Geography

• Natural hazard


  A natural event such as an earthquake, volcanic eruption, tropical storm or flood that has the potential to cause damage, destruction and death when it interacts with humans
• Types of natural hazard

  • Tectonic hazards (earthquakes and volcanoes)
  • Geomorphological hazards (flooding)
  • Atmospheric hazards (tropical storms)
  • Biological hazards (forest fires)
• Classifying hazards is made difficult because some may be caused by more than one physical process or influenced by human processes
• Hazard risk


  The probability or chance that a natural hazard may take place
• Factors affecting hazard risk

  • Increase in the number of people vulnerable to the natural hazard
  • Increase in the frequency and magnitude of the natural hazard
  • People's inability to cope with the natural hazard
• World population has increased
• More people are living near hazard-prone areas because they cannot move or do not have the financial means to migrate away, it's worth staying or simply they don't want to move
• Increase in the frequency and magnitude of hazards

  Due to climate change and deforestation/urbanisation
• Primary effects


  property, biuldings and homes destroyed
• Secondary effects


  Indirect effects of a natural hazard, e.g. economic slowdown, spread of disease, further destruction
• Primary effects of an earthquake

  • Property, buildings and homes destroyed
  • People injured and killed
  • Ports, bridges, roads and railways damaged
  • Pipes and electric cables broken
• Secondary effects of an earthquake

  • Business reduced and money spent repairing damage
  • Blocked transport infrastructure hindering emergency services
  • Broken gas pipes and fallen electricity cables starting fires
  • Burst water pipes leading to lack of clean water and poor sanitation
• Primary effects of a volcanic eruption


  • Property and farmland destroyed
  • People and livestock injured and killed
  • Air travel halted due to airborne volcanic ash
• Secondary effects of a volcanic eruption

  • Economy slows
  • Emergency services struggle to arrive
  • Ice melts, causing flooding
  • Lahars (mudflows) destroying property and killing people
• There are also positive effects of tectonic hazards, such as increased tourism and fertile farmland
• Responses to tectonic hazards

  • Immediate (issuing warnings, rescue, treatment, shelter, recovery)
  • Long-term (repair, rebuild, improve regulations, restore utilities, resettle, economic recovery, increased monitoring)
• Responses vary depending on factors like development level, resources, and effectiveness of warning systems
• Amatrice, Italy (2016) earthquake had 299 killed, 400 injured, US$25.4 billion damage, and 4,454 homeless
• Gorka, Nepal (2015) earthquake had 8,841 killed, 16,800 injured, US$5 billion damage, and 1 million homeless
• Conditions which cause tropical storms

  • Low latitudes (5-30 degrees north/south of Equator)
  • Warm ocean temperatures (above 27°C at 60-70m depth)
  • Between summer and autumn
  • Low wind shear
• Formation of tropical storms

  1. Air heated above warm oceans rises rapidly

  2. Strong winds form as rising air draws up more air and moisture

  3. Rising air spins around calm central eye due to Coriolis effect

  4. Rising air cools and condenses, forming clouds and rainfall

  5. Cold air sinks in eye, making it calm and clear

  6. Storm travels across ocean with prevailing wind

  7. Loses power on meeting land
• Primary effects of Typhoon Haiyan

  • 50% of houses destroyed
  • 6,190 people died
  • 4.1 million made homeless
  • US$12 billion of damage
  • Damage to rice cost US$53 million
  • Oil barge ran aground, causing 800,000-litre oil leak
  • 1.1 million tonnes of crops destroyed
• Secondary effects of Typhoon Haiyan

  • Infection and diseases spread due to contaminated water
  • Power supplies cut off for a month
  • Many schools destroyed, affecting education
  • Fishing industry disrupted by oil leak
  • Airport and roads blocked by debris
  • Survivors fearful of starving took government food stocks
  • Rice prices rose nearly 12%
  • Mangroves contaminated by oil leak
  • Flooding caused landslides and water contamination
• Immediate responses to Typhoon Haiyan


  • Government televised warning for people to prepare and evacuate
  • 800,000 people evacuated to reinforced shelters
  • Over 1,200 evacuation centres set up
  • Essential equipment and medical supplies sent out
  • Emergency aid supplies arrived within 3 days
  • Curfew imposed to reduce looting
• Ivorians fearful of starving to death took government stocks of food due to a lack of supplies
• By 2014 rice prices had risen by nearly 12%
• Ten hectares of mangroves were contaminated by the oil barge leak
• Flooding caused landslides and contamination of surface and groundwater
• The government televised a warning for people to prepare and evacuate
• Authorities evacuated 800,000 people. Many went to Tacloban indoor stadium, which had a reinforced roof to withstand typhoon winds; however, unfortunately it flooded
• Over 1,200 evacuation centres were set up to help the homeless
• The Philippine government ensured essential equipment and medical supplies were sent out, but in one region medical supplies and equipment were washed away
• Emergency aid supplies arrived three days later by plane. Within two weeks, over 1 million food packs and 200,000 litres of water were distributed
• The government imposed a curfew two days after the typhoon to reduce looting
• The celebrity couple the Beckhams, the X Factor TV show, and brands such as Coca-Cola, FIFA and Apple used their status to raise awareness and encourage public donations
• Thirty-three countries and international organisations pledged help? More than US$1.5 billion was pledged in foreign aid
• A 'cash for work' programme


  Paid people to clear debris and rebuild the city
• Oxfam replaced fishing boats
• In July 2014, the Philippine government declared a long-term recovery plan 'Build Back Better'. Buildings would not just be rebuilt but upgraded to protect against future disasters
• Rebuilding was slow-100,000 families were still in temporary accommodation in 2015!