Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Politics : The Trump Presidency -- Ignore unavailable to you. Want to Upgrade?

To: i-node who wrote (19261)	5/24/2017 7:19:25 PM
From: combjelly	2 Recommendations Recommended By i-node Mannie Read Replies (2) \| Respond to of 356191

Between rising sea levels, erosion of the MIssissippi Delta and subsidence, the future of NOLA is pretty grim. Unless we want to dome it over, that is. Even without rising sea level, the erosion of the delta means that NOLA is sooner or later going to be surrounded by the Gulf. That is because we have dams on most of the tributaries of the Mississippi. And that means there isn't the silt coming down the river that there used to be. Without the silt settling in the marshes, as the water gets squeezed out of the existing silt, the bottom of the marshes sink. That allows the saltwater to intrude into the marshes, shifting the salinity to saltier. That causes the Spartina alterniflora(marsh grass) to die. That means that wave action causes the silt to erode. Erosion means that there is more salt water intrusion. Do you see where this is going? Now the upside, so to speak, is that the shrinking delta decreases the forces that are trying to shift the Mississippi from its present banks to the other river basin at Atchafalaya. The Mississippi alternates between the two as the delta builds up, lowering the gradient of the river flow until the pressure causes it to jump banks, typically in a flood. Then the old delta erodes away and a new one is formed at the new river mouth. The general rule of thumb is that if a river diverts more than one third of its flow in a flood, the river will jump banks. Such an event occurred in the 1930s. The Huey P. Long Spillway was built to force the Mississippi back. So the erosion of the delta is a mixed blessing for NOLA. So, what do you think?