geography paper 1

• A natural hazard can be defined as a natural event that has a social impact
• Types of natural hazards


  • Tectonic hazards (volcanoes, tsunamis, earthquakes)
  • Biological hazards (forest fires)
  • Geomorphological hazards (flooding, mudslides, rockslides)
  • Atmospheric hazards (hurricanes, tornadoes, lightning, rain)
• Why do people live in hazardous areas?


  • They don't want to leave
  • They believe defences will protect them
  • They don't believe the hazard will occur
  • Economic reasons (jobs, facilities)
  • Social reasons (don't know where to go, language barriers)
• Human activity impacts climate change


  Leads to more flooding and extreme weather events
• Tectonic plates


  • They are part of the Earth's crust and are constantly moving
  • Oceanic crust is thin and less dense than continental crust
  • Destructive plate margin (continental-continental, continental-oceanic)
  • Conservative plate margin (plates move against each other)
  • Constructive plate margin (plates move away from each other)
• Primary effects


  First effect of a natural hazard on the population
• Secondary effects


  After effects of a natural hazard over a longer timescale
• Immediate response


  How people react as the event is happening and immediately afterwards
• Long-term response


  How people react in the weeks/months after the event
• High Income Country (HIC)


  Country with Gross National Income over $12,000 per person
• Low Income Country (LIC)


  Country with Gross National Income less than $12,000 per person
• Earthquakes in HIC


  • Chile (8.8 Richter, $30 billion cost)
• Earthquake in LIC


  • Nepal (7.9 Richter, $5 billion cost)
• Mitigating volcanic risks


  1. Map affected areas

  2. Evacuation plans

  3. Restrict land usage

  4. Emergency shelters and supplies

  5. Educate population
• Predicting volcanic eruptions


  1. Monitor temperature, gases, gravity changes

  2. Use satellite data to monitor ground movements
• Mitigating earthquake risks


  1. Map affected areas

  2. Locate critical buildings away from hazards

  3. Secure furniture in buildings

  4. Educate population

  5. Stockpile supplies

  6. Conduct earthquake drills
• New technology helps us better understand and protect against earthquakes
• Mapping areas affected by earthquakes

  • Identify areas that might be affected so hospitals and important buildings can be situated safely
  • Ensure buildings have furniture fastened down to reduce damage from flying objects
  • Educate local population on what to do in an earthquake
  • Stockpile food and medical supplies
  • Have earthquake drills to practice response
• Protecting against earthquakes


  • Use new technology to build earthquake-resistant buildings
  • Predicting earthquakes is much harder than other tectonic hazards, no clear warning signs
• Smartphones have accelerometers and GPS which can detect earthquakes minutes before they occur
• Pressure belts


  Important factors affecting global weather
• Climate cells


  Important factors affecting global weather
• Differences in the angle of the sun's energy hitting the Earth causes variations in heating at the equator and poles
• Features of global atmospheric circulation


  • Descending cool dry air and high pressure
  • Descending cool dry air and high pressure by the poles
  • Rising warm moist air and low pressure
• The tilt of the Earth and its rotation are responsible for seasonal changes in the positions of climate cells
• Locations and timings of tropical storms


  • Hurricanes in Atlantic/E Pacific Aug-Oct
  • Cyclones in Indian/S Pacific Jan-Mar
  • Typhoons in W North Pacific May-Dec
• Conditions for tropical storm formation


  • Low altitude
  • High temperature
  • High sea temperature
  • Sea 60-70m deep
• Wind speed categories for tropical storms

  Category 1, 2, etc. based on wind speed in km/h
• Tropical storm formation


  1. Air over warm oceans heated, rises under low pressure

  2. Air brings more air and moisture, resulting in strong winds

  3. Coriolis effect causes air to spin around calm center

  4. Evaporated moisture condenses and cools, drawing more moisture upwards

  5. Large clouds and heavy rainfall form
• Eye of the storm


  Dry and calm area as cold air sinks, stops storm gaining energy from water
• Climate change effects on tropical storms


  Increased temperatures, sea levels, and moisture lead to more frequent and destructive storms
• Typhoon Haiyan in 2013 was a category 5 storm with 275km/h winds and 15m waves, causing $12 billion in damage and 6,200 deaths
• Effects of Typhoon Haiyan


  • 90% of Tacloban destroyed
  • Hundreds of thousands displaced
  • Roads impassable, delaying aid delivery
  • Oil spill with environmental damage
  • Power, water, food supplies cut off, leading to looting
• Immediate response was evacuation and international aid, long-term response is rebuilding with better infrastructure and shelters
• Reducing effects of tropical storms


  • Plan storm shelters
  • Prepare disaster supply kits
  • Educate people on response plans
  • Install storm shutters, drains, and reinforced buildings
  • Remove trees that could damage buildings
• Weather agencies can predict storm paths and impacts to issue warnings
• UK extreme weather hazards


  • Snow and extreme cold
  • Strong winds
  • Droughts
  • Extreme rainfall and flooding
• 2013-2014 Somerset Levels flooding was due to heavy rainfall, high tides, and clogged riverbed
• Response to Somerset Levels flooding


  • Dredged rivers
  • Raised road levels
  • Installed tidal barricades
• Extreme weather in the UK is becoming more frequent and varied due to climate change caused by human activities