LA Efforts To Redirect Sediment To Mississippi Delta Probably Useless, Given Rate Of Sea Level Rise

[hatrack]

The state of Louisiana is proceeding with ambitious plans to redirect the Mississippi River and rebuild some of its rapidly vanishing wetlands - but even this massive intervention may not be enough to save the most threatened lands from fast rising seas, scientists concluded in a study published Wednesday.

EDIT

The scientists actually took their samples in areas of solid land where you would hardly expect there was once open water or a marsh - but then, that's just the point. The Mississippi River is a great builder of land as it carries large volumes of sediment and silt downstream. Some of that sediment is now trapped behind dams along the length of the river, but much still reaches the delta. The problem is that factors that drive wetland loss are simply more powerful - the sinking of the land (subsidence), the intrusion of saltwater as seas rise, the dissolution of wetlands that have been cut into canals to support oil and gas pipes, and more.

And on top of that, sea-level rise is now occurring much faster than it did when the Bayou Lafourche land was built. The current rate is about 3.2 millimeters per year, and it is believed to be accelerating. But when the Lafourche subdelta grew, the sea-level rise rate was just .6 millimeters per year. "Lafourche formed during a relatively favorable time when the rate of sea-level rise was about as low as it can get in this region," said Törnqvist.

The conclusion is that, well - the river just may not be able to keep pace. That's even though the Louisiana Coastal Protection and Restoration Authority, using funds from the BP settlement, is moving forward with two large sediment "diversions" that within a few years could start channeling huge volumes of river water in new directions, in a bid to protect areas around New Orleans in particular. Many scientists have applauded the plan as a way of harnessing nature's power to counter land loss.

EDIT

https://www.sfgate.com/news/article/Seas-are-rising-too-fast-to-save-much-of-the-12825922.php

[Farmer-Rick]

1. I was trying to figure out how LA California could affect the Mississippi River.

Oh, never mind.