4th Edition - 2011

Chapter 2Chapter 2

Natural and Technological Hazards Natural and Technological Hazards and Risk Assessmentand Risk Assessment

Key DefinitionsKey Definitions Hazard: Hazard: as a “source of danger that may or may as a “source of danger that may or may

not lead to an emergency or disaster and is named not lead to an emergency or disaster and is named after the emergency/disaster that could be so after the emergency/disaster that could be so precipitated.”precipitated.”

Risk: Risk: the interaction of a hazard likelihood and the interaction of a hazard likelihood and the consequences should it occur the consequences should it occur

Emergency Event: Emergency Event: one that requires the efforts of one that requires the efforts of one or more of the emergency services to manageone or more of the emergency services to manage

Disaster:Disaster: an emergency event that exceeds the an emergency event that exceeds the capacity of emergency services in one or more capacity of emergency services in one or more critical areascritical areas

Natural HazardsNatural Hazards

Exist in the natural environment and Exist in the natural environment and pose a threat to human populations pose a threat to human populations and communities.and communities.

Exacerbated by human developmentExacerbated by human development

FloodsFloods

Can be slow or fast risingCan be slow or fast rising Many causes, including large-scale weather Many causes, including large-scale weather

systems, thunderstorms, snowmelt, ice systems, thunderstorms, snowmelt, ice jams, and dam failuresjams, and dam failures

The most frequent and widespread disaster The most frequent and widespread disaster in many countries around the worldin many countries around the world

EarthquakesEarthquakes A sudden, rapid shaking of the earth caused by the A sudden, rapid shaking of the earth caused by the

breaking and shifting of rock beneath the earth’s breaking and shifting of rock beneath the earth’s surfacesurface

Active seismic zones have been identified around Active seismic zones have been identified around the globe – millions exposedthe globe – millions exposed

Difficult to predictDifficult to predict Often cause secondary disasters, such as fires, Often cause secondary disasters, such as fires,

landslides, avalanches, tsunamis, or dam failures, landslides, avalanches, tsunamis, or dam failures, among others.among others.

Measured by the Richter Scale or Modified Measured by the Richter Scale or Modified Mercalli Intensity ScaleMercalli Intensity Scale

HurricanesHurricanes Tropical wave Tropical wave →→ tropical depression tropical depression →→ tropical storm tropical storm

→ → hurricanehurricane Hurricane must have sustained winds greater than 74 Hurricane must have sustained winds greater than 74

mph.mph. Storm surge, rains, and high winds cause damageStorm surge, rains, and high winds cause damage US hurricane season – June 1 to November 30US hurricane season – June 1 to November 30 Described using the Saffir-Simpson ScaleDescribed using the Saffir-Simpson Scale Hurricane tracking has advanced rapidlyHurricane tracking has advanced rapidly Hurricane Katrina the most costly disaster in US Hurricane Katrina the most costly disaster in US

historyhistory

Storm SurgesStorm Surges Dramatic rises in sea level and large coastal waves Dramatic rises in sea level and large coastal waves

that cause flooding and erosionthat cause flooding and erosion Most common from late fall to early spring but can Most common from late fall to early spring but can

develop year-rounddevelop year-round Usually associated with extra-tropical cyclones Usually associated with extra-tropical cyclones

(nor’easters) in the North Atlantic Ocean and the (nor’easters) in the North Atlantic Ocean and the Gulf of Mexico, and severe winter low-pressure Gulf of Mexico, and severe winter low-pressure systems in the North Pacific Ocean and the Gulf of systems in the North Pacific Ocean and the Gulf of AlaskaAlaska

Katrina storm surge reached 28 feet, devastated the Katrina storm surge reached 28 feet, devastated the Gulf CoastGulf Coast

Modeled using SLOSHModeled using SLOSH

TornadoesTornadoes Rapidly rotating vortex or funnel of air extending Rapidly rotating vortex or funnel of air extending

groundward from a cumulonimbus cloudgroundward from a cumulonimbus cloud Approximately 1,200 tornadoes are spawned by Approximately 1,200 tornadoes are spawned by

thunderstorms each yearthunderstorms each year Can lift and move huge objects, destroy or move Can lift and move huge objects, destroy or move

buildings, and siphon waterbuildings, and siphon water People living in valleys have the greatest exposurePeople living in valleys have the greatest exposure Tornado Alley: TX, OK, AR, MO, and KS.Tornado Alley: TX, OK, AR, MO, and KS. Measured by the Enhanced Fujita-Pearson ScaleMeasured by the Enhanced Fujita-Pearson Scale Safe rooms are the greatest defenseSafe rooms are the greatest defense

WildfiresWildfires

Surface fire: Surface fire: most common; burns along forest floor; most common; burns along forest floor; moves slowly and kills or damages trees;moves slowly and kills or damages trees;

Ground fire: Ground fire: usually started by lightning; burns on or usually started by lightning; burns on or below the forest floorbelow the forest floor

Crown fire: Crown fire: spreads rapidly by wind and moves spreads rapidly by wind and moves quickly by jumping along the tops of treesquickly by jumping along the tops of trees

Risk increases as people move into the wildland-urban Risk increases as people move into the wildland-urban interfaceinterface

Severe drought and fuel buildup have led to a Severe drought and fuel buildup have led to a significant increase in US wildfiressignificant increase in US wildfires

Mass Movement HazardsMass Movement Hazards

Horizontal or lateral movement of large quantities Horizontal or lateral movement of large quantities of physical matterof physical matter

Most prevalent in rugged/varied topographyMost prevalent in rugged/varied topography Can include:Can include:

– LandslidesLandslides– MudflowsMudflows– Lateral SpreadsLateral Spreads– Rock FallsRock Falls– AvalanchesAvalanches– Land SubsidenceLand Subsidence– Expansive SoilsExpansive Soils

TsunamisTsunamis

A series of waves generated by an undersea A series of waves generated by an undersea disturbance such as an earthquake, landslide, or disturbance such as an earthquake, landslide, or volcanic eruptionvolcanic eruption

Travel from area of disturbance at high speeds, across Travel from area of disturbance at high speeds, across long distanceslong distances

Waves slow down and rise when they approach the Waves slow down and rise when they approach the shoreline, reaching heights of up to 100 feetshoreline, reaching heights of up to 100 feet

Most deaths are caused by drowningMost deaths are caused by drowning The 2004 Indian Ocean tsunami killed between The 2004 Indian Ocean tsunami killed between

150,000 and 200,000 people in 11 countries150,000 and 200,000 people in 11 countries

VolcanoesVolcanoes A break in the earth’s crust from which molten A break in the earth’s crust from which molten

rock (magma) exits onto the surfacerock (magma) exits onto the surface When pressure from gases and magma increases, When pressure from gases and magma increases,

eruptions occureruptions occur Lava, gas, rock, may spread over large areasLava, gas, rock, may spread over large areas Volcanic ash may travel hundreds of miles, can Volcanic ash may travel hundreds of miles, can

contaminate water, cause electrical storms, and contaminate water, cause electrical storms, and collapse roofscollapse roofs

An erupting volcano can trigger tsunamis, flash An erupting volcano can trigger tsunamis, flash floods, earthquakes, rock falls, and mudflows, floods, earthquakes, rock falls, and mudflows, among other secondary hazardsamong other secondary hazards

Severe Winter StormsSevere Winter Storms Consist of extreme cold and heavy snow or iceConsist of extreme cold and heavy snow or ice A blizzard combines heavy snowfall, high winds, A blizzard combines heavy snowfall, high winds,

extreme cold, and iceextreme cold, and ice In the US, the weather patterns are from four In the US, the weather patterns are from four

sources:sources:1.1. The North Pacific Ocean or the Aleutian Islands The North Pacific Ocean or the Aleutian Islands 2.2. Canadian and Arctic cold frontsCanadian and Arctic cold fronts3.3. The Great LakesThe Great Lakes4.4. The Atlantic Ocean and Gulf of MexicoThe Atlantic Ocean and Gulf of Mexico

In 2006, the Federal Government began measuring In 2006, the Federal Government began measuring Severe Winter Storms using NESIS Severe Winter Storms using NESIS

DroughtDrought A prolonged shortage of available water caused by a deficiency A prolonged shortage of available water caused by a deficiency

of rainfall or because of exceptionally high temperatures and of rainfall or because of exceptionally high temperatures and low humiditylow humidity

Drought differs from other hazards in three ways:Drought differs from other hazards in three ways:– The onset and end are difficult to determine because the The onset and end are difficult to determine because the

effects accumulate slowly and may linger even after the effects accumulate slowly and may linger even after the apparent termination of an episodeapparent termination of an episode

– The absence of a precise and universally accepted definition The absence of a precise and universally accepted definition adds to the confusion about whether a drought exists, and if adds to the confusion about whether a drought exists, and if it does, the degree of severity; and it does, the degree of severity; and

– Drought effects are less obvious and spread over a larger Drought effects are less obvious and spread over a larger geographic area.geographic area.

Extreme TemperaturesExtreme Temperatures

Major diversions from average seasonal Major diversions from average seasonal temperaturestemperatures

Can cause injuries, fatalities, and major economic Can cause injuries, fatalities, and major economic impacts when prolonged or coincide with other impacts when prolonged or coincide with other disaster eventsdisaster events

Extreme Heat - 10 degrees or more above regional Extreme Heat - 10 degrees or more above regional averages lasting for several days or weeksaverages lasting for several days or weeks

Extreme Cold – no accepted ‘standard’, but occur Extreme Cold – no accepted ‘standard’, but occur when temperatures fall far below averages for an when temperatures fall far below averages for an extended timeextended time

Coastal ErosionCoastal Erosion

Measured as the rate of change in the position or Measured as the rate of change in the position or horizontal displacement of a shoreline over a horizontal displacement of a shoreline over a period of timeperiod of time

Generally is associated with storm surges, Generally is associated with storm surges, hurricanes, windstorms, and flooding hazardshurricanes, windstorms, and flooding hazards

May be exacerbated by human activities such as May be exacerbated by human activities such as boat wakes, shoreline hardening, and dredgingboat wakes, shoreline hardening, and dredging

ThunderstormsThunderstorms

Heavy rainstorms that may be accompanied by Heavy rainstorms that may be accompanied by strong winds, hail, lightning, tornadoes.strong winds, hail, lightning, tornadoes.

Generated when the following exist:Generated when the following exist:– Unstable warm air rising rapidly into the atmosphere; Unstable warm air rising rapidly into the atmosphere;

– Sufficient moisture to form clouds and rain; Sufficient moisture to form clouds and rain;

– Upward lift of air currents caused by colliding weather Upward lift of air currents caused by colliding weather fronts (cold and warm), sea breezes, or mountainsfronts (cold and warm), sea breezes, or mountains

May occur singly, or in clustersMay occur singly, or in clusters

HailstormsHailstorms

An outgrowth of a severe thunderstorm An outgrowth of a severe thunderstorm Balls or lumps of ice greater than 0.75 inchBalls or lumps of ice greater than 0.75 inch Occur more frequently during late spring Occur more frequently during late spring

and early summerand early summer Cause nearly $1 billion in property and crop Cause nearly $1 billion in property and crop

damage annually.damage annually.

Technological HazardsTechnological Hazards

Exist because of human innovation and Exist because of human innovation and activityactivity

Newer and less understood than natural Newer and less understood than natural hazardshazards

Include hazards that are non-intentional, Include hazards that are non-intentional, such as transportation accidents, and such as transportation accidents, and intentional, such as terrorism.intentional, such as terrorism.

Structural FiresStructural Fires

Can be triggered or exacerbated by Can be triggered or exacerbated by lightning, high winds, earthquakes, lightning, high winds, earthquakes, volcanoes,and floodsvolcanoes,and floods

Lightning is the most significant natural Lightning is the most significant natural contributor to fires affecting the built contributor to fires affecting the built environmentenvironment

Buildings with rooftop storage tanks for Buildings with rooftop storage tanks for flammable liquids are particularly flammable liquids are particularly susceptiblesusceptible

Dam FailureDam Failure

Potentially the worst flood eventPotentially the worst flood event Usually the result of neglect, poor design, Usually the result of neglect, poor design,

or structural damage caused by a major or structural damage caused by a major event such as an earthquakeevent such as an earthquake

When a dam fails, a gigantic quantity of When a dam fails, a gigantic quantity of water is suddenly let loose downstream, water is suddenly let loose downstream, destroying anything in its pathdestroying anything in its path

Hazardous Materials IncidentsHazardous Materials Incidents Chemical substances, if released or misused, can Chemical substances, if released or misused, can

pose a threat to the environment or healthpose a threat to the environment or health HazMats may be explosive, corrosive, flammable, HazMats may be explosive, corrosive, flammable,

poisonous, and/or radioactivepoisonous, and/or radioactive Most often released because of transportation, Most often released because of transportation,

manufacturing, or storage accidentsmanufacturing, or storage accidents May cause death, serious injury, long-lasting May cause death, serious injury, long-lasting

health effects, and damage to buildings, homes, health effects, and damage to buildings, homes, and other propertyand other property

Nuclear AccidentsNuclear Accidents Exposure to radiation is the main hazardExposure to radiation is the main hazard Exposure could come from plant material Exposure could come from plant material

releaserelease Area affected determined by amount Area affected determined by amount

released, wind direction and speed, and released, wind direction and speed, and weatherweather

On-site ERPs approved by the NRC - Off-On-site ERPs approved by the NRC - Off-site plans evaluated by FEMAsite plans evaluated by FEMA

TerrorismTerrorism The use of force or violence against persons or The use of force or violence against persons or

property in violation of the criminal laws of the property in violation of the criminal laws of the United States for purposes of intimidation, United States for purposes of intimidation, coercion, or ransomcoercion, or ransom

Before 9/11, most US terrorism involved bombsBefore 9/11, most US terrorism involved bombs Effects vary death/injury to property damage and Effects vary death/injury to property damage and

service disruptionservice disruption Governments reduce vulnerability by increasing Governments reduce vulnerability by increasing

security security Terrorism may be domestic or internationalTerrorism may be domestic or international

CBRN IncidentsCBRN Incidents

Family of weapons characterized by their Family of weapons characterized by their broad-sweeping intended effects, such as broad-sweeping intended effects, such as inflicting mass casualties and/or physical inflicting mass casualties and/or physical destructiondestruction

Include:Include:– ChemicalChemical– BiologicalBiological– NuclearNuclear– RadiologicalRadiological

Chemical WeaponsChemical Weapons Naturally-occurring or manmade liquids, gases, or solids Naturally-occurring or manmade liquids, gases, or solids

(typically in the form of dust) (typically in the form of dust) Toxic effects on humans, animals, plants, or propertyToxic effects on humans, animals, plants, or property Must be delivered onto or around intended victims to be Must be delivered onto or around intended victims to be

effectiveeffective– AerosolizedAerosolized– DroppedDropped– SplashedSplashed– Poured Poured – Released by bombsReleased by bombs– Sprayed from containers or vehiclesSprayed from containers or vehicles

Detection a challengeDetection a challenge

Biological WeaponsBiological Weapons

Organisms or toxins either naturally Organisms or toxins either naturally occurring or genetically engineered, that occurring or genetically engineered, that can kill or incapacitate people, livestock, can kill or incapacitate people, livestock, and cropsand crops

There are 3 basic groups:There are 3 basic groups:– BacteriaBacteria– VirusesViruses– ToxinsToxins

Most are difficult to grow and maintainMost are difficult to grow and maintain

Radiological WeaponsRadiological Weapons

Commonly referred to as a “dirty bomb” or Commonly referred to as a “dirty bomb” or “radiological dispersion device (RDD)”“radiological dispersion device (RDD)”

Use common explosives to spread radioactive Use common explosives to spread radioactive materials over a targeted areamaterials over a targeted area

Distinct from nuclear blasts (much more Distinct from nuclear blasts (much more localized) localized)

Presence of radiation may not be recognized, Presence of radiation may not be recognized, will be harmful to those exposed, and may be will be harmful to those exposed, and may be very difficult to remove or containvery difficult to remove or contain

Nuclear WeaponsNuclear Weapons Cause great harm through the activation of a fission or Cause great harm through the activation of a fission or

fusion chain reaction fusion chain reaction Possible only through the advanced technology and using Possible only through the advanced technology and using

only the most refined nuclear materials only the most refined nuclear materials Explosion emits intense light and heat, damaging pressure, Explosion emits intense light and heat, damaging pressure,

and disperses radioactive debris over a widespread area and disperses radioactive debris over a widespread area leading to the contamination of air, water, and ground leading to the contamination of air, water, and ground surfaces for miles around. surfaces for miles around.

The likelihood of a terrorist organization developing an The likelihood of a terrorist organization developing an operational nuclear weapon is almost niloperational nuclear weapon is almost nil

A successful use of a nuclear weapon would cause A successful use of a nuclear weapon would cause thousands of deaths and destroy billions in propertythousands of deaths and destroy billions in property

Hazards Risk ManagementHazards Risk Management

Process by which individuals, communities, and Process by which individuals, communities, and countries deal with the hazard risks they face countries deal with the hazard risks they face

A primary function of governmentA primary function of government Many different methodologies existMany different methodologies exist A four-step process that includes: A four-step process that includes:

– Identifying the hazardsIdentifying the hazards

– Assessing risk for each hazard identifiedAssessing risk for each hazard identified

– Analyzing hazard risks in relation to each otherAnalyzing hazard risks in relation to each other

– Treating hazard risk according to prioritizationTreating hazard risk according to prioritization

Hazard IdentificationHazard Identification All hazards that have or could affect an area of All hazards that have or could affect an area of

focus are identified and describedfocus are identified and described Done through:Done through:

– Historical studyHistorical study– BrainstormingBrainstorming– Scientific analysisScientific analysis– Subject matter expertiseSubject matter expertise

For more common hazards the presence of the For more common hazards the presence of the hazard will be obvioushazard will be obvious

For new or changing hazards the knowledge or For new or changing hazards the knowledge or opinion of experts is requiredopinion of experts is required

Hazard profiling a key componentHazard profiling a key component

Hazard Risk AssessmentHazard Risk Assessment

The threat posed by each hazard is investigatedThe threat posed by each hazard is investigated Risk calculated according to two equal factors: Risk calculated according to two equal factors:

– Hazard likelihood Hazard likelihood – Hazard consequenceHazard consequence

These factors inform us of how concerned we These factors inform us of how concerned we should be about the existence of a hazard, and should be about the existence of a hazard, and what we can do to prevent or treat the hazardwhat we can do to prevent or treat the hazard

Generally, high likelihood / high consequence Generally, high likelihood / high consequence hazards are of greatest concernhazards are of greatest concern

Can be qualitative or quantitativeCan be qualitative or quantitative

Hazard Risk AnalysisHazard Risk Analysis Determines the relative seriousness of hazard risks that Determines the relative seriousness of hazard risks that

have been identified and assessedhave been identified and assessed Most communities have a range of competing Most communities have a range of competing

budgetary pressures and are therefore unable to fully budgetary pressures and are therefore unable to fully mitigate all hazard riskmitigate all hazard risk

Commonly conducted through a risk matrixCommonly conducted through a risk matrix– A graph that represents risk likelihood and consequence on A graph that represents risk likelihood and consequence on

the X and Y axesthe X and Y axes Vulnerability analysis can help to determine what is Vulnerability analysis can help to determine what is

causing risks, why certain risks rank above others, and causing risks, why certain risks rank above others, and what can be done to increase resilience or decrease what can be done to increase resilience or decrease vulnerability through the various risk treatmentsvulnerability through the various risk treatments

Hazard Risk TreatmentHazard Risk Treatment Reduction in either the likelihood or impacts of a Reduction in either the likelihood or impacts of a

hazard hazard Hazard risks are treated through hazard mitigation Hazard risks are treated through hazard mitigation

and disaster preparednessand disaster preparedness Risk treatment option selection takes the risk Risk treatment option selection takes the risk

assessment methodology beyond process to assessment methodology beyond process to decision-making and actiondecision-making and action

Analysis of cost effectiveness, acceptability by Analysis of cost effectiveness, acceptability by society, and long term positive and negative society, and long term positive and negative impactsimpacts

Process technical / politicalProcess technical / political

Risk Management TechnologyRisk Management Technology

In the last 15 years, technological advances have In the last 15 years, technological advances have refined the ability to identify and understand the refined the ability to identify and understand the nature of hazards and develop better risk nature of hazards and develop better risk assessment methodsassessment methods

Recent technological advances include:Recent technological advances include:– satellite and aerial imagery and radar to map satellite and aerial imagery and radar to map

floodplains and coastal erosionsfloodplains and coastal erosions

– loss estimation from various earthquake scenariosloss estimation from various earthquake scenarios

– safe rooms for homes in tornado-prone areassafe rooms for homes in tornado-prone areas

Social and Economic Risk FactorsSocial and Economic Risk Factors Strong correlation between disasters and povertyStrong correlation between disasters and poverty Risk assessments consider populations homogeneous Risk assessments consider populations homogeneous Social advocacy work to raise vulnerability awareness Social advocacy work to raise vulnerability awareness

of ‘special populations’ of ‘special populations’ Katrina revealed the socioeconomic vulnerability Katrina revealed the socioeconomic vulnerability

divide divide The social makeup of a population is based upon a The social makeup of a population is based upon a

diverse set of factors that includes education, culture, diverse set of factors that includes education, culture, local government, social interaction, values, laws, local government, social interaction, values, laws, beliefs, and other aspects of societybeliefs, and other aspects of society