Global Hazards

Question 1

What is a hazard?

Answer 1

Something thats a potential threat to human life or property

Question 2

What is a disaster?

Answer 2

Realisation of a hazard

Question 3

What is a natural hazard?

Answer 3

Caused by natural processes

Question 4

What is a hydrological hazard?

Answer 4

Caused by climatic processes (floods)

Question 5

what is a geophysical hazard?

Answer 5

Caused by land processes (earthquakes)

Question 6

What is a disaster risk equation?

Answer 6

Risk = (hazards X vulnerability) / capacity to cope
Risk: likelihood that humans will be seriously affected by a hazard
Vulnerability: how susceptible a population is to damage caused by a hazard
Capacity to cope: ability to deal with the consequences of a hazard

Question 7

Give 3 ways which can increase the risk of a disaster

Answer 7

The frequency/severity of a hazard increases
Peoples vulnerability increases
Capacity to cope decreases

Question 8

What are the 5 main human factors that increase meteorological hazards?

Answer 8

Rapid population growth/urbanisation (mainly LEDCs)
Increasing global poverty increases vulnerability
Exploitation of resources (deforestation)
Increasing media coverage/reporting gives an impression that more hazards are occuring
In LEDCs, poorer people are forced to move to marginal land which is often more at risk from flooding/land slides

Question 9

What are the 2 main physical factors that increases meteorological hazards?

Answer 9

Impact of global warming is thought to increase the frequency/magnitude of hazards,in particular more flooding and longer droughts as well as an increase in hurricanes. Glaciers melting is another factor
El Nino can influence global warming patters and the Pacific in particular, this can make the prediction of HM hazards harder

Question 10

Explain why improvements in risk management strategies has resulted in less deaths

Answer 10

Prediction: improved technologies
Prevention: trying to stop hazards becoming a disaster (sea defenses)
Preparedness: education people on what they should do during a disaster (earthquake drills, better trained emergency services, emergency supplies/shelter, better understanding of secondary impacts - disease)

Question 11

Why are global economic losses increasing rapidly?

Answer 11

If disasters occur in MEDCs/NICs, there is a greater actual financial cost - will continue as countries develop
Relative financial cost may be more in LEDCs but the actual cost may be lower
Many TNCs are located in LEDCs/RICs - may be vulnerable to loss of property/interruption of manufacturing
Tourism in a country can be severely effected for several years after an event (lose income)
If major global hubs (San Francisco) are affected, this can have a global impact on stock markets and the price of commodities

Question 12

What is climate

Answer 12

Defined as average conditions over a 30yr period

Question 13

What is weather?

Answer 13

Day to day variations on temperature, precipitation etc

Question 14

What is ENSO?

Answer 14

Temporary change in climate, lasting for a few months of years, that affects weather patterns

Question 15

What are El Nino and La Nina?

Answer 15

El Nino Southern Oscillation (ENSO) - a cyclical change in ocean circulation, air pressure and weather patterns in the pacific
La Nina is exaggerate normal behaviour
Can lead to extreme weather events, such as flooding and drought

Question 16

What are normal Pacific conditions?

Answer 16

East to West air flow (trade winds)
These winds warm waters towards Australia and Asia, allowing cold water to up-well off the West coast of South America
High pressure, subsiding air dominates over South America meaning dry, hot conditions under clear skies
Low pressure, convecting air sits over North Australia and Indonesia meaning hot, humid conditions and rainfall

Question 17

What are El Nino conditions?

Answer 17

Occurs usually every 3-7 years, trade winds weaken significantly
Allows warm surface water to flow back towards the East Pacific, preventing cold water from reaching the surface
Warm surface water off the coast of Peru/Chile heats the air above, leading to convection, low pressure and rainfall in an area that is normally dry
Over North Australia and Indonesia, high pressure and subsiding air appears leading to dry weather

Question 18

What are La Nina conditions?

Answer 18

Usually follows a particularly strong El Nino phase
Can persist for several months or years
In Pacific: intense version of normal conditions, areas which are normally dry have drought, areas which are normally wet have intense rainfall and flooding