You are here
Definition of Tornado
Tornadoes are violent rotating funnel shaped clouds which extend from the ground to the base of a thunderstorm. They are the result of powerful thunderstorms and can reach rotational speeds of 300miles/hr. Damage paths can be as much as 1 mile in width and 50 miles in length. The formation is usually rapid and transparent until debris and dust becomes buoyant in the swirling winds. Before a tornado hits, there can be a period of calm air, similar to that of the period before a hurricane hits.
In Trinidad and Tobago we rarely see tornadoes as they are defined above. A swirling vortex is seen that doesn’t extend from the base of the cloud to the ground. These do not have an established scientific definition but can be as dangerous as a tornado so the same precautions must be taken.
Formation of Tornadoes
A thunderstorm develops due to a change in wind direction and an increase in wind speed with altitude. This creates a horizontal rotation of the air in the lower atmosphere due to a pressure difference.
Air rises upward due to the low pressure system causing the rotational air to tilt from horizontal to vertical.
The area of rotation grows and can grow as much as the width of the thundercloud.
List and discussion of Vulnerabilities
• Type and density of infrastructure
Squatter settlements and low income housing are more susceptible to these risks even though it is not limited to them. There is usually loose roofs, walls, galvanize and this poses a serious threat when they become mobilized by the wind.
• Belief and customs/ Lack of knowledge
There is a belief especially in Trinidad and Tobago that tornadoes are only found abroad. Due to this there is very little attention paid to this type of hazard. Also if one was to occur, there would be a very slow and belated response to depart for safety.
• Traffic and road networks
Throughout the day there is usually heavy traffic congestion, especially along the East-West corridor. A tornado can quickly formed during severe weather conditions and the hot road can the perfect pathway for a tornado, with stranded motorists in its path
• Livestock and Agriculture
In many areas, farming is the main source of financial income. Most animals are stored in very fragile pens and coups and on flat plains. This makes them a direct target for a tornado.
• Poor design of buildings
If the consideration of a tornado was not taken into account during the design and construction of a building, this makes them vulnerable if one does occur.
• Resource based economy
Trinidad and Tobagohas a petroleum based economy and a tornado like any other disaster can cause billions of dollars in damages if sensitive and expensive equipment used for the extraction of oil and gas and the production of other chemicals are damaged.
Secondary Hazard Impacts
The occurrence of a tornado can trigger secondary hazard impacts especially of a technological nature, for example:
- Damaged Household LPG (gas) tanks: these tanks may explode and cause further damage like fires, blast waves, projectiles, ear drum rupture and hemorrhaging.
- Damaged toxic chemical and high pressure tanks: Chlorine tanks near pools, Nitrogen and Oxygen tanks in hospitals. These could result in chemical hazards and fire
Sewer line ruptures: This may contaminate water lines and become a biological disaster. There may be the spread of diseases e.g. cholera and E Coli infection.
How to reduce the risk of tornado hazard
- Formulation and implementation of proper building codes
- Cooperation of the public with relevant authorities
- Public education and awareness in schools, media and community centers about tornadoes
- Proper evacuation procedures for public buildings
- Addressing the traffic situation
- Proper storage for animals
- Agency, U.S. Environmental Protection. Terms of Environment:Glossary, Abbreviations and Acronyms. october 2, 2006. (accessed December 16, 2010).
- Schmidlin, Thomas. RIsk Factors and Social Vulnerability. 2004.
- The Online Tornado FAQ (by Roger Edwards, SPC)
- Risk Factors and Social Vulnerability
- International Strategy for Disaster Reduction