Chapter 2. Natural and Technological Hazards and Risk Assessment. Learning Outcomes: Chapter2. After completing this chapter You should be able to:

Transcription

1 Chapter 2 Natural and Technological Hazards and Risk Assessment Learning Outcomes: Chapter2 After completing this chapter You should be able to: Describe the range of natural hazards that affect Gaza Strip Explain the scales and systems used to measure the magnitude of hazards and disasters Discuss technological hazards (man made) and their causes and effects Explain how hazard risks are assessed and to develop Risk Assessment Suggest Risk Controls to ommunity/organization Implement & Review Risk Controls Discuss Social and economic risk factors and how they influence a community s risk profile. 1

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 Types of Hazards Natural Hazards Technological Hazards (MAN Made) Combined types (mix between natural and MAN- Made) Natural Hazards Exist in the natural environment and pose a threat to human populations and communities. Exacerbated by human development 2

3 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 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 3

4 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 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 4

5 Tornadoes Rapidly rotating vortex or funnel of air extending ground ward 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 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 wild-land-urban interface Severe drought and fuel buildup have led to a significant increase in US wildfires 5

6 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 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 6

7 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 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: 1. The North Pacific Ocean or the Aleutian Islands 2. Canadian and Arctic cold fronts 3. The Great Lakes 4. The Atlantic Ocean and Gulf of Mexico In 2006, the Federal Government began measuring Severe Winter Storms using NESIS 7

8 Drought (Deficiency) 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. 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 8

9 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 عواصف رعدیة 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 9

10 عواصف ثلجیة 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. 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. 10

11 Energy Electrical Includes contact with exposed wires and contact with high voltage Gravity Includes falls, trips and slips of persons as well as objects falling, working at heights Vibration Includes vibration to parts or to the whole body Acoustic/Noise Includes exposure to single, sudden sound or long term exposure Energy Pressure systems Pressure in hydraulic and pneumatic Kinetic Energy a) The body hitting objects Hitting objects with part of the body b) Hit by moving objects Being hit by moving objects but excluding falling objects c) Explosion An explosion may also include heat as a hazard d) Penetrating objects This includes all objects that can penetrate including needles 11

12 Biological Weapons Biological /Microbiological Includes bacterial, fungal, viral, parasitic or human/animal tissue/fluids blood products Organisms or toxins either naturally occurring or genetically engineered, that can kill or incapacitate people, livestock, and crops Most are difficult to grow and maintain Chemical Flammable Refers to chemicals which burn Corrosive Refers to chemicals which will corrode tissue or metals Toxic Refers to chemicals which will poison a worker Oxidizers Refers to chemicals which will provide oxygen to a fire, or react readily Compressed Gases Refers to gases which under high pressure 12

13 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 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 13

14 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 Hazardous Materials Incidents Chemical substances, if released or misused, can pose a threat to the environment or health Haz-Mats 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 14

15 CBRN Incidents Family of weapons characterized by their broad-sweeping intended effects, such as inflicting mass casualties and/or physical destruction Include: Chemical Biological Radiological Nuclear 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 15

16 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 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 16

17 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 (The eradication or minimisation of the adverse affects of risks to which a community or an organisation is exposed.) The Process of Risk Management Identifying the hazards. Evaluating the associated risks. Controlling the risks. Classify Activities/ Disaster (Work, Product, Services/Natural, Man-made) Identify Hazard Assess / analyze the Risk Risk Control Review Risk Control 17

18 Practical Risk Assessment (from BS8800) Classify work activities Identify hazards Determine risk Decide if risk is tolerable Prepare risk control action plan (if necessary) Review adequacy of action plan The Process of Risk Management RISK MANAGEMENT Activity Characterisation Hazard Identification RISK ASSESSMENT Option Analysis RISK REDUCTION Implementation Monitoring Risk Estimation Decision Making Audit or Review 18

19 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/description is a key component 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 19

20 Hazard Characteristics General description of the hazard The location of the hazard and spatial extent of its effects The duration of an event caused by the hazard Seasonal or other time-based patterns followed by the hazard Speed of onset of an actual hazard event Availability of warnings for the hazard 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 20

21 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 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 21

22 Risk Assessment Is the process of evaluating the risk to safety & health from hazards at work Types - Qualitative (subjective risk assessment) - Semi-quantitative - Quantitative How To Assess Risk 1) Look for the Hazards 2) Decide who might be harmed & how 3) Evaluate the risk and check what is done to prevent it from happening 4) Record finding 5) Review assessment and revise it if necessary 22

23 Decide if risk is tolerable Qualitative - (Use Risk Matrix) -table scales for likelihood and severity Fatality Major injuries Minor injuries First aid or near misses Decide if risk is tolerable Based on statistic Likelihood Very likely Likely Unlikely Highly Unlikely (Risk = Severity x Likelihood ) 23

24 Qualitative Risk Table Severity Likelihood V/Likely Likely Unlikely H/Unlikely Fatality High High High Medium Major Injuries Minor Injuries First Aid/ N/misses High High Medium Medium High Medium Medium Low Medium Medium Low Low Semi-Quantitative RA Severity Categories 1. First Aid 2. Less than 4 days MC 3. More than 4 days MC 4. Fatality & Permanent Disability (MC: stands for Medical leave) 24

25 Semi-Quantitative RA Likelihood Occurrence 1. Yearly 2. Monthly 3. Weekly 4. Daily Semi-Quantitative Risk Table Likelihood S E V E R I T y Yearly Monthly Weekly Daily First Aid < 4 Days MC > 4 Days MC Fatality & Permanent Disability

26 Quantitative Risk Assessment In cases where hazards are numerous and complex eg; Chemical process plant Should have Job Safety Analysis (JSA) - describe job in less than 10 steps - List things that can go wrong - eg; Changing a Car Wheel Actions & Recommendations EL- Eliminate SL- Substitute IS- Isolation EC- Engineering Control AC - Administration Control PPE- Personal Protection Equipment 26

27 Actions & Recommendations For example; EL - stop work, cover hazard SL - use other route, other material.. IS - put up temporary barrier, EC - construct permanent wall,.. AC - put up notice, job rotation, PPE - gloves, respirator, 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 27

28 Thank You for Your Attention End of chapter 2 28