THE CONCEPT OF HAZARD IN A GEOGRPAHICAL CONTEXT
Nature, form & impacts of natural hazards (geophysical, atmospheric, hydrological)
Natural Hazard: natural events that occur in the lithosphere, atmosphere, and hydrosphere
that pose a potential threat to people and the built/natural environment
Types of Natural Hazard
Geophysical: caused by lithospheric processes – volcanoes, earthquakes, tsunamis
Atmospheric: caused by atmospheric processes – tropical storms, droughts, wildfires
Hydrological: causes by hydrospheric processes – floods, avalanches
Characteristics of Natural Hazards
▪ Origin and effects are clear e.g. earthquakes causing buildings to collapse
▪ Short-warning time
▪ Exposure to the risk is involuntary – particularly in LIC’s
▪ Primary impacts pose greatest threat to people and the built/natural environment
▪ Requires emergency response
How does a hazard become a disaster?
Disaster: when a hazard impacts people and the built/natural environment
Deggs Model: Bradford Disaster Scale:
Quantitatively defines disaster based on
number of fatalities
Fatalities Magnitude
32 1.5
95 1.98
166 2.22
1000 3.0
25,000 4.38
Destruction of Earth 10
,Risk & Vulnerability
Risk: likelihood people and the built/natural environment are impacted by a hazard
Why do people but themselves at risk?
▪ Hazard events are unpredictable – difficult to predict frequency, magnitude, or scale
▪ Lack of alternatives – socio-economic factors e.g. can’t give up homes, land, employment
▪ Changing level of risk – external factors influence risk level e.g. global warming increases
intensity of atmospheric hazards such as tropical storms and wildfires
▪ Costs/benefits – e.g. volcanic land rich in nutrients = higher yields = higher income
▪ Hazard Perception
Vulnerability: susceptibility to the impacts of a hazard
Factors affecting vulnerability:
Social:
• Perception
• Experiences
Economic:
• HIC’s less vulnerable – invest more in protection e.g. sea walls, aseismic buildings
• LIC’s vulnerable – can’t invest in protection + high pop density = live in hazardous areas
Geographical:
• More vulnerable at plate boundaries to geophysical hazards – earthquakes, tsunamis
Hazard Perception
How the threat of a hazard is viewed determines action taken and expected govt response
Fatalism: hazards are a part of living in an area – impacts can’t be mitigated = remain
Adaptation: reduce vulnerability to hazards – mitigation, prevention, prediction, protection
Fear: sense of vulnerability – migrate to areas perceived to be unaffected by hazard
Determinants of hazard perception
▪ Wealth
HIC’s – higher capacity to cope – e.g. investment in mitigation strategies such as sea walls
+ aseismic buildings = sense of preparedness
LIC’s – sense of helplessness increases with level of poverty = fatalistic
▪ Education
Greater education = greater understanding of the risks of hazards & mitigation strategies
▪ Past experience
People in hazard-prone areas experiences of hazards influence future hazard perception
▪ Culture (religion/ethnicity)
e.g. some religions view hazards as ‘acts of God’ = fatalistic approach
▪ Personality
e.g. some fear hazards – migrate, others find them exciting
, Responses to Hazards
Hazard Management
Resilience: sustained ability to utilise resources to respond to, withstand, and recover from
the effects of hazards – minimises long-run impacts of hazards – quickly return to normality
Integrated risk management: risk analysis considering socio-economic and political factors
to determine the acceptability of damage/disruption and actions taken to minimise impact:
1.) Establish context: strategic/organisational/risk context?
2.) Identity risks: what can happen? How can it happen?
3.) Analyse risks: likelihood? Consequences? Level of risk?
4.) Evaluate risks (prioritisation)
5.) Risk reduction plan + public awareness/communication strategy
6.) Monitor & review process
Prediction: ability to provide warnings so action can be taken to reduce hazards impacts –
facilitated by improved monitoring, information, and communications technology - e.g.
National Hurricane Centre (Florida) uses info from satellites and land/sea/air recordings.
Prevention: unrealistic/costly - seeding clouds in potential tropical storms to increase
precipitation, weakening the system as it approaches land
Protection: reducing the impact of hazards on people and the built/natural environment
Adaption: modify built environment e.g. sea walls, aseismic buildings
Preparedness: prearranged measures that aim to reduce the impact of hazards on people
and the built/natural environment through public education and awareness programmes,
evacuation procedures, emergency medical/food/shelter supplies, and insurance
Success of hazard management depends on:
➢ Incidence: how often a hazard occurs
➢ Magnitude: how powerful a hazard is
➢ Distribution: spatial coverage of a hazard – tsunamis can cross large oceans, volcanic
eruptions can impact the global climate. Earthquakes/volcanoes = tectonic plate
boundaries, tropical storms = 50 – 250 N/S of the equator
➢ Level of development: LIC’s lack wealth and technology to reduce impacts of a hazard
Nature, form & impacts of natural hazards (geophysical, atmospheric, hydrological)
Natural Hazard: natural events that occur in the lithosphere, atmosphere, and hydrosphere
that pose a potential threat to people and the built/natural environment
Types of Natural Hazard
Geophysical: caused by lithospheric processes – volcanoes, earthquakes, tsunamis
Atmospheric: caused by atmospheric processes – tropical storms, droughts, wildfires
Hydrological: causes by hydrospheric processes – floods, avalanches
Characteristics of Natural Hazards
▪ Origin and effects are clear e.g. earthquakes causing buildings to collapse
▪ Short-warning time
▪ Exposure to the risk is involuntary – particularly in LIC’s
▪ Primary impacts pose greatest threat to people and the built/natural environment
▪ Requires emergency response
How does a hazard become a disaster?
Disaster: when a hazard impacts people and the built/natural environment
Deggs Model: Bradford Disaster Scale:
Quantitatively defines disaster based on
number of fatalities
Fatalities Magnitude
32 1.5
95 1.98
166 2.22
1000 3.0
25,000 4.38
Destruction of Earth 10
,Risk & Vulnerability
Risk: likelihood people and the built/natural environment are impacted by a hazard
Why do people but themselves at risk?
▪ Hazard events are unpredictable – difficult to predict frequency, magnitude, or scale
▪ Lack of alternatives – socio-economic factors e.g. can’t give up homes, land, employment
▪ Changing level of risk – external factors influence risk level e.g. global warming increases
intensity of atmospheric hazards such as tropical storms and wildfires
▪ Costs/benefits – e.g. volcanic land rich in nutrients = higher yields = higher income
▪ Hazard Perception
Vulnerability: susceptibility to the impacts of a hazard
Factors affecting vulnerability:
Social:
• Perception
• Experiences
Economic:
• HIC’s less vulnerable – invest more in protection e.g. sea walls, aseismic buildings
• LIC’s vulnerable – can’t invest in protection + high pop density = live in hazardous areas
Geographical:
• More vulnerable at plate boundaries to geophysical hazards – earthquakes, tsunamis
Hazard Perception
How the threat of a hazard is viewed determines action taken and expected govt response
Fatalism: hazards are a part of living in an area – impacts can’t be mitigated = remain
Adaptation: reduce vulnerability to hazards – mitigation, prevention, prediction, protection
Fear: sense of vulnerability – migrate to areas perceived to be unaffected by hazard
Determinants of hazard perception
▪ Wealth
HIC’s – higher capacity to cope – e.g. investment in mitigation strategies such as sea walls
+ aseismic buildings = sense of preparedness
LIC’s – sense of helplessness increases with level of poverty = fatalistic
▪ Education
Greater education = greater understanding of the risks of hazards & mitigation strategies
▪ Past experience
People in hazard-prone areas experiences of hazards influence future hazard perception
▪ Culture (religion/ethnicity)
e.g. some religions view hazards as ‘acts of God’ = fatalistic approach
▪ Personality
e.g. some fear hazards – migrate, others find them exciting
, Responses to Hazards
Hazard Management
Resilience: sustained ability to utilise resources to respond to, withstand, and recover from
the effects of hazards – minimises long-run impacts of hazards – quickly return to normality
Integrated risk management: risk analysis considering socio-economic and political factors
to determine the acceptability of damage/disruption and actions taken to minimise impact:
1.) Establish context: strategic/organisational/risk context?
2.) Identity risks: what can happen? How can it happen?
3.) Analyse risks: likelihood? Consequences? Level of risk?
4.) Evaluate risks (prioritisation)
5.) Risk reduction plan + public awareness/communication strategy
6.) Monitor & review process
Prediction: ability to provide warnings so action can be taken to reduce hazards impacts –
facilitated by improved monitoring, information, and communications technology - e.g.
National Hurricane Centre (Florida) uses info from satellites and land/sea/air recordings.
Prevention: unrealistic/costly - seeding clouds in potential tropical storms to increase
precipitation, weakening the system as it approaches land
Protection: reducing the impact of hazards on people and the built/natural environment
Adaption: modify built environment e.g. sea walls, aseismic buildings
Preparedness: prearranged measures that aim to reduce the impact of hazards on people
and the built/natural environment through public education and awareness programmes,
evacuation procedures, emergency medical/food/shelter supplies, and insurance
Success of hazard management depends on:
➢ Incidence: how often a hazard occurs
➢ Magnitude: how powerful a hazard is
➢ Distribution: spatial coverage of a hazard – tsunamis can cross large oceans, volcanic
eruptions can impact the global climate. Earthquakes/volcanoes = tectonic plate
boundaries, tropical storms = 50 – 250 N/S of the equator
➢ Level of development: LIC’s lack wealth and technology to reduce impacts of a hazard
