Thursday, September 18, 2008
Notes on the loss of the coastal lands in Southeast La.
Louisiana Coastline quiz next Thursday.
- Notes from Times-Picayune interactive graphic:
1. New Orleans (NO) area called Southeast La.
2. Region was created by Miss. R.
3. Geological history: the dynamic river changes course and changes the land.
Ex. in Red River: change in position of pivot in downtown railroad bridge.
4. Most current maps do not tell the truth about loss of coastal land. Based on 1930’s coastline.
5. End of an ice age some 4000 years ago: melting glaciers caused seas to rise. Gulf waters covered La., including Spt.
6. Region from Spt south to coast is called Gulf Coastal Plain. Essentially flat land.
7. Miss. delta land below NO is the product of the Miss. R.
8. Miss. water is rich in nutrients. Its sediment, alluvial soil, maximizes crop growth. If the Miss. flow is cut off, the land is lost.
9. NO established in 1718. Spt est. in 1835.
10. Levee from Frennch “lever,” to rise.
11. Levees protected NO from flooding. Canals aided shipping and helped create dry land from swamp.
12. Levees cut off the deposit of sediment - sediment keeps the land healthy. Jetties keep rivers navigable by preventing erosion, but also stop the natural deposit of sediment.
13. Coastal canals were dredged so men could drill oil and gas wells. They are part of the erosion of the coast.
14. Subsidence, sinking land, is affecting the La. coast.
Other locations affected by subsidence: Venice, Italy, also California, Florida, Texas, other places in La.
15. Saltwater intrusion kills marsh plants and promotes erosion. It is caused by subsidence and canals.
16. Invasive species: nutria. This rodent eats marsh vegetation, enhancing erosion.
17. Sea level is rising worldwide, in part due to global warming. La flooding will grow in severity along with sea level rise.
18. Geologists predict severe land loss ahead. NO will be surrounded by seawater.
19. Solutions will costs trillions. Congress has thus far declined to pay the full bill.
20. Louisiana’s small population and lack of economic power mean that Congress will ignore our requests.
21. Will Congress increase its aid because of the national importance of the seafood and oil industries?