04-25-2014, 10:54 AM
I agree, but not 100%.
Agree with the idea that nature is generally cyclical, in particular with regard to most beach erosion. Agree also in the sense that I'm not convinced some of the 'beach repair' methods actually work in some, or perhaps any, situations (jettys, offshore breakers, reef balls, dredging/reclamation, etc.).
However, in some places, beach erosion appears to have been documented over long periods with no cycle - i.e. the shoreline only moves in one direction. That Sandals-sponsored report from a few years ago had aerial surveys of Long Beach showing erosion, in the long term, going in one direction. IIRC it was a decent (to my non-scientifically trained mind) period of time between each contour in the graph plot (10 years maybe?). Some areas showed greater and more consistent retreat of shoreline than others (I think the report was making that point - that the locale of Sandals' property was bearing the brunt of something done up by Hedo area). Sure - they may have had an agenda and cherry-picked which aerials to use in their elevation contour plots, but in general I do believe the beach is eroding.
There have been enough places in the world that have shown loss/decay of offshore reefs increased chance of beach erosion that I believe reefs are important for shoreline protection.
In LA the loss of shoreline has been documented for years (nearly a century). Most scientific studies agree that the canals through the onshore swamps combined with the straightening of the Mississippi River are the main contributors to the loss. (btw - "Bayou Farewell" by Mike Tidwell is a good read, IMHO). There may be a few studies that demur on the cause but I haven't heard/read any that dispute the idea that the shoreline is receding (and rapidly).
Will the shoreline move back out some day in LA? Maybe. Global sea level studies going back 10,000 and 100,000s of years show changes in both directions through various ice ages and warming periods. (the sound you hear is that huge can of worms now opening ...) Are changes to sea levels caused by human practices part of a "natural" cycle? Dunno. The sun is supposed to explode in some 2+ billion years and one could take the long view that it doesn't really matter what we do to the sea level. I prefer to believe that in the near term (next few 100 years or so) what we do to the environment does matter.
Perhaps in 100,000 years some change will allow the LA shoreline to rebuild. Or perhaps the apes will be riding their horses along the rebuilt LA shoreline as Charlton Heston bellows "You maniacs, you blew it up".
Agree with the idea that nature is generally cyclical, in particular with regard to most beach erosion. Agree also in the sense that I'm not convinced some of the 'beach repair' methods actually work in some, or perhaps any, situations (jettys, offshore breakers, reef balls, dredging/reclamation, etc.).
However, in some places, beach erosion appears to have been documented over long periods with no cycle - i.e. the shoreline only moves in one direction. That Sandals-sponsored report from a few years ago had aerial surveys of Long Beach showing erosion, in the long term, going in one direction. IIRC it was a decent (to my non-scientifically trained mind) period of time between each contour in the graph plot (10 years maybe?). Some areas showed greater and more consistent retreat of shoreline than others (I think the report was making that point - that the locale of Sandals' property was bearing the brunt of something done up by Hedo area). Sure - they may have had an agenda and cherry-picked which aerials to use in their elevation contour plots, but in general I do believe the beach is eroding.
There have been enough places in the world that have shown loss/decay of offshore reefs increased chance of beach erosion that I believe reefs are important for shoreline protection.
In LA the loss of shoreline has been documented for years (nearly a century). Most scientific studies agree that the canals through the onshore swamps combined with the straightening of the Mississippi River are the main contributors to the loss. (btw - "Bayou Farewell" by Mike Tidwell is a good read, IMHO). There may be a few studies that demur on the cause but I haven't heard/read any that dispute the idea that the shoreline is receding (and rapidly).
Will the shoreline move back out some day in LA? Maybe. Global sea level studies going back 10,000 and 100,000s of years show changes in both directions through various ice ages and warming periods. (the sound you hear is that huge can of worms now opening ...) Are changes to sea levels caused by human practices part of a "natural" cycle? Dunno. The sun is supposed to explode in some 2+ billion years and one could take the long view that it doesn't really matter what we do to the sea level. I prefer to believe that in the near term (next few 100 years or so) what we do to the environment does matter.
Perhaps in 100,000 years some change will allow the LA shoreline to rebuild. Or perhaps the apes will be riding their horses along the rebuilt LA shoreline as Charlton Heston bellows "You maniacs, you blew it up".