Class 14a: Natural hazardsNatural hazards and disastersNatural hazards and disastersFour types of impacts1906 San Francisco Earthquake1906 San Francisco Earthquake1989 Loma Prieta EarthquakeNatural hazards and disastersHurricane Jeanne (2004)Natural hazards and disasters1991 East Bay Hills Fire1991 East Bay Hills FireFour stages of responseTypes of mitigationClass 14a: Natural hazards• Vulnerability and disaster • Geologic events• Climatic eventsNatural hazards and disasters• Natural disaster: damage to life or property• Natural hazard: risk of natural disaster• Combination of physical and human geography• Droughts, floods, hurricanes, earthquakes, volcanoesNatural hazards and disasters• Trigger events are natural• But “disasters” are man-made• Humans can increase risk– Building on a hillside• Or increase vulnerability– Building in a floodplainFour types of impacts• Direct damage• Emergency response hampered• Short-term service interruptions• Long-term economic loss1906 San Francisco Earthquake• Sunday 5 A.M.; 40 seconds; 8.2 magnitude• 3000 dead; 3/5 of housing, all of CBD• Multiple, interrelated hazards– Earthquake led to fire• Failure of “lifelines”– Water mains and tanks ruptured1906 San Francisco Earthquake• Learning from mistakes– Structural damage Æ stronger codes– Larger water supply (Hetch Hetchy)•Or not!– Reservoir on fault line– Fire debris became Marina District1989 Loma Prieta Earthquake• Weekday, 5 P.M; 15 sec.; 7.1 magnitude• 62 dead; 12,000 homeless; $6 billion• Interrelated hazards– Worst damage on fill from 1906• Failure of lifelines (Bay Bridge)Natural hazards and disasters• Most deaths in poor countries• Squatter settlements, unclaimed land• Few warning systems, evacuation plans• Few building codes• Deliberate risksHurricane Jeanne (2004)• 2,000 dead in Haiti; 12 in Dominican Rep.• Haiti is 98% deforested• Very poor, very high birth rates• French land system: land divided by heirs• 71% of fuel from charcoal (wood)• No early warning systemNatural hazards and disasters• Most property damage in rich countries• Loss of life avoided• Prime real estate often disaster-prone• More reporting, reimbursement• “Solutions” may give false sense of security1991 East Bay Hills Fire• Oct. 20: 25 dead, 2,700 homes, $1.5 billion, 5,100 homeless: 9 hours• Risk factors– Vegetation (flammable eucalypts)– Fire suppression policy– Wood houses, decks– Narrow, winding roads1991 East Bay Hills Fire• Interrelated hazards: drought, fire• Failure of lifelines: narrow roads, incompatible fire equipment• Rebuilt immediately (high property values)• But with vegetation, material restrictionsFour stages of response• Preparation and readiness• Emergency response• Recovery (short- and long-term)• MitigationTypes of mitigation• Warning systems, evacuation planning• Building regulations• Land use planning and land acquisition• Education• Habitat
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