PMT Hazards

• Hazard


  A potential threat to human life and property caused by an event
• Hazards can be human caused or occur naturally (natural hazards)
• An event will only become a hazard when it is a threat to people
• Natural disaster

  An event that occurs when a vulnerable population is exposed to a hazard
• Major types of geographical hazard

  • Geophysical
  • Atmospheric
  • Hydrological
• Hazards can also be a mixture of these geographical processes
• Hydrometeorological hazards


  Hazards that are both atmospheric and hydrological
• Hazard perception

  People's viewpoints of how dangerous hazards are and what risk they pose
• Lifestyle factors

  Economic and cultural elements that affect people's hazard perceptions
• Wealth


  The financial situation of a person that affects how they perceive hazards
• Experience


  Someone who has experienced more hazards may be more likely to understand the full effects of a hazard
• Education


  A person who is more educated about hazards may understand their full effects on people and how devastating they can be
• Religion and beliefs


  Some may view hazards as put there by God for a reason, or being part of the natural cycle of life
• Mobility


  Those who have limited access to escape a hazard may perceive hazards to be greater threats than they are
• Fatalism


  The viewpoint that hazards are uncontrollable natural events, and any losses should be accepted as there is nothing that can be done to stop them
• Active responses to hazards

  1. Prediction

  2. Adaptation

  3. Mitigation

  4. Management

  5. Risk sharing

  
• New Zealand is an example of where risk sharing has worked
• Incidence


  Frequency of a hazard
• Distribution


  Where hazards occur geographically
• Intensity

  The power of a hazard, i.e. how strong it is and how damaging the effects are
• Magnitude


  The size of the hazard, usually this is how a hazard's intensity is measured

  
• Magnitude and intensity are not interchangeable terms
• Level of development

  Economic development will affect how a place can respond to a hazard
• Even if the hazard is identical, an area with a lower level of development is less likely to have effective mitigation strategies as these are costly
• There are many high income countries that are not as prepared for natural hazards as they should be, meaning they lack the management strategies for an event
• The Park Model


  A graphical representation of human responses to hazards, showing the steps carried out in the recovery after a hazard
• The Hazard Management Cycle

  Outlines the stages of responding to events, showing how the same stages take place after every hazard

  
• Stage 3 - Reconstruction

  1. Restoring the area to the same or better quality of life

  2. Area back to normal - ecosystem restored, crops regrown

  3. Infrastructure rebuilt

  4. Mitigation efforts for future event
• Control line

  A model to compare hazards
• An extremely catastrophic hazard


  Would have a steeper curve than the average and would have a slower recovery time than the average
• The Hazard Management Cycle

  1. Preparedness

  2. Response

  3. Recovery

  4. Mitigation

  
• Hazard models

  • The unpredictability of hazards makes the models less effective at accurately representing human responses to hazards
• Can hazard models be applied to every hazard? Are some hazards more complicated and require a more complex model?

  
• Does the model take any aspects of hazards into account such as level of development?

  
• Inner core

  Solid ball of iron/nickel, very hot due to pressure and radioactive decay
• Outer core

  Semi-molten, iron/nickel
• Mantle


  Mainly solid rock, high in silicon, top layer is semi-molten magma (asthenosphere)
• Asthenosphere


  Semi-molten layer constantly moves due to convection currents
• Lithosphere


  Broken up into plates, majority within mantle, top is the crust

  
• Crust

  The thin top of the lithosphere, oceanic crust is dense and destroyed by plate movement, continental crust is less dense and not destroyed