Storm Hazards Flashcards
What conditions are required for a tropical storm to form?
- Ocean temperature above 27°C
- Depth of more than 70m
- 5° N or S of the equator for Coriolis Effect
- Area of low pressure (depression)
What is the sequence of tropical storm formation?
- Warm air rises leaving low pressure below
- More warm air drawn in and rises
- Warm air condenses into cumulonimbus clouds
- Systems spins due to Coriolis Effect
- Constant energy supply from the ocean generates higher wind speeds
What is the eye of the storm?
- An area of extreme low pressure in the centre of the storm
- Characterised by calm, cloudless weather
What is the eyewall?
- Surrounds the eye of the storm
- Most intense and powerful. with high winds and torrential rain
What is storm surge?
- Sea level rapidly rises as the water bulges upwards and is pushed towards the coastline
- Caused due to the low pressure above the ocean
What are the secondary hazards caused by tropical storms?
- Storm surge
- Coastal and river flooding
- Landslides
What is the spatial distribution of tropical storms?
Located between 5° and 20° N and S of the equator (Coriolis Effect)
How do tropical storms rotate in both Hemispheres?
- Northern Hemisphere = anti-clockwise
- Southern Hemisphere = clockwise
How is tropical storm magnitude measured?
Saffir-Simpson Scale (1-5)
- CAT 1 = Not very intense
- CAT 5 = Very intense
What is the frequency of storm hazards?
- JUN-NOV in N Hemisphere
- NOV-APR in S Hemisphere
- Intense storms are thought to be increasingly frequent
What is the regularity of storm hazards?
- Occur in the same geographic areas
- Do not follow a set route
How predictable are storm hazards?
- Difficult to predict
- Rapid onset
- May intensify and take an erratic path
What are social impacts of tropical storms?
- Debris in high winds
- Buildings destroyed
- Homelessness
- Crop failure
What are economic impacts of tropical storms?
- Businesses destroyed
- Agricultural land damaged
- Economic decline
- Rebuilding cost and insurance payouts
What are environmental impacts of tropical storms?
- Beaches eroded and sand displaced
- Coastal habitats destroyed
- Coastal flooding
- Water contamination
What are political impacts of tropical storms?
- Government buildings destroyed
- International aid debt
- Pressure for climate action
What are examples of preparedness?
- Monitoring ocean conditions
- Weather satellites
- Evacuation plans
- Education
What are examples of prevention?
- Cannot be avoided
- Climate change action
What are examples of mitigation?
- Search and rescue
- Clear loose debris before storms
- Protection strategies such as drills
- Increased infrastructure resilience
What are examples of adaptation?
- Land-use planning
- Move away from high risk areas
- Engineering strategies such as seawalls
- Wind-resistant buildings
What type of buildings are at highest risk during a tropical storm?
Informal housing built on marginal land
What are small-scale pressure impacting tropical storm damage?
- Lack of education and training
- Food insecurity
What are large-scale pressure impacting tropical storm damage?
- R to U migration
- Rapid population growth
- Large outstanding debt
- Unsustainable exploitation (e.g. deforestation)
