Introduction
A tempestuous storm with force of winds up to 300 miles an hour is recognized as tornado. Shaped like a funnel, tornado appears to be a gray or black colored cloud moving towards the ground from its base of origin. An average tornado proceeds from southwest to northwest at a speed of 30-70 miles/hour but it can move into any direction or stay stationary in extremely rare cases. Tornadoes are sometimes accompanied by hurricanes. Tornadoes are atmospheric hazards that have the strength to uproot buildings and trees and turn them into deadly missiles within seconds. They are the most destructive natural hazards that strike the nation every year resulting in huge loss of lives and properties. The range of damage can extend 50 miles long and one mile wide. USA is the most Tornedo hit country in the whole world. On an average the country sees around 1,200 tornedoes per year which is almost four times more than the number of times tornadoes strike the whole of Europe. In USA tornedoes are more prevalent on the eastern side of the Rocky Mountains including northern and central parts of Kansas, Alabama and Mississippi, north-eastern Texas and Georgia. Louisiana and South Carolina are one of the most tornedo prone areas in USA. This area is often referred as the Dixie Alley. Alabama, Mississippi and Florida experience the maximum number of tornedoes every year but not of all them are of high category. Northern part of Texas is a tornado prone zone which experiences some high category tornedoes than most of the other parts of USA.This paper will mainly focus on the tornadoes of the Dixie Alley and analyze how the risk of damage to life and property can be mitigated during the tornedoes.
Tornedoes in Dixie Alley: USA
USA has what is known as the Tornado Alley starting from the north of Texas and expanding up to Canada. This area is considered to be the most tornedo prone in the world. However, Dixie Alley experiences more number of high category tornedoes than any other place in the world. Dixie Alley suffers the maximum number of casualties than any other region due to high population density and high category tornedoes hitting the area. Over the last 50 years Alabama and Kansas have witnessed the maximum number of F5 tornadoes. Dixie Alley tornedoes are distinct in characteristics than tornedoes of other region. Due to the presence of Gulf of Mexico, tornedoes in the region often gather lot of moisture and are generally rain wrapped. This makes it difficult to see the actual core of the tornedoes. Hilly topography, heavy forest makes those tornedoes more devastating. Although most of the tornedoes occur between May and June in USA, Dixie Valley is an exception. This area does not have a pattern for tornedoes. Dixie Alley has seen Super Tuesday Tornedo during February 2008 in winter which is not a tornado season. Tornedoes usually form in the region during the transition season when cold air and hot air clash with each other. The Gulf of Mexico brings about this type of temperature imbalance every year leading to a tornado outbreak. Some of the well-known tornadoes are the Great Natchez, Enigma of 1884, Deep South tornado outbreak of 1932, Tupelo-Gainesville tornado outbreak of 1936, Carolina’s tornado outbreak of 1984 and Super Tuesday tornado outbreak of 2008. April tornedo outbreak of 2011 in Dixie alley was the 4th deadliest tornado in the history of USA, killing 300 people.
Tornedoes in Dixie Alley: Hazard Assessment
Hazard assessment is essential to create a good mitigation plan for avoiding the damaging impact of tornadoes. Once a tornado is detected by the meteorological department, it is essential to determine how hazardous the tornado is going to be. Fujita scale (F-Scale) or the enhanced Fujita scale (EF-Scale) are the two mostly used scales to measure the power of a tornado. If a tornado is detected to be in the range of EF-0 to EF-2 (in Enhanced Fujita Scale) then the mitigation planning would be completely different from the preparation undertaken to tackle EF-4 or EF-5 tornedoes. EF-4 and EF tornedoes are the most devastating ones with the potency to inflict maximum damage to a place. Also the emergency management agency like FEMA and the state and local government need to evaluate the probability and frequency of tornedoes in the tornado prone region. If tornedoes are as infrequent as once in 20 years then the action plans will be different from that of Dixie Alley which sees more than 3-4 small and big tornedoes every year. The region also experiences tornedoes greater than EF-3 once in every 5 years. Once the frequency and category is determined for a tornado, the area which is likely to receive the maximum impact needs to be determined. For example, although central and western Texas is very close to Dixie Alley, it sees almost no tornedoes and therefore, implementing a tornado mitigation plan in that region will be sheer wastage of money. On the other hand, Alabama and lower Mississippi valley are the most commonly affected areas in need of maximum risk mitigation plans against tornadoes.
Tornedoes in Dixie Alley: Vulnerability Assessment
Vulnerability assessment depends on region to region. For example, New York may have less chances of structural vulnerability as most of the buildings are steel and concrete made. However, the same cannot be said for Dixie Alley. This region is one of the highest populated in the whole of USA and therefore, chances of human casualties is one of the big concerns during tornedoes. Another problem in this area is that it has the maximum number of manufactured houses in all of USA easily destructible by tornedoes. For this reason the potential structural damage in Dixie Alley due to tornadoes is enormous. As most of the tornedoes take form in and around the Gulf of Mexico before hitting Dixie Alley, a lot of rain precedes and follows the tornado. This may also cause widespread flood and flood related loss in the region.
Tornedoes in Dixie Alley: Mitigation Plans
A comprehensive tornedo risk mitigation plan should be in place for Dixie Alley. Because of the typical nature of the region the plan in Dixie valley should give special focus on structural damage, flood related damage and relocation options. Dixie Alley has the maximum number of manufactured homes in USA and because of that this area sees more tornado related structural damage than any other area. These structural damages often contribute to higher number of loss of human lives. The first action plan that should be taken in the region is to make people aware about safe shelters and tornado safe homes. Firstly, people should be made aware of building houses in such a way that the structures can withstand most of the tornedoes. Federal and state government should provide required help to assist people acquire relevant knowledge about tornado safe houses. Secondly, there should be enough number of safe shelters all across the region to accommodate maximum number of people during and immediately after the disaster. The federal and state government should help build those shelters and then the local administration can run awareness campaigns to inform people about where to move during the crisis. A lot of Dixie Alley states like Oklahoma, Kansas and Alabama do not have sufficient number of shelters and therefore these states require more attention from all corners.
Another big factor conducive to enormous damage immediately after a tornado in Dixie Alley is the accompanying flood. Over the last few years the state and local government with the help of FEMA have started relocating people to high lands and areas where there are less chances of flood during the crisis. FEMA is also making efforts to identify flood prone areas and convince the local government not to grant permission to build houses in that region. These small precautionary disaster plans help in the reduction of damaging impact of tornadoes to a great degree. The Dixie Alley area is also home to a lot of dams. Dam failures contribute to huge floods accounting for economic, agricultural and human life loss. FEMA also has started making endeavors to examine the vulnerabilities of the dams closely and giving recommendation to improve structures. For Example, Decker and Longhorn Dam in Austin, Texas is going through a structural change to decrease its chances of failure owing to a tornado outbreak.
Conclusion
Tornedoes are natural disasters which cannot be stopped by human forces. We need to understand the impact of a tornado and act in a way to mitigate the risk of damage and loss. To do it first we need to understand the severity of the tornado. Once we understand that, we need to also find out the areas likely to be affected by tornadoes and how vulnerable those areas are. Then the federal, local and state government should combine together to create an action plan to minimize the risk of loss of human life and economic loss due to tornadoes. Once pre tornado and post tornado action plans are made, all concerned parties should work together to implement that into action. If the government and people of the affected region come together and act according to a plan then in future tornado related casualties and economic losses will be minimized.
Bibliography
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