vulnerability to disasters
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TRANSCRIPT
VulnerabilityAnalysis
David AlexanderUniversity College London
The components of risk
Physical disaster
Magnitude
Frequency
Duration
Human vulnerability
ExposureLocation of hazard
Environment
ResistanceLifestyle and earnings
Health
Resilience
Adjustments
Risk reduction activities
Preparations for disaster
After Ian Davis (2005)
Uncertain future:
long-term trendsclimatechangecapacity to adapt
Livelihoods:security and
wealth generation
Hazardsand risks:disaster
preparedness
Governance:democratic participation in decision
making
RESILIENCE:managing risks
adapting to changesecuring resources
Vulnerability is constructed socially
• it is mainly the result of social,economic, political and culturalfactors in decision-making
• it is becoming harder to reduce.
Trends in disaster losses are unsustainable.In the second half of the 20th century
the world experienced increases of:
• 250% in the number of recorded disasters
• 500% in number of disasters with victims
• 500% in the number of affected people
• 1640% in the costof insured damage.
• 1500% in the totalcost of disasters Disasters
1900-2010
Then (1950s) Now (2013)
Under-reporting of disasters
More complete recording
Counting only direct effects
Quantifying indirect effects
Smaller population of hazardous places
Larger population, greater densities
Less inequality Growing inequality and
marginalisation
Less fixed capital at risk
Relentless accumulation of fixed capital
Simpler socio-economic networks
More complex networks
• social and technologicalcomplexity are increasing
• fixed capital is being accumulated
• the world is becoming more polarised
• urbanisation and thegrowth of "mega-cities".
Societies are becomingmore vulnerable
Vulnerability approach
• people, not physical forces, are theprincipal cause of risks and disasters
• focus on reducing community vulnerability
• "soft" rather than "hard" approaches
• "bottom-up" (grass roots) approach.
A sample of the annualpattern of casualtiesin natural disasters
A sample of the annual patternof losses in natural disasters
Death
tolls
Economic losses
Differential impact of disasters
Developing countries anddepressed urban areasof developed countries
Developed countries andthe richest cities ofthe developing world
What exactly is vulnerability?
RiskCivil defence
Hazard
Vulnerability
Threat
Exposure
Response
Mitigation Protection
Civil protection
Vulnerability is...
• the potential degree of loss resultingfrom a particular hazard or setof hazards of a given magnitude
• the potential for harm
• something that is constructed socially
• the inverse of capability(coping, resilience).
UNESCO / UNDRO (1982) Definitionsof Hazard and Risk Terminology
Vulnerability (V): the degree of lossto a given element or set of elementsat risk resulting from the occurrenceof a hazardous phenomenon of a givenmagnitude. It is expressed on a scalefrom 0 (no damage) to 1 (total loss)
Vulnerability
Total: life isgenerallyprecarious
Residual: caused bylack of modernisation
Newlygenerated:caused bychanges in
circumstances
Delinquent:caused bycorruption,negligence,
etc.
Economic:people lackadequateoccupation
Technologicaltechnocratic:caused by
the riskinessof technology
Primary• cause and effect
Secondary• interaction of causes
• coincidences
Complex• complicatedinteractions
VULNERABILITY
(Hazard x Vulnerability x Exposure)Resilience= Risk
[ → Impact → Response]
Hazard x (Vulnerability / Resilience)[x Exposure]
= Risk[ → Impact → Response]
....alternatively:-
VulnerabilityHazard
An asset is notvulnerable unlessit is threatenedby something
A hazard is nothazardous unless
it threatenssomething
RISKExtremeevents
Elementsat risk
Resilience
Exposure
Disaster management
Emergency management
Crisis management
Risk management
Vulnerability management
Hypothetical
Concrete Concentrated
Diffuse
Vert
ical axis s
cales:
Hazard
: pr
obability o
f oc
curr
enc
eVulne
rability: po
tent
ial damage
Risk: va
lue o
f pr
obable c
osts
and
los
ses
Severity
Risk as productof hazard andvulnerability
Total annualpredicted costsand losses
Risingvulnerabilitywith increasingseriousness ofpotentialconsequences
Falling hazardwith diminishingprobability ofoccurrence
Fat-tailed distribution
The role ofperception
Riskamplification
factors
Riskmitigationfactors
Totalvulnerability
Risk perceptionfactors- +
positivenegative
DIALECTIC
Causes of disasternatural geophysical,technological, social
Historysingle andcumulativeimpactof pastdisasters
Humancultures
constraintsand
opportunitiesIMPACTS
Adaptationto risk
RESILIENCE
Diffusion of information
Perceptual filter
Cultural filter
Emergency not decoded
Emergency decoded
Ignorance
Imagesof reality
Symbolicconstructions
Enlightenment
Long term
Short term
Emic components
Etic components
METAMORPHOSISOF CULTURE
Experiences of culture[mass-media and consumer culture]
Accumulated cultural traits and beliefs
Inherited cultural background
Ideological(non-scientific)interpretations
of disaster
Learned(scientific)
interpretationsof disaster
Valuesystem
Familyculture
Workculture
Peergroupculture
Personalculture
National culture
Regional culture
Technologyorganisationssafety culture
Ethnologysocieties
community culture
Psychologyethnic groups
individual culture
Communicationmass media
multicultural societies
Filter
Perception
Culture
Decision
Action
Result
Positive Negative
Risk
Accurate Inaccurate
Technologyas risk
mitigation
Technologyas a source
of vulnerability
Research,development
and investmentin technology
individualfamilypeer grouporganisationcommunitysocietyinternational C
ultu
ral filter
Sociocentrism Technocentrism
Culturalfilter
Riskmanagementpractices
Benign
Malignant
Technologyas a source ofrisk reduction
Technology asan inadvertentsource of risk
Technologyas a deliberatesource of risk
Ceaselessdevelopmentof technology
Large disaster
Increasedexpenditure
Return ofcomplacency
Risk-expenditure cycle
Deaths, injuries,hardship, damage, disruption
Review
Reduced riskNo disaster
Reducedexpenditure
Increased risk
Disaster
Public outcry Rhetoric
Logic
Laws
Safety culture
The evolution ofa safety culture
What exactly is resilience?
Vulnerability = 1 / resilience
Resilience: mechanisms for avoidingimpacts or absorbing them by coping
Coping strategies:• indigenous• imported
What is resilience [resiliency]?
• a combination of resistance andadaptation (coping, capacity, capability)
• ability to maintain livelihoods and tenorof life in the face of disaster shocks
• local autonomy and self-sufficiency.
Attitud
e
Theingredientsof resilience
• robustness: resist stresswithout loss of function
• redundancy: ability to continuefunctioning during periods of disruption
• ingenuity: ability to identifyproblems and mobilise resources
• rapidity: ability to satisfy objectivesand priorities so as to reduce losses.
The four dimensions of RESILIENCE:-
Recoveryand
reconstruction
Mitigationandresilience
Preparationandmobilisation
Emergencyintervention
Quiescence
Crisis
The disastercycle
needs to be shortenedneeds to belengthened
preparationfor the
next event
warningand
evacuation
recovery andreconstruction
repair ofbasic
services
emergencymanagementand rescue
isolation
impact
needs to bestrengthenedRisk reduction and disaster mitigation
Conclusions
Disasteropens awindow ofopportunityfor positivechange andgreatersecurity
The optimistic view
What is sustainable vulnerability reduction?
• it is centred upon the local level(but is harmonised from above)
• through consultation it has the supportand involvement of the population
• plans tackle all the phases of thedisaster cycle - in an integrative way
• it is a fundamental, every-day servicefor the population and is taken seriously.
HUMANCONSEQUENCES
OF DISASTER
“ORTHODOX” MODEL
PHYSICALEVENT
HUMANVULNERABILITY
“RADICAL CRITIQUE” (K. HEWITT et al.)HUMAN
CONSEQUENCESOF DISASTER
HUMANVULNERABILITY
PHYSICALEVENT
PROPOSAL FOR A NEW MODEL
HUMANCONSEQUENCES
OF DISASTER
HUMANVULNERABILITY
CULTURE HISTORYPHYSICALEVENTS
CONTEXT & CONSEQUENCES
Resilience against disasters:Ten suggestions for action
Organisednon-structural
protection
Enhancedstructuralprotection
Planning,warning andpreparedness
Fusion withsustainability
agenda
Policy outcomes
Protection strategy
Tell people what to do in a crisis.
Develop urban search andrescue capacity on site.
Reduce non-structural aswell as structural hazards.
Plan flexibly.
Create networks.
Encourage governance.
Adapt and disseminate good practice.
Ensure that Disaster Risk Reduction(DRR) programmes are sustainable
Create a strategy for recoveringfrom the next disaster.
Create a culture of resilienceagainst disasters.
...and avoid themyth of panic:
it should not betreated as a
relevant factorin emergency
planning
Exposure Sensitivity
Capacity toadapt
VULNERA-BILITY
Dimensions ofvulnerability:• exposure• sensitivity• capacityto adapt
Components ofthe dimensions
Measures of the components
Vulnerability• Dimensions• Components• Measures
Exposure Sensitivity
Capacityto adapt
VULNERA-BILITY
Physical dimensions
Age of theinfrastructure
Age andincome of the
populationDemo-graphy
Technology
Res-ponse
ManagementstructureAccess to
information andtechnology
Exposedres-
ources
Exposedpopulation
Intensity
Frequency
Location
Number
Wealth andwell being
Taxrevenues
Emergencyplans
Level ofeducation
Informationservices
Analysis
• registered• archived• forgotten• ignored
Vulnerabilitymaintained-
• utilised• adopted• learned
Disasterriskreduced
+
LessonsPast
events
The process ofdisaster riskreduction(DRR)
A guide to recognizingvulnerability in the field
How to estimate vulnerability in the field
Elements:
• buildings and physical structures
• lifelines and infrastructure
• patterns of activity
that put people at risk
• perceptions of hazard
• concentrations and patterns
of elements at risk.
NB: Most of the following slides showpost hoc indications
of vulnerability.
Squatter settlementin Bangladesh Flood level
Normal river level
Rather than mitigating the sources ofvulnerability to disaster, globalisation ismaintaining, exporting and reinforcingthem by its divide-and-rule strategies
PeruvianAndes,EasternCordillera
Rock debrisslide-fall
Destroyedhouses
The 'megacity' problem
Tehran
Tehran
Kathmandu
Kathmandu
İstanbul
İstanbul
Tokyo
Poor buildingquality
(low seismicresistance)
Proximityto epicentreand faultrupture
Topographicamplification
Sedimentaryamplification
Q E
T S
Concentrationof casualties
C
C = f { E,Q,S,T }
Deaths
Injuries
Q E
T S
Vulnerabilityto earthquakes
'Window' of active faultwith mullion slickensides
and normal (verticaldownwards) displacement
Seismic consolidation-compaction subsidence
at fault boundary
Vulnerability in theconnection betweenwall and joist leadsto collapse of the structure in anearthquake
Random rubblemasonry withpowdery limemortar is amajor sourceof vulnerabilityin historic andold buildings.
Collapse often beginsat roof level if roofstructure is too rigidand poorly tied tovertical load-bearingmembers.
Cornices,parapetsand other façadedetails areparticularlyvulnerable todamage inearthquakes.
[four people werecrushed to death here]
Inadequatelyconstructedframe buildingsare vulnerable toprogressive collapse.
Stairwells areoften the mostvulnerable partof the buildingduringearthquakes,and the firstpart that peopleuse as they tryto escape.
Zone of interference
Differential movements
Pre-earthquakeroof-line
Replacementstonework
Self-protection during earthquakes andtornadoes is NOT fostered by the myth thatit is safe to shelter under desks and tables.
Rim of caldera blastedapart in A.D. 79
Cone activeA.D. 1631-1944
Europe's most densely populated municipality(population 80,000 in 4.5 sq.km)
0 1 2 3 4 5 km
Tyrrhenian
Sea
Mt Vesuvius
Portici
Ercolano
( and Herculaneum)
Mt Somma
Naples
Barra
Pompeii
Torre
del Greco
Torre
Annunziata
San Giuseppe
Vesuviano
Main lava flow, pyroclastic flow
and lahar hazard areas
Densely
settled areas
Tephra
fallout areas
Population at riskmin: 650,000
max: 3.1 million
Somma-Vesuvius Portici (pop. 80,000)
1631pyroclastic flow
1631 pyroclastic flow(4000 dead in Portici)
recent flank cone
19th centurylava flows
homes of 1-3 million people
MountVesuvius
Forward thrust
Nodes arefirst to fail
Columnsshear throughunder sustainedpressure
Landslide direction
Spontaneoustoppling failure
in unconsolidatedsands
Backwardrotation of
toppled blocks
Bedrooms wherefour people died
Spontaneous total failure of foundations
Spontaneous totalfailure of r-c frame bldg
...with someforward thrust
Tranquil Alpine scene
...with debris flow
...and severalbrand-new hotelsat its foot
...and bouldersthat went
right through!
david.alexander@ucl.ac.ukemergency-planning.blogspot.comPresentations can be downloaded from:-
www.slideshare.com/dealexander
Thank youfor yourattention!