INTRODUCTION TO NATURAL HAZARDS

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INTRODUCTION TO NATURAL HAZARDS
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Hurricane Ike

• Average in peak winds
• WAY above average in size (entire Gulf of
  Mexico!)
• Example for natural hazards?
• History
• Response

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The Great Galveston Storm of 1900

• Killed 6000 to 12,000
• Little warning
• 15 storm surge (9 high barrier island)

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Hurricane Ike

• Category 2 at landfall (110 mph sustained)
• Crossed Galveston Island
• Surge 15 maximum

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Case History Hurricane Katrina (1)

• Made landfall on August 29, 2005, to the east of
  New Orleans
• Storm surge 36 m (920 ft)
• Diameter of serious damage path about 160 km
  (100 miles)
• 80 of New Orleans underwater
• Official number of deaths 1,836
• Property damages tens of billions
• Estimated costs for recovering and rebuilding
  hundreds of billions

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Map of and profile across New Orleans
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Case History Hurricane Katrina (2)

• Regional subsidence 14 m (312 ft) per 100
  years
• Sea level rise 20 cm (8 in.) last 100 years due
  to global warming and extraction of GW, oil, and
  gas
• Geographic location vulnerable to hurricanes,
  storms, and inland floods
• Aware of risks and warnings in place
• Insufficient funds for monitoring and maintaining
  the levees and floodwalls
• Poor coordination in initial emergency response
  efforts
• Rebuild better design and planning, better
  technology and knowledge, broader awareness (but
  same problem!)

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Natural Hazards
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Types of Natural Hazards
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Hazard Magnitude and Frequency

• Magnitude Intensity of a natural hazard in terms
  of the amount of energy released
• Could also include the area and/or population
  affected
• Frequency Recurrence interval of a disastrous
  event
• May exceed the span of human observation!
• Magnitude and Frequency Generally an inverse
  relation between them

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Cost-benefit analysis

• Most damages are associated with hazards of
  moderate frequency and magnitudes
• What might annual for water look like?

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Mixed Blessings of Natural Hazards

• Not all hazardous processes exert harmful or
  deadly consequences.
• Examples Chinas sorrow (Yellow R.) Nile
• Benefits Supplying nutrients to soil, flushing
  away pollutants, changing local landscape
• Death and damages Great loss of human life and
  grave damage to property
• More loss of life from a major natural disaster
  in a developing country more property damage
  occurs in a more developed country

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Catastrophic Potential of Hazards
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Hazard Evaluation (1)

• Fundamental Principles
• Most natural hazards are predictable in space
  from scientific evaluation
• Risk analysis a critical component in
  understanding impacts
• Different hazards are linked
• Hazardous events are repetitive
• Importance of hazard planning and hazard
  mitigation

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Hazard Evaluation (2)

• Study historic data Hazards are repetitive
  events
• Observations of present conditions
• Location and effects of past hazards
• Measuring the changes or rates of change
• Occurrence and recurrence intervals
• Historic trends of hazards

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Hazard Evaluation (3)

• Studying linkages Spatial and temporal links
• Linkages between adjacent locations
• Linkages between past, present, and future
  conditions
• Linkages between hazards, e.g., volcano and
  mudflow
• Geologic setting and hazards, e.g., rock
  fractures and landslides

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Disaster Prediction and Warning (1)

• Identifying the locations of a potential hazard -
  mapping
• Determining the probabilities of a hazardous
  event at a given magnitude - history
• Observing precursor events or signs
• Forecasting the hazard
• Warning the public

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Disaster Prediction and Warning (2)
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Risk Assessment

• Risk determination
• Type, location, probability, consequences
• Risk estimate Product of probability and
  consequences
• Risk threshold Acceptable risks
• Put probability and consequences into perspective
• Societys perception and willingness
• Limitations and opportunities of risk assessment

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Risk Statistics

• Annual loss of life about 150,000 (mostly in
  developing countries)

• Financial loss gt20 billion (mostly in developed
  countries)

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Risk Impact (2)

• Risk impact estimation
• To human life Potential injury and loss of life
• To property Damage and destruction
• To society Services and functions of society
• To economy Manufacturing, mining, commercial,
  real estate, etc.
• To natural environment Direct or indirect
  adverse impact

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Human Response to Hazards (1)
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Human Response to Hazards (2)
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Human Response to Hazards (3)
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Human Response to Hazards (4)

• General response in a given location
• Combination of reactive and anticipatory response
• Artificial control of natural processes
• Taking little or no action, being optimistic
  about chances of making it through disasters

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Global Climate and Hazards
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Population Growth and Natural Hazards
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Land-Use Change and Natural Hazards (1)
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Applied and Critical Thinking Topics