Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


Edexcel AS Unit 1 - World at Risk

No description

Rupert Heathcote

on 28 April 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Edexcel AS Unit 1 - World at Risk

Unit 1 Global Challenges
Define what the following terms mean:
Natural Hazard
Hydro- meteorological hazard
Geophysical hazard
Chronic hazard
World at Risk
Natural Hazard

A naturally occurring process or event which has the potential to cause loss of life or property.

Without people it is just a natural event not a hazard, it needs the interaction of people to make it a hazard


The realisation of hazard. Although there is no universally agreed definition of the scale of loss which has to occur in order to qualify as a disaster


The exposure of people to a hazardous event which may present a potential threat to people or their possessions


To be susceptible to physical or emotional injury or attack (from natural hazards)

Cyclone Thunderstorms Wildfire

What is the connection between the pictures in this group?

Hydro-meteorological Hazard

Natural hazards that are caused by water, the weather or by a combination of both

Tsunami Earthquake Landslide

What is the connection between the pictures in this group?

Geophysical Hazard

Natural hazards caused by the physical processes that act upon, above or within the earth. For example – earthquakes, volcanoes, landslides

Chronic Hazard

A hazard that is long term-term and persistent e.g. El-Nino or Global Warming

Vulnerable population:
susceptible to human
and economic loss

No interaction of human and physical systems

Hazardous Event
e.g flood or earthquake

No hazard or disaster

The disaster equation

Vulnerable population:
susceptible to human
and economic loss

Interaction of human and physical systems

Hazardous Event
e.g flood or earthquake


The disaster equation
Look at the following list of hazardous events and decide if it is a natural event or natural hazard
1 A cyclone affecting Hong Kong
2 A hurricane passing over a remote unpopulated island
3 An avalanche in a ski resort
4 An avalanche high on mountainous slopes remote from any settlement


The Disaster Risk Equation

Hazards x Vulnerability

Risk =
Capacity to cope
The risk of disaster grows as global hazards and people’s vulnerability increases, while their capacity to cope decreases
Important to know that vulnerability is not the same as poverty

For example, in an earthquake, it is possible for middle class to be more affected by the collapse of their unsafe homes than the poor in a shanty town whose flimsy homes collapse and cause little damage
Produce spider diagrams to explain how the following factors can effect vulnerability:

Wealth of people
Technical ability of a country

Vulnerability Factors

The impacts of any hazard are a result of peoples vulnerability, not necessarily the hazard’s strength. People remain exposed to risk (i.e. vulnerability) for a variety of reasons:

Importance of Vulnerability

1. Vulnerable people do not live in dangerous places because they want to; they do it because they have to. Land may be cheaper, or unwanted by others

2. Vulnerable people cannot afford to build well, even if building regulations are enforced.

3. Rapid urbanisation has forced the poor into high risk areas of cities

4. Changing risk – Rising sea levels mean that safe areas are now prone to flooding and storm surges. Deforestation of watersheds reduces interception and increases the risk of flooding.

5. Cost v Benefits – e.g. benefits of fertile soils on volcanoes vs. risk of eruption

How do EM-DAT define disaster?

Is the world more hazardous now?

So would you expect the number of deaths to increase as well?

It is clear that the number / frequency of reported natural disasters has increased, but what factors could influence this?

International monitoring agencies e.g. CRED, EM DAT
More vulnerable populations living in marginal areas
Increase in hydrometerological hazards – climate change
Unfortunately in the developing world this is not always the case

There is a decreasing number of deaths due to hazards- WHY?
Better understanding of natural disasters
Better preparedness
Better technology

Majority of costs incurred in developed countries

There is a decreasing number of deaths but an increase in economic effects.
Since 1980, the average annual economic cost of hazards has risen from less than $20 bn to more than $160 bn.

Economic Costs

Frequency: How often an event of a certain size (magnitude) occurs.

Magnitude: The size of an event e.g. force of a gale on the Beaufort scale or size of earthquake on Richter scale

Using your handout answer the following questions

1) Using the four graphs, outline the trends in global disasters (5)
2) Suggest why the number of disasters has increased, but the number of deaths has fallen (5)
3) Study the two world maps and describe the patterns shown (5)
4) Suggest why Asia has the greatest number of deaths from natural disasters (5)

A country or area which is extremely disaster prone
Combination of exposure to geophysical hazards, hydrometerological hazards and the vulnerability of the population

Identification of these areas is very important for planning – especially in poorer countries where hazard planning may not always be a priority.

Disaster hotspots

You need to learn case studies of both the Philippines and Californian hotspots in depth

Statistics / examples
Simple sketch map
Types of hazard and why experienced there
Interaction between the populations and the natural hazards

Disaster hotspots

La Nina
Occasionally as an El-Nino year dies out, a third weather condition arises - La-Nina
An exaggerated version of normal conditions
Current – El Niño to return Spring 2014

El Niño – The Christ Child (in Spanish)
During El Niño winds across the Pacific change direction and blow from West to East.
This changes the weather patterns around the Pacific.
Occurs every 3 – 7 years although they appear to be getting more regular.
Normal Year
The trade winds move warm surface water towards the western Pacific
Cold water wells up along the west coast of S.America (near Peru)
Upwelling important for fish stocks in Peru
El Nino Year
Air pressure over West coast of S. America becomes low and air over west Australia high pressure
The normal east to west trade winds over pacific are disrupted and warm water ‘sloshes’ eastwards
No upwelling on S. American coast

Full transcript