Flood controls blamed for floods in Mississippi, Louisiana
Thursday, April 5, 2018, 3:37 PM - Measures taken in the Louisiana River to prevent flooding in Mississippi and Louisiana may have made matters worse, according to a study published this week in the journal Nature.
Researchers used 500 years of data from tree rings and sediment in the area to determine the frequency of flooding.
They found the river has burst its banks more over the past 150 years than any other time period.
Researchers say climate change is likely responsible for 25 per cent of the recent floods. Changes in weather cycles also likely play a role.
READ MORE about the 2016 floods in Louisiana
But the paper argues that cycle changes alone would only contribute to a small increase in flood events.
"The other likely culprit is something we've done to the river or basin," Lead researcher Samuel Munoz of Woods Hole Oceanographic Institution told the Associated Press.
The Mississippi River Basin drains all or part of 31 states as well as Calgary and Saskatchewan.
"Their palaeoflood record is compelling. ... And if the authors are correct, and collective efforts to subdue the Mississippi have inadvertently pushed it to rise higher than ever, then the time might have come to consider loosening its restraints," Scott St. George of the University of Minnesota wrote in a commentary on the study.
Some experts have argued the findings are weak and don't account for changes to the landscape over the past five centuries.
St. George believes climate change is a larger driver of flood than the study shows and has called for further research.
The complete paper can be found online.