In response to this question one has first to identify what is meant by sinking. As has been amply demonstrated on mainstream news and by climate change experts and scientists over the past few years, sea levels are rising. Therefore, effectively one could say that part of the reason that New Orleans is sinking is because it is literally being drowned by rising seas.
However, as the sea level rises are fairly universal in the global sense, for instance if they are rising in the East at a certain rate per annum the west would be experience a similar rise, then one would not expect the problem to be any more severe in New Orleans than it is elsewhere. Yet this is not the case. According to scientists, including Dr Chip, Director of the US Geographical Survey team and Dr Shea Penland, a coastal geologist, New Orleans is sinking at the rate of three feet per century. This is in fact eleven times the global average.
It is easy to think that sinking at 0.36 inches per year is no a great deal. However, if you consider that elsewhere the rate is 0.04 per year the concern grows. Concern becomes even more intense when you take into account the fact that at present the greater part of New Orleans is actually eight feet below sea level, with some areas even lower. In fact it is predicted at the current rate that by this time next century New Orleans could be like the lost city of Atlantis, in other words completely submerged.
What is more apparent from these statistics of course is that this sinking phenomenon cannot be simply driven by global sea rises, for the reasons given earlier. There must therefore be other contributing factors. Indeed, the scientists mentioned above have been able to identify the problem, which is related to existence of wetlands, a combination of mud and thousands of years of accumulated silt.
New Orleans, like most of Louisiana, is built on or close to wetlands bordering the Mississippi River. In the early years of the development of the city much of these wetland areas were drained in order to ensure that the buildings had secure foundations. This had the effect of lowering the level of the city streets below sea level, in effect sinking the city. In addition, despite being drained, unlike other types of soil, the wetland composition is porous and does not provide a very strong foundation. It is also subject to subsidence. In effect therefore, one of the problems facing New Orleans is that slowly but surely the wetlands are subsiding or sinking into the water, dragging the city down with it.
Actually, the term slowly in this context is perhaps inappropriate, especially when one considers that this is happening at the rate of 25 square miles a year. It becomes even more frightening when one calculates that this relates to the loss of 307acres a week, or just over a quarter of an acre every hour.
It therefore follows that, unless urgent and drastic action is taken to address this problem, not only by restoring coastal defences but also by attacking the greater issue of climate change the "Big Easy" may not survive as a place to take our great, great grandchildren to visit, except through diving experiences. That would be a loss for them and, more importantly, for the many thousands of people who call New Orleans their home and have suffered enough disaster over the past few years.
chargement...
