Rushing water is so powerful that it resembles a wall of concrete. Water itself is very heavy. A single bathtub full weighs about 1,500 pounds. Imagine this same amount of water crashing through the streets at 80 miles per hour, like it did in Florence, Italy, in 1966. The water also carries along mud, earth, boulders, and other debris - anything not firmly attached to the ground. In 1955 in the U.S., a flood was able to carry away a wooden, four-story hotel. When water rushes through a town or village in this way, it takes everything in its path, including cars, animals, and people. Humans can die from being battered or drowned. The water sometimes mixes with oil and sewage, destroying buildings and objects. Mud will also pour into everything, clogging roads, blocking drains, and burying possessions. Even after the water drains away, a lot of destruction is left behind. Roads, bridges, and railroads are often broken or washed away. Telephone lines are cut so communication is difficult. In 1887 China, more than a million residents starved to death because a flood ruined crops, leaving no other source of food. Floodwater is also polluted, spreading disease quickly.
Floods prediction
Orbiting satellites were originally sent up to help predict weather. Since their creation, they have been invaluable in forecasting flash floods. Because they orbit miles above the earth, they can send images of clouds back to earth each half hour. These pictures are studied by scientists, who look for changes in cloud growth and temperatures to find the possibility of heavy rains. Weather satellites gather information that is used to predict strong thunderstorms, hurricanes, and flash floods. Computers are then used to predict the effects of heavy rains. These results are then sent to the National Weather Service (NWS) in the United States and smaller local weather offices across the nation and the world. The NWS involves 1500 river-monitoring and 4,000 rainfall-measuring stations, as well as a network of observers who keep a sharp eye out for rising water. Once this information is relayed to people, they can be prepared for flood conditions if necessary. The NWS also has a system of twelve River Forecast Centers that makes long-range predictions for 97% of the United States. Data from local stations are sent to these centers, where hydrologists make flood forecasts by comparing it to historical records, taking into account the season, river channel topography, soil conditions, rainfall intensity, and weather. The forecasts are sent to the general public, and warning, if necessary, is then given.
Ten worst floods
Date LocationDead 1887, September-October Hwang Ho (Yellow) River, China Over 900,000 1939 North China 500,000 1642 Kaifeng, Honan Province, China Over 300,000 1099 England and the Netherlands 100,000 1287, December 14 The Netherlands 50,000 1824 Russia 10,000 1421, November 18 The Netherlands 10,000 1964, November-December Mekong Delta, South Vietnam 5,000 1951, August 6-7 Manchuria 4,800 1948, June Foochow, China 3,500
Floods glossary
artificial levee: raised banks that increase a river’s water capacity bypass channels: special structures that redirect overflowing dam water coastal flooding: seashore flooding caused by high tides usually brought about by storms concrete dam: a man-made dam erected across a river valley to hold back water cumulonimbus: a very large thundercloud that brings heavy rain, hail, or snow dam: a barrier made of any material, which stops the flow of rivers and streams delta: a triangular area of swampy land created here the mouth of a river branches into several streams dike: a barrier usually made of earth, which runs alongside a river to keep it from overflowing at high water dysentery: an infection of the intestine caused by drinking polluted water earthen dams: dams made up of earth and stone embankment: raised banks that increase a river’s water capacity flash flood: a faster, more dangerous flow of water that results from tropical storms, dam failures, or excessive rain and snow; the flooding of an area that occurs in a matter of hours flood: the submerging with water of a normally dry area floodgates: locks or gates built across a river, which can be opened or closed to prevent flooding downstream flood barriers: special structures built across river mouths to prevent flooding flood plain: the plain next to a river where flooding occurs levee: a barrier usually made of earth or clay, which runs alongside a waterway to keep it from overflowing reservoir: a body of water stored in an artificial or natural pond or lake spillway: a specially built structure to catch overflowing water from dams tropical storm: an ocean storm that forms in the tropics typhoid: a dangerous infectious fever caused by drinking polluted water wetlands: land, such as a bog or marsh, that has wet and spongy soil
Floods references McCann, Janice, and Betsy Shand. Surviving Natural Disasters: How to Prepare for Earthquakes, Hurricanes, Tornados, Floods, Wildfires, Thunderstorms, Blizzards, Tsunamis, Volcanic Eruptions, and other calamities. Salem: Dimi Press, 1995. Waterlow, Julia. The Violent Earth: Flood. New York: Thomson Learning, 1993. Waters, John. Flood! New York: Crestwood House, 1991.
Souces: Materials of this page is obtained from thinkquest.org
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