Hurricane Katrina

What can be done and has been done to prevent this disaster from re-occurring?

Background

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A city underwater due to Hurricane Katrina
Hurricane Katrina was the costliest of its season and one of the five deadliest hurricanes to hit the United States. It has been stated that over 1800 people were killed, more than 700 people went missing and more then $81 billion dollars in damages were incurred from this single hurricane. This category five hurricane reached wind speeds of up to 175 mph and affected seven states plus parts of Cuba and the Bahamas. Many people have wondered why Hurricane Katrina caused such enormous damage and what can be done to prevent another disaster such as this from re-occurring.

About Hurricanes

A hurricane is a large rotating mass of a low pressure system that is can be several hundred kilometers in diameter. In the northern hemisphere, hurricanes will turn counterclockwise because of the coriolis effect caused by the rotation of the earth. A hurricane is marked by strong winds and torrential rainfall in the area of the storm. A hurricane can only be developed when the temperature of the ocean waters is at least 80 degrees Fahrenheit. Also, there must be unstable, warm, and humid air that is followed by weak upper level winds blowing in the same direction as the developing storm
Before a storm is considered a hurricane, it first starts off as a tropical disturbance where there is a zone of low pressure with a cluster of thunderstorms. Next, it is upgraded to a tropical depression where surface winds begin to strengthen and flow around and into a core. This is where the storm begins to rotate counterclockwise (in the northern hemisphere only). Once the system reaches wind speeds of 39 miles per hour or greater it is now called a tropical storm and is assigned a name according to its yearly alphabetical order with the exclusion of the letters: Q, U, X, Y and Z; due to the relatively small amounts of names that begin with those letters. As the storm moves towards land, converging surface winds flow up the central core. When this warm moist air cools and condenses, it releases its heat that had been stored which in turn warms the surrounding air causing it to rise faster and faster. Once wind speeds reach 75 miles per hour, it is considered to be a hurricane.
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Hurricane cloud formation
A typical hurricane that hits the East Coast of the United States will get its start off the coast of Africa, where the ocean is rich with warm waters. As it moves westward, it picks up the heat and moisture from the warm waters and grow stronger until it hits the coast or reaches cool waters. The hurricane will lose its fuel or power in cool water and may once again gain force once in warmer waters. Once over land, a hurricane will lose its strength because there is no warm water to keep fueling the storm.

Effects

The effects of a hurricane can be devastating depending on where the storm hits. Most damages caused by a hurricane are not caused by the torrential rainfall but by mass flooding that is caused by a storm surge. Any time a hurricane passes over the waters, it creates a bulge in the ocean because of the vacuum like force that draws up air and moisture through the core. This bulge in the ocean can grow to be several meters in height. In places that are not prepared for storm surges, such as New Orleans, Louisiana, levees can be destroyed; sending massive amounts of water into the cities as illustrated, multiple floodwalls failed. In places where there are large developments, the costs of a hurricane can be great. As demonstrated by New Orleans, Hurricane Katrina caused over $81 billion dollars in damage. The levees in Alabama were only made to withstand a category three hurricane, yet Katrina was a category five with wind speeds over 175 mph. The storm surge reached as high as 28 feet on the eastern side of the eye and the levees broke in several places. The New Orleans "bowl" doesn't allow the water to flow away from the city. In light of the recent cyclone Bangladesh, countries that are less developed will see high numbers of deaths due to drowning or contamination of drinking water.
Why the failure?
Why the failure?


In addition, Hurricane Katrina caught the US unprepared for such a large natural disaster. The area not only experienced devastating ecological, environmental and economic damages but also exposed problems in governmental political policies, health management, public safety and emergency response.

What Can Be Done To Prevent Another Disaster?

In August 25, 2006, a study was released by the American Society of Civil Engineers, also known as the ASCE. What was released was a set of essential recommendations towards preventing another disaster from striking the Gulf area. These were the list of recommendations that was made by the ASCE:
  • "Keep safety at the forefront of public priorities by having all responsible agencies reevaluate their policies and practices to ensure that protection of public safety, health and welfare is the top priority for infrequent but potentially devastating impacts from hurricanes and flooding. Also encourage Congress to establish and fund a mechanism for nation-wide 'Levee Safety and Rehabilitation,' as is done for major dams.
  • Quantify and periodically update the assessment of risk. This approach should be extended to all areas in the United States that are vulnerable to major losses from hurricanes and flooding.
  • Determine the level of acceptable risk in the community through quality programs of public risk communication in New Orleans and other areas threatened by hurricanes and flooding.
  • Correct the system's deficiencies by establishing mechanisms to incorporate changing information, making the levees survivable if overtopped, strengthening the I-walls and levees, and upgrading the pumping stations.
  • Assign a single individual, a licensed engineer, the responsibility of managing critical hurricane and flood protection system such as the one in the New Orleans.
  • Implement more effective mechanisms for coordination and cooperation (for example, those responsible for maintenance of the system must collaborate with system designers and must upgrade their inspection, repair and operations to ensure that the system is hurricane and flood-ready).
  • Upgrade engineering design procedures to place greater emphasis on safety.
  • Engage independent experts in high-level reviews of all critical life safety structures, including hurricane and flood protection system."

Many case studies are still being conducted in the years following Hurricane Katrina on how to prevent a disaster of such magnitude from occurring again. However, the best step that can be taken to prevent another disaster from happening would be to revitalize the wetlands that once existed at the mouth of the Mississippi River.

What Has Been Done To Prevent Another Disaster?

Before the rivers that drained out of the Mississippi River were dammed, enormous amounts of wetlands had existed at the mouth of the river that acted as a buffer zone against storm surges that came to hit the land. This was what had saved the city before in previous decades before the dams were built. However, once the dams were built, deposits from the river and more importantly water from the river had been cut off from feeding into these wetlands to keep them preserved. In a study done by the National Academy of Science, they stated that the Louisiana Wetlands cannot be preserved to what it once was. Although efforts were done by President Bush to revitalize the wetlands, studies indicated that it only slowed the destruction of the wetland by only 20 percent.
To prevent another disaster from happening, some parts of New Orleans have been red tagged as not rebuildable because of future disasters that can strike. Currently there are steps taking place to better evacuate the people from areas that would be strongly affected by another hurricane. Levees are being redesigned to be able to withstand another Katrina strength hurricane. Newer pumps are in the process of being installed so that they will better pump out water that does enter the city and there are many other steps that have been taken to prevent another disaster from occurring. Although there is no way to fully prevent a disaster from occurring, there are steps that can be taken to reduce the damages that are incurred from a natural disaster.



Sources:

  1. U.S. Department of Health & Human Services. Hurricane Katrina. Aug. 27,2007 http://www.hhs.gov/disasters/emergency/naturaldisasters/hurricanes/katrina/index.html
  2. President George W. Bush. President Address Nation, Discusses Hurricane Katrina Relief Efforts. Sept. 3, 2005 http://www.whitehouse.gov/news/releases/2005/09/20050903.html
  3. American Society of Civil Engineers. LESSONS FROM HURRICANE KATRINA. Aug. 25, 2006 http://www.asce.org/pressroom/news/display_press.cfm?uid=2809
  4. Richard D. Knabb, Jamie R. Rhome, and Daniel P. Brown. Tropical Cyclone Report Hurricane Katrina. Aug. 23-30, 2005 www.nhc.noaa.gov/pdf/TCR-AL122005_Katrina.pdf
  5. U.S. Geological Survey. Louisiana Coastal Wetlands: A Resource At Risk. Nov. 3, 1995 http://marine.usgs.gov/fact-sheets/LAwetlands/lawetlands.html
  6. National Academy of Engineering of The National Academies. New Orleans and the Wetlands of Southern Louisiana. Nov. 26, 2007 http://www.nae.edu/NAE/bridgecom.nsf/weblinks/MKEZ-6MYST9?OpenDocument
  7. Louisiana Homeland Security and Emergency Preparedness. 2006 Louisiana Citizen Awareness & Disaster Evacuation Guides. Aug. 2, 2007. http://www.ohsep.louisiana.gov/evacinfo/stateevacrtes.htm
  8. MSNBC News Services. Efforts to revive New Orleans get back in gear. Sept. 25, 2005 http://www.msnbc.msn.com/id/9438536/
  9. http://news.nationalgeographic.com/news/2005/09/0902_050902_katrina_levees.html
  10. http://www.cnn.com/2005/WEATHER/08/28/tropical.weather/index.html
  11. http://www.nhc.noaa.gov/HAW2/english/basics/naming.shtml
  12. http://danswenson.com/paper/katrinagraphics/08levee-walls.jpg