Warning and Evacuationin Disaster Situations

Warning and Evacuationin Disaster Situations

David AlexanderUniversity College London

WARNING SYSTEMSWARNING SYSTEMS

KANSAS5 dead, 150 injuredOKLAHOMA

38 dead, 669 injured

TEXAS1 dead, 12 injured

Monday 3 May 199976 tornadoes in 7 hours

damage exceeded $500 million4319 buildings destroyed

WARNING TIME: 20-120 minutesONLY 44 DEATHS

Largest tornado max.F5 (420-510 km/hr)path 130 km x 1.5 km

What does this picturetell us about warningand preparedness?

What does this picturetell us about warningand preparedness?

Definition:-Definition:-

A warning is a recommendationor order for action to take placebased on a prediction or forecast.

A warning is a recommendationor order for action to take placebased on a prediction or forecast.

Predictions and forecastsshould be made by scientists

(or other appropriateand qualified experts)

Predictions and forecastsshould be made by scientists

(or other appropriateand qualified experts)

Warnings should be issuedby civil authorities (such as

as an emergency management agency)on the basis of valid predictions.

Warnings should be issuedby civil authorities (such as

as an emergency management agency)on the basis of valid predictions.

Scientists

Hazard Hazard

EvaluationEvaluation

Administrators

Riskcommunication

Riskcommunication

Decisionto warn Decisionto warn

General Public

Warning Warning

Protective action

Protective action

The warning processThe warning process

OrganisationalOrganisational SocialSocialTechnicalTechnical

PrecisePrecise DiffuseDiffuse

Factors that influence theeffectiveness of a warningFactors that influence theeffectiveness of a warning

• how predictable the hazard is• how predictable the hazard is

• how long the precursors (if any) last• how long the precursors (if any) last

• how quickly the disasterstrikes (speed of onset)

• how quickly the disasterstrikes (speed of onset)

• how far the impact can be controlled• how far the impact can be controlled

• frequency, duration and size of impact.• frequency, duration and size of impact.

A warning system consistsof a combination of:-

A warning system consistsof a combination of:-

• physical and social components• physical and social components

• technology and organisation• technology and organisation

• planning and communication.• planning and communication.

• monitoring and evaluation• monitoring and evaluation

Stages in the warning processStages in the warning process

• decision-makers recognizeexistence of hazard and decideto create a warning system

• decision-makers recognizeexistence of hazard and decideto create a warning system

• they decide who to warn, aboutwhat, and how to warn them

• they decide who to warn, aboutwhat, and how to warn them

• a system is designed to monitor changesin the hazard and issue warnings

• a system is designed to monitor changesin the hazard and issue warnings

• the system is installed and tested.• the system is installed and tested.

• what is likely to happen -the nature of the impact

• what is likely to happen -the nature of the impact

• when it is likely to happen -the time window of the prediction

• when it is likely to happen -the time window of the prediction

• where it is likely to happen -the geographical area affected.

• where it is likely to happen -the geographical area affected.

What a warning message should say:-What a warning message should say:-

What a warning message should say:-What a warning message should say:-

• what actions are required• what actions are required

• who to contact for further information.• who to contact for further information.

• what the consequences of theimpact are expected to be

• what the consequences of theimpact are expected to be

• whether the response isobligatory or merely recommended

• whether the response isobligatory or merely recommended

Stages in the warning processStages in the warning process

• the public must be educated torespond appropriately to a warning

• the public must be educated torespond appropriately to a warning

• the system must be tunedto make it work better

• the system must be tunedto make it work better

• changes in the hazard aredetected and monitored

• changes in the hazard aredetected and monitored

• incoming information iscollated and evaluated.

• incoming information iscollated and evaluated.

The phases of warning:-The phases of warning:-

• warning message sent• warning message sent

• content evaluated• content evaluated

• risk perceived• risk perceived

• choice of behaviour• choice of behaviour

• action taken(choice realised).

• action taken(choice realised).

• message received• message received

Transmission of warning messages:-

Transmission of warning messages:-

• a hazard watch- "conditions have occurred that

normally precede a disaster"

• a hazard watch- "conditions have occurred that

normally precede a disaster"

• a hazard warning- "impact is certain,

or at least very likely".

• a hazard warning- "impact is certain,

or at least very likely".

Post-warning actionsPost-warning actions

• issue of all-clear, stand-downand end-of-emergency messages

• issue of all-clear, stand-downand end-of-emergency messages

• debriefing and hindsight review• debriefing and hindsight review

• revising and testing the warning system.• revising and testing the warning system.

Factors that influence theeffectiveness of a warning:-Factors that influence the

effectiveness of a warning:-

• what the probable consequencesof the impact are

• what the probable consequencesof the impact are

• how much assistance is available• how much assistance is available

• quality of personneland command structure

• quality of personneland command structure

• legal responsibilities.• legal responsibilities.

Warning messages that succeed are:-Warning messages that succeed are:-

• from official (and credible) sources• from official (and credible) sources

• clear, consistent, precise• clear, consistent, precise

• repeated and confirmed• repeated and confirmed

• the content of messages• the content of messages

• how messages are interpreted.• how messages are interpreted.

But social factors influence...But social factors influence...

• the channels of communication• the channels of communication

People interpret warning messagesdifferently according to...People interpret warning messagesdifferently according to...

• circumstances• circumstances

• personality factors• personality factors

• revised and repeated warning messageswill almost certainly be needed.

• revised and repeated warning messageswill almost certainly be needed.

• social contexts• social contexts

Public reaction to warnings needsto be monitored and the resultsfed back to the issuers of warnings

Public reaction to warnings needsto be monitored and the resultsfed back to the issuers of warnings

The initial response to warningstends to be disbelief, followed

by confirmation behaviour

The initial response to warningstends to be disbelief, followed

by confirmation behaviour

Public awareness and participationare crucial to the success

of warning systems.

Public awareness and participationare crucial to the success

of warning systems.

Warning verification processesWarning verification processes

• normalcy bias: lack of confirmingevidence (usually visual)

• normalcy bias: lack of confirmingevidence (usually visual)

• latent confirmation: does theinformation square with beliefsand personal knowledge?

• latent confirmation: does theinformation square with beliefsand personal knowledge?

• socialisation of response:seeking confirmation fromfamily, friends and colleagues

• socialisation of response:seeking confirmation fromfamily, friends and colleagues

• contact with officialdom.• contact with officialdom.

• unconflicted inertia: thetendency to undervalue warnings

• unconflicted inertia: thetendency to undervalue warnings

• cognitive dissonance: uneasewhen two conflicting beliefsare held simultaneously

• cognitive dissonance: uneasewhen two conflicting beliefsare held simultaneously

• some deviant behaviour is possible.• some deviant behaviour is possible.

• panic is an unlikelyresponse to warnings

• panic is an unlikelyresponse to warnings

People who react best to warningsPeople who react best to warnings

• are under 40 but over 25• are under 40 but over 25

• are female• are female

• are not members of an ethnic minority• are not members of an ethnic minority

• have not lived long in the areabut are well integrated with thecommunity and its institutions.

• have not lived long in the areabut are well integrated with thecommunity and its institutions.

• have middle-to-high social status• have middle-to-high social status

• are parents with children living at home• are parents with children living at home

• live near relatives andutilise kinship networks

• live near relatives andutilise kinship networks

• are well able to understand the risk.• are well able to understand the risk.

People who react best to warningsPeople who react best to warnings

How much time does it take to warna community of modest dimensions

(a small town, for instance)?

How much time does it take to warna community of modest dimensions

(a small town, for instance)?

• 3-4 hours for 90% of inhabitants• 3-4 hours for 90% of inhabitants

• using various means of communication:- official emergency personnel- informal contacts- the mass media

• using various means of communication:- official emergency personnel- informal contacts- the mass media

• longer warnings lead to moreconfirmation behaviour

• longer warnings lead to moreconfirmation behaviour

• confirmation is most importantwhen impacts are common.

• confirmation is most importantwhen impacts are common.

Examples of imprecise predictionsthat led to inefficient warnings

Examples of imprecise predictionsthat led to inefficient warnings

• an 86% chance of amagnitude 7 earthquake inSouthern California in 25 years

• an 86% chance of amagnitude 7 earthquake inSouthern California in 25 years

• a 5% chance that a magnitude5.1 earthquake would occurin the San Francisco Bay regionduring specified 5-day periods

• a 5% chance that a magnitude5.1 earthquake would occurin the San Francisco Bay regionduring specified 5-day periods

• a 20% chance of a magnitude 5.1or greater in a restricted area ofS. California over a 30-day period.

• a 20% chance of a magnitude 5.1or greater in a restricted area ofS. California over a 30-day period.

Nevado del Ruiz, Colombia, Nov. 1985:the worst failure of warning processes

in modern times.

Nevado del Ruiz, Colombia, Nov. 1985:the worst failure of warning processes

in modern times.

Nevado del Ruiz, 13 November 1985Nevado del Ruiz, 13 November 1985

• a nocturnal phreatic eruptionwith attenuated precursors

• a nocturnal phreatic eruptionwith attenuated precursors

• 23,000 dead in lahars (mudflows),most in the town of Armero

• 23,000 dead in lahars (mudflows),most in the town of Armero

• a hazard map had been made• a hazard map had been made

• the volcano was heavily instrumented• the volcano was heavily instrumented

• there was a failure of communicationbetween scientists, civil authoritiesand the general public.

• there was a failure of communicationbetween scientists, civil authoritiesand the general public.

Parkfield, California,1992-3: a 90% chanceof a mag. 6 earthquake

Parkfield, California,1992-3: a 90% chanceof a mag. 6 earthquake

300 scientific instrumentsdeployed, 80 of themrecording continuously

300 scientific instrumentsdeployed, 80 of themrecording continuously

The earthquake didn't happen!The earthquake didn't happen!

EVACUATIONEVACUATION

Evacuation is the most widespreadand effective short-term measure

to protect the publicagainst sudden-impact disasters

Evacuation is the most widespreadand effective short-term measure

to protect the publicagainst sudden-impact disasters

BUT: it is not always appropriate,feasible or advisable.

BUT: it is not always appropriate,feasible or advisable.

Types of evacuationTypes of evacuation

Sort-term Long-term

Pre-impactEmergency protection

Preventative

Post-impact RescueFor

reconstruction

The 'evaluation-dissemination subsystem'The 'evaluation-dissemination subsystem'

• identify and measure risk• identify and measure risk

• collect and interpret data• collect and interpret data

• decide to evacuate• decide to evacuate

• determine content of message to public• determine content of message to public

• apportion these tasksto appropriate agencies.

• apportion these tasksto appropriate agencies.

• transmit message• transmit message

• direct evacuation and monitor result• direct evacuation and monitor result

The phases of evacuationThe phases of evacuation

• decision time• decision time

• notification time• notification time

• evaluation time• evaluation time

• preparation time• preparation time

• verification time.• verification time.

• journey time• journey time

Some precepts of evacuationSome precepts of evacuation

• evacuation should only be attempted ifthere is enough time to accomplish it

• evacuation should only be attempted ifthere is enough time to accomplish it

• evacuation should move people intoprogressively safer areas, notthrough areas of danger

• evacuation should move people intoprogressively safer areas, notthrough areas of danger

• bottlenecks must be managed• bottlenecks must be managed

• destinations need to be planned.• destinations need to be planned.

The evacuee's choiceThe evacuee's choice

• be unaware and do nothing• be unaware and do nothing

• understand the risk but do nothing• understand the risk but do nothing

• do something to protect oneself,but not evacuate

• do something to protect oneself,but not evacuate

• prepare to evacuate but not go• prepare to evacuate but not go

• evacuate.• evacuate.

Immediate

adaptive

actions

ADAPTIVE

Eventual

adaptive

actions

Efforts to

confirm

information

Failure to act

on received

information

Total

denial of

threat

MALADAPTIVE

A CONTINUUM OF PUBLIC REACTIONSTO HAZARD IMPACT WARNINGS

Supply

interpretable

information

ADAPTIVE

Supply

"raw"

information

Supply

theoretical

information

Fail to

deliver

information

Have no

applied

contacts

MALADAPTIVE?

A CONTINUUM OF SCIENTISTS' REACTIONSTO THE NEED FOR USABLE INFORMATION

Sociological processesin family evacuation

Sociological processesin family evacuation

Evacuation by....Evacuation by....

• default• default

• invitation• invitation

• compromise• compromise

• decision.• decision.

Things that facilitate evacuationThings that facilitate evacuation

• a personal action plan• a personal action plan

• is what the mass media say consistent?• is what the mass media say consistent?

• can one calm fears of looting?• can one calm fears of looting?

• are there public information centres?• are there public information centres?

• do potential evacuees have faith inthe authorities and institutions thatissue the evacuation order? .

• do potential evacuees have faith inthe authorities and institutions thatissue the evacuation order? .

Factors that influence thechoice of destination

Factors that influence thechoice of destination

• will relatives offer shelter?• will relatives offer shelter?

• how long is the warning time?• how long is the warning time?

• how long is the evacuee expectedto be away from home?

• how long is the evacuee expectedto be away from home?

• how well-prepared is the evacuee?• how well-prepared is the evacuee?

• from what social class is the evacuee?• from what social class is the evacuee?

• what is the risk?• what is the risk?

Efficiency of evacuations asreported in the research literature(Sorenson & Mileti 1988 and other sources)

Efficiency of evacuations asreported in the research literature(Sorenson & Mileti 1988 and other sources)

• minimum 32% in low-risk areas• minimum 32% in low-risk areas

• maximum 98% in high-risk areas• maximum 98% in high-risk areas

• almost 90% left within 1 hour• almost 90% left within 1 hour

• nearly 60% left within 10 minutes• nearly 60% left within 10 minutes

• 60-88% went to friends and relatives.• 60-88% went to friends and relatives.

• 6-36% went to public shelters• 6-36% went to public shelters

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emergency-planning.blogspot.comwww.slideshare.net/dealexanderdavid.alexander@ucl.ac.uk

emergency-planning.blogspot.comwww.slideshare.net/dealexanderdavid.alexander@ucl.ac.uk