Elements of Risk Analysis – Hazard and Vulnerability Session 2 Dr. Bijan Khazai Risk Analysis...

Elements of Risk Analysis – Hazard and Vulnerability

Session 2

Dr. Bijan Khazai

Risk AnalysisFundamentals of Risk Analysis 1

Risk AnalysisFundamentals of Risk Analysis

2

Learning Objectives

Learn The basic elements and processes of hazard analysis. The basic dimensions and elements in vulnerability analysis. The concepts of multi-hazard, exposure, susceptibility and

resilience.

Understand Spatial, dimensional and temporal components of hazard

analysis. Progression of vulnerability associated with root causes,

dynamic pressures, and unsafe conditions. Scales, sectors and components for vulnerability analysis. Use of indicators in vulnerability analysis. Coupling and interaction between hazard and vulnerability and

the dependency of vulnerability on hazard.


Hazard Analysis

Hazard analysis describes and assesses the probability of occurrence of an extreme natural event at a specific place, at a specific time, and with specific intensity and duration for a vulnerable population.

Where? How Big? How Often?

Output: Severity of event by location

This map shows relative shaking hazards in the United States and Puerto Rico. During a 50-year time period, the probability of strong shaking increases from very low (white), to moderate (light blue, green, and yellow), to high (orange, pink, and red). Blue dots are past earthquakes.

Map not to scale. Source: USGS

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Where, How Big, How Often?

Where are the areas which are potentially threatened?

Analyze extent of impacted area1spatialanalysis

How bad can it get? What are the dimensions?

Analyze local characteristics With what intensity and force do hazards occur? On what scale to the hazards occur?

2dimensionalanalysis

3temporalanalysis

When and how often are future hazards to be expected?

Analyze frequency and duration of the hazard event Intervals (or cycles) of recurrence

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Multi-hazard Analysis Analysis of only single hazards in an

area might lead to a misjudgement of the „all hazards“ risks for these areas.

Indexing can be one way of combining different hazards in one map.

Hazards may be weighted equally or weights can be assigned based on the frequency of each hazard.

Comparisons between the impact of different natural hazards on a population are more correctly performed by examining risk rather than hazard indicators.

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Vulnerability

Paradox: Measuring vulnerability without precisely defining it!

“Vulnerability defined as conditions determined by physical, social, economic, and environmental factors or processes, which increase the susceptibility of a community to the impact of hazards.” (UNISDR, 2004)

Multi-structures of Vulnerability Exposure/Value Fragility/Susceptibility Coping Capacity/Resilience

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Progression of Vulnerability

Source: Blaike et al. (1996)

Earthquake

Wind storms

(cyclone/hurricane/Typhoon)

Flooding

Volcanic eruption

Landslides

Drought

Virus and pests

Ideologies:▪Political Systems▪Economic Systems

Lack of:Legal frameworksInstitutionsTrainingAppropriate skillsLocal InvestmentsPress FreedomEthical Standards in public life

Macro ForcesRapid Population changeRapid Urbanization

Physical Environment:Dangerous LocationsUnprotected buildings and infrastructure

Economy:Livelihoods at riskLow income level

Social Relations:Populations at riskLack of solidarity

Public actions and Institutions:Lack of disaster preparedness

THE PROGRESS OF VULNERABILITY

Limited Access to:▪Power▪Structures▪Resources

ROOT CAUSES DYNAMIC PRESSURES

UNSAFECONDITIONS

HAZARDS

1 2 3

Disaster

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Hazard Interventio

n

Vulnerability

Intervention

VULNERABILITY

LACK OFRESILIENCE

SUSCEPTIBILITYand FRAGILITY

Adjusted from MOVE (2009)

A Vulnerability Framework

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EXPOSURE

Spatial/Temporal

Capacity to anticipate

Capacity to cope

Capacity to recover

HAZARD

Exposure Reduction

Fragility / SusceptibilityReduction

Resilience Improvement


Resilience Resilience is the capacity of an individual, community,

organization, city, nation to respond, cope and recover from a disaster.

Resilience in physical and social systems can be seen as having four infrastructural qualities:

Robustness: the inherent strength or resistance in a system to withstand external demands without degradation or loss of functionality;

Redundancy: system properties that allow for alternate options, choices, and substitutions under stress;

Resourcefulness: the capacity to mobilize needed resources and services in emergencies; and

Rapidity: the speed with which disruption can be overcome and safety, services, and financial stability restored.

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Vulnerability Dependency on Hazard

Maize

Sorghum

Degree of Vulnerability of an infrastructure, a community, a society or a process should be related to the magnitude of the hazard in question through fragility curves (or fragility functions).

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Scales, Sectors and Components of Vulnerability

“fractal” nature of Vulnerability

“Ministry of Education”

“School District”

“School Principal”

Source: Villagrán, (2001) 11


Vulnerability Analysis - Indicators Many aspects of vulnerability cannot be directly measured

or observed, though they can be described.

Indicators have been used broadly in economic, social and environmental analysis of vulnerability.

Vulnerability indicators should provide information regarding the susceptibility, coping capacity and resilience of a system.

Below is a mathematical description of risk as a function of the nature of a hazard and the vulnerability to that hazard.

)(X)(ity Vulnerabil),X(Hazard(Risk intangible tangible/irect;direct/ind (i.e., esConsequencTime) Group, Scale, Component, Sector,f

.

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A Social Vulnerability Index

1 Family Structure

2 Poverty

3 Unemployment

4 Disability

5 Home/Land Ownership

Fragility Factors (-)

Resilience Factors (+)Theme

Conceptual

Framework

Quantitative

Indicators

1 Social Networks

2 Risk Perception

3 Risk Mitigation

4 Community Preparedness

5 MobilitySocial Social Vulnerability Vulnerability

IndexIndex

Social Fragility

•How do personal attributes and living situations affect vulnerability?•How do finances contribute to recovery?

Coping Capacity

•How do social networks affect vulnerability?•How does access to services affect vulnerability?

Source: MIS model , 2009

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Process of Risk Analysis

Exposed AssetsPhysical, Social, Environmental, Financial

DAMAGES & LOSSES

EVENT

Susceptibility

RISKCoping Capacity

Physical

Financial

Social

Environmental

VULNERABILITY

Tim

eS

pace

INTERVENTION14

TimeSpace

HA

ZA

RD

Elements of Risk Analysis – Hazard and Vulnerability Session 2 Dr. Bijan Khazai Risk Analysis...

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