Lecture 06 Vulnerability Assessment

8/20/2019 Lecture 06 Vulnerability Assessment

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INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION

Session 5:

Vulnerability assessment

Cees van Westen


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Objectives

Understand the types of vulnerability: physical, social, economicand environmental;

Understand the complexity in approaches used for vulnerabilityand the varying ways in which it is defined;

Indicate the ways in which vulnerability can be expressed.

Outline the main approaches used for flood, earthquae andlandslide vulnerability assessment


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Small repetition: vulnerability and risk


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Defining vulnerability-

!he concept of vulnerability originated from the social sciencesin response to the pure ha"ard oriented perception of disasterris in the #$%&s.

'!he degree of loss to a given element at ris or set of elementsat ris resulting from the occurrence of a natural phenomenon ofa given magnitude and expressed on a scale from & (no damage)to # (total damage)* ( U+-O, #$$#)

ince that time different disciplines are woring with theconcept of vulnerability and the concept of vulnerability hasbroadened


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Disaster management spiral


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Widening concept of vulnerability!

Source:(Birkmann 2005)

/ultipledefinitions anddifferentconceptualframewors of

vulnerabilityexist, becauseseveral distinctgroups havedifferent views

on vulnerability.


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Definitions of vulnerability-!

'!he degree of loss to a given element at ris or set of elements at risresulting from the occurrence of a natural phenomenon of a givenmagnitude and expressed on a scale from & (no damage) to # (totaldamage)* ( U+-O, #$$#)

'0xposure to ris and an inability to avoid or absorb potential harm ( 1elling, 2&&3). In this context, he defines physical vulnerability as thevulnerability of the physical environment; social vulnerability asexperienced by people and their social, economic, and political systems;and human vulnerability as the combination of physical and socialvulnerability* (in 4ilagr5n de 6e7n, 2&&8)

'!he characteristics of a person or group in terms of their capacity toanticipate, cope with, resist and recover from impacts of a ha"ard* (9laiie,annon et al. #$$).

'!he conditions determined by physical, social, economic andenvironmental factors or processes, which increase the susceptibility of acommunity to the impact of ha"ards '(U+


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Definitions of vulnerability-"!

!he potential to suffer harm or loss, related to the capacity toanticipate a ha"ard, cope with it, resist it and recover from itsimpact. 9oth vulnerability and its antithesis, resilience, aredetermined by physical, environmental, social, economic,political, cultural and institutional factors* (1roventiononsortium, 2&&%)

4ulnerability = (0xposure ) > (-esistance ) > -esilience

0xposure: at ris property and population;

-esistance: /easures taen to prevent, avoid or reduce loss;

-esilience: ?bility to recover prior state or achieve desired post


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C#aracteristics of vulnerability!

(Source: UN-ISDR).

Vulnerability is: multi


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$ypes of vulnerability-

•

Physical Vulnerability: meaning the potential for physical impact on thebuilt environment and population. The degree of loss to a given element atrisk or set of elements at risk resulting from the occurrence of a naturalphenomenon of a given magnitude and expressed on a scale from 0 (nodamage) to 1 (total damage)”.ulnerability is analy!ed per group of constructions ( i.e. structural types)having similar damage performance"

#t is an intrinsic $uality of a structure and it does not depend on location.• Economic vulnerability: the potential impacts of ha!ards on economic

assets and processes (i.e. business interruption% secondary effects such asincreased poverty and &ob loss) ulnerability of different economic sectors%

• Social vulnerability: the potential impacts of events on groups such as thepoor% single parent households% pregnant or lactating 'omen% thehandicapped% children% and elderly" consider public a'areness of risk% abilityof groups to selfcope 'ith catastrophes% and status of institutional structuresdesigned to help them cope.

• Environmental vulnerability: the potential impacts of events on theenvironment.


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Coping capacity and resilience-!

apacity: ? combination of all strength and resources availablewithin a community or organi"ation that can reduce the level ofris, or the effect of a disaster*.

apacity may include physical, institutional, social or economicmeans as well as silled personal or collective attributes such as

leadership and management. apacity may also be described ascapability* (U+


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Coping capacity and resilience-"!

-esilience is the capacity of a system,community or society potentially exposed toha"ards to adapt, by resisting or changing inorder to reach and maintain an acceptable levelof functioning and structure.

!his is determined by the degree to which thesocial system is capable of organi"ing itself toincrease its capacity for learning from pastdisasters for better future protection and toimprove ris reduction measures.(U+


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%esilience


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%esilience


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Conceptual frame-&orks of vulnerability:$#e Double Structure of Vulnerability

4ulnerability: external< and internal side; 0xternal side relates to: exposure to riss

and shocs 10?:e.g. social inequalities, assets control by

upper classes; C01: population dynamics and capacities to

manage the environment

0!: relates vulnerability to the incapacity ofpeople to obtain or manage assets vialegitimate economic means

Internal side relates to :capacity toanticipate, cope with, resist and recoverfrom the impact of a ha"ard

B!h: control of assets and resources,capacities to manage crisis situations andresolve conflicts ;

?!?: how people act as react freely or as aresult of societal, economical or governmentalconstraints;

/??: mitigation of vulnerability via access to

assets.

Bohle’s concepual !rame"ork #or

$ulnera%ili& anal&sis.


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Conceptual frame-&orks of vulnerability:'ressure and %elease (')%* +odel

-oot causes are related to economic, demographic, and politicalprocesses as a function of economic structure, legal definitionsof rights, gender relations, and other elements of the ideologicalorder and reflect the distribution of power in a society (9laiie,annon et al. #$$).

ynamic pressures are processes and activities that Dtranslate*the effects of root causes into the vulnerability of unsafeconditions

Unsafe conditions: are the specific form in which vulnerability ofa population is expressed in time and space in conEunction witha ha"ard

Fey characteristics of vulnerable groups in society are socialclass, caste, ethnicity, gender; disability; age and seniority.


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+OV, project


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ender and vulnerability

a) Unequal gender relations arising from patriarchal structures cancreate new vulnerabilities or worsen existing ones for women andgirls in disasters.

b) /en and women have different entitlementsGaccess to resourcesand abilities to reduce their vulnerability through various coping and

adaption practices c) /en may be more mobile and have more opportunities to use large

blocs of time on a single pursuit (e.g. livelihood activities) whilewomen generally cannot because of their range of reproductiveduties and thus are disadvantaged in postdisaster recovery

d) Homen are a heterogeneous group and cannot be assumed to beequally vulnerable, everywhere and all of the time


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ender and vulnerability

e) Aender is a cross cutting issue which can qualify all vulnerabilitydimensions.

f) Aender should be understood as an inclusive term and not simply abinary (male, female) one. Aroups definedGselfdefining astransgender or non heterosexual are particularly invisible and

under


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)ge and vulnerability

(a) hildren are often at or near the top of any list of vulnerable

groups (data on why: stage of physical, intellectual and emotionaldevelopment; greater surface area: body mass ratio; general lac ofpower and agency; but examples of their exercise of agency and risreduction actions and potential must also be acnowledged

In terms of ris groups, urban children in poverty facedisproportionate riss from climate change. hildrens vulnerabilitycomes from their state of rapid development; their relative inabilityto deal with deprivation, stress and extreme events; theirphysiological immaturity; and their limited life experience. Hhileurban children generally fare better than rural children do, this is notthe case for those living in extreme urban poverty. On the more

positive side, children can also bevery resilient to stresses and shocsbut require adequate support and protection.

(b) elderly people have been identified as at greater ris in heatwaves


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Disability and vulnerability

1eople with disabilities may be vulnerable indisasters because of their impairments andbecause they are more liely to be living inpoverty, and they may be institutionalised anddependent on others.

!hey are generally marginali"ed from disasterris reduction planning or adaptation

mechanisms. isasters also create disabilities.


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.olistic vulnerability and risk assessment:,/ample : Villagr0n de 1e2n

!hese methods mostly use indicators for vulnerability and are based one/pert opinion.

0xample #: 4illagr5n de 6e7n ' sectoral approach* having 3 dimensionsof vulnerability, which each 8 'types of vulnerability.;

Ca"ard intensity is notfurther specified, themethod is based on a veryhigh magnitude event.


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.olistic vulnerability and risk assessment: :,/ample : Villagr0n de 1e2n

!his sectoral approach, is proposed from a policy point of view, seemsuseful since it promotes the assigning of responsibilities for reducingvulnerabilities to those private or public institutions in charge of thesectorJ

!he method uses matrices to calculate a vulnerability index, which isgrouped in 3 classes (high, medium and low).

/atrix to asses the structuralvulnerability index of a housein regarding volcanic eruptions.

3 subclasses are based on

historic research of volcanicimpacts on housing in entral?merica.


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.olistic vulnerability and risk assessment:,/ample ": $3

!he A!K framewor is an expert


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!he model assigns 3 possible values ( low=# , medium=2 orhigh=3) to the each of the indicators, and uses weights for thevulnerability index when calculating it for each type of ha"ard

!he different indicators

were weighted accordingto their importance forthe specific ha"ard


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!he whole concept of the community based disaster ris index:


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!he whole concept of the community based disaster ris index:


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Ca"ard is scored on the basis of 1robability and Intensity.

!he 3% indicators are scored and weighted and one final risindex is produced. epending on the scaled indicator values, thefactor indices vary between & and #&&.


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Compre#ensive community based risk assessment-",/ample ": $3

Ca"ard is scored on the basis of 1robability and Intensity. !he 3% indicators are scored and weighted and one final ris

index is produced. epending on the scaled indicator values, thefactor indices vary between & and #&&.


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Overall vulnerability calculation!

!he vulnerability indicators, defining the physical, economic,social and environmental vulnerability can be aggregated andcombined into an overall vulnerability value.


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Overall vulnerability calculation!

One of the tools very suitable to combine and weigh thediffident vulnerability factors is the use of Spatial +ulti Criteria)nalysis.

i k i di i fi i d


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%isk indices: Disaster Deficiency 4nde/(O!D! Cardona*

The Disaster Deficit Index measures countryrisk from a macroeconomic and financial

perspective according to possible catastrophic

events. MCE loss = Maximum Considered

Event

E is the economic value of all the property exposed;V( ) is the vulnerability function, hich relates the

intensity of the event ith the fraction of the value

that is lost if an event of such intensity takes place;

IR is the intensity of the event associated to the

selected return period;

FS is a factor that corrects intensities to account for

local site effects; and

K is a factor that corrects for uncertainty in the

vulnerability function

0conomic resilience is a composite index whichis made by combining M indicators:

Insurance and reassurance payments (@#p)

-eserve funds for disasters (@2p)

?id and donations (@3p)

+ew taxes (@p)

9udgetary reallocations (@Mp)

0xternal credit (@8p)

Internal credit (@%p)

! ""# greater than $.% reflects the country&s inability to cope ith extreme

disasters even by going into as much debt as possible. The greater the ""#,the greater the gap beteen losses and the country&s ability to face them


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$#e 'revalent Vulnerability 4nde/ is made up of a series of indicators thatcharacteri"e prevalent vulnerability conditionsreflected in exposure in prone areas, socioeconomic

weanesses and lac of social resilience in general.

%isk indices: Disaster Deficiency4nde/ (O!D! Cardona*

$#e 1ocal Disaster 4nde/

identifies the social and environmental rissresulting from more recurrent lower level events(which are often chronic at the local andsubnational levels).

6I = number of deaths F

6I?

= number of people affected ?

6I6= economic losses

9ased on esInventar database


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%isk indices: Disaster Deficiency 4nde/(O!D! Cardona*

The Risk Management Index

brings together a group of indicators thatmeasure a country&s risk management

performance. These indicators reflect the

organi'ational, development, capacity and

institutional actions taken to reduce

vulnerability and losses, to prepare for

crisis and to recover efficiently from

disasters.

(M#(# = risk identification

(M#((

= risk reduction

(M#"M = disaster management

(M#)* = governance and financial protection.


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Objectives

Understand the types of vulnerability: physical, social, economicand environmental;

Understand the complexity in approaches used for vulnerabilityand the varying ways in which it is defined;

Indicate the ways in which vulnerability can be expressed.

Outline the main approaches used for flood, earthquae andlandslide vulnerability assessment


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Small repetition: vulnerability and risk


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$ypes of losses!


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+easuring vulnerability!

Different types of vulnerability: physical, social, economical,environmental;

Different levels of scale. ifferent levels of scale require oftendifferent methods. 0.g. in the analytical models the datarequirement increases with more complex methods;

Different #aard types. +ot all methods of vulnerabilityquantification are used for the different ha"ard types. Different #aard intensities and indicators for ha"ard intensity.

Flooding Landslides Earthquakes

ater depth

*lo' velocity

*lo' durationave heightTime of onset

aterlevel ascend rate

+round movement displacements

elocity of ground movement

,unout distance#mpact forces from rock falls

-ercalli intensity

eak ground acceleration

eak ground velocityermanent ground displacement/pectral acceleration


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,/pressing vulnerability

Vulnerability indices: based on indicators of vulnerability; mostly no direct relation with the different

ha"ard intensities. !hese are mostly used for expressing social, economic andenvironmental vulnerability;

Vulnerability table: the relation between ha"ard intensity and degree of damage can also be given in a

table.

Vulnerability curves: that are constructed on the basis of the relation between ha"ard intensities and

damage data %elative curves: they show the percentage of property value as the damaged share

of the total value to ha"ard intensity.

)bsolute curves: show the absolute amount of damage depending on the ha"ardintensity; i.e. the value of the asset is already integrated in the damage function;

6ragility curves: provide the probability for a particular group of elements at ris to be in or

exceeding a certain damage state under a given ha"ard intensity.


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+et#ods of +easuring p#ysical vulnerability

Group Method Description

Empirical

methods

nalysis o!

observeddamage

ased on the collection and analysis of statistics of damage that occurred in recent and

historic events. ,elating vulnerability to different ha!ard intensities.

E"pert opinion ased on asking groups of expert on vulnerability to give their opinion e.g. on the

percentage damage they expect for the different structural types having different intensities

of ha!ard. #n order to come to a good assessment of the vulnerability% many expert have to

be asked and this is time consuming% and sub&ective in general. ,eassessments ofvulnerability after building upgrading or repair are difficult to accommodate.

Score

ssignment

-ethod using a $uestionnaire 'ith different parameters to assess the potential damages in

relation to different ha!ard levels. The score assignment method is easier to update e.g. if'e think about earth$uake vulnerability before and after application of retrofitting.

nalyticalmodels

Simple

nalytical

models

/tudying the behavior of buildings and structures based on engineering design criteria%

analy!ing e.g. seismic load and to derive the likelihood of failure% using computer based

methods from geotechnical engineering. sing e.g. shake tables and 'ind tunnels% as 'ell ascomputer simulation techni$ues"

Detailed

nalyticalmethods

sing complex methods. #t is time consuming% needs a lot of detailed data and 'ill be used

for assessment of individual structures


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Observed data!

@or events that are relatively frequent and widespread it ispossible to collect information on the degree of physicaldamage to buildings or infrastructure after the event hasoccurred;

0.g for floods and earthquaes;

6arge enough samples can e obtained in order to mae acorrelation between the intensityGmagnitude of the ha"ard.

Damage assessment tools for empirical


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Damage assessment tools for empiricalmet#ods

-emote sensing; -apid monitoring using

video cameras;

1articipatory AIapproaches;

0xisting data bases;

0xpert opinion


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,/ercise

0xpert opinion

#ask $%&' E"pert opinion ingenerating a vulnerabilitycurve (duration )$ minutes*

In the figure above there are 4 differentbuildings, each ith different characteristics.Imagine the flood ill take !lace in the area,and the aterlevel is rising sloly butconstantly. "o ould the four buildings beaffected#

$ra 4 a!!ro%imate vulnerability curves in thegra!h.


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)nalytical +et#ods

)nalytical met#od study the behavior of buildings and

structures based on engineering design criteria, analy"ing e.g.seismic load and to derive the lielihood of failure, usingcomputer based methods from geotechnical engineering.

Using e.g. shae tables and &ind tunnels, as well as computersimulation tec#ni7ues!

0.g. shae table: ?dobe house ( earth bric) hp:,,""".&ouu%e.com,"ach$/'1h3B2*4NR3

Computer simulation tec#ni7ues: modeled collapse of masonrystructures during an earthquae which has been analy"ed using athree


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,art#7uake vulnerability curves-!

onstructed based on the effects of the #$$M earthquae in

Fobe in #$$M. !he relation between the damage and theearthquae intensity is expressed in the /odified /ercalli cale

,art#7uake vulnerability curves-"


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,art#7uake vulnerability curves-"%)D48S

http://www.youtube.com/watch?v=AL7Kh31tB2M&NR=1


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,art#7uake vulnerability table!

# k l b l


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,art#7uake vulnerability!

ifferent buildings can respond indifferent manners to the sameearthquae ground motion;

onversely, a given building will actdifferently during differentearthquaes.

? response spectrum is a graph thatplots the maximum response values ofacceleration, velocity anddisplacement against period andfrequency.

C?KU


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6lood vulnerability

@lood damage functions describe therelationship between hydraulicparameters and the relative damageor damage factor of the element atris.

@actor to be considered: flood depth (m) flow velocity (mGs) critical flow velocity (mGs) water


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6lood e/ample : 89 6lood data base and damage

functionsentre 6.%C from +iddlese/ 8niversity!

erivation of damage curves from synthetic damage data;

/ain variables: depth of flood water within the buildings and the depthand extent of floodwater on the floodplain.

4elocity is assumed to cause in rare cases structural failure.

!he data base has #&& residential and more than ten non residential

property types. osts relate to restoration to pre


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6lood e/ample ": .OW)S data base from ermany

6lood e/ample : Damage functions of t#e Dutc#-"


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6lood e/ample : Damage functions of t#e Dutc# "Standard +et#od-"

6lood e/ample : Damage functions of t#e Dutc#


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6lood e/ample : Damage functions of t#e Dutc#Standard +et#od-

1 d lid l bilit t


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1andslide vulnerability assessment-

/ass movement vulnerability depends on: velocity, magnitude and intensity of the mass movement; type of mass movement; 6andslide runout distance.

ifficult to define since: 6ac of useful ha"ard intensity scales:wide variety of processes (fall,

slide, flow, creep, spread) that may occur under different conditionsand with different velocities;+o common agreed intensity scales.

6ac of historical damage databases: often isolated features;

Often the vulnerability = #

%esulting in t#e use of ,/pert Opinions!

1andslide vulnerability assessment is still in it infant stages; and needs to gainmore attention in order to be able to make 7uantitative assessments of landslide risk!

1andslide vulnerability assessment-": e/pert


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1andslide vulnerability assessment ": e/pertopinions on landslides!!

(ource: Alade 2&&3 P modified after 6eone et al. #$$8)

1andslide vulnerability assessment-"< e/pert


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1andslide vulnerability assessment "< e/pertopinions!

Cistorical debris flows and the evaluation of he thicness of the debrisflow material in relation to the degree of loss. Cowever, this didnt giveenough information, so the main input for the vulnerability curves cameagain from expert opinion

1andslide vulnerability assessment-< e/pert


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1andslide vulnerability assessment < e/pertopinions!

-oc fall vulnerability:

1articularly for roc


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'opulation vulnerability-!

1opulation vulnerability: physical vulnerability (direct) of the population (inEury, casualties,and homelessness)

social vulnerability( indirect) and capacity.

?naly"e the effect of the damage of the building on the

population inside of the building; !he severity levels and the percentages of affected people

should be combined with the temporal distribution patterns ofthe population;

1hysical impact classified into different severity classes ( C?KU)

'opulation vulnerability "


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'opulation vulnerability-"!

6ining of building damage from 0arthquaes to severityclasses. (C?KU).

'opulation vulnerability


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'opulation vulnerability-!

+C0/?!I method: relating the percent of building damage tothe fraction of the population affected in 0arthquaes.

'opulation vulnerability =


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'opulation vulnerability-=!

1opulation vulnerability for landslides from the Cong Fongarea; based on an extensive database of slope failures andassociated inEuries and casualties.

'opulation loss estimation


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'opulation loss estimation

'ager


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'ager

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Lecture 06 Vulnerability Assessment