WASHINGTON – A new research has predicted that the Mississippi River Delta in the US would drown by the year 2100.
“There’s just not enough sediment to sustain the delta plain,” study author Michael Blum of Louisiana State University in Baton Rouge, told National Geographic News.
Deltas are coastal landmasses created from a river’s sediment deposits as the water flows out to sea. The Mississippi River’s delta plain, for example, includes the lacy “toe” of southern Louisiana.
All deltas are degrading to some extent, as their sediment settles and sinks.
Today, sediments collected along the Mississippi cover about 23,360 square miles (60,500 square kilometers) ranging in thickness from less than 33 feet (10 meters) upstream near Memphis, Tennessee, to about 328 feet (100 meters) in the delta at the tip of southern Louisiana.
The drainage basin of the roughly 2,350-mile-long (3,782-kilometer-long) river, however, includes about 40,000 dams and levees built over the past century.
These structures control flooding and improve navigation, but they also trap sediment or funnel it completely through to the sea.
Previous studies suggested that dams and reservoirs built since 1950 have trapped as much as 70 percent of the river’s natural amount of sediment.
With less material feeding it, the delta plain has been experiencing erosion.