Hurricane Katrina

HURRICANE KATRINA

The 6th strongest Atlantic hurricane ever recorded. Hurricane Katrina formed over the Bahamas on August 23rd during the 2005 hurricane season, travelling over the Gulf of Mexico, via Florida, Louisiana, Mississippi,



As the initial low-pressure system passed over the Caribbean islands it lost energy, which it then regained whilst passing over the Gulf of Mexico, with the system becoming a hurricane. It reached its peak strength on August 28th 2005

TIMELINE OF EVENTS

FLORIDA (25 August) – The initial stages

Winds hit 80mph and rainfall was very heavy (exceeding 14 inches in places) and there was a storm surge of 3-5 feet causing significant damage

LOUISIANA and NEW ORLEANS(August 29)



80% of New Orleans and the surrounding area is below sea level and the relief is very flat, especially the land alsonside Lake Pontchartrain. The area is drained by the Mississippi and the cities are located on the floodplains.

The initial prediction was for a storm surge that would be greater than 28 feet which would go over the levees that were in place to protect the city from flooding

On August 29 the inevitable happened and a storm surge broke the levee protection flooding most of the city, and canals allowed water to flow from the lake into low areas of the city.

In Louisiana, wind speeds hit 125 miles per hour and there was a storm surge of approximately 12 foot in Grand Isle.

There was also heavy rainfall of 8-10 inches in the east and 15 inches around the area of Slidell which contributed to a storm surge and caused lake Pontchartrain to rise

It was the eye of the hurricane that passed over New Orleans.

Here, the high winds and storm surges greatly weakened the city’s levee system and caused huge failures of the levees and flood walls protecting both New Orleans and Louisiana.

The major levee failures in the city included the 17th street canal levee, the London Avenue canal and the industrial canal, leaving 80% of the city flooded, as well as the Mississippi Gulf Outlet breaching its levees in over 20 places which substantially contributed to the flooding of New Orleans.

The quality of housing also contributed to the amount of destruction as the houses were typically made of wood and built on stilts, which would topple very easily

MISSISSIPPI (29 August)

There was sustained winds of 120 mph contributing to a storm surge of 27 foot, that penetrated up to 12 miles inland along bays and rivers. This was accompanied by heavy rains of 8-10 inches which greatly contributed to flooding in the area



THE IMMEDIATE EFFECTS
Environmental
Sustained strong winds
Torrential rainfall
Flooding (storm surge of 6 metres)
Localised tornadoes
landslides
Flooded roughly 80% of the city.
1.3 million acres of forest lands in Mississippi were destroyed
Wildlife killed
The storm surge caused substantial beach erosion - Dauphin Island was pushed closer towards land. The lands that were lost were also breeding grounds for marine mammals, turtles and fish as well as migratory species

Social
1200 Deaths
1 million Homeless
Riots and Lootings
Suicide


Economic
Katrina is estimated to be responsible for $75 billion in damages
Hundreds of thousands of local residents were left unemployed
Katrina redistributed New Orleans’s population across the southern United States. Houston, Texas saw an increase of 35,000 people
Buildings destroyed
In Mississippi, 90% of the structures within half a mile of the coastline were completely destroyed.
Infrastructure destroyed
Almost 900,000 people in Louisiana lost power.
Crops destroyed

SECONDARY, LONG TERM EFFECTS
Economic crisis – jobs, lack of money, deprivation
Potential food shortages – if crop supplies destroyed
Potential Disease outbreak – cholera and typhoid
Mental health issues – depression and suicide