The Effect of Subsidence and Sea Level Rise on Land and Coastal Habitat Loss in Coastal Louisiana

About the Author

In 1927 flooding in the lower Mississippi River forced nearly 700,000 people (table 1) to move from their homes (U.S. Army Corp of Engineers, 1999). Waters began to rise in August of 1926 and passed flood stage at Cairo, Illinois in January of 1927. The flood destroyed levees from Illinois to the Gulf of Mexico (Barry, 2002). The river was in flood stage for 153 consecutive days and inundated 69,930 km2 of land (fig 1). The flood of 1927 was a reminder that humans were capable of managing natural systems but could not control them. As a result management strategies for the river were scrutinized and altered.

Map showing area that water covered during the flood of the Mississippi River in 1927. Modified from the U.S. Army Corps of Engineers Jim Addison 1999

Since then, new flood control structures and systems have been implemented to minimize such events in the future. The U.S. Army Corp of Engineers abandoned their flood control strategy of “levees only” to pursue one that would include meander cutoffs, flood outlets, upstream reservoirs, and other measures (Barry, 2002). However, human alteration of natural processes like river flooding has had indirect effects on other geomorphic processes.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mike Andree

Dickinson College

Carlisle Pennsylvania

Last updated May 11, 2005