drainage

drainage,

in agriculture, the removal of excess water from the soil, either by a system of surface ditches, or by underground conduits if required by soil conditions and land contour. Diesel or centrifugal pumps are sometimes used to drain large areas. Drainage was practiced in the Nile basin c.400 B.C. and in ancient Rome. Today drain pipes of clay, concrete, or plastic, laid several feet underground, are much used in the United States, where c.110 million farm acres (44.5 million hectares) were artificially drained in 1987. Proper drainage improves soil structure; increases efficiency of phosphorus fertilizer; conserves soil nitrogen; and controls waterlogging, leaching, and salinization of soils caused by irrigationirrigation,
in agriculture, artificial watering of the land. Although used chiefly in regions with annual rainfall of less than 20 in. (51 cm), it is also used in wetter areas to grow certain crops, e.g., rice.
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drainage,

in mining, removal of water seeping into shafts and other underground mine workings from the surrounding ground. Unless seeping water is removed continually, it may endanger haulage and mining equipment, weaken supporting structures, and, in some instances, flood the mine completely. Water in a mine is drained into sumps, or reservoirs, usually excavated below the lowest working level of the mine, and is then removed by pumps. Methods to minimize seepage include the sealing of visible fissures through which water enters and the injection of concrete into the ground surrounding the shafts.

Drainage

An assembly of pipes and fittings, in the ground, used for the removal of wastewater or rainwater from a building or site.

Drainage

the removal of ground and surface water from working shafts (in mines) and quarries and during the driving of vertical, inclined, and horizontal mines, pits, and trenches. Drainage normally involves the raising of the water, but from adits and trenches it is done by gravity flow. The various systems of shaft (mine) or quarry drainage used on open and underground mines include drainage ditches, header pipes to carry the water from the underground drainage devices (sheet and flow-through filters), subsidiary and main catchment basins, a main pump chamber, and pressure piping. In open mines, ground and surface (rain) water moves via a network of drainage ditches on the levels to the main catchment basin and is removed from the quarry by pumps. In sinking vertical and horizontal mineshafts, drainage occurs by means of hoisting vessels (buckets and skips) and face pumps when the flow is small (up to 10 cu m per hr); for flows of 10-40 cu m per hr, suspended vertical pumps are used; when the flow is heavier, one of the special techniques (plugging, freezing, drawdown, and in unstable rocks, the drop-shaft method) is used. Extensive use is made of screw-type face pumps in sinking horizontal shafts.

REFERENCE

Ripp, M. G., A. I. Petukhov, and A. M. Miroshnik. Rudnichnye ventiliatornye i vodootlivnye ustanovki. Moscow, 1968.

V. A. BOIARSKII

Drainage

the prevention or elimination of the unfavorable effects of water in human economic activity. Drainage is most important for agriculture, where the removal of excess water from the soil root zone is a type of land reclamation that makes it possible to till new lands and increase productivity. Drainage involves hydraulic engineering methods, agricultural techniques, and management measures based on hydraulic engineering methods of controlled removal of water from the soil root zone. Drainage improves soil moisture and ventilation, accelerates the thawing and drying of the soil in the spring, and promotes the development of beneficial microflora and the growth of crops. This makes it possible to increase grain crop yields on drained lands to 30–40 quintals per hectare (ha), vegetables to 600–800 quintals, potatoes to 200–300 quintals, and hay to 100–120 quintals per ha, that is, an increase of 50–200 percent over the yield on unreclaimed land. Drainage is one of the principal means of increasing the productivity of lands with excess water, and it ensures efficient use of machinery and new chemicals.

Drainage is also necessary to protect cities, towns, and industrial facilities against seepage of groundwater from reservoirs or seas, to improve forest growth, and to protect mining operations.

Drainage in agriculture was first practiced in Egypt in 3000 B.C. (the Fayyum Oasis). In 2000 B.C., clay drainage systems were used to drain arable lands in Mesopotamia, and stone drainage systems were used in the vineyards of ancient Rome. The coastal lowlands of the Netherlands have been drained since the ninth and tenth centuries. The first drainage systems using handmade ceramic pipes were built near Bosworth, England, in the 16th century. Open canals were first used for drainage in Europe in the late 18th century. In the early 19th century drain tiles were used in Europe, and by the end of the century, in the United States. Russians knew about drainage in the late 14th century, but it was not until the second half of the 19th century that it was introduced in the Poles’e, the northwestern provinces, and the Central Industrial Zone (the former Tver’, Vladimir, Riazan’, Moscow, and Yaroslavl provinces); in the 1890’s, drainage systems were built in Western Siberia (the Barabinsk and Ishim steppes).

At the beginning of the 20th century the total area of drained land in the world did not exceed 20 million hectares (ha), which included 2.5 million ha in Russia (2.8 million ha in 1913). In the 20th century the greatest amount of drainage work has been done in the United States (more than 40 million ha of large tracts had been drained by 1972), Canada, Japan, India, Poland, Great Britain, Hungary, Finland, Sweden, the Netherlands (polders), and the German Democratic Republic. By 1972 more than 100 million ha were being drained in the world, 10.9 million ha in the USSR (nonchernozem zone of the European part of the RSFSR, Byelorussia, the Baltic Region, Western Siberia). Extensive, efficient drainage work is under way in the Poles’e, the Meshchera Lowland, Colchis, the valley of the Amur River, and the Baltic Region.

Marshes as well as marshy mineralized soils that are permanently or temporarily wet are drained for agricultural use. The drainage systems (open or subsurface) have drainage networks that ensure removal of excess water to the reclamation standard (depth of groundwater that ensures that the soil root zone receives the moisture necessary for high yields). Drainage methods and equipment are determined by the source of the water and the agricultural use of the land.

If the source is atmospheric water, surface runoff is accelerated by means of open or closed (subsurface) collectors. If the source is groundwater, flow is accelerated and the level of groundwater is lowered to the reclamation standard by means of a drainage system or widely spaced deep channels. Groundwater flow is intercepted by catch channels (on the side of the drainage basin) or lateral drains (on the side of the river or reservoir). Where the source is confined groundwater, the piezometric surface of the water is lowered by vertical drainage or deep drains, and as an accompanying measure surface runoff is accelerated. If the source is water from slopes, the lands being drained are surrounded on the side bordering the slope by channels, and anti-erosion steps are taken to hold back water and reduce overland runoff. When excess water is due to floods, the area is protected by levees (embankments) on the side of the river, lake, or sea; in addition, a drainage network with sluices on the main channel is built, and pumping stations for mechanical water removal are constructed.

Agricultural reclamation measures are also initially used to drain heavy grained soils and upland swamps, primarily those whose water content is due to atmospheric precipitation. These include ridging, narrowstrip plowing, bedding, ridge planting, planting of row crops (in the Far East and Colchis), mole plowing, and other procedures that are effective only in combination with an operating drainage network.

It is usually impossible to use drained lands without soil improvement work such as cutting and removing brush and small trees; removing grassy mounds, stumps, root remains, and boulders; filling in holes and ditches; plowing and preparing drained virgin land; packing and grading the surface of peat soils; applying organic and mineral fertilizers, including lime; and growing preliminary crops to eliminate variations in soil fertility. During dry periods drained lands are irrigated (sprinkled or supplied with water through drains by sluicing the channels of the drainage network) by means of drainage-irrigation systems.

The agricultural use of drained lands is determined by geographic location, soil fertility, and the technical and management conditions of initial development. In the USSR, floodplains and low-lying marshes located near large population and industrial centers are being developed for vegetable and fodder crops. In the forest-steppe and steppe zones industrial crops such as hemp, flax, sugar beets, and potatoes are raised on drained lands. The moist subtropical Black Sea coastal area of the Caucasus is most suited for the growing of tea, citrus fruits, tung tree, laurel, and bamboo; in the Far East soybeans and rice are raised on drained land (see Table 1).

Table 1. Use of drained lands in the USSR (thousands of hectares)
¹1ncluding 4,373,500 hectares drained by drainage systems
	1965	1970	1972
Total area of drained lands........	10,600	10,214	11,427¹
Including land under
Grain crops ..............	1,441	1,423	1,708
Industrial crops ............	198	211	260
Potatoes, vegetables, and melons	227	207	245
Fodder crops .............	1,430	1,705	2,014
Hayfields and pastures .......	3,486	3,318	3,869

In 1972 the yield on drained lands in the USSR was (in thousands of tons) 3,484.6 of grain, 38.19 of flax fiber, 2,346.7 of sugar beets (to be used for making sugar), and 2,578.5 of potatoes.

REFERENCES

Brudastov, A. D. Osushenie mineral’nykh i bolotnykh pochv, 4th ed. Moscow, 1955.
Kostiakov, A. N. Osnovy melioratsii, 6th ed. Moscow, 1960.
Maslov, B. S., V. S. Stankevich, and V. Ia. Chernenok. Osushitel’nouvlazhnitel’nye sistemy. Moscow, 1973.

S. F. AVER’IANOV

drainage

[′drān·ij] (civil engineering) Removal of groundwater or surface water, or of water from structures, by gravity or pumping. (hydrology) The pattern followed by the waters of an area as they pass or flow off in surface or subsurface streams. (petroleum engineering) The movement of reservoir oil or gas toward a wellbore due to the reduced pressure that results from penetration of the reservoir by the well.

drainage

1. A drainage system, either artificial or natural. 2. The water that is drained off. 3. The removal, by natural or artificial means, of surface water or groundwater.

drainage

a system of watercourses or drains

drainage

[drān´ij] systematic withdrawal of fluids and discharges from a wound, sore, or cavity.capillary drainage that effected by strands of hair, surgical gut, spun glass, or other material of small caliber which acts by capillary attraction.closed drainage airtight or water-tight drainage of a cavity so that air or contaminants cannot enter; for example, drainage of an empyema cavity carried out by means of an intercostal drainage tube passing into an airtight receiving vessel.open drainage drainage of a cavity through an opening in the chest wall into which one or more drainage tubes are inserted, the opening not being sealed against the entrance of outside air.percutaneous drainage drainage of an abscess or collection of fluid by means of a catheter inserted through the skin and positioned under the guidance of computed tomography or ultrasonography.postural drainage see postural drainage.tidal drainage drainage of the urinary bladder by an apparatus that alternately fills the bladder to a predetermined pressure and empties it by a combination of siphonage and gravity flow.

drain·age

(drān'ăj), Withdrawal of fluids from a wound or other cavity.

drainage

(drā′nĭj)n. Medicine The removal of fluid or purulent material from a wound or body cavity.

drainage

Surgery 1. The withdrawal of fluids from a body cavity or region.2. Discharge, see there. See Percutaneous transhepatic biliary.

drain·age

(drān'ăj) Continuous flow or withdrawal of fluids from a wound or other cavity.

drainage

(dran'ij) The flow or withdrawal of fluids, such as blood, infused saline, pus, and collected debris, from a cavity, organ, surgical site, or wound. See: autodrainage; drain

active drainage

Drainage in which negative pressure is maintained in the drainage tube. It is used in treating pneumothorax and in certain types of drains or catheters in the intestinal tract, body cavity, or surgical wound. Synonym: negative pressure drainage; suction drainage. See: Wound Drainage Systems: Negative Pressure

autogenic drainage

A diaphragmatic breathing pattern used by patients with respiratory illnesses (e.g., cystic fibrosis, bronchiectasis) to clear the lungs of mucus and other secretions. Various techniques are used, all of which combine positive reinforcement of deep breathing and voluntary cough suppression for as long as possible before evacuating the airways of mucus.

capillary drainage

Drainage by means of capillary attraction.

chest drainage

Placement of a drainage tube in the chest cavity, usually in the pleural space. The tube is used to drain air, fluid, or blood from the pleural space so the compressed and collapsed lung can expand. The tube is connected to a system that produces suction. This helps to remove the material from the pleural space and also prevents air from being sucked into the space.

closed drainage

Drainage of a wound or body space into a self-contained, sealed collecting system.

closed sterile drainage

A sterile tube draining a body site, such as the abdominal cavity or pleural space, that is designed to prevent the entry of air and bacteria into the tubing or the area being drained.

lymphatic drainage

Manual lymphatic drainage.

manual lymphatic drainage

Abbreviation: MLD
Gentle massage techniques used to correct localized lymphedema, e.g., in patients who have swelling of an arm after mastectomy with lymph node dissection. The therapist assists lymphatic flow from the extremity toward the heart. Synonym: lymphatic drainage

negative pressure drainage

Active drainage.

open drainage

Drainage of a wound or body cavity using absorbent materials or catheters that are in contact with the ambient conditions outside the patient.

POSTURAL DRAINAGE OF LUNGS: posterior apical segments of the right and left upper lobes

POSTURAL DRAINAGE OF LUNGS: anterior apical segments of the right and left upper lobes

POSTURAL DRAINAGE OF LUNGS: anterior segments of the right and left upper lobes

POSTURAL DRAINAGE OF LUNGS: posterior segment of the left upper lobe

POSTURAL DRAINAGE OF LUNGS: posterior segment of the right upper lobes

POSTURAL DRAINAGE OF LUNGS: left lingula

POSTURAL DRAINAGE OF LUNGS: right middle lobe

POSTURAL DRAINAGE OF LUNGS: anterior basal segments of the right and left lung

POSTURAL DRAINAGE OF LUNGS: posterior basal segments of the right and left lung

POSTURAL DRAINAGE OF LUNGS: left lateral segment of the lower lobes

POSTURAL DRAINAGE OF LUNGS: superior segment of the right and left lower lobes

postural drainage

A passive airway clearance technique in which patients are positioned so that gravity will assist the removal of secretions from specific lobes of the lung, bronchi, or lung cavities. It can be used for patients with pneumonia, chronic bronchitis, cystic fibrosis, bronchiectasis, inhaled foreign bodies, before surgery for lobectomy, or in any patient having difficulty with retained secretions. A side effect of the treatment in some patients is gastroesophageal reflux. See: illustration

Patient care

Physical tolerance to the procedure is evaluated. The respiratory therapist teaches and assists the patient in the procedure, as ordered, by positioning the patient for effective drainage of the affected lung region(s). The patient is encouraged to remove secretions with an effective cough. To decrease the risk of aspiration, the patient should not perform the procedure after meals. Chest vibration and percussion are often performed at the same time to assist movement of retained secretions in the lung.

suction drainage

Active drainage.

through-and-through drainage

Irrigation and drainage of a cavity or an organ such as the bladder by placing two perforated tubes, drains, or catheters in the area. A solution is instilled through one catheter, and the other tube collects the returned fluid actively (by suction) or passively.

tidal drainage

A method, controlled mechanically, of filling the bladder with solution by gravity and periodically emptying the bladder with a catheter. It is usually used when the patient lacks bladder control as in injuries or lesions of the spinal cord.

Wangensteen drainage

See: Wangensteen tube

drain·age

(drān'ăj) Continuous flow or withdrawal of fluids from a wound or other cavity.

drainage

drain·age

drainage

drain•age

drainage

drainage

drain

drainage

drainage,

drainage,

Drainage

Drainage

REFERENCE

Drainage

REFERENCES

drainage

drainage

drainage

drainage

drainage

drain·age

drainage

drainage

drain·age

drainage

active drainage

autogenic drainage

capillary drainage

chest drainage

closed drainage

closed sterile drainage

lymphatic drainage

manual lymphatic drainage

negative pressure drainage

open drainage

postural drainage

Patient care

suction drainage

through-and-through drainage

tidal drainage

Wangensteen drainage

drain·age

drainage

Synonyms for drainage

noun sewerage

Synonyms

Synonyms for drainage

noun emptying something accomplished by allowing liquid to run out of it

Synonyms

Related Words