4-2. flood

4-2. FLOOD4-2-1. Generals

• Overflow of water that submerges land which is usually dry

• Occurs whenever/wherever the water is supplied more than the drainage capacity (how about sea flooding?)

• Upstream vs. downstream flooding

4-2-2. Stream (River)

• The main drainage of the watershed – so critical for the flooding

• Probably the most significant medium for erosion, transportation & sedimentation on land

• We are still heavily dependent on streams

http://thebritishgeographer.weebly.com/river-landforms.html

http://thebritishgeographer.weebly.com/river-landforms.html

Meandering Mississippi River. http://www.nasa.gov/mission_pages/landsat/news/40th-earthasart.html

4-2-3. Flood Damage

Function of • Water precipiation• Drainage capability• Landforms• Floodplain usage• Population

4-2-4. Flood Effects

• Primary• Loss of life• Damages to the properties• Loss of the soils• Pollution of water

• Secondary• Disease (epidemic)• Shortage of supplies (food, water etc)• Economic hardship• Psychological damage

4-2-5. Human Interference

• Artificial walls (levee)• Channel dredging• Dams

• Discuss “Four Major Rivers Projects”

For the third time in 15 years the Mississippi River massively burst its banks this spring, inundating tiny Missouri towns such as Winfield (population 720) and Foley (population 178), causing potentially billions of dollars' worth of destruction—although the damages are still being assessed—and hiking corn prices to $8.00 a bushel in the wake of the lost crop

http://www.ehponline.org/members/2008/116-9/spheres.html

http://igbs.kr/content.asp%3FMco...eNo%3D11

Soyang Dam

Flood Damage in Longarone Village

A church tower remains standing in the Italian village of Lon-garone after flood waters from the Vaiont Dam roared through the village, destroying most of it and killing over 2,000 people. October 10, 1963.

http://www.corbisimages.com/Enlargement/Enlargement.aspx?id=BE025609&ext=1

1963. 10. 9. Italy Vaiont Dam Disaster

http://engjjang.egloos.com/viewer/10488208

4-2-6. Flood Forcasting?

http://serc.carleton.edu/images/quantskills/methods/quantlitf

http://www.trincoll.edu/~jgourley/GEOS%20112%20Stream%20Discharge.htm

4-2-7. Urbanization and Flood

http://wps.prenhall.com/esm_keller_introenvgeo_3/21/5391/1380326.cw/content/index.html

4-2-8. Measures

• Regulations on floodplain usage• Insurance• Preparation (of food and other sup-

plies) for emergencies• Hazard map

http://pinalcountyaz.gov/DEPARTMENTS/PUBLICWORKS/FLOODCONTROLDISTRICT/FLOODPLAIN/Pages/FloodplainTerms.aspx

4-2-9. Deadliest Floods (from Wikipedia “Flood”)

Death toll Event Location Date

2,500,000–3,700,000 1931 China floods China 1931

900,000–2,000,000 1887 Yellow River (Huang He) flood China 1887

500,000–700,000 1938 Yellow River (Huang He) flood China 1938

231,000Banqiao Dam failure, result of Typhoon Nina. Ap-proximately 86,000 people died from flooding and another 145,000 died during subsequent disease.

China 1975

230,000 Indian Ocean tsunami Indonesia 2004

145,000 1935 Yangtze river flood China 1935

100,000+ St. Felix's Flood, storm surge Netherlands 1530

100,000 Hanoi and Red River Delta flood North Vietnam 1971

100,000 1911 Yangtze river flood China 1911