Chapter 2

1. Chapter 2 Natural and Technological Hazards and Risk Assessment 4th Edition - 2011

2. Key Definitions • Hazard: as a “source of danger that may or may not lead to an emergency or disaster and is named after the emergency/disaster that could be so precipitated.” • Risk: the interaction of a hazard likelihood and the consequences should it occur • Emergency Event: one that requires the efforts of one or more of the emergency services to manage • Disaster: an emergency event that exceeds the capacity of emergency services in one or more critical areas

3. Natural Hazards • Exist in the natural environment and pose a threat to human populations and communities. • Exacerbated by human development

4. Floods • Can be slow or fast rising • Many causes, including large-scale weather systems, thunderstorms, snowmelt, ice jams, and dam failures • The most frequent and widespread disaster in many countries around the world

5. Earthquakes • A sudden, rapid shaking of the earth caused by the breaking and shifting of rock beneath the earth’s surface • Active seismic zones have been identified around the globe – millions exposed • Difficult to predict • Often cause secondary disasters, such as fires, landslides, avalanches, tsunamis, or dam failures, among others. • Measured by the Richter Scale or Modified Mercalli Intensity Scale

6. Hurricanes • Tropical wave → tropical depression → tropical storm → hurricane • Hurricane must have sustained winds greater than 74 mph. • Storm surge, rains, and high winds cause damage • US hurricane season – June 1 to November 30 • Described using the Saffir-Simpson Scale • Hurricane tracking has advanced rapidly • Hurricane Katrina the most costly disaster in US history

7. Storm Surges • Dramatic rises in sea level and large coastal waves that cause flooding and erosion • Most common from late fall to early spring but can develop year-round • Usually associated with extra-tropical cyclones (nor’easters) in the North Atlantic Ocean and the Gulf of Mexico, and severe winter low-pressure systems in the North Pacific Ocean and the Gulf of Alaska • Katrina storm surge reached 28 feet, devastated the Gulf Coast • Modeled using SLOSH

8. Tornadoes • Rapidly rotating vortex or funnel of air extending groundward from a cumulonimbus cloud • Approximately 1,200 tornadoes are spawned by thunderstorms each year • Can lift and move huge objects, destroy or move buildings, and siphon water • People living in valleys have the greatest exposure • Tornado Alley: TX, OK, AR, MO, and KS. • Measured by the Enhanced Fujita-Pearson Scale • Safe rooms are the greatest defense

9. Wildfires • Surface fire: most common; burns along forest floor; moves slowly and kills or damages trees; • Ground fire: usually started by lightning; burns on or below the forest floor • Crown fire: spreads rapidly by wind and moves quickly by jumping along the tops of trees • Risk increases as people move into the wildland-urban interface • Severe drought and fuel buildup have led to a significant increase in US wildfires

10. Mass Movement Hazards • Horizontal or lateral movement of large quantities of physical matter • Most prevalent in rugged/varied topography • Can include: • Landslides • Mudflows • Lateral Spreads • Rock Falls • Avalanches • Land Subsidence • Expansive Soils

11. Tsunamis • A series of waves generated by an undersea disturbance such as an earthquake, landslide, or volcanic eruption • Travel from area of disturbance at high speeds, across long distances • Waves slow down and rise when they approach the shoreline, reaching heights of up to 100 feet • Most deaths are caused by drowning • The 2004 Indian Ocean tsunami killed between 150,000 and 200,000 people in 11 countries

12. Volcanoes • A break in the earth’s crust from which molten rock (magma) exits onto the surface • When pressure from gases and magma increases, eruptions occur • Lava, gas, rock, may spread over large areas • Volcanic ash may travel hundreds of miles, can contaminate water, cause electrical storms, and collapse roofs • An erupting volcano can trigger tsunamis, flash floods, earthquakes, rock falls, and mudflows, among other secondary hazards

13. Severe Winter Storms • Consist of extreme cold and heavy snow or ice • A blizzard combines heavy snowfall, high winds, extreme cold, and ice • In the US, the weather patterns are from four sources: • The North Pacific Ocean or the Aleutian Islands • Canadian and Arctic cold fronts • The Great Lakes • The Atlantic Ocean and Gulf of Mexico • In 2006, the Federal Government began measuring Severe Winter Storms using NESIS

14. Drought • A prolonged shortage of available water caused by a deficiency of rainfall or because of exceptionally high temperatures and low humidity • Drought differs from other hazards in three ways: • The onset and end are difficult to determine because the effects accumulate slowly and may linger even after the apparent termination of an episode • The absence of a precise and universally accepted definition adds to the confusion about whether a drought exists, and if it does, the degree of severity; and • Drought effects are less obvious and spread over a larger geographic area.

15. Extreme Temperatures • Major diversions from average seasonal temperatures • Can cause injuries, fatalities, and major economic impacts when prolonged or coincide with other disaster events • Extreme Heat - 10 degrees or more above regional averages lasting for several days or weeks • Extreme Cold – no accepted ‘standard’, but occur when temperatures fall far below averages for an extended time

16. Coastal Erosion • Measured as the rate of change in the position or horizontal displacement of a shoreline over a period of time • Generally is associated with storm surges, hurricanes, windstorms, and flooding hazards • May be exacerbated by human activities such as boat wakes, shoreline hardening, and dredging

17. Thunderstorms • Heavy rainstorms that may be accompanied by strong winds, hail, lightning, tornadoes. • Generated when the following exist: • Unstable warm air rising rapidly into the atmosphere; • Sufficient moisture to form clouds and rain; • Upward lift of air currents caused by colliding weather fronts (cold and warm), sea breezes, or mountains • May occur singly, or in clusters

18. Hailstorms • An outgrowth of a severe thunderstorm • Balls or lumps of ice greater than 0.75 inch • Occur more frequently during late spring and early summer • Cause nearly $1 billion in property and crop damage annually.

19. Technological Hazards • Exist because of human innovation and activity • Newer and less understood than natural hazards • Include hazards that are non-intentional, such as transportation accidents, and intentional, such as terrorism.

20. Structural Fires • Can be triggered or exacerbated by lightning, high winds, earthquakes, volcanoes,and floods • Lightning is the most significant natural contributor to fires affecting the built environment • Buildings with rooftop storage tanks for flammable liquids are particularly susceptible

21. Dam Failure • Potentially the worst flood event • Usually the result of neglect, poor design, or structural damage caused by a major event such as an earthquake • When a dam fails, a gigantic quantity of water is suddenly let loose downstream, destroying anything in its path

22. Hazardous Materials Incidents • Chemical substances, if released or misused, can pose a threat to the environment or health • HazMats may be explosive, corrosive, flammable, poisonous, and/or radioactive • Most often released because of transportation, manufacturing, or storage accidents • May cause death, serious injury, long-lasting health effects, and damage to buildings, homes, and other property

23. Nuclear Accidents • Exposure to radiation is the main hazard • Exposure could come from plant material release • Area affected determined by amount released, wind direction and speed, and weather • On-site ERPs approved by the NRC - Off-site plans evaluated by FEMA

24. Terrorism • The use of force or violence against persons or property in violation of the criminal laws of the United States for purposes of intimidation, coercion, or ransom • Before 9/11, most US terrorism involved bombs • Effects vary death/injury to property damage and service disruption • Governments reduce vulnerability by increasing security • Terrorism may be domestic or international

25. CBRN Incidents • Family of weapons characterized by their broad-sweeping intended effects, such as inflicting mass casualties and/or physical destruction • Include: • Chemical • Biological • Nuclear • Radiological

26. Chemical Weapons • Naturally-occurring or manmade liquids, gases, or solids (typically in the form of dust) • Toxic effects on humans, animals, plants, or property • Must be delivered onto or around intended victims to be effective • Aerosolized • Dropped • Splashed • Poured • Released by bombs • Sprayed from containers or vehicles • Detection a challenge

27. Biological Weapons • Organisms or toxins either naturally occurring or genetically engineered, that can kill or incapacitate people, livestock, and crops • There are 3 basic groups: • Bacteria • Viruses • Toxins • Most are difficult to grow and maintain

28. Radiological Weapons • Commonly referred to as a “dirty bomb” or “radiological dispersion device (RDD)” • Use common explosives to spread radioactive materials over a targeted area • Distinct from nuclear blasts (much more localized) • Presence of radiation may not be recognized, will be harmful to those exposed, and may be very difficult to remove or contain

29. Nuclear Weapons • Cause great harm through the activation of a fission or fusion chain reaction • Possible only through the advanced technology and using only the most refined nuclear materials • Explosion emits intense light and heat, damaging pressure, and disperses radioactive debris over a widespread area leading to the contamination of air, water, and ground surfaces for miles around. • The likelihood of a terrorist organization developing an operational nuclear weapon is almost nil • A successful use of a nuclear weapon would cause thousands of deaths and destroy billions in property

30. Hazards Risk Management • Process by which individuals, communities, and countries deal with the hazard risks they face • A primary function of government • Many different methodologies exist • A four-step process that includes: • Identifying the hazards • Assessing risk for each hazard identified • Analyzing hazard risks in relation to each other • Treating hazard risk according to prioritization

31. Hazard Identification • All hazards that have or could affect an area of focus are identified and described • Done through: • Historical study • Brainstorming • Scientific analysis • Subject matter expertise • For more common hazards the presence of the hazard will be obvious • For new or changing hazards the knowledge or opinion of experts is required • Hazard profiling a key component

32. Hazard Risk Assessment • The threat posed by each hazard is investigated • Risk calculated according to two equal factors: • Hazard likelihood • Hazard consequence • These factors inform us of how concerned we should be about the existence of a hazard, and what we can do to prevent or treat the hazard • Generally, high likelihood / high consequence hazards are of greatest concern • Can be qualitative or quantitative

33. Hazard Risk Analysis • Determines the relative seriousness of hazard risks that have been identified and assessed • Most communities have a range of competing budgetary pressures and are therefore unable to fully mitigate all hazard risk • Commonly conducted through a risk matrix • A graph that represents risk likelihood and consequence on the X and Y axes • Vulnerability analysis can help to determine what is causing risks, why certain risks rank above others, and what can be done to increase resilience or decrease vulnerability through the various risk treatments

34. Hazard Risk Treatment • Reduction in either the likelihood or impacts of a hazard • Hazard risks are treated through hazard mitigation and disaster preparedness • Risk treatment option selection takes the risk assessment methodology beyond process to decision-making and action • Analysis of cost effectiveness, acceptability by society, and long term positive and negative impacts • Process technical / political

35. Risk Management Technology • In the last 15 years, technological advances have refined the ability to identify and understand the nature of hazards and develop better risk assessment methods • Recent technological advances include: • satellite and aerial imagery and radar to map floodplains and coastal erosions • loss estimation from various earthquake scenarios • safe rooms for homes in tornado-prone areas

36. Social and Economic Risk Factors • Strong correlation between disasters and poverty • Risk assessments consider populations homogeneous • Social advocacy work to raise vulnerability awareness of ‘special populations’ • Katrina revealed the socioeconomic vulnerability divide • The social makeup of a population is based upon a diverse set of factors that includes education, culture, local government, social interaction, values, laws, beliefs, and other aspects of society