It is often talked about that New Orleans is one the worst placed to build a city geographically. After Hurricane Katrina, that statement could be seen as true. However, what about Hurricane Betsy? Hurricane Betsy was a Category 3 hurricane from 1965 that was just as strong as Hurricane Katrina. However, the reason it didn't cause as much damage to New Orleans as Katrina was because of the coastal wetlands that act as a buffer to "drain" Hurricanes of their strength. Because hurricanes feed off of warm water from the ocean, when it hits any sort of land, such as the vegetation found in the wetlands, the hurricane's strength lessens. In fact, for every 2.7 miles of wetlands, storm surges are reduced by about 1 foot. Take that into account when considering that over 1,900 square miles of wetlands have eroded since the 1930's.
Not only does erosion of the wetlands affect humans, but many different species of wildlife have a home there, and if that is gone, where will they live?
So, what is causing the coastal wetlands to erode? 70% of the cause are man made levees. From my previous blog entry, you read that the construction of levees along the Mississippi River to prevent flooding have also caused the New Orleans area to slowly sink below sea level (although that topic is up to much debate). Another side-effect is the erosion of the wetlands. Without the levees, normal flooding every Spring from the Mississippi would bring vital sediment, nutrients, and fresh water to the wetlands, causing life in that area. But, with the man-made levees in place, flooding does not occur, cutting short the very things the wetlands need to survive.
What are we doing to help? Currently, about $14 billion is needed to manually deposit sediment and divert river water. However, a recent energy bill has given $540 million, about half a billion dollars, to anti-erosion projects. This may seem like a lot, but it is only enough to recover about 10-15% of the lost wetlands. About $2 billion is earmarked for Army Corps of Engineers projects in a new water resources bill that is as of now making its' way to Congress.
A way New Orleans is affecting the ecosystem of its' area is by the drainage of flood waters from Hurricane Katrina, which bring back with it the particulate matter and organic chemicals that are commonly found in an urban environment. The main reason for these chemicals presence in the flooded water is from broken sewers and flooded industrial plants. The stretch of the Mississippi Rover between Baton Rouge and New Orleans contains more than 140 chemical plants and oil refineries. This stretch of land is commonly referred to as Cancer Alley because of its' detrimental effects on the community surrounding it. The dumping of chemicals from plants such as these is what has contributed to the contaminated runoff. The reason these chemicals are dangerous is because once they get back into lakes, rivers, and oceans, they kill the wildlife. Organic chemicals dangerously reduce the amount of oxygen found in water, disabling the waters' ability to support life. Particulate matter clouds the water, which diminishes the amount of sun able to reach plants and enable them to grow.
With everything like this happening in New Orleans ecosystem, I find it sad that this is what man has done to the home that nature has given it.
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