Tectonic Processes and Hazards EQ2 Flashcards
What is the definition of a natural hazard?
A perceived natural or geophysical event that has the potential to threaten both life and property.
What is the definition of a natural disaster?
The realisation of a hazard when in causes a significant impact of a vulnerable population. 10 or more people killed or 100 or more people affected. Impact are serious disruptions to the functioning of a community, creating widespread losses and impacts.
What is the Deggs model?
It shows the interaction between hazards, disaster and human vulnerability. With a Venn diagram with the hazardous event on one side and a vulnerable population of the other side overlapping to cause a disaster.
What is the determining the relationship between risk, hazards and people difficult?
Prediction is key to understanding risk
- unpredictability (timing, magnitude and location of the event can vary)
- lack of alternatives (people may stay in a hazardous event due to lack of alternatives)
- dynamic hazards (the threat is not constant and is constantly changing)
- cost benefit (benefit of staying in a hazardous location outweigh the negatives)
- Russian Roulette reaction (the acceptance of risk)
What is the hazard risk equation?
The relationship between hazards and disaster can be understood using the hazard risk equation
Risk = (hazard x vulnerability)/capacity to cope
What is resilience?
Resilience is the ability of a system, community or society exposed to hazard risk resist, absorb and recover (‘bounce back’) from the effect of a hazard.
How is resilience defined?
According to the UNISDR resilience is determined by the degree to which the community has the necessary resources and capability of organising itself both prior to during the time of need.
What does a community with a high resilience and high capacity to cope have?
- emergency evacuation, rescue and relief systems
- they react quickly by helping each other, reducing the amount of people affected
- land use planning reducing number at risk
What is the definition of risk?
The exposure of people to a hazardous event. It’s the probability of a hazard occurring that evade river the loss of lives and or livelihood.
How does age of a population affect a communities resilience?
Ages is a significant factor, with children and the elderly likely to suffer much more from a range of hazards. It is shown by the disaster risk and age index.
What does the disaster risk and age index highlight?
Complied by the UNISDR it highlights
- an trend of ageing populations
- the acceleration of risk in world increasingly exposed to a range of hazards
E.g. 56% of the people who died in the Japan 2011 Tsunami were 65 or over.
What is the Pressure and Release model?
The PAR model suggests that the socio-economic context of a hazard is important. In poor badly governed (root causes) places with rapid change and low capacity (dynamic pressures) and low coping capacity (unsafe conditions) combine with natural hazards to create a disaster.
What is included in root causes on the PAR model?
Limited access to power, structure and resources and poor governance.
What is included in dynamic pressure in the PAR model?
Lack of
- appropriate skills
- training
Macro forces
- rapid population change
- rapid urbanisation
- deforestation
- dept repayments
What is included in unsafe conditions in the PAR model?
- fragile physical environment
- fragile local economy
- vulnerable society
How does the factors in the PAR model progress to form high vulnerability?
Root causes (limited access to power and resources), create vulnerability as they result in inadequacies in training and standards in government (dynamic pressures). These dynamic pressures produce unsafe conditions in the physical and social environment. Physically unsafe environment induce dangerous locations and buildings with low resilience to hazards and economic being inadequacies in preparedness.
How can the PAR model be used for Haiti’s earthquake?
Root causes
- $1200 GDP per capita (low)
- 50% of population under 20 years (high dependency)
Dynamic pressures
- lack of education, training and investment
- rapid population change and urbanisation
Unsafe conditions
- 25% of people live in extreme poverty
- 80% of Port-au-Prine housing is informal slums
What are a social impacts of tectonic hazards?
Social impacts include anything that has affect a community or an individual . This includes death, injury and wider health impacts such as psychological ones.
What are economic impacts of a tectonic hazard?
This includes any financial impacts that the hazard has caused. This can include loss of property, businesses, infrastructure and economic opportunities.
What is environmental impacts of a tectonic hazard?
The effect of a tectonic hazard on the environment. This can be damage or destructive of habitats or physical systems.
How has the impact of different tectonic hazards changed over time?
- the impacts from volcanic eruptions are very small and still declining (especially death toll)
- earthquakes still have a very large impacts as significant ones and common and widespread
- tsunami impacts still have very large impacts although they are infrequent.
How do impacts very between developed and developing countries?
- although economic costs tend to be higher in developed nations (more advanced technology and infrastructure), developing countries have greater proportional economic impacts.
- deaths in developed counties are normally lower (better governed and development) then in LICs
- only a small promotion (1%) will experience direct exposure to volcanic activity
- 8% of population in the poorest countries exposed to natural hazards but only just over 1% in richer nations.
What factors affect economic losses?
- levels of development
- insured vis non insured losses
- population density
- degree of urbanisation / land value
- relative i,pacts in a counties GDP (between 1998-2017 1.8% of developing countries GDP in economic losses due to tectonic hazard compared with 0.4% in HICs)
What is the definition of magnitude?
Magnitude can be viewed as the size or strength of the tectonic events. Generally, larger magnitude events tend to have larger impact.