Geophysical Hazard Risk (DP IB Geography)
Revision Note
Factors Affecting Hazard Risk
Vulnerability
Vulnerability is how susceptible an area or population is to damage from a particular hazard event
This can be affected by a number of factors, including:
Economic factors – level of development and technology
Social factors – education and gender
Demographic factors – population density and structure
Political factors – governance
Hazard risk equation
The greater the vulnerability and the lower the capacity to cope, the greater the risk to the population, environment and economy
The greater the hazard magnitude and the lower the capacity to cope, the greater the risk of disaster
The hazard risk equation allows a judgement to be made regarding an area's resilience
The equation can help explain why hazards such as the Nepal (2015) earthquake and the New Zealand (2016) earthquake can be similar in magnitude but have such different impacts
Almost 9,000 people died in Nepal whereas only two people died in New Zealand
Economic factors affecting vulnerability
Levels of development and wealth impact upon:
Building quality and design – in Nepal, 2015, many buildings collapsed due to poor construction, materials and design
Access to technology – lack of access to TVs, radios, phones and computers means that people can't keep up-to-date with warnings and information about actions to take, such as evacuation
Insurance – people in poorer countries are less likely to have insurance to cover the costs of rebuilding
Social factors affecting vulnerability
Education
Level of education often affects people's income levels and their ability to afford good-quality housing
Public education regarding the hazard risks and actions to take reduces the vulnerability of the population
Gender – women are among the most vulnerable groups in hazard events
Gender inequalities in society affect the way in which women are impacted by and recover from hazard events
Women are often caregivers and have responsibilities for children and the elderly; this impacts their ability to react to the hazard. During the 2004 Indian Ocean tsunami women were more likely to suffer injuries or be killed than men
Demographic factors affecting vulnerability
Population density – areas with high population density are more vulnerable to hazard events because:
It makes it harder to evacuate
Buildings are more tightly packed, which increases the impact if some collapse
Age – the elderly and the young are more vulnerable. In the case of the elderly this may be due to lack of mobility:
In the 1995 Kobe earthquake, the death rate in the over 75s was significantly higher than any other age group
Disabilities – people with disabilities are up to four times more likely to die as a result of a hazard event
Political factors affecting vulnerability
Governance – the way in which a country or region is run is known as governance; this also impacts vulnerability and resilience:
National governance refers to how the whole country is run
Local governance is how local areas are run
If a place has good governance, that means it is well run and the local or national government is effective:
These areas are more able to cope with hazard events and will have a faster recovery
Alternatively, weak or poor governance leads to increased vulnerability and impacts on the area's ability to cope with a hazard event
Poor governance impacts on the ability of governments to:
Plan for hazard events using techniques such as hazard mapping and land-use zoning
Educate the population about the risk and how best to protect themselves
Predict events as they do not have the technology and equipment available
Prepare by ensuring that stocks of water, food, medical equipment and shelter are available
Poor governance may also be linked to:
A lack of openness, which means that governments are not held to account
Corruption can have a number of impacts:
Money is not spent on preparation
Construction companies can get around building regulations or land-use zoning by bribing officials
In Turkey, corruption related to construction led to increased deaths in the Izmit earthquake (1999) and the more recent Kahramanmaras (2023) earthquake
Progression of vulnerability
The pressure and release model takes into account the socio-economic context of a hazard
Pressure model
The pressure model demonstrates how there are a range of factors that increase vulnerability and why some areas lack resilience
Within the pressure mode there are:
Root causes – related to resources, decision making and governance, these lead to dynamic pressures
Dynamic pressures – relate to education, urbanisation and population change, which create unsafe conditions
Unsafe conditions – poor-quality housing and infrastructure, poverty
These are then combined with the hazard itself to increase risk
The pressure model
Release model
The release model demonstrates that vulnerability can be reduced and resilience increased by addressing:
Safety
Reducing the pressures
Addressing the root causes
Hazard mitigation
The release model
Examiner Tip
It is essential for the exam that you are able to outline the factors which affect a population/areas vulnerability to a hazard event. These may be two mark questions which ask you to briefly describe how a particular factor impacts vulnerability. Alternatively, it may be a 10 mark question which asks you to examine the relative importance of different factors.
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