tag:blogger.com,1999:blog-5876214674823177618.post6810768790271400589..comments2023-12-21T23:14:14.347-06:00Comments on NOLA-dishu: West Bay Diversion to close?Clayhttp://www.blogger.com/profile/11905149250548893628noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-5876214674823177618.post-89835422875087565322011-10-27T18:32:58.104-06:002011-10-27T18:32:58.104-06:00Take a look at Wax Lake:
http://en.wikipedia.org/...Take a look at Wax Lake:<br /><br />http://en.wikipedia.org/wiki/Wax_Lake<br /><br />Built in 1942. Took years to show results, but it now shows up as a "green" area on coastal land loss maps.<br /><br />http://www.nwrc.usgs.gov/upload/landloss11X17.pdf<br /><br />Wax Lake is one of the green spotches in central Louisiana.Clayhttps://www.blogger.com/profile/04317258394378203986noreply@blogger.comtag:blogger.com,1999:blog-5876214674823177618.post-38214420847662500012011-10-27T08:51:24.522-06:002011-10-27T08:51:24.522-06:00The time scale for measuring the effects of sedime...The time scale for measuring the effects of sediment diversions is much larger than the 2003-2009 period over which measurements were taken. On the physical model I used in grad school, 30-50 years was the minimum time period we needed to see and measurable land building.<br /><br />Two understand why it takes so long, one must first realize that a diversion is a man-made duplication of a natural event, a crevasse and following new distributary formation. hopefully that new distributary would result in the formation of its own delta.<br /><br />The first thing that will occur though is not land building, rather it is scour. The new channel will likely be SCOURING FOR 20 YEARS. At the end of that initial time period hopefully levees and bifurcations in the channel begin to form. This is the point at which land can actually be successfully created.<br /><br />Water that does make it over the levees or in the area between bifurcated flow will have a lower velocity than that in the newly scoured channel (which will have developed an equilibrium between its velocity and sediment carry capacity by this point). Thus slowing down the water at this point will not allow the flow to maintain the sediment which will then either fall out of suspension, stop saltating along the bottom, etc.<br /><br />This is when land begins to truly form. 30-50 years out. Look at West Bay, look at Cubit's gap. Both are highly successful human caused deltas, and each follow this same time period. 7 years is much to soon to make a determination about Est bay. Period.CoastingThroughTheSouthhttps://www.blogger.com/profile/10717316028234034496noreply@blogger.com