DISASTER SCENARIOS

A PRIMER OF KNOWLEDGE THAT CAN MULTIPLY AND SPILL OVER FOR

THE BENEFIT OF MILLIONS

Walter Hays, Global Alliance for Disaster Reduction, University of

North Carolina, USA

DISASTER SCENARIOS FOR SEVERE

WINDSTORMS

HURRICANES, TYPHOONS, AND CYCLONES

SEVERE WINDSTORMS: HURRICANES

• In the Atlantic, Caribbean, Gulf of Mexico, and Eastern Pacific areas cyclonic tropical storms with well-formed central “eyes” and with wind speeds above 74 mph are referred to as HURRICANES.

SEVERE WINDSTORMS: TYPHOONS

• The exact same phenomenon in the Western Pacific Ocean region is called a TYPHOON.

Physics Of A Typhoon

SEVERE WINDSTORMS: CYCLONES

• The exact same phenomenon in the Indian Ocean region is called a CYCLONE.

SEVERE WINDSTORMS: TYPHOONS OR CYCLONES

• People in South East Asia occasionally refer to severe windstorms as either TYPHOONS or CYCLONES.

SEVERE WINDSTORMS: NOR’EASTERS

• People on the USA’s and Canada’s eastern seaboard and Northern Europe occasionally experience severe windstorms known as NOR’EASTERS.

DEVELOPING A REALISTIC DISASTER SCENARIO FOR

A COMMUNITY FACING SEVERE WINDSTORMS

POLICY POLICY ADOPTIONADOPTION

POLICY POLICY ADOPTIONADOPTION

RISK ASSESSMENT

• VULNERABILITYVULNERABILITY

• EXPOSUREEXPOSURE

• EVENTEVENT

POLICY ASSESSMENT

• COSTCOST

• BENEFITBENEFIT

•CONSEQUENCESCONSEQUENCES

A POLICY FRAMEWORKA POLICY FRAMEWORK

SEVERE SEVERE WIND-WIND-

STORMSSTORMS

SEVERE SEVERE WIND-WIND-

STORMSSTORMSEXPECTED EXPECTED

LOSSLOSS

EXPECTED EXPECTED LOSSLOSS

THE KEYS: 1) KNOW YOUR REGION’S

METEOROLOGICAL HISTORY,

2) KNOW YOUR COMMUNITY

1325 HURRICANE PATHS: 1851-2004

• EACH HURRICANE HAS PREDICTABLE PHYSICAL CHARACTERISTICS THAT CAN BE USED TO DEVELOP DISASTER SCENARIOS WITHIN A REALISTIC POLICY FRAMEWORK.

HURRICANE BILL’S PATH: AUGUST 12-24, 2009

• THE PATH IS A STARTING POINT FOR ANY DISASTER SCENARIO FOR HURRICANES OR TYPHOONS.

TYPHOON MORAKOT’S PATH: AUGUST 3-10, 2009

• THE STATE- OF- PREPAREDNESSOF COMMUN-ITIES LOCATED IN THE LAND-FALL AREA DEFINES THE POSSIBILITY OF DISASTER.

FACTORS THAT ENHANCE DESTRUCTIVENESS

• Very low pressure in the “eye” (increases the height of storm surge and likelihood that wind will lift roofs off buildings and pop out windows after landfall)

FACTORS THAT ENHANCE DESTRUCTIVENESS

• Low vertical wind shear along the path of the storm (maintains storm’s cohesiveness and rotation)

FACTORS THAT ENHANCE DESTRUCTIVENESS

• A long path passing through warm water and a slow rate of travel (increases the likelihood that the storm will grow in strength and become a RAINMAKER after landfall)

FACTORS THAT ENHANCE DESTRUCTIVENESS

• Wind field and rain bands extending 500 km or more from the “eye” (increases area of potential wind damage, flooding, landslides, and need for evacuation).

HURRICANE DEAN: PREPARING FOR EVACUATION, AUGUST 19, 2007

FACTORS THAT ENHANCE DESTRUCTIVENESS

• Landfall in rain-saturated areas having steep slopes (increases likelihood of landslides (mudflows))

TYPHOON MORAKOT: TAIWAN

FACTORS THAT ENHANCE DESTRUCTIVENESS

• Landfall in populated areas that are unprepared:

• increases the likelihood of inadequate warning, inadequate evacuation, inadequate wind engineering (e.g., roof systems, “safe rooms”), inadequate safe havens, and inadequate INSURANCE.

RISK ASSESSMENT FOR HURRICANES, TYPHOONS,

AND CYCLONES

A RISK ASSESSMENT

• A risk assessment involves the probabilistic integration of:

• The hazard (e.g., severe windstorms) and their potential disaster agents (winds, storm surge, etc) that are directly related to the location of the community and the path/size of the storm.

HAZARDSHAZARDSHAZARDSHAZARDS

ELEMENTS OF A SCENARIOELEMENTS OF A SCENARIOELEMENTS OF A SCENARIOELEMENTS OF A SCENARIO

EXPOSUREEXPOSUREEXPOSUREEXPOSURE

VULNERABILITYVULNERABILITYVULNERABILITYVULNERABILITY LOCATIONLOCATIONLOCATIONLOCATION

RISKRISKRISKRISK

HAZARDS OF A SEVERE WINDSTORM (AKA POTENTIAL DISASTER AGENTS)

• WIND FIELD (COUNTER CLOCKWISE OR CLOCKWISE DIRECTION; CAT 1 (55 mph) TO CAT 5 (155 mph or greater)

• STORM SURGE

• RAIN BANDS OF HEAVY PRECIPITATION

• LANDSLIDES (MUDFLOWS)

• COSTAL EROSION

• POSSIBILILITY OF TORNADOES

An element’s vulnerability (fragility) is the result of a community’s actions or

nature’s actions that change the destructiveness of the storm

MANKIND’S CONTRIBUTIONAn element’s vulnerability

(fragility) is the result of flaws that enter during the planning,

siting, design, and construction of a community’s buildings and

infrastructure.

TYPHOON MORAKOT: TAIWAN

TYPHOON MORAKOT: TAIWAN

MANKIND’S ACTIONS THAT INCREASE VULNERABILITY

• Urban development or industrial development along coastlines prone to severe windstorms that generate storm surges, high-velocity wind, and heavy precipitation.

TYPHOON MORAKOT: CHINA

MANKIND’S ACTIONS THAT INCREASE VULNERABILITY

• A community locating its dwellings, schools, hospitals, etc., and infrastructure in areas susceptible to storm surge, flooding, and high winds.

TYPHOON MORAKOT: TAIWAN

TYPHOON MORAKOT: TAIWAN

TYPHOON MORAKOT: CHINA

NATURE’S CONTRIBUTIONS THAT INCREASE VULNERABILITY

• Warm ocean water (creates the low pressure zone for the “eye” of the storm)

• Warm ocean water along the path of the storm (keeps the storm energized and increases the wind field strength)

NATURES CONTRIBUTIONS THAT INCREASE VULNERABILITY

• Low vertical wind shear (keeps the storm organized)

• Stalled weather systems (prolongs rain fall, especially after landfall).

WIND PENETRATING BUILDING ENVELOPE

SEVERE WINDSTORMS

SEVERE WINDSTORMS

UPLIFT OF ROOF SYSTEM

FLYING DEBRIS

STORM SURGE

IRREGULARITIES IN ELEVATION AND PLAN

SITING PROBLEMS

FLOODING AND LANDSLIDES

CAUSES OF DAMAGE

CAUSES OF DAMAGE

“DISASTER LABORATORIES”

“DISASTER LABORATORIES”

DISASTER RISK REDUCTION

COMMUNITYCOMMUNITYCOMMUNITYCOMMUNITY

DATA BASES DATA BASES AND INFORMATIONAND INFORMATIONDATA BASES DATA BASES AND INFORMATIONAND INFORMATION

•SEVERE WINDSTORMS•INVENTORY•VULNERABILITY•LOCATION

RISK ASSESSMENTRISK ASSESSMENT

RISK

ACCEPTABLE RISK

UNACCEPTABLE RISK

SEVERE WINDSTORM SEVERE WINDSTORM RISK REDUCTIONRISK REDUCTION

•PREVENTION/MITIGATION•PREPAREDNESS•EMERGENCY RESPONSE•RECOVERY and RECONSTRUCTION• EDUCATIONAL SURGES

POLICY OPTIONSPOLICY OPTIONS

Wind profileWind profile

Storm Hazards:Storm Hazards:-Wind pressure-Surge-Rain-Flood-Waves-Salt water-Missiles-Tornadoes

OceanOceanOceanOcean

Gradient WindGradient Wind

EMERGING TECHNOLOGIES FOR SEVERE WINDSTORMS

EMERGING TECHNOLOGIES FOR SEVERE WINDSTORMS

• REAL TIME FORECASTS OF PATH AND PHYSICAL EFFECTS

• MEASUREMENT TECHNOLOGIES (E.G., DOPPLER RADAR, WIND SPEEDS; PRESSURE, INTERNATIONAL SPACE STATION)

• REAL TIME FORECASTS OF PATH AND PHYSICAL EFFECTS

• MEASUREMENT TECHNOLOGIES (E.G., DOPPLER RADAR, WIND SPEEDS; PRESSURE, INTERNATIONAL SPACE STATION)

• METEOROLOGICAL HISTORIES

• WIND ENGINEERING • STORM SURGE MAPS • STORM CHASER

PLANES/DRONES• WARNING SYSTEMS• RISK MODELING (E.G.,

HAZUS, INSURANCE UNDERWRITING)

• METEOROLOGICAL HISTORIES

• WIND ENGINEERING • STORM SURGE MAPS • STORM CHASER

PLANES/DRONES• WARNING SYSTEMS• RISK MODELING (E.G.,

HAZUS, INSURANCE UNDERWRITING)

SAVING LIVES

WIND ENGINEERING

“SAFE ROOMS”

EVACUATION

TYPHOON MORAKOT: TAIWAN

POLICY POLICY ADOPTIONADOPTION

POLICY POLICY ADOPTIONADOPTION

RISK ASSESSMENT

• VULNERABILITYVULNERABILITY

• EXPOSUREEXPOSURE

• EVENTEVENT

POLICY ASSESSMENT

• COSTCOST

• BENEFITBENEFIT

•CONSEQUENCESCONSEQUENCES

TOWARDS DISASTER RISK REDUCTION TOWARDS DISASTER RISK REDUCTION FOR SEVERE WINDSTORMSFOR SEVERE WINDSTORMS

SEVERE SEVERE WIND WIND

STORMSSTORMS

SEVERE SEVERE WIND WIND

STORMSSTORMSEXPECTED EXPECTED

LOSSLOSS

EXPECTED EXPECTED LOSSLOSS