Key Terms Flashcards
Define adaptation.
The attempts by people / communities to live with hazard events.
By adjusting their living conditions, people are able to reduce their levels of vulnerability.
(Eg avoiding building on sites that are vulnerable to storm surges but stay within that same area).
Define fatalism.
A view of a hazard event that suggests that people can’t influence or shape the outcome, therefore nothing can be done to mitigate against it. Can be seen as “God’s will”.
People with such an attitude put in place no preventative measures.
Define natural hazards.
Events which are perceived to be a threat to people and the built and natural environment.
They occur in the physical environments of the atmosphere, lithosphere and hydrosphere.
Define perception.
The way in which an individual or group views the threat of a hazard event. This will ultimately determine the course of action taken by individuals / response they expect from the government.
Define frequency.
The distribution of a hazard through time.
Define magnitude.
The assessment of the size of the impact of a hazard event.
Define fear in the context of hazards.
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 an area and move away to regions perceived to be unaffected by the hazard.
Define community preparedness
Prearranged measures that aim to reduce the loss of life and property damage through public education and awareness programmes, evacuation procedures, the provision of medical, food and shelter supplies and the taking out of insurance.
Define integrated risk management.
The process of considering the social economic and political factors involved in risk analysis; determining the acceptability of damage / disruption and deciding the actions to be taken to minimise damage / disruption.
Define prediction.
The ability to give warnings so they action can be taken to reduce the impact of hazard events.
Improved monitoring, information and communications tech have meant that predicting hazards and issuing warnings have become more important in recent years.
Define primary effects.
The effects of a hazard that result directly from that event.
Eg lava, pyroclastic flow. Or ground shaking in earthquakes.
Define secondary effects.
The events that result from the primary impact of the hazard event.
Eg in volcanoes - flooding (from melting ice chaos and glaciers) and lahars. Eg in earthquakes - tsunamis and fires (from ruptured gas pipes).
Define resilience.
The sustained ability of individuals or communities to be able to utilise available resources to respond to, withstand, and recover from the effects of natural hazard events.
Communities that are resilient are able to miniseries the effects of the event, enabling them to return to normal life ASAP.
Define lahars.
These are formed form volcanic ash mixing with water and flowing downhill. Essentially they’re volcanic mudflows.
Define lava.
Molten rock (magma) flowing onto the surface.
- acid lava solidifies quickly but basic (basaltic) lava tends to flow some distance before solidifying.
Define lithosphere.
The layer of the Earth which consists of the crust and upper section of the mantle.
It’s this later which is split into a number of tectonic plates.
Define pyroclastic flows.
Formed when hot gas (over 800*C) and tephra.
After ejection form the volcano they can flow down the sides of a mountain at speeds over 700km.
Define tephra.
The solid matter ejected from a volcano into the air.
It ranges form volcanic bombs (large) to ash (fine).
Define earthquake.
As the crust of the Earth is constantly moving, there tends to be a slow build up of stress within the rocks. When this pressure is released, parts of the surface experience an intense shaking motion for a short period.
Define retrofitting.
In earthquake-prone areas, buildings and other structures can be fitted with devices eg shock absorbers and cross bracing to make them more earthquake proof.
Define tsunami.
Giant sea waves generated by shallow focus underwater earthquakes, violent volcanic eruptions, underwater debris slides and landslides into the sea.
Define mitigation.
Strategies designed to reduce / eliminate risks to people and property from natural hazards. Money spent prior to a hazardous event to reduce the impact can result in substantial savings in life and property following the event.