geography 1

• A natural hazard is an event that causes damage to the environment, people or property.
• What increases hazard risk?

  If the population is more vulnerable to hazard, the risk is higher. This is because they lack resources to deal with the effects of a hazard. This means that they have higher risk and will be unable to protect themselves accordingly.
• Explain two human developments that increase the risk of people being affected by natural hazards. 4 marks

  One factor is climate change. This is because as temperatures rise, the earth has more energy. This means that there will be more frequent and intense storms.

  
  

  Another factor is poverty. This is because LICs may not have access to protective measures in homes such as flood defence or earthquake proof homes. This means that they're more at risk of hazards as a result will be more affected, and won't be able to afford aid or rescue services
• HIC case study CHILE

  27th February 2010

  8.8 magnitude

  Along destructive plate margin

  
  

  P EFFECTS - 500 killed, 12,000 injured, 52 ports and airports damaged, lost water supplies and power

  
  

  S EFFECTS - 1500km roads damaged, tsunami warnings issued

  
  

  Responses - international aid, reconstruction plans, power restored in homes after 10 days, after 24hrs highways fixed allowing traffic.
• LIC case study NEPAL

  25th April 2015

  7.9 magnitude

  
  

  P EFFECTS - 9000 died, 20,000 injured (half population), 3 million left homeless, 7000 schools destroyed

  
  

  S EFFECTS - avalanche on Mount Everest that killed 19 people

  
  

  Responses - roads cleared allowing traffic, search and rescue, international aid India donated 1 billion dollars
• How does CLIMATE CHANGE affect hazard risk

  As global temperatures increase, the atmosphere has more energy meaning more frequent and intense storms.

  The sea levels rise and cause changes in rainfall causing more floods and tropical storms.
• How does FARMING increase hazard risk

  Land next to volcanoes is very fertile due to nutrients therefore people want to live there to sell crops which increases the local income, so these populations will be at higher risk.
• How does URBANISATION affect hazard risk

  densely populated areas are more at risk because houses will be built closer together, so natural hazards will affect more people.

  
  

  housing demand exceeds the supply, so people will be forced to live in cheaper houses that aren't fit to withstand hazards.
• How does POVERTY affect hazard risk

  LICs may not have access to things such as flood defence and earthquake proof buildings. Their homes may be built on unstable land with bad quality materials that won't withstand hazards. They also may not afford healthcare or aid.
• To what extent do tectonic hazards vary in areas of contrasting wealth? 9 marks

  Tectonic hazards will occur wether its in a HIC or LIC. For example, in LIC Nepal in 2015, they suffered a 7.9 magnitude earthquake resulting in the death of 9000 people and injury of 20,000 around half of their population. In comparison, HIC Chile also suffered an earthquake measuring 8.8 on the Richter scale in 2010. It resulted in only 500 deaths. This could be due to better quality buildings and prevention strategies, which made their infrastructure less vulnerable to collapse as opposed to Nepal.
• To what extent do tectonic hazards vary in areas of contrasting wealth? paragraph 2

  The economic effects were more significant in HIC Chile than Nepal. For example, in Chile the damage costs were $30billion whereas in Nepal, they were six times less at $5billion. This means that they have more to repair long term and it is more costly due to the higher quality infrastructure needing to be repaired. The economic damage wasn't as significant in LIC Nepal due to poorer quality buildings.
• To what extent do tectonic hazards vary in areas of contrasting wealth? paragraph 3

  Another effect more significant in LIC Nepal is damage to ports and airports. For example, Nepal's airport became congested as aid arrived due to weak infrastructure. This means that aid couldn't reach people and it delayed immediate help. As a result more people would've been injured and the congestion would've slowed movement in and out of the airport, which also economically affects the area.
• Monitoring

  Volcanoes: Changes in the area can be detected such as

  • ground deformation
  • gases in the air
  • vibrations and smaller eruptions

  Earthquakes:

  • small tremors in the ground
  • ground deformation
• Prediction

  Volcanoes: historical trends can indicate the time frames of when similar events will happen allowing effective evacuation

  Earthquakes: historical records can predict strength if energy has been built up for more time
• Planning

  Volcanoes: dividing areas into different levels of risk, important buildings built far away from high risk areas

  Earthquakes: drills, identifying areas to protect infrastructure
• Conservative plates:

  Don't pass each other smoothly so friction builds up, when the plates finally slip past each other pressure is released sending energy that causes impactful earthquakes
• Destructive continental

  Continental plates moving towards each other, when they meet there is no subduction because they're of equal density. Powerful earthquakes form.
• Constructive

  Move away from each other, hot magma rises to fill the gap causing volcanoes. Fiery but less explosive
• Hadley cell

  At the equator, hot air rises, moves to higher latitudes(30) then sinks
• Ferrel cell

  60 degrees, moist air rises, travels to lower latitudes (30) then sinks
• Polar cells

  60 degrees north and south of equator, moist air rises and travels to the poles at 90 degrees where it sinks
• why is there low pressure at the equator and at 60 degrees


  heat from the sun is more concentrated
• why is there high pressure at the poles and at 60 degrees


  due to sinking air and the angle being far from the sun.
• when air rises...

  there is low pressure
• when air sinks...........

  there's high pressure
• how does global atmospheric circulation affect weather?

  Its cloudy and wet in the UK because it is case to where polar air meets warm subtropic air from the south. The rising air cools and condenses forming clouds and air
• What does rising air do

  it cools and condenses forming clouds and rain
• what is a tropical storm

  large area of low pressure where warm air rises and forms clouds as the air condenses .
• where do tropical storms form

  in the tropics, 5-15 degrees north and south of the equator because of higher INSOLATION meaning that the temperatures are higher
• Sea temperatures must be above 27 degrees to provide the heat and moisture that causes the warm air to rise in the low pressure area
• How do tropical storms form?

  1. Air is heated above the surface of warm tropical oceans. The warm air rises rapidly under low pressure conditions. The rising air draws up large volumes of moisture and air from the ocean causing strong winds. The spinning of the earth causes the air to spin upwards
• How do tropical storms form?

  2. As the air rises it cools and condenses to form large towering clouds that generate torrential rain. The heat given off when the air cools powers the tropical storm and draws more water from the ocean
• How do tropical storms form?

  3. Smaller thunderstorms join together to form a giant spinning storm. When the winds reach 75mph it officially becomes a tropical storm
• How do tropical storms form?

  The storm forms an eye at the centre where air sinks rapidly. Therefore there's no clouds so its drier and calmer. The outer edge of the eye is the eyewall where there's more intense conditions such as heavy winds and strong rain.
• How are topical storms formed?

  5. The tropical storm travels across the ocean along the prevailing wind wind gathers strength
• How are tropical storms formed?

  6. The tropical storm meets land and loses energy. Heat and moisture supply from the ocean is cut off. Friction with the land slows the storm and it begins to weaken
• Why do storms have a seasonal pattern

  Due to heat
• Give one condition for tropical storms to form

  27 degrees and above
• Give two reasons why tropical storms eventually lose their energy

  1. friction with the land weakens the storm
  2. when the storm meets land the moisture supply is cut off
• Give one reason why the number of tropical storms may change in the future

  Climate change causes sea surface temperatures to increase so they may occur outside the hazard zone