5.1- The Concept Of A Natural Hazard Flashcards
(44 cards)
What is a natural hazard?
Events which are perceived to be a threat to people, the built environment and the natural environment- they occur in the physical environments of the atmosphere, lithosphere and hydrosphere
Give some examples of natural/environmental hazards
- volcanic activity
- seismic events
- tropical storms (typhoon/cyclone/hurricane)
Natural hazards can cause disruption to
- to human systems, including death and injury
- property and communication system damage and the disruption of economic activities
Hazards are highly variable in terms of their:
- nature (type)
- cause (origin)
- magnitude
- frequency
- location
- scale of impact
How can we categorise hazards?
- hydro-meteorological= those caused by running water and its processes (hydro) and those associated with or caused by weather patterns (meteorological)
- geophysical= those caused by Earth processes-> two types:
a) internal earth processes of tectonic origin
b) external earth processes of geomorphological origin involving mass movement
What are some examples of hydro-meteorological hazards?
Floods, hurricanes, storms, blizzards and drought
What are some examples of geophysical hazards?
Earthquakes, tsunamis, volcanic eruptions, landslides
Explain how sometimes there may be an overlap between hydro-meteorological hazards and geophysical hazards
A snow avalanche may be hydro-meteorological in origin but geophysical as an event
What’s the key difference between a natural hazard and a natural disaster?
- natural hazard= event that is potential threat to people and/or property
- natural disaster= event where losses are actually experienced/hazard realised
Natural hazards and their effects on people tend to have the following common characteristics
- their origins are clear and the effects they produce are distinctive such as earthquakes causing buildings to collapse
- most natural hazards only allow a short warning time before the event (some hardly at all)
- most losses to life and damage to property occur shortly after the event although the effects of natural hazards can be felt in communities a long time after e.g. disease, disruption to communications and economic activities)
- the scale and intensity of an event requires an emergency response
What does risk refer to?
The probability of harmful consequences or expected losses (deaths, property, livelihoods, economic activity disrupted or environment damaged) resulting from interactions between natural or human-induced hazards and vulnerable conditions
People consciously put themselves at risk from natural hazards- why?
- hazard events are unpredictable (cannot predict the frequency, magnitude or scale of a natural hazard event)
- lack of alternatives due to social, political and economic factors meaning people cannot simply uproot themselves from one place and migrate to another
- changing levels of risk- deforestation for example could result in more flooding from torrential rain associated with tropical storms due to reduced interception and also greater risk of landslides
- cost/benefit- Californian cities for example have a high risk of earthquakes but residents see the many advantages there as greater than the potential risk
- PERCEPTION
What does perception in geographical context refer to?
The way in which an individual or group view the threat of a hazard event which will ultimately determine the course of action taken by individuals or the response they expect from governments and other organisations
What is the risk equation?
Risk (R)= Hazard (H) X vulnerability to hazard (V)
——————————————————————
Capacity to recover/ cope (C)
What does vulnerability in geographical context refer to?
The conditions determined by physical, social, economic and environmental factors or processes which increase the susceptibility of a community to the impact of hazards
What does capacity refer to in geographical context?
A combination of all the strengths and resources available within a community, society or organisation that can reduce the level of risk or effects of a disaster e.g. capacity of community to recover from a particular natural hazard
Question raised of whether the risk is the same for all people in an area I.e. are some people more vulnerable than others?
- a similar sized natural hazard event can have widely varying impacts in different parts of the world
- people’s wealth and level/ advancement of technology they can apply do affect the degree to which the hazard event will impact upon them
- in general, HICs can protect themselves by constructing sea defences and earthquake-resistant buildings as well as increasing preparedness by making people more aware of the risks through education
- people of cities in LICs much more vulnerable
- as such urban areas have grown, more and more people have been forced to live in hazardous areas such as very steep hillsides prone to landslides and in the lowest lying parts where they are at risk from tropical storms and tsunamis
People react to the threat of hazards in varying ways because of the way in which individuals receive and process information- perception is influenced by many factors:
- socio-economic status
- level of education
- religion/ cultural background
- family and marital status
- past experiences
- values, personality and expectations
Perception of a hazard will ultimately determine the course of action taken by individuals in order to
Modify the event or the responses they expect from governments and other organisations
Explain how there is often a great difference in the perception of a hazard between people of differing levels of economic development
- in wealthier areas there is a sense that the better prepared you are, the more you will be able to withstand the impact of the hazard and perhaps even prevent the disaster from taking place
- this is usually based upon government and community action and is backed by capital that will fund technologically-based solutions
- the sense of helplessness in the face of hazards tends to increase with the level of poverty and the deprivation of the community
- even in wealthier countries there are groups of disadvantaged people who tend to look upon natural hazards as part of their way of life as they are viewed as unavoidable; just as the bulk of people in LICs see the impacts of these events as being part of the conditions of poverty
People may perceive natural hazards in the following ways:
- fatalism (acceptance)
- adaption
- fear
Explain concept of fatalism
- such hazards are natural events that are part of living in an area
- some communities would go as far to say that they are “God’s will”
- action is therefore usually direct and concerned with safety
- losses are accepted and inevitable and people remain in situ
Explain adaption
people see that they can prepare for and therefore survive the event( 3ps) by prediction, prevention and/or protection depending upon the economic and technological circumstances of the area in question
Explain fear
The perception of the hazard is such that people feel so vulnerable to an event that they are no longer able to face living in the area and emigrate to regions perceived to be unaffected by the hazard
