Storm Hazards

• Tropical storms


  Weather depressions caused by low pressure
• Names of tropical storms in different regions

  • Hurricanes (Atlantic)
  • Typhoons (Pacific)
  • Cyclones (Indian Ocean)
• All tropical storms need the same conditions to form and can cause severe disruption
• How tropical storms develop

  1. Warm, moist air rises, causing an area of lower air pressure below

  2. Air from surrounding areas with higher air pressure pushes in to the low pressure area

  3. Warm, moist air continues to rise and cool, forming clouds

  4. The whole system of clouds and wind spins and grows, fed by the ocean's heat and water evaporating from the surface

  5. Storms north of the equator spin counterclockwise, storms south of the equator spin clockwise (Coriolis force)

  6. An eye forms in the center, with very low air pressure and calm, clear conditions
• Saffir-Simpson scale


  Classification of tropical storms according to their wind speed
• Hazards created by tropical storms

  • High winds
  • Storm surge
  • Heavy rainfall
• Primary effects of tropical storms

  • People injured or killed by debris
  • Drowning
  • Buildings destroyed or damaged
  • Electric supplies cut off
  • Sewage released
  • Water supplies contaminated
• Secondary effects of tropical storms

  • People left homeless
  • Lack of clean water and sanitation, water-borne diseases
  • Road and rail networks blocked
  • Unemployment from damaged businesses
  • Food shortages from crop/livestock damage
• Immediate responses to tropical storms

  1. Evacuate people before storm

  2. Rescue and provide medical support

  3. Set up temporary shelters

  4. Provide water and food

  5. Recover dead bodies

  6. Update digital maps using satellite photos
• Long-term responses to tropical storms

  1. Repair and rebuild properties

  2. Rehouse people

  3. Repair transport infrastructure

  4. Improve forecasting and early warning systems

  5. Provide grants and aid

  6. Improve building regulations

  7. Offer incentives for economic recovery
• A tropical storm is a low pressure, spinning storm with high winds and torrential rain
• Conditions for tropical storm formation

  • Warm ocean temperatures (>26-27°C)
  • Unstable air pressure (convergence of high and low pressure)
  • Presence of winds but not too strong
  • Location 5-20° from equator (Coriolis effect)
  • Trigger event (thunderstorm, high sea temp, low pressure)
• Formation of tropical storms

  1. Warm, moist air rises, leaving low pressure below

  2. Warm air from surrounding areas moves into low pressure and rises

  3. Warm air cools, condensing into thunderstorm clouds

  4. Coriolis effect causes spinning motion

  5. Constant energy from warm air causes faster spinning and higher winds

  6. Eye of low pressure forms in center

  7. Eyewall of most intense winds and rain surrounds the eye

  8. Storm reaches land, loses energy source and eye collapses
• Saffir-Simpson scale


  Measures magnitude of tropical storms based on wind speed
• Tropical storms form in the Northern Hemisphere from June-November, and the Southern Hemisphere from November-April
• Regularity of tropical storms

  • Irregular, as their path does not follow a set route but depends on the storm and climatic conditions
• Predictability of tropical storms

  • Can be predicted more accurately as they approach land, using satellite tracking and forecasting models
  • Probability of storms hitting an area can also be predicted based on past trends and climate data
• Hazards caused by tropical storms

  • High winds
  • Flooding
  • Landslides
  • Storm surges
• Types of storm hazard impacts

  • Environmental
  • Economic
  • Social
  • Political
• Risk management strategies for storm hazards

  1. Risk assessment and mapping

  2. Community education and awareness

  3. Early warning systems

  4. Evacuation plans and drills

  5. Meteorological monitoring

  6. Data collection and analysis

  7. Research and scientific partnerships

  8. Activation of emergency services

  9. Implementation of evacuation orders

  10. Emergency shelters and relief supplies

  11. Maintenance of critical infrastructure

  12. Assessment of impacts

  13. Infrastructure repair and rebuilding

  14. Support for affected communities

  15. Review and improvement of response plans

  16. Building codes and standards

  17. Flood control systems

  18. Vegetation management