flood

—floodable, adj. —flooder, n. —floodless, adj. —floodlike, adj.

/flud/, n.

1. a great flowing or overflowing of water, esp. over land not usually submerged.

2. any great outpouring or stream: a flood of tears.

3. the Flood, the universal deluge recorded as having occurred in the days of Noah. Gen. 7.

4. the rise or flowing in of the tide (opposed to ebb).

5. a floodlight.

6. Archaic. a large body of water.

v.t.

7. to overflow in or cover with a flood; fill to overflowing: Don't flood the bathtub.

8. to cover or fill, as if with a flood: The road was flooded with cars.

9. to overwhelm with an abundance of something: to be flooded with mail.

10. Auto. to supply too much fuel to (the carburetor), so that the engine fails to start.

11. to floodlight.

v.i.

12. to flow or pour in or as if in a flood.

13. to rise in a flood; overflow.

14. Pathol.

a. to suffer uterine hemorrhage, esp. in connection with childbirth.

b. to have an excessive menstrual flow.

[bef. 900; ME flod (n.), OE flod; c. Goth flodus, OHG fluot (G Flut)]

Syn. 1. FLOOD, FLASH FLOOD, DELUGE, FRESHET, INUNDATION refer to the overflowing of normally dry areas, often after heavy rains. FLOOD is usually applied to the overflow of a great body of water, as, for example, a river, although it may refer to any water that overflows an area: a flood along the river; a flood in a basement. A FLASH FLOOD is one that comes so suddenly that no preparation can be made against it; it is usually destructive, but begins almost at once to subside: a flash flood caused by a downpour.

DELUGE suggests a great downpouring of water, sometimes with destruction: The rain came down in a deluge. FRESHET suggests a small, quick overflow such as that caused by heavy rains: a freshet in an abandoned watercourse. INUNDATION, a literary word, suggests the covering of a great area of land by water: the inundation of thousands of acres. 8, 9. inundate, deluge.

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High-water stage in which water overflows its natural or artificial banks onto normally dry land, such as a river inundating its floodplain.

Uncontrollable floods likely to cause considerable damage commonly result from excessive rainfall in a brief period, but they may also result from ice jams during the spring rise in rivers, and from tsunamis. Common measures of flood control include improving channels, constructing protective levees and storage reservoirs, and implementing programs of soil and forest conservation to retard and absorb runoff from storms.

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 high-water stage in which water overflows its natural or artificial banks onto normally dry land, such as a river inundating its floodplain. The effects of floods on human well-being range from unqualified blessings to catastrophes. The regular seasonal spring floods of the Nile River prior to construction of the Aswān High Dam, for example, were depended upon to provide moisture and soil enrichment for the fertile floodplains of its delta. The uncontrolled floods of the Yangtze River and the Huang Ho in China, however, have repeatedly wrought disaster when these rivers habitually rechart their courses. Uncontrollable floods likely to cause considerable damage commonly result from excessive rainfall (rain) over brief periods of time, as, for example, the floods of Paris (1658 and 1910), of Warsaw (1861 and 1964), of Frankfurt am Main (1854 and 1930), and of Rome (1530 and 1557). Potentially disastrous floods may, however, also result from ice jams during the spring rise, as with the Danube River (1342, 1402, 1501, and 1830) and the Neva River (in Russia, 1824); from storm surges such as those of 1099 and 1953 that flooded the coasts of England, Belgium, and The Netherlands; and from tsunamis (tsunami), the mountainous sea waves caused by earthquakes, as in Lisbon (Lisbon earthquake of 1755) (1755) and Hawaii ( Hilo, 1946).

      Floods can be measured for height, peak discharge, area inundated, and volume of flow. These factors are important to judicious land use, construction of bridges and dams, and prediction and control of floods. Common measures of flood control include the improvement of channels, the construction of protective levees and storage reservoirs, and, indirectly, the implementation of programs of soil and forest conservation to retard and absorb runoff from storms.

      The discharge volume of an individual stream is often highly variable from month to month and year to year. A particularly striking example of this variability is the flash flood, a sudden, unexpected torrent of muddy and turbulent water rushing down a canyon or gulch. It is uncommon, of relatively brief duration, and generally the result of summer thunderstorms or the rapid melting of snow and ice in mountains. A flash flood can take place in a single tributary while the rest of the drainage basin remains dry. The suddenness of its occurrence causes a flash flood to be extremely dangerous.

      A flood of such magnitude that it might be expected to occur only once in 100 years is called a 100-year flood. The magnitudes of 100-, 500-, and 1,000-year floods are calculated by extrapolating existing records of stream flow, and the results are used in the design engineering of many water resources projects, including dams and reservoirs, and other structures that may be affected by catastrophic floods.

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