Natural hazards Flashcards
(49 cards)
what is a natural hazard
events that are perceived to be a threat to people, the built environment and the natural environment.
geophysical
driven by the earth’s own internal energy sources, for example, plate tectonics, volcanoes, seismic activity.
hydrological
driven by water bodies, mainly the oceans, for example, floods, storm surges, tsunamis.
atmospheric
driven by processes at work in the atmosphere, for example, tropical storms, droughts.
why do we avoid looking at the frequency and magnitude?
- Damage occurs almost immediately or after hazard occurs.
- do not choose to be exposed to the impacts.
- clear origins of courses
- distinctive effects e.g. collapse of the built environment and infrastructure.
The UN’s definition of disaster
- 10+ people killed
- 100+ people affected
- a state of emergency
- international assistance called for
1990 Swiss Re insurance
Defined disaster as an event where at least 20 people died, or injured + damage of $16M.
risk
The chance of loss from an event that cannot be entirely controlled
vulnerability
the quality or state of being exposed to the possibility of being attacked or harmed, either physically or emotionally.
hazard
A potentially damaging physical event, that may cause – loss of life or injury
- property damage
- social/economic disruption
- environmental degradation
capacity
a combination of all strengths and resources available within a community, society or organisation that can reduce the level of risk, or effects of a disaster.
how is capacity measured?
R = H × V
c
Risk (R) = Frequency of hazard (H) × Vulnerability (V)
÷ capacity to cope
what is the effect of increasing hazards?
as the risk of disaster grows as global hazards and people’s vulnerability increases, while their capacity to cope increases.
Perception
this is the way in which someone understands or interprets a hazard. People tend to respond to hazard depending on their understanding and interpretation.
Fatalism
An optimistic or accepting approach, while people believe that hazards are part of life or ‘acts of god’.
domination
this is the perspective suggests that hazards are predictable and that they can be better understood by scientific research.
Adaptation
this perspective takes view that hazards are influenced by natural and human events and so we change our lives to reduce impacts
what makes people vulnerable?
- food stocks destroyed as a result of hazard event: famine.
- water contaminated by power plants or debris from infrastructure.
- corrupt government: Laissez-faire approach or use up the money themselves.
what types of hazards can be prevented?
- Avalanches: slopes to offset/control in order to prevent a larger avalanche.
- flooding: prevented = engineering solutions
- volcanic eruptions - satellite images
which types pf hazards cannot be predicted?
- Earthquakes - can figure out areas of risk though.
- Tornadoes.
- Tsunamis - cannot be adapted.
how can the built environment be salvaged?
- earthquake-proof buildings
- raising houses on stilts in flood areas
- Flood defences
- retrofitting existing structures to improve their defences
- hazards cannot be adapted in any way by people but can dilute impact where it helps.
can all events be predicted to the same degree?
nope, but satellite images and radar technology helps to predict large-scale extreme climatic events. volcanoes can be closely monitored and some predictability can be gained.
can earthquakes be predicted?
NOPEEE - devasting effects over large areas due to not knowing the signs.
how will recognizing warning signs help?
key to prediction + recognising warning signs = actions.
then only long term prep can help them.
