Natural Hazards

Natural Hazards

• What are the greatest risks?– Are these risks increasing?

• What are the costs associated with environmental hazards?– Are the relative costs the same around the

world?– What controls these costs?

• How do we define risk?

So… What are common hazards

• Let’s list the hazards people think of when of when they think of natural hazards

• Which of these are the most dangerous in the U.S.?

• Which are the most expensive (in the U.S.)?

Data for U.S. ???Hazard Annual Number of

Deaths per Year

Tornadoes & Windstorms 218

Lightning 120

Flooding 86

Tropical Cyclones 55

Earthquakes 50+ ?

Mass Wasting 25

Volcano <1

Coastal Erosion 0

Drought 0

Frost & Freezing 0 ?

Data is a 150 year average from 19th and 20th centuries (Keller, 1999).

Number of Hazard Events World Wide

Type of Hazard No of EventsTornadoes (U.S. only)FloodTropical Cyclone TsunamiEarthquakeWind (other than tornado)DroughtLandslideWild fireExtreme temperatureTemperate winter stormVolcanoTornadoes (non-US)FamineStorm surge

947623891337986899793782448269259240168847718

For 20th century data from WHO (2002), U.S. tornado data are only for 1950-1995 for only F2-F5 size events

Numbers of Deaths Associated with Natural Disasters Worldwide

Type of Hazard Deaths Injuries Homeless Largest Event Death Toll

Floods 6,851,740 1,033,572 123,009,662 China 1931 3,700,000

Earthquakes 1,816,119 1,147,676 8,953,296 Tangshan, China 1976 242,000

Tropical cyclones 1,147,877 906,311 34,272,470 Bangladesh 1970 300,000

Volcanoes 96,770 11,154 197,790 Martinique 1902 30,000

Mass Wasting 60,501 8,071 3,759,329 Soviet Union 1949 12,000

Extra-tropical storms 36,681 117.925 12,606,891 N. Europe 1953 4,000

Heat waves 14,732 1,364 0 India 1998 2,541

Tsunamis 10,754 789 Not counted Sanriku, Japan 1933 3,000

Cold waves 6,807 1.307 17,340 India 1982 400

Tornadoes 7,917 27,887 575,511 Bangladesh 1989 800

Wild Fires 2,503 1,658 140,776 Oklahoma, U.S. 1918 1,000

Data for 20th century, based on WHO (2002) data.

EarthquakeFlood Tropical storm Wind StormWild FireDroughtCold waveHeat waveTotal

Worldwide Hazard Ranking by Cost

Type Cost$248,624,900,000$206,639,800,000 $80,077,700,000 $43,890,000,000 $20,212,800,000 $16,800,000,000 $9,555,000,000 $5,450,000,000$631,250,200,000

Cost of natural hazards, summarized by type for top 100 most costly events of 20 th century (WHO, 2002).

F5 Tornado that hit GreensburgKansas, May 4, 2007 -Doppler radar gave a 20-minute warning

-Tornado was 1.5 miles across at its base

-95% of the town was leveled

http://www.chaseday.com/tornadoes.htm

Lightening strikes 100 times/second worldwide, with the greatest number of hits in central Africa. In the U.S. the greatest number of lightening strikes occur in Florida.

The Empire State building is hit on average 100 times/year.

Sean & Michael McQuilken, 1975

Define some terms

• What are precursor events?

• What is forecasting?

• How do warnings work?

• What is risk?– What is acceptable risk?

• What is the purpose of insurance?