Storm Hazards

Question 1

What is a tropical storm?

Answer 1

Huge spinning storms, with strong winds and torrential rain. Develop over warm waters.

Question 2

Conditions required for a tropical storm?

Answer 2

• Disturbance. near sea-surface e.g area of low pressure
• Sea water above 27°C, at least 50m below surface.
• Convergence of air in lower atmosphere
• Location at least 5° from equator, required Coriolis effect.

Question 3

Shape of Tropical Storms?

Answer 3

Circular, hundreds of km wide, last 7-14 days.
Spin in anticlockwise direction in northern hemisphere and clockwise direction in southern hemisphere.
Centre of the storm is an area of very low pressure called the eye.
Raising air spirals around the eye in the eye-wall, cause strong winds.

Question 4

How is storm magnitude measured?

Answer 4

Saffir-Simpson Scale

- Based on windspeed. Category 1-5.

Question 5

What are the hazards of Storms?

Answer 5

High Winds - more than 300km/h 
Storm Surges 
Heavy Rain 
Flooding 
Landslides

Question 6

Impacts of storm hazards?

Answer 6

Social - drown, injured/killed by debris, houses destroyed, electricity cut off, sewage contaminate water, disease spread, lack of food
Economic - buildings, businesses, agriculture land destroyed
Environmental - beaches eroded, habitats damaged, pollution, blocked water courses.
Political - people blame authorities for shortages, cause unrest, expensive repairs.

Question 7

Responses to reduce impacts of storm hazards?

Answer 7

Short-term : evacuating from areas at risk
Long-term :
- Prevention (studied to understand where is likely to be at risk)
- Preparedness (emergency services training, evacuation routes and education)
- Adaptation (buildings to withstand storms)

Question 8

Example?

Answer 8

Hurricane Katrina