HURRICANE KATRINA FLOOD

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HURRICANE KATRINA FLOOD

• BY
• JESSICA KANG

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Facts

• Formed over the Bahamas on August 23, 2005
• Crossed southern Florida (category 1)
• Turned into category 3 on August 29, 2005 and
  caused severe damage along the Gulf Coast from
  central Florida to Texas
• The most severe damage occurred in New Orleans,
  Louisiana

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More Facts

• At least 1,836 lives were lost, making it one of
  the deadliest U. S. hurricanes
• 705 are still missing
• Costliest hurricane 88.5 billion

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History

• New Orleans is located on a delta formed by the
  Mississippi River
• First settled by the French on the natural levee
  along the Mississippi bank (known today as the
  French Quarter)
• North of the natural levee, the land slopes down
  into a swamp

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History

• Around 1900, large pumps were introduced to drain
  this wetland
• Water was pumped up into canals and drained into
  Lake Pontchartrain
• By 1950, houses and buildings made up the city
  that we know of today

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Geologic Setting

• Since New Orleans rests on a delta and it is
  being drained, the city is continuously sinking
• This is because there is peat (unstable organic
  soil) found in the swamp

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Three Processes Behind Ground Subsidence on Peat

• Consolidation due to loss of water, when the
  peat loses volume in response to the loss of
  support offered by internal water pressure
• Compaction under load, both self-loading and
  imposed by other sediments or built structures,
  when the highly porous peat restructures into a
  denser material
• Wastage on exposure to air, when the peat simply
  oxidises and disappears where loss of water
  leaves it above the water table.

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Artificial Levees

• Knowing that the natural levees would not be
  enough to protect this sinking city, artificial
  levees were built.
• But they werent enough to withstand Katrina. . .

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How the Levees Failed

• Caused by under seepage through the levee silt
• The silt washed out and formed cavities in the
  levees, which grew larger
• Eventually, the levees collapsed

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Solutions Its Complicated!

• To rebuild or not to rebuild. . . Ethical issues
• Rebuild
• Continue building higher levees as the city keeps
  sinking
• Is it the right thing to do to rebuild in a
  hurricane prone area?
• Not to Rebuild
• Most people want to hear good news
• In the short-run it may be good, but in the
  long-run?
• Who is going to be responsible for the victims?
• Many victims were thrown out of their trailer
  that was provided as shelter after the disaster
• Government aid has also been cut off

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Works Cited

• Risk Management Solutions Inc. Hurricane
  Katrina Lessons of a Super Cat.
  http///www.rms.com. Web. 24 Feb. 2010.
• Robertson, Ian N. "Lessons from Hurricane Katrina
  storm surge on bridges and buildings." Journal of
  Waterway, Port, Coastal and Ocean Engineering
  133.6 (2007) 463-483. GeoRef. EBSCO. Web. 24
  Feb. 2010.
• Waltham, Tony. "The flooding of New Orleans."
  Geology Today 21.6 (2005) 225-231. GeoRef.
  EBSCO. Web. 24 Feb. 2010.
• Hurricane Katrina. http//en.wikipedia.org/wiki/Hu
  rricane_Katrina
• http//farm1.static.flickr.com/31/43339467_fbed138
  83f.jpg
• http//www.nhc.noaa.gov/HAW2/english/history/katri
  na_2005_map.gif
• http//lh3104.k12.sd.us/Event/katrina-new-orleans-
  flooding3-2005.jpg
• http//www.nytimes.com/2009/12/29/us/29trailer.htm
  l?_r1