Theoretical Frameworks (Edexcel A Level Geography)

Prediction & Forecasting

• The accuracy of prediction and forecasting of tectonic hazards depends on the type and location of the hazard

• Scientists use prediction and forecasting to help with planning and preparation for hazards

  • Prediction is knowing when (temporal scale) and where (spatial scale) a hazard will occur 

  • Forecasting gives a percentage chance of a hazard occurring over a set period of time

Earthquakes

• It is not possible to predict earthquakes

  • An understanding of tectonic activity can help scientists identify areas most at risk

  • Over 90% of earthquakes occur on or near plate boundaries

• Scientists are constantly researching to improve forecasting - research has focussed on:

  • Seismic gap theory - to highlight areas at high risk as they have not experienced an earthquake for some time

  • Radon emissions

  • Animal behaviour

• No method has yet proved to be reliable

Volcanic eruptions

• There are signs warning of an eruption before most volcanic eruptions

• Volcanologists (scientists who studied volcanoes) monitor changes using GPS, tilt meters, satellites, seismometers and gas detection

• Signs of an eruption include:

  • Magma rising which can be detected by heat sensors and satellites

  • Changes in surface level as rising magma causes bulges

  • Increased emissions of sulphur dioxide and other gases

  • Increased seismic activity caused by magma movement detected by seismometers

• Improved prediction of volcanic eruptions has led to a decrease in the death toll

Tsunami

• For earthquake-induced tsunami scientists are unable to predict the earthquake itself

• When the earthquake happens this will be detected by the global network of seismometers, these will locate the epicentre of the earthquake

  • Ocean monitoring technology can then be used to detect tsunami

  • Warnings can then be issued to coastal areas which may be affected

• Improvements and advances in technology are constantly changing prediction and forecasting

• Systems are regularly updated and reviewed particularly after a hazard event

• In the Asian 2004 tsunami errors in the system increased the number of deaths

  • In Indonesia the sensor system had been struck by lightning so did not work

  • In India the warning went to the wrong official

  • The sensors in the region were limited 

• In the 2011 Japanese tsunami the height of the tsunami was underestimated so the warnings were not accurate

Hazard Management Cycle

• The hazard management cycle is how the events of one hazard event inform planning and preparation for the next hazard event

• The time taken for each stage will vary due to:

  • Level of development

  • Magnitude of the hazard

  • Quality of governance

  • Aid available

• These factors will have most impact on the response and recovery stages

Advantages of the hazard management cycle

• It can be used by organisations and individuals

• The cycle enables them to both prepare for and respond to hazardous events

• It identifies potential hazards

• Reduces the risks and saves lives

• Improves the level of preparation

Disadvantages of the hazard management cycle

• It may not be possible for smaller or less wealthy communities/countries to implement the hazard management cycle

• Some hazards are less predictable, which means hazard management cannot account for every eventuality

• Implementation of strategies may face opposition from local communities

• Communication of the strategies may not reach all communities 

Park's Model

• Park's model is also known as the disaster response curve

• This shows the impact of a hazard event on people's quality of life over time

• The curve demonstrates where different management strategies are implemented before, during and after the event

• The curve will vary for each event and area depending on the level of:

  • Preparation and planning

  • Development 

  • Aid both national and International

• Developing countries tend to be impacted more and recover more slowly

• This can be clearly seen on the disaster response curve

Advantages of Park's model

• It can be applied to a range of hazards

• The model can be used to assess risk and provide a framework for preparedness

• The level of economic activity and social stability are shown, which makes it easy to compare differences based on the level of development

• Useful to analyse the responses to a hazard event and the sequence of events

Disadvantages of Park's model

• It only shows the impact of a single event

• Quantitative data, such as the number of deaths and building destruction, is not shown

• Preventative measures are not shown

• The resources required may mean that smaller/less developed communities can not afford to implement it