Hazards Flashcards
Define hazard
Elements of the physical environment that are harmful to humans and caused by forces extraneous to them
What is the difference between natural phenomenon and natural hazards?
A natural phenomenon is a physical event that does not threaten human beings whereas a hazard is a perceived event that threatens both life and property
How can human interference cause a natural hazard to occur?
- Build on unstable slopes
- Urbanise volcanic zones
- Live in areas with active faults
- Live on coasts susceptible to hurricanes and tsunamis
What does WORMS tell us about natural hazards?
It is the common characteristics that natural hazards, and their effects on people, tend to have
What does WORMS stand for?
Warning
Origins
Risk exposure
Most loss
Scale and intensity
What does warning tell us about a natural hazard?
Most natural hazards only allow a short warning time before the event
What does origins tell us about natural hazards?
The origins are clear and the effects that they produce are distinctive, such as earthquakes causing buildings to collapse
What does risk exposure tell us about natural hazards?
Exposure to the risk is involuntary, although this applies to the populations of less well developed countries. In developed areas, most of the people who occupy hazardous areas are often well aware of the risks, which they choose to minimise or even ignore
What does most loss tell us about natural hazards?
Most losses to life and damage to property occur shortly after the event although the effects of natural hazards can be felt in communities long after that time
What does scale and intensity tell us about hazards?
If the scale and intensity of the event requires an emergency response
What is a disaster?
A disaster occurs as a result of a hazard. For example, living on or near a fault line is a hazard, whereas an earthquake on the fault line that has enormous impacts on people and property is a disaster
What are the 3 main types of hazards?
Geophysical, atmospheric and hydrological
What is a geophysical hazard?
Driven by the Earth’s own internal energy sources, for example, plate tectonic, volcanoes, seismic activity
What is an atmospheric hazard?
Driven by processes at work in the atmosphere, for example, tropical storms, droughts
What is a hydrological hazard?
Driven by water bodies, mainly the oceans, for example, floods, storm surges, tsunamis
What are case studies for geophysical hazards?
Mount Etna, 2011 Japanese tsunami, Haiti 2021 earthquake
What are case studies for atmospheric hazards?
What are case studies for hydrological hazards?
Why do people put themselves at risk of hazards?
Hazard events are unpredictable, Lack of alternatives, changing the level of risk, cost/benefit and perception
How are hazards classified?
- Tectonic
- Geomorphological
- Atmospheric
- Magnitude, scale or size
- Frequency of occurrence
- Length of warning time
- Spatial distribution
What does people’s perception of potential hazards depend upon?
- Magnitude
- Frequency
- Duration
- Areal extent
- Speed of onset
- Future probability
What does vulnerability of a hazard depend on?
Exposure; sensitivity; and the resilience of the population, economy, land use and development, infrastructure and critical facilities, cultural assets, natural resources
What is the equation for disaster risk?
Disaster RISK (R) = Hazard (H) x Vulnerability (V) / resilience
What are the 2 things in the model of disaster risk?
Vulnerable population and hazard
