Natural Hazards

• A natural hazard is a natural process which could cause death, injury or disruption to humans, or destroy property and possessions.
• A natural disaster is a natural hazard that has actually happened.
• Extreme events which do not pose any threat to human activity are not counted as hazards.
• Geological hazards are caused by land and tectonic processes.
• Volcanoes and earthquakes are geological hazards.
• Meteorological hazards are caused by weather and climate.
• Tropical storms and other extreme weather events are meteorological hazards.
• Hazard risk is the probability of people being affected by a hazard in a particular area.
• The factors that affect hazard risk are vulnerability, capacity to cope and the nature of natural hazards.
• Vulnerability:

  The more people that are in an area exposed to natural hazards, the greater the probability they will be affected by a natural hazard.
• Capacity to Cope:

  The better a population can cope with an extreme event, the lower the risk of them being severely affected.
• Nature of Natural Hazards:

  • Type - the risk from some hazards is greater than others
  • Frequency - natural hazards that occur more often may carry a higher risk
  • Magnitude - more severe natural hazards tend to have a greater effect
• The primary effects of natural disasters are the immediate impacts caused by the hazard itself.
• Examples of Primary Effects:

  • Buildings and roads destroyed
  • Death/injury
  • Crops and water supplies damaged/contaminated
  • Electricity cables, gas pipes and communications networks can be damaged
• The secondary effects of natural disasters happen later on, often as a result of primary effects.
• Examples of Secondary Effects:

  • The initial hazard can trigger other hazards
  • Aid and emergency vehicles can't get through because of blocked roads etc.
  • Disease can spread due to shortages of clean water
  • Food shortages if crops are damaged
  • Weakened economy
• Immediate Responses:

  • Evacuation
  • Treating the injured and rescue
  • Recover dead bodies
  • Provide temporary electricity and gas
  • Provide food, drink and shelter
  • Aid workers, supplies or financial donations
• Long-Term Responses

  • Repair homes / rehouse people
  • Repair infrastructure
  • Reconnect damaged supplies
  • Improve forecasting, monitoring and planning
  • Improve building regulations
  • Boost economic recovery