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Hazard, Risk,Vulnerability and Disaster?

How these terms are interconnected to each other?

Objectives of the discussion

Distinguish between the concepts of hazard, hazard event, secondary hazards, multiple hazards and disasterClassify and describe types of hazardsExplain hazard characteristics such as magnitude, frequency, intensity and rate of onset and their importance

• Conduct hazard identification, hazard assessment and hazard mapping and explain their functional value

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Risk Management

Asian Disaster Preparedness Center Training & Education Division

HAZARD is any substance,phenomenon or situation, which hasthe potential to cause disruption ordamage to people,their property, their

services and their environment.

There is apotential foroccurrenceof an event

Classification of Hazards

Natural

Biological

Technological

Societal

LANDUSE-LAO PDR

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Atmospheric S ingle elemen t

Exce s s rainfallFre ez ing rain (glaze)HailHeavy s nowfallsHigh wind speedsExtreme tempe ra tures

AtmosphericComb ined elemen ts/even ts

Hurricane s‘Glaze’ stormsThunde rstormsBlizza rdsTornadoesHe at/cold stres s

2. HydrologicFloods – river and coa stalWa ve ac tionDroughtRapid g lacier ad vance

3. GeologicMass -movemen t

Land slides Muds lide s Avalanche s

Ea rthquakeVolcan ic erupt ionRa pid sed imen t move ment

4. BiologicEpide mic in hu mansEpide mic in p lan tsEpide mic in an imalsLocus ts

5. Tech nologicTranspo rt acciden tsIndus trial explos ion s and f iresAcciden tal relea se of toxicchem icalsNuclea r ac cident sCollapse of pub lic bu ildings

Secondary hazards

These are hazards that follow as a result of other hazard events. Hazards secondary to an earthquake may be listed as follows to illustrate the concept. Primary hazard is the earthquake. Secondary hazards are

• Building collapse• Dam failure • Fire • Hazardous material spill • Interruption of power/ water supply/ communication/ transportation/ waste disposal • Landslide • Soil liquefaction• Tsunami (tidal wave)• Water pollution Rate of onset

Include rapid-onset and slower-acting (slow onset) natural hazards.

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Multiple hazards

When more than one hazard event impacts the same area, there arises amultiple hazard situation. These different hazard events may occur at thesame time or may be spaced out in time.

The Return Period

Majority of hazards have return periods on a human time-scale.Examples are five-year flood, fifty-year flood and a hundred year flood.This reflects a statistical measure of how often a hazard event of a givenmagnitude and intensity will occur. The frequency is measured in terms ofa hazard’s recurrence interval.

Climate Change

Sea level riseGlobal worming

Hazards on the rise?

• Urbanization• Population growth• Land degradation• poverty

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Hazard assessmentINTRODUCTION

• A hazard is a potentially damaging event and the measure of hazard is it’s probability of occurrence at a certain level of severity within a specified period of time in a given area.

• Hazard identification implies to “what might happen and where?”

• Hazard assessment implies to “How and when?”

HAZARD ASSESSMENT"The process of studying the nature "The process of studying the nature

of natural /man made hazards of natural /man made hazards determining its essential determining its essential features(degree of severity features(degree of severity ,duration,extent of the impact ,duration,extent of the impact area)and their relationshiparea)and their relationship"."...

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Quantitative ApproachQuantitative Approach

• Use mathematical functions with numerical values

• Each variable will describe the relationship among parameters that characterize the phenomena

ASSESSMENT APPROACHES

• Use qualitative descriptions (such as low, medium or high) instead of numerical values

Qualitative ApproachQualitative Approach

ASSESSMENT APPROACHES

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Deterministic Approach.Deterministic Approach.

• Determined through associated physical characteristics and analysis of consequences.

ASSESSMENT METHODS

Probabilistic ApproachProbabilistic Approach

• Estimates the probability of each hazard affecting an area or region, and likelihood of occurrence and can be determined through research studies, simulation studies, etc (eg. Flood/erosion simulation studies, slope stability calculations, landslide hazard zonation).

ASSESSMENT METHODS

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Informal Ranking Informal Ranking • Uses subjectively defined scales to rank the

hazards and associated risks according to an area specific or country specific ranking system.

ASSESSMENT METHODS

USAGE OF HAZARD INFORMATION IN NATURAL

HAZARD ASSESSMENT

Sources. Sources.

(1) Myths and legends, (2) Historic records,(3) Research data.

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Hazard Zonation mappingHazard Zonation mapping

• Hazard maps outline zones that are defined in terms of the probability of occurrence of potentially damaging phenomena within a certain span of time within a specified location or an area.(Varnes,1984)

HAZARD ASSESSMENT TECHNIQUES AND TOOLS

Data presentationMethods to be consideredMethods to be considered. . Maps Maps Cross sections Cross sections Block diagramsBlock diagramsGISGISRequirements and LimitationsRequirements and Limitations-Perception of what hazards can do and where?-Projections into the future.-Forecast the future.

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Vulnerability

Vulnerability is a concept which describes factors or constraints of an economic, social, physical or geographic nature, which reduce the ability to prepare for and cope with the impact of hazards.

VULNERABLE AREA

There is a potential for an event to

occur

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Categories of Vulnerabilities

• Hazard-specific: – a characteristic which makes the element concerned susceptible to

the force/s or impact of a hazard. The geo-physical and locational attributes of the element/s concerned are considered in this category. Based on the present-knowledge of the distribution and frequency of hazards, a community or country may be threatened by specific hazards.

Categories of Vulnerabilities• Setting-specific:

– this is concerned with the prevailing socio-economic arrangement of the area concerned as to whether it is predominantly rural orurban. There are inherent setting characteristics that may be common to both as well as exclusive to each which contribute to the general susceptibility of the area.

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Characteristics of Urban Setting Vulnerabilities

• Concentrations and Crowdedness - the three aspects are crowdedness and disease; crowdedness and buildings; crowdedness and resource base.

• Numbers of Peoples and Activities - the two aspect of this condition are Technologies and the Management System.

• Proximity to Man-made Hazards - the aspects considered are Technological hazards, Economic hazards, and Social Hazards

Other Factors Contributing to Urban Vulnerability

• Interdependency of Lifelines

– Major lifelines of the urban area are dependent on each other to

function effectively. This interdependency is a factor that may

contribute to the area’s vulnerability.

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Other Factors Contributing to Urban Vulnerability

• Social and Organizational Dimension

– The existing arrangement of a society regarding relationships ofindividuals, groups and institutions may create adverse situations that weakens the these elements’ capabilities to face or withstand hazards and contribute instead to the intensifying of the effects.

Other Factors Contributing to Urban Vulnerability

• Attitudinal and Motivational Dimension

– The prevalent worldview of the society or certain

groups within society may contribute to a passive or

non-active stance regarding the disasters that beset the

area.

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Capacity

Definition of Capacity

• The resources, means and strengths

possessed by persons, communities,

societies or countries which enable them to

cope with, withstand, prepare for, prevent,

mitigate or quickly recover from a disaster.

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Dimensions• Awareness

– this state of being refers to a population’s level of understanding of the hazards, the warning systems, preparedness measures and the ability to respond or utilize information to counter the effects of the hazards;

• Laws and Regulations– these refer to a society’s existing statutes that guide the use of

resources for preparation and response to risks brought about byhazards;

Dimensions

• Prevention and Mitigation Activities and Projects– these refer to the existing and proposed actions and

activities designed to impede the occurrence of a disaster event and/or prevent such an occurrence having harmful effects on the communities and key installations;

• Preparedness– this refers to measures which enable governments,

communities and individuals to respond rapidly and effectively to disaster situation

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Dimensions

• Public, Government and NGO Participation and

Resources:

– this refers both to the relationship the three sectors (i.e., public,

government and no) and the use of resources relative to the

disasters in the area

Types of ResourcesThere are two (2) types of resources: national and international. The national resources have two (2) subdivisions: government resources and non-government resources.• National Resources are “assets” and/or “wealth”

which a country possesses• International Resources are external “means”

which a country may tap or access for disaster management purposes.

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Evaluation of Resources by Assessing

• Capability

• Availability

• Durability

• Operational Integrity

Coping Mechanisms

• Actions resorted to by individuals or groups

in face of adverse effects of a disaster in

order to survive/withstand and move

towards normalization.

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RISK is the probability that negative consequences may arise when hazards interact with vulnerable areas, people, property, environment.RISK is a concept which describes a potential set of consequences that may arise from a given set of circumstances.

VULNERABLE AREA

Elements at risk

There is a potential for an event to occur. Therefore there is a risk

Risk

Concepts of the Risk and its Analysis:

The Risk Triangle:

RISK

Exposure

VulnerabilityHazar

d

Risk is a combination of the interaction of hazard, exposure, and vulnerability, which can be represented by the three sides of a triangle.

If any one of these sides increases, the area of the triangle increases, hence the amount of risk also increases.

If any one of the sides reduces, the risk reduces.

If we can eliminate one side there is no risk.

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Parameters of RiskHazards are the source of risks

Hazards create risks by exposing pre-existing vulnerabilities

The risk that a community faces is mitigated by its level of

preparedness, response and recovery or readiness

Consequence Measure Tangible Intangible

Deaths No. of People

Loss of active individuals.

Social and psychological effects of remaining community.

Injuries No. of people % disability

Medical Costs loss of productivity.Temporary loss of economic activity.

Social and psychological effects of relatives & injured, pain & recovery.

Continued…..

HOW TO DEFINE POSSIBLE ELEMENTS AT RISK

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Loss

Physical Damage

No. of damagedhouses, structures etc., agricultural areas. Level of damage %

Replacement costs, rehabilitation & repairs cost.

Cultural losses, Social effects.

Emergency operations

No. of man-days Equipment and resources hours.

Mobilisation costs Investments in preparedness measurers.

Stress & overwork of relief workers.

Consequence Measure Tangible Intangible

Continued…..

Loss

Disruption of

Economy

No. of lost working days, value of production lost.

Cost of lost productivity.

Opportunities competitiveness reputation.

Social Disruption

No. of displaced, No. of homeless.

Cost for temporary housing, relief, health care.

Psychological, social contacts cohesion morale.

Environmental Impact

Scale &

Severity

Maintenance&

repair cost.

Health risks, Future disaster risk.

Consequence Measure Tangible Intangible

Continued…..

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Damages

TANGIBLE LOSSESTANGIBLE LOSSES -Measurable effects in

Monetary Terms.

INTANGIBLE LOSSESINTANGIBLE LOSSES -Effects those can not

be converted to Monetary Terms.

DAMEGES CAUSED BY DISASTERS

PREPAREDNESSPREPAREDNESS

WATCH OUT! THE ROCK IS

FALLING

Short term risk reduction measures taken in anticipation of a disaster to ensure that appropriate and effective actions are

taken in the aftermath.

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MITIGATIONMITIGATION Strong buildings & structures,strict building codes compliance,landuse planning,capacity building,awareness creation etc.

•Long term risk reduction measures taken prior to the impact of a disaster to minimize its effects (sometimes referred to as

structural and non-structural measures).

What are we going to manage?Disasters or Disaster Risk

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What do you mean by hazard?What are the type of vulnerabilities?

How do we reducerisk due to

natural hazards ?

What is the inter-connection between

vulnerability and capacity?

Thank you