/dray"nij/, n.
1. the act or process of draining.
2. a system of drains, artificial or natural.
4. something that is drained off.
5. Surg. the drainage of fluids, as bile, urine, etc., from the body, or of pus and other diseased products from a wound.
[1645-55; DRAIN + -AGE]

* * *

      in agriculture, the artificial removal of water from land; drainage is employed in the reclamation of wetlands, in the prevention of erosion, and as a concomitant of irrigation in the agriculture of arid regions.

      A brief treatment of drainage follows. For full treatment, see irrigation and drainage.

      Drainage is an ancient practice, but apparently until recent times it was regarded as less important than irrigation. The first drains were most likely ditches for channelling floodwaters back to the rivers. The addition of linings of less porous materials greatly improved drainage efficiency. The most significant 20th-century development in drainage technology was the application of land-grading techniques to facilitate uniform runoff.

      Land may be smoothed with proper slopes and ditches so as to remove excess water before it enters the soil and thus prevent erosion, leaching of nutrients, and standing pools of water on the surface, and to permit early spring planting. If carefully planned, this smoothing also can prepare the land for surface irrigation, thus serving two purposes by one earth-moving operation. After excess water enters the soil, its removal is an expensive and specialized undertaking that is not directly connected with irrigation, although it sometimes may be necessary for irrigated land. Modern drainage systems may be divided into two categories, surface and subsurface. The typical surface system consists of field drains, field ditches, a main collection ditch, and an outlet. As the term implies, a surface system is designed to remove water that collects on top of the soil. Surface drainage is especially important for soils that absorb water slowly. The field drains vary in configuration according to topography, parallel drains being indicated for uniform surfaces and site-specific ones for areas of uneven accumulation.

      Subsurface drainage systems consist of small conduits, a submain, a main, and an outlet. The conduits, equivalent to the field drains in a surface system, collect the water in the soil and drain it into the larger arteries.

      Factors determining the most efficient drainage system design for a particular property include soil type, land configuration, amount and pattern of rainfall, and types of crops to be grown. Soils of high sand or silt content are generally suited to subsurface drainage, while soils of high clay content generally require surface systems.

* * *

Universalium. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • drainage — [ drɛnaʒ ] n. m. • 1848; de drain 1 ♦ Opération d assainissement des sols trop humides, par l écoulement de l eau retenue en excès dans les terres. ⇒ assainissement, assèchement. Drainage d une prairie, d un marais, d un polder. Travaux de… …   Encyclopédie Universelle

  • Drainage [1] — Drainage,1 eine Anlage zur Entwässerung, zur Beseitigung der in der Ackerkrume und im Untergrund angesammelten schädlichen Feuchtigkeit vermittelst unterirdisch eingelegter Sickerungen. Notwendig ist die Beseitigung der stauenden Nässe im Boden… …   Lexikon der gesamten Technik

  • Drainage — (n. d. engl. to drain, spr. drēn, »ableiten«) ist die Befreiung nassen und versumpften Bodens von seiner überschüssigen Nässe durch unterirdische Leitungen. Dieses Verfahren war schon im Altertum (Columella, II, 2, 9), wenn auch in äußerst… …   Meyers Großes Konversations-Lexikon

  • Drainage — Drain age, n. 1. A draining; a gradual flowing off of any liquid; also, that which flows out of a drain. [1913 Webster] 2. The mode in which the waters of a country pass off by its streams and rivers. [1913 Webster] 3. (Engin.) The system of… …   The Collaborative International Dictionary of English

  • Drainage — (spr. Dränahsch), Drainirung, v. engl. Drain (spr. Drähn, d.h. Kanal, Röhre), die Entwässerung des Bodens mittelst einer Leitung von gebrannten Thonröhren (Drains, Drainröhren). Sie hat den Zweck, bei quelligem Boden das Quellwasser, bei… …   Pierer's Universal-Lexikon

  • Drainage [2] — Drainage der Tunnelgewölbe, s. Tunnelbau …   Lexikon der gesamten Technik

  • Drainage — Drainage, s. Entwässerung …   Herders Conversations-Lexikon

  • drainage — index outflow Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

  • drainage — 1650s, from DRAIN (Cf. drain) + AGE (Cf. age) …   Etymology dictionary

  • drainage — ► NOUN 1) the action or process of draining. 2) a system of drains …   English terms dictionary

  • drainage — [drān′ij] n. 1. the act, process, or method of draining 2. a system of drains; arrangement of pipes, etc. for carrying off waste matter 3. that which is drained off 4. a region or area drained, as by a river …   English World dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”