The Most Natural Disasters That Befall Several Times A Year

Hurricanes are common natural disasters that befall several times a year. Most often, their wind strength are ranked less than Category 3, however occasionally, when conditions are favourable, they can grow into gigantic storms that bring devastation to anything in its vast reach; Hurricane Katrina of 2005 is the infamous one that pertain to the above description. Description of the Event While Katrina was only ranked sixth on the record in terms of wind strength recorded in the Atlantic basin, it is often recognized as the deadliest hurricanes to ever hit the United States. (http://www.livescience.com/22522-hurricane-katrina-facts.html). The massive storm had once had hurricane-force wind extending 120 miles out from the eye and tropical†¦show more content†¦Vulnerability New Orleans is very vulnerable to the disaster. Geographically, 80% of New Orleans is positioned below sea level. The bowl shape city made it prone to flooding (see figure 2). In addition, the city is surrounded by the Mississippi River to the South, Lake Pontchartrian to the north and Lake Borgne to the east, which significantly intensified the flooding problem. Furthermore, New Orleans is built on a delta marsh, which means that the ground is very impermeable, allowing floodwater to stay remain and build upon the surface. Finally, because of the depletion of wetlands, there were very little interception of the storm surge. Causes Hurricane Katrina originated on August 23 over the Bahamas as a result of the interaction of a tropical wave and the remnants of a previous tropical depression. As conditions further favoured its development into a tropical storm, it made its first landfall on August 25 in Florida. While scientist predicted that Katrina would move further Northward after landfall, it made a sudden change of course towards the Gulf of Mexico in the west. Due to the low wind shear, and the generally warmer sea temperature of the Gulf Loop Current, Katrina intensified rapidly. On August 28th, Katrina underwent a second intensification where it subsequently became a category five hurricane with maximum sustained winds of 175 mph. At this time, the strong upper-trophospheric ridge