1-2-1-vulnerability-and-resilience

Natural Hazard & Disasters

Natural hazards

• A hazard is an event which has the potential to cause harm to the environment, people or the economy 

• A natural hazard is an event caused by environmental processes and would occur without the presence of humans

  • The term hazard is used because of the potential impact when the natural event interacts with humans

• A disaster occurs when harm actually occurs to the environment, people or the economy

• The UN defines a disaster as:

Vulnerability & Resilience

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:

  • Level of development

  • Population density

  • Size of hazard

  • Preparation and planning

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 2 people died in New Zealand

Factors affecting resilience

• There are many factors affecting the resilience of a country or area including

Pressure & Release Model

• 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 which 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 the risk

Release model

• The release model demonstrates vulnerability can be reduced and resilience increased by addressing:

  • Safety 

  • Reducing the pressures

  • Addressing the root causes 

  • Hazard mitigation

Social & Economic Impacts

• The social and economic impacts of tectonic hazards vary 

• In developed countries, the impacts are likely to be lower but this is not always the case and depends on all the factors outlined in the PAR model

Volcanic eruptions

• The differences in impact were not simply the result of Iceland being a developed country

  • Population densities in Iceland are much lower

  • There are a higher number of settlements around Mount Merapi

  • There was a much larger pyroclastic flow from Mount Merapi

Earthquakes