Hazards: The Concept Of A Hazard Flashcards
What is a natural hazard?
A perceived event that threatens both life and property.
- They often result in disasters that cause some loss of life and/or damage to the built environment and create severe disruption to human activities.
What are the 3 forms of a natural hazard?
- geophysical
- atmospheric
- hydrological
What is a geophysical hazard?
Driven by the earths own internal energy sources, for example plate tectonics, volcanoes, seismic activity.
What is an atmospheric hazard?
Driven by processes at work in the atmosphere, e.g. tropical storms, droughts
What is a hydrological hazard?
Driven by water bodies, mainly the oceans, e.g. floods, storm surges and tsunamis
What is a disaster?
a major hazard event that causes widespread disruption.
The UN records a hazard event as a disaster if one or more of the following criteria are met:
> 10 people killed
>100 people displaced
- Government declares a state of emergency
- A request for international assistance by the national government
What is a risk?
The of a hazard causing harm
What does vulnerability mean?
The characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard.
When does a natural event become a hazard?
A natural event becomes a hazard when there is an interaction with people and human activities. This because there is the possibility for disaster.
What are some physical factors that may determine the risk and impact of a natural hazard?
- magnitude of the hazard
- relief —> topography
- frequency —> previous occurrences
- location
What are the human factors that may determine the risk and impact of a natural hazard?
- population density
- Built environment
- economy —> government, etc
- wealth (studier houses)
- age
Why do people continue to put themselves in the way of risk?
- unpredictable nature of hazards
- lack of alternatives
- changing level of risk in some places
- costs vs benefits
- their religion
- past experiences
- personality (some may find them exciting)
- family
- education
- wealth (insurance, ability to recover, stronger infrastructure)
What is fatalism?
The view that humans are powerless against natural hazards and should simply accept them. The phrase ‘it’s in the hands of the Gods’
What is risk sharing?
The burden of loss is shared amongst parties, such as whole communities uniting or govs taking a lead in compensating for the losses of its people.
What is mitigation?
Actions taken to reduce or eliminate the long-term risk to human life and property from natural hazards, such as creating exclusion zones or developing building codes for seismic areas - aseismic design
What is preparation?
The creation of plans and actions to reduce vulnerability in the event of a disaster. It does not avert/eliminate the hazard, simply deals with the consequences more effectively - e.g. planning for distribution of emergency shelters.
What is prediction?
The view that hazards can be foreseen and therefore the risk presented an be reduced - e.g. weather forecasting
What is adaptation?
This involves changing human routines and practises to reduce the risk, such as the seasonal farming of flood plains or installation of hurricane shutters along beachfront homes.
What are some examples of preparedness?
- Education and raising public awareness
- Practising earthquake drills
- Ensuring medical supplies and food aid is ready
What are some examples of responses?
- Communicate warnings and evacuate people to safety
- Search and rescue teams sent out to rescue survivors
- Providing immediate assistance such as shelter
What are some examples of recovering from a natural hazard?
- Restore running water and ensure food aid is being provided
- Reconstruction of homes
- Rebuilding businesses and getting back to economic normality
What are some examples of mitigation?
- Designing buildings to be earthquake resistant.
- Heightening and strengthening defences such as sea walls.
- Ensuring survivors have help in the form of aid and insurance to reduce long-term impacts.
- hazard mapping
What are the phases of a park model?
- pre-disaster - before the event
- the disruption - during or directly after the event
- relief
- rehabilitation
- reconstruction
What does the shape of the park model represent?
- the steepness of the downward curve during disruption depends on the nature of the event. A tsunami or earthquake would have immediate disruptive impacts (meaning it would be a steeper curve). A volcano may give weeks of warning, during which time, preparations can be made to mitigate the impacts so would have a less steep curve
- the depth of the curve is the factor of the scale of the disaster, which is dependant on the magnitude of the event and the nature of the locality.
What is the relief stage of the park model?
- hours - days after the event
- immediate local and possibly global response in the form of aid, expertise, search and rescue
What is the rehabilitation phase on the park model?
- days - weeks (maybe months) after the event
- longer lasting phase, when infrastructure and services are restored, albeit possibly temporarily, to allow the reconstruction phase to begin as soon as possible
What is the reconstruction phase in the park model?
- weeks-years after the event
- restoring to the same, or better, quality of life as before the event took place. This is likely to include measures to mitigate against a similar level of disruption, in case event occurs again.
What are some strengths of the park model?
- how hazards events vary over time
- can be adapted to show impact severity and speed/onset (start) (e.g. steepness and gradient shows onset, depth shows severity)
- focusses on quality of life (not simply the actions taken)
- helps us understand preparedness and success of responses/recovery
What are some weaknesses of the park model?
- simplistic
—> E.g. multi-hazard zones (Haiti)
What is the hazard management cycle?
Illustrates the ongoing process by which governments, businesses and society plan for and reduce the impact of disasters, react during and recover after an event.
- can manage both pre and post event situations
What are the strengths of the hazard management cycle?
- management strategies sequencing (e.g. for wildfires- need to clear bush before fire, need to build watchtowers before)
- model for action at all stages to help speed up recovery process/minimise impact of future hazards.
What are some of the weaknesses of the hazard management cycle?
- too basic - no depth or adaption to show the impact of the event
- some hazards are difficult to prep for
- centred around human responses
