlands and barrier islands are eroded, Louisiana’s coast will become entirely vulnerable

Above: A series of maps from the Offical Louisiana State Map collection, courtesy of the Louisiana Geological Survey (LGS)

to the full force of hurricanes, jeopardizing the lives and overall health of the people who live here.

	Barrier Islands (photo: G. Stone)	Research is being conducted to find ways to achieve balance between humans and the coastal environment. As scientists continue to study the coastal ecosystem and associated processes of land building, they are compiling data to figure out exactly how the wetlands and barrier islands work with nature. This will help them to develop better strategies for restoring and strengthening the natural coastal protection systems of Louisiana.
	Davis Pond Diversion Project (photo: New Orleans USACE)	One of the main research goals is to help to return the wetlands and barrier islands as much as possible to their original state. Engineering solutions are also necessary. So far in Louisiana these have included creating new diversions of the Mississippi River that create a more natural flow, and the deposit of the lost sediment to restore the system. Flood protection structures such as passive barrier systems could also be explored. Such systems would be designed to be less intrusive to the ecosystem and to allow sediment flows to nourish existing wetlands most of the time, but which could be closed when storms threaten.



Resources and Links
Below are just a few of the many artcles, maps, and links on the vast topic of Louisiana wetland and barrier island loss and hurricanes:
Landloss poster (HPHC and LGS) - view a composite map of Louisiana land loss over the past century USACE landloss poster (2001) Hurricane Land Change Information. USGS National Wetlands Research Center, 2006. "Why is the land in South Louisiana disappearing?" LACOAST, 2003. Louisiana's Wetlands: A Lesson in Nature Appreciation. NIEHS, 2006.
Louisiana CPRA LSU Coastal Research Initiative. 2006. Louisiana Hurricane Resources. Louisiana Sea Grant, 2005. Wetlands erosion raises hurricane risk. MSNBC, 2005. Louisiana's Barrier Islands - A Vanishing Resource. USGS, 1995.

Barrier Islands (photo: G. Stone)

Research is being conducted to find ways to achieve balance between humans and the coastal environment.

As scientists continue to study the coastal ecosystem and associated processes of land building, they are compiling data to figure out exactly how the wetlands and barrier islands work with nature. This will help them to develop better strategies for restoring and strengthening the natural coastal protection systems of Louisiana.

Davis Pond Diversion Project (photo: New Orleans USACE)

One of the main research goals is to help to return the wetlands and barrier islands as much as possible to their original state.

Engineering solutions are also necessary. So far in Louisiana these have included creating new diversions of the Mississippi River that create a more natural flow, and the deposit of the lost sediment to restore the system.

Flood protection structures such as passive barrier systems could also be explored. Such systems would be designed to be less intrusive to the ecosystem and to allow sediment flows to nourish existing wetlands most of the time, but which could be closed when storms threaten.

Resources and Links

Below are just a few of the many artcles, maps, and links on the vast topic of Louisiana wetland and barrier island loss and hurricanes:

Landloss poster (HPHC and LGS) - view a composite map of Louisiana land loss over the past century

USACE landloss poster (2001)

Hurricane Land Change Information. USGS National Wetlands Research Center, 2006.

"Why is the land in South Louisiana disappearing?" LACOAST, 2003.

Louisiana's Wetlands: A Lesson in Nature Appreciation. NIEHS, 2006.

Louisiana CPRA

LSU Coastal Research Initiative. 2006.

Louisiana Hurricane Resources. Louisiana Sea Grant, 2005.

Wetlands erosion raises hurricane risk. MSNBC, 2005.

Louisiana's Barrier Islands - A Vanishing Resource. USGS, 1995.