The land is sinking under my feet

[gwynhefar]

So I'm reading this book called Bayou Farewell all about the coastal erosion in Louisiana. It's an eye-opening experience. How is it that no one outside of Louisiana seems to know about this? Here's a few facts to get you started:

• Louisiana currently contains 25% of the total US wetlands.


• Louisiana is currently loosing land at the rate of 35 square miles a year. To put that in perspective, that's 46 football fields a day.


• Louisiana has one of the highest rates of coastal erosion in the world.

See, the way the wetlands work is that the Mississippi river carries all this sediment down and deposits it on the Louisiana coast. This loose sediment sinks as it settles and some of it is carried away by wind and waves, but there is always more being deposited by the river's floods to replace that which is being lost. That is, until people settled here and started building dams and levees. Now the Mississippi doesn't flood anymore, so there's no sediment replacing that which is settling.

And this is a very serious issue because no wetlands means no shrimp and crab fisheries (A significant percentage of the US seafood harvest comes from Louisiana), no nesting grounds for rare and endangered migratory birds coming across the Gulf, and most importantly, no buffer between the heavily populated areas of New Orleans and its environs and the hurricanes coming up the Gulf. After Katrina, the author of this book I'm reading went so far as to say that it's murder to move people back to New Orleans without taking action to build up the coast.

Although this has been on my mind since I started reading the book, today I found another sobering reminder. I was researching LSU history for a patron and found an old 1871 map of Louisiana. I practically didn't recognise the coastline. Whole stretches of land are gone. The bays are so much smaller on the old map than they are on the current one. All the features of the coastline are so much sharper and narrower now than they were then. Lakes that used to be miles inland are now simply bays. It's very scary.

Comments

Sadly...

[pickmansraven.livejournal.com]

The main reason the wetlands are disappearing is that Mother Nature is being diverted. :(

I was watching a show on the Discovery channel about how the Corps of Engineers has been diverting the MiIssissippi into it's current channel, which is causing all the silt to be dumped into the Gulf, instead of the wetlands. Apparently the old Miss has been trying to change it's course for years now, but the Corps has kept it in the same channel.

I also saw something about that when I last visited NOLA, and how New Orleans wouldn't really BE the city it was w/o the Levee's & Corps work. (Though the wetlands and other natural areas would be MUCH better off.)

*sigh* Big urban Southern Port, or Mother Nature. Hard to decide, eh?

Re: Sadly...

[gwynraven.livejournal.com]

Indeed. Although I've read a very convincing proposal to build a river diversion off one of the bends before the Mississippi hits New Orleans. The proposed structure would divert about 20% of the river's flow into three separate mini rivers that would deposit sediment in the wetland area. The rest of the Mississippi would flow by New Orleans like usual. Even the 20% of the river diverted would halt the land loss within 20 years and reverse it to land gain within 50.

Unfortunately, the State is broke and probably won't fund the proposal. I definitely plan on voting for it if it ever makes its way on the ballot, but I'm not holding my breath.

[gwynraven.livejournal.com]

I know. I knew there was coastal erosion going on in the Gulf before moving here, but I was amazed to discover just how extensive the damage is. It's a real shame that people don't seem to view it as a priority. One report I read said that if Katrina had hit 50 years ago, the storm surge that reached New Orleans would have been half what it was. That's how much protection the wetlands give the city. And that's how much of that protection has been lost in just the past 50 years.

[gothwalk.livejournal.com]

We were shown maps of that entire area, and given a description of it as a disaster waiting to happen when I did geography in college. Essentially, there are places where you can safely mess with rivers, and places where you can't. The sheer size of the Mississippi makes it a losing proposition.

[kk1raven.livejournal.com]

In an odd coincidence, I found a copy of that book at a Goodwill store last week. I haven't had time to read it yet, but it looks really interesting. Where did you find the author's post-Katrina comments?

[gwynraven.livejournal.com]

I was talking about the book with someone at the Unitarian Church and she mentioned that she'd heard him speak recently and that was one of the things he said.

[phantom_wolfboy]

What I don't understand is why the football field (or, for really large measurements, Texas) is used as the standard of measurement. I have no idea how large a football field is; 46 of them is no easier to imagine than 35 square miles.

Don't mind me; that's just something that comes into my mind every time I encounter such a statistic.

[gwynraven.livejournal.com]

Well, most people have been to a football field at one point in their lives, and thus have a mental picture that is easier to comprehend than a number like 35 sq mi. Think an awful lot of land.