Two words, 4 ways to define –But which one is which???

‘A perceived natural/geophysical event that has the potential to threaten both life and property’ (Whittow)

‘The realisation of a hazard, when it causes a significant impact on the vulnerable population’ - Degg

A geophysical hazard event would not be such without, for example, people at or near its location. That is to say, earthquakes would not be hazards if people did not live in buildings that collapse as a result of ground shaking. Many hazards occur at the interface between natural and human systems.

10 or more people are killed and/or100 or more people are affected.

The Centre for Research on the Epidemiology of Disasters (CRED) states that a hazard becomes a disaster when:

A hazard:

Lesson 5LO: To be able to examine how disasters come about

because of the interaction between hazards, vulnerability and resilience.

Key Enquiry Question 2: Why do some tectonic hazards develop

into disasters?

Key terms:HazardDisasterRiskResilienceDevelopment

Concept Checker: 1.4a. Definition of a natural hazard and a disaster, the

importance of vulnerability and a community’s threshold for resilience, the hazard risk equation.

1.4b. The Pressure and Release model (PAR) and the complex inter-relationships between the hazard and its wider context.

From the UN

The UN’s International Strategy for Disaster Reduction states that a disaster is:

‘A serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using its own resources.’

Degg’s Model: The Relationship between hazard, disaster and vulnerability

Hazardous event(e.g. earthquake)

Vulnerable Population

No disaster

Human activity and physical processes DO NOT interact and there is no disaster

(e.g. a volcanic eruption on a remote unpopulated island)

Degg’s model: The Relationship between hazard, disaster and vulnerability

Hazardous event(e.g. earthquake)

Vulnerable Population

DISASTER!!

The more severe the hazard or the more vulnerable the population, the larger disaster

Disaster and Vulnerability- Draw and annotate Degg’s model

Degg’s Model

Disaster

Vulnerability

Hazard

Event

Physical environment:

•Dangerous Locations

•Unprotected buildings

Socioeconomic environment:

•Weak local economy (poverty)

•Lack of disaster preparedness

•Prevalence of hunger and

endemic disease

Local scale:

•Lack of training, skills, food

security, ethical standards

Macro scale

•Rapid population change

•Rapid urbanisation

•Debt repayment issues

•Over exploitation if

resources/deforestation

•Limited access to power,

structures and resources,

i.e poverty

•Failing political, social and

economic systems

High Winds

Floods

Droughts

Landslides

Tsunamis

Volcanic Eruptions

Earthquakes and

secondary

landslidesBiohazards

and pests

The more vulnerable the

population, the higher the

risk for disaster.

Hazard-risk formula

Risk= hazard x exposure x (vulnerability/ manageability)

This formula tries to incorporate all various components that influence the amount of risk a hazard may produce for a community.

Manageability here can be linked to coping capacity and resilience)

Risk: why do people remain exposed to hazards? Create a mind-map in pairs.

UNPREDICTABILITY:Not always predictable when or where an event will take place. Also difficult toknow the likely magnitude of the event.Human activity and physical changes also mean that for example sea level is risinggiving a greater chance of lowlands flooding. Moreover deforestation of drainagebasins increase the frequency and magnitude of flooding.

LACK OF ALTERNATIVES:Difficult to uproot and move to another location giving up homes, land andemployment. Often the world’s most vulnerable are the poor who are forced to liveon unsafe floodplains or steep hillsides.

CHANGING LEVELS OF RISK:Deforestation can make an area once safe from flooding more susceptible. As canthe effects of global warming eg sea level rise

RUSSIAN ROULETTE:Optimism, turning a ‘blind eye’, ‘acts of god’, part of the living process. Peopleare comforted by the statistics which show that the risk of death is lower than thatfrom influenza or car accidents. They also believe that if a high magnitude eventoccurs then it may be safe for a few years, this is not always true.

COST V. BENEFIT:Many hazardous areas offer advantages that in people’s minds outweigh the risk.

Cost-Benefit Analysis (it’s worth the risk)

• Flood plains have very fertile soils e.g. Bangladesh

Why are some places/people more at risk than others?

Some areas have an increased risk of disasters having high-

HAZARD VULNERABILITY

Hazard Vulnerability: is the capacity of a person or group to anticipate, cope with, resist and recover

from the impact of a natural hazard

What factors can affect this?

Vulnerability quadrant

High Risk, high security

Low Risk, low securityLow Risk, high security

High Risk low Security

Ph

ysic

al e

xpo

sure

to

haz

ard

s (r

isk)

Human Vulnerability to disaster (insecurity)

Draw the quadrant (axes only) and place the following countries on it into one of the four main categories: UK, California, Haiti, Angola, Bangladesh, Iceland

From this what can we interpret about hazards and disasters in MEDC and LEDCs?

• Warning and emergency response systems

• Population growth• Community initiatives• Government disaster

assistance programmes• Insurance• Hard engineering• Urbanisation and urban

sprawl

• Environmental degradation

• Scientific understanding• Economic wealth• Ageing population• Ageing infrastructure• Heavy reliance on water,

power and communication systems

• Loss of community memories of disasters

Which factors increase vulnerability to hazards and make disasters more likely? Sort these statements into the two categories.

Decreased Vulnerability Increased Vulnerability

The Pressure and Release (PAR) Model

• Read pages 17 and 18 and write a brief summary on it in your own words.

• How might you use this model to assess the risk of a community and advise them on how easiest to reduce the risk they are at?