Geophysical Hazard Risk (DP IB Geography)

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