![Fields SW from Sevilla](https://upload.wikimedia.org/wikipedia/commons/5/51/Fields_SW_from_Sevilla.jpg)
Irrigation (also referred to as watering) is the practice of applying controlled amounts of
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
to
land
Land, also known as dry land, ground, or earth, is the solid terrestrial surface of the planet Earth that is not submerged by the ocean or other bodies of water. It makes up 29% of Earth's surface and includes the continents and various isla ...
to help grow
crops,
landscape plants, and
lawns. Irrigation has been a key aspect of
agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...
for over 5,000 years and has been developed by many cultures around the world. Irrigation helps to grow crops, maintain landscapes, and
revegetate disturbed soils in dry areas and during times of below-average rainfall. In addition to these uses, irrigation is also employed to protect crops from
frost, suppress
weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
growth in
grain fields, and prevent
soil consolidation
Soil consolidation refers to the mechanical process by which soil changes volume gradually in response to a change in pressure. This happens because soil is a two-phase material, comprising soil grains and pore fluid, usually groundwater. When ...
. It is also used to cool
livestock
Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animal ...
, reduce
dust
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in ho ...
, dispose of
sewage, and support
mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic ...
operations.
Drainage
Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic condition ...
, which involves the removal of surface and sub-surface water from a given location, is often studied in conjunction with irrigation.
There are several methods of irrigation that differ in how water is supplied to plants.
Surface irrigation
Surface irrigation is where water is applied and distributed over the soil surface by gravity. It is by far the most common form of irrigation throughout the world and has been practiced in many areas virtually unchanged for thousands of years.
S ...
, also known as gravity irrigation, is the oldest form of irrigation and has been in use for thousands of years. In
sprinkler irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure water devices.
Micro-irrigation
Micro-irrigation, also called Micro-spray,localized, low-volume, low-flow, or trickle irrigation, is an irrigation method with lower water pressure and flow than a traditional sprinkler system. Low-volume irrigation is used in agriculture for r ...
is a system that distributes water under low pressure through a piped network and applies it as a small discharge to each plant. Micro-irrigation uses less pressure and water flow than sprinkler irrigation.
Drip irrigation
Drip irrigation or trickle irrigation is a type of micro-irrigation system that has the potential to save water and nutrients by allowing water to drip slowly to the roots of plants, either from above the soil surface or buried below the surface. ...
delivers water directly to the root zone of plants.
Subirrigation
Subirrigation also known as seepage irrigation, is a method of irrigation where water is delivered to the plant root zone. The excess may be collected for reuse.
Subirrigation is used in growing field crops such as tomatoes, peppers, and sugar ...
has been used in field crops in areas with high water tables for many years. It involves artificially raising the water table to moisten the soil below the root zone of plants.
Irrigation water can come from
groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...
(extracted from
springs or by using
wells), from surface water (withdrawn from
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of w ...
s,
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
s or
reservoirs
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including control ...
) or from non-conventional sources like
treated wastewater,
desalinated water
Desalination is a process that takes away mineral components from saline water. More generally, desalination refers to the removal of salts and minerals from a target substance, as in soil desalination, which is an issue for agriculture. Saltw ...
,
drainage water, or
fog collection
upright=1.3, ''Atrapanieblas'' or fog collection in Alto Patache, Atacama Desert, Chile">Atacama_Desert.html" ;"title="Alto Patache, Atacama Desert">Alto Patache, Atacama Desert, Chile
Fog collection is the harvesting of water from fog using ...
. Irrigation can be supplementary to
rainfall
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
, which is common in many parts of the world as
rainfed agriculture, or it can be full irrigation, where crops rarely rely on any contribution from rainfall. Full irrigation is less common and only occurs in arid landscapes with very low rainfall or when crops are grown in semi-arid areas outside of rainy seasons.
The environmental effects of irrigation relate to the changes in quantity and quality of
soil
Soil, also commonly referred to as earth or dirt
Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty.
Common types of dirt include:
* Debri ...
and
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
as a result of irrigation and the subsequent effects on natural and social conditions in
river basins
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the ...
and downstream of an
irrigation scheme. The effects stem from the altered
hydrological conditions caused by the installation and operation of the irrigation scheme. Amongst some of these problems is depletion of underground
aquifers
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...
through
overdrafting
Overdrafting is the process of extracting groundwater beyond the equilibrium yield of an aquifer. Groundwater is one of the largest sources of fresh water and is found underground. Groundwater depletion is comparable to a bank account in which mor ...
. Soil can be over-irrigated due to poor
distribution uniformity Distribution uniformity or DU in irrigation is a measure of how uniformly water is applied to the area being watered, normally expressed as percentage, and not to be confused with efficiency. The distribution uniformity is often calculated when pe ...
or
management
Management (or managing) is the administration of an organization, whether it is a business, a nonprofit organization, or a Government agency, government body. It is the art and science of managing resources of the business.
Management includ ...
wastes water, chemicals, and may lead to
water pollution
Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. ...
. Over-irrigation can cause deep drainage from rising water tables that can lead to problems of irrigation
salinity requiring
watertable control Watertable control is the practice of controlling the height of the water table by drainage. Its main applications are in agricultural land (to improve the crop yield using agricultural drainage systems) and in cities to manage the extensive under ...
by some form of
subsurface land drainage.
Extent
![Share of agricultural land which is irrigated, OWID](https://upload.wikimedia.org/wikipedia/commons/a/a8/Share_of_agricultural_land_which_is_irrigated%2C_OWID.svg)
In year 2000, the total fertile land was 2,788,000 km
2 (689 million acres) and it was equipped with irrigation infrastructure worldwide. About 68% of this area is in Asia, 17% in the Americas, 9% in Europe, 5% in Africa and 1% in Oceania. The largest contiguous areas of high irrigation density are found in Northern and Eastern India and Pakistan along the Ganges and Indus rivers; in the Hai He, Huang He and Yangtze basins in China; along the Nile river in Egypt and Sudan; and in the Mississippi-Missouri river basin, the Southern Great Plains, and in parts of California in the United States. Smaller irrigation areas are spread across almost all populated parts of the world.
By 2012, the area of irrigated land had increased to an estimated total of 3,242,917 km
2 (801 million acres), which is nearly the size of India. The irrigation of 20% of farming land accounts for the production of 40% of food production.
Global overview
The scale of irrigation increased dramatically over the 20th century. In 1800, 8 million hectares globally were irrigated, in 1950, 94 million hectares, and in 1990, 235 million hectares. By 1990, 30% of the global food production came from irrigated land. Irrigation techniques across the globe includes canals redirecting surface water,
[ Peterson 2016] groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...
pumping, and diverting water from dams. National governments lead most irrigation schemes within their borders, but private investors and other nations,
especially the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
,
China, and European countries like the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
,
[ McNeill 2000 pp.169-170.] also fund and organize some schemes within other nations.
Irrigation enables the production of more crops, especially
commodity crops
A cash crop or profit crop is an Agriculture, agricultural crop which is grown to sell for profit. It is typically purchased by parties separate from a farm. The term is used to differentiate marketed crops from staple crop (or "subsistence crop") ...
in areas which otherwise could not support them. Countries frequently invested in irrigation to increase
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...
,
rice
Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and '' Porteresia'', both wild and domesticat ...
, or
cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor pe ...
production, often with the overarching goal of increasing self-sufficiency.
Water sources
Groundwater and surface water
Irrigation water can come from
groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...
(extracted from
springs or by using
wells), from surface water (withdrawn from
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of w ...
s,
lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
s or
reservoirs
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including control ...
) or from non-conventional sources like
treated wastewater,
desalinated water
Desalination is a process that takes away mineral components from saline water. More generally, desalination refers to the removal of salts and minerals from a target substance, as in soil desalination, which is an issue for agriculture. Saltw ...
,
drainage water, or
fog collection
upright=1.3, ''Atrapanieblas'' or fog collection in Alto Patache, Atacama Desert, Chile">Atacama_Desert.html" ;"title="Alto Patache, Atacama Desert">Alto Patache, Atacama Desert, Chile
Fog collection is the harvesting of water from fog using ...
.
While
floodwater harvesting belongs to the accepted irrigation methods,
rainwater harvesting
Rainwater harvesting (RWH) is the collection and storage of rain, rather than allowing it to run off. Rainwater is collected from a roof-like surface and redirected to a tank, cistern, deep pit (well, shaft, or borehole), aquifer, or a reservoir ...
is usually not considered as a form of irrigation. Rainwater harvesting is the collection of runoff water from roofs or unused land and the concentration of this.
Treated or untreated wastewater
Other sources
Irrigation water can also come from non-conventional sources like
treated wastewater,
desalinated water
Desalination is a process that takes away mineral components from saline water. More generally, desalination refers to the removal of salts and minerals from a target substance, as in soil desalination, which is an issue for agriculture. Saltw ...
,
drainage water, or
fog collection
upright=1.3, ''Atrapanieblas'' or fog collection in Alto Patache, Atacama Desert, Chile">Atacama_Desert.html" ;"title="Alto Patache, Atacama Desert">Alto Patache, Atacama Desert, Chile
Fog collection is the harvesting of water from fog using ...
.
In countries where humid air sweeps through at night, water can be obtained by
condensation onto cold surfaces. This is practiced in the vineyards at
Lanzarote using stones to condense water.
Fog collectors are also made of canvas or foil sheets. Using condensate from air conditioning units as a water source is also becoming more popular in large urban areas.
a Glasgow-based startup has helped a farmer in Scotland to establish edible saltmarsh crops irrigated with sea water. An acre of previously marginal land has been put under cultivation to grow
samphire
Samphire is a name given to a number of succulent salt-tolerant plants ( halophytes) that tend to be associated with water bodies.
*Rock samphire, ''Crithmum maritimum'' is a coastal species with white flowers that grows in Ireland, the Uni ...
,
sea blite, and
sea aster; these plants yield a higher profit than potatoes. The land is flood irrigated twice a day to simulate tidal flooding; the water is pumped from the sea using wind power. Additional benefits are soil remediation and
carbon sequestration
Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in lan ...
.
Competition for water resources
Until 1960s, there were fewer than half the current number of people on the planet. People were not as wealthy as today, consumed fewer calories and
ate less meat, so less water was needed to produce their food. They required a third of the volume of water we presently take from rivers. Today, the competition for
water resources is much more intense. This is because there are now
more than seven billion people on the planet, increasing the likelihood of
overconsumption
Overconsumption describes a situation where a consumer overuses their available goods and services to where they can't, or don't want to, replenish or reuse them. In microeconomics, this may be described as the point where the marginal cost of ...
of food produced by water-thirsty animal agriculture and intensive farming practices, and there is increasing competition for water from
industry
Industry may refer to:
Economics
* Industry (economics), a generally categorized branch of economic activity
* Industry (manufacturing), a specific branch of economic activity, typically in factories with machinery
* The wider industrial sector ...
,
urbanisation
Urbanization (or urbanisation) refers to the population shift from rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It is predominantly the ...
and
biofuel crops. Farmers will have to strive to increase productivity to meet growing
demands for food, while industry and cities find ways to use water more efficiently.
Successful agriculture is dependent upon farmers having sufficient access to water. However,
water scarcity
Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two types of water scarcity: physical or economic water scarcity. Physical water scarcity is whe ...
is already a critical constraint to farming in many parts of the world.
Irrigation methods
There are several methods of irrigation. They vary in how the water is supplied to the plants. The goal is to apply the water to the plants as uniformly as possible, so that each plant has the amount of water it needs, neither too much nor too little. Irrigation can also be understood whether it is ''supplementary'' to rainfall as happens in many parts of the world, or whether it is full'' irrigation' whereby crops rarely depend on any contribution from rainfall. Full irrigation is less common and only happens in arid landscapes experiencing very low rainfall or when crops are grown in semi-arid areas outside of any rainy seasons.
Surface irrigation
![LevelBasinFloodIrrigation](https://upload.wikimedia.org/wikipedia/commons/a/ae/LevelBasinFloodIrrigation.JPG)
Surface irrigation, also known as gravity irrigation, is the oldest form of irrigation and has been in use for thousands of years. In ''surface'' (''furrow,'' ''flood'', or ''level basin'') irrigation systems, water moves across the surface of agricultural lands, in order to wet it and infiltrate into the soil. Water moves by following gravity or the slope of the land. Surface irrigation can be subdivided into furrow,'' border strip or basin irrigation''. It is often called ''flood irrigation'' when the irrigation results in flooding or near flooding of the cultivated land. Historically, surface irrigation is the most common method of irrigating agricultural land across most parts of the world. The water application efficiency of surface irrigation is typically lower than other forms of irrigation, due in part to the lack of control of applied depths. Surface irrigation involves a significantly lower capital cost and energy requirement than pressurised irrigation systems. Hence it is often the irrigation choice for developing nations, for low value crops and for large fields. Where water levels from the irrigation source permit, the levels are controlled by dikes, usually plugged by soil. This is often seen in terraced rice fields (rice paddies), where the method is used to flood or control the level of water in each distinct field. In some cases, the water is pumped, or lifted by human or animal power to the level of the land.
Surface irrigation is even used to water urban gardens in certain areas, for example, in and around
Phoenix, Arizona
Phoenix ( ; nv, Hoozdo; es, Fénix or , yuf-x-wal, Banyà:nyuwá) is the capital and most populous city of the U.S. state of Arizona, with 1,608,139 residents as of 2020. It is the fifth-most populous city in the United States, and the on ...
. The irrigated area is surrounded by a
berm
A berm is a level space, shelf, or raised barrier (usually made of compacted soil) separating areas in a vertical way, especially partway up a long slope. It can serve as a terrace road, track, path, a fortification line, a border/ separation ...
and the water is delivered according to a schedule set by a local
irrigation district In the United States an irrigation district is a cooperative, self-governing public corporation set up as a subdivision of the State government, with definite geographic boundaries, organized, and having taxing power to obtain and distribute water f ...
.
A special form of irrigation using surface water is
spate irrigation, also called floodwater harvesting. In case of a flood (spate), water is diverted to normally dry river beds (wadis) using a network of dams, gates and channels and spread over large areas. The moisture stored in the soil will be used thereafter to grow crops. Spate irrigation areas are in particular located in semi-arid or arid, mountainous regions.
Micro-irrigation
![Dripperwithdrop](https://upload.wikimedia.org/wikipedia/commons/4/43/Dripperwithdrop.png)
''Micro-irrigation'', sometimes called localized irrigation, low volume irrigation, or trickle irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Traditional drip irrigation use individual emitters, subsurface drip irrigation (SDI), micro-spray or micro-sprinklers, and mini-bubbler irrigation all belong to this category of irrigation methods.
Drip irrigation
![dripirrigation](https://upload.wikimedia.org/wikipedia/commons/4/4e/Dripirrigation.png)
Drip (or micro) irrigation, also known as trickle irrigation, functions as its name suggests. In this system, water is delivered at or near the
root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...
zone of plants, one drop at a time. This method can be the most water-efficient method of irrigation, if managed properly; evaporation and runoff are minimized. The field
water efficiency
Water efficiency is the practice of reducing water consumption by measuring the amount of water required for a particular purpose and is proportionate to the amount of essential water used.Vickers, Amy. “Water use and conservation." Amherst, MA ...
of drip irrigation is typically in the range of 80 to 90 percent when managed correctly.
In modern agriculture, drip irrigation is often combined with
plastic mulch
Plastic mulch is a product used in plasticulture in a similar fashion to mulch, to suppress weeds and conserve water in crop production and landscaping. Certain plastic mulches also act as a barrier to keep methyl bromide, both a powerful fumigant ...
, further reducing evaporation, and is also the means of delivery of fertilizer. The process is known as ''
fertigation''.
Deep percolation, where water moves below the root zone, can occur if a drip system is operated for too long or if the delivery rate is too high. Drip irrigation methods range from very high-tech and computerized to low-tech and labor-intensive. Lower water pressures are usually needed than for most other types of systems, with the exception of low energy center pivot systems and surface irrigation systems, and the system can be designed for uniformity throughout a field or for precise water delivery to individual plants in a landscape containing a mix of plant species. Although it is difficult to regulate pressure on steep slopes, pressure compensating
emitters are available, so the field does not have to be level. High-tech solutions involve precisely calibrated emitters located along lines of tubing that extend from a computerized set of
valves
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fitting ...
.
Sprinkler irrigation
![TravellingSprinkler](https://upload.wikimedia.org/wikipedia/commons/2/2a/TravellingSprinkler.JPG)
In ''sprinkler'' or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system using sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a ''solid-set'' irrigation system. Higher pressure sprinklers that rotate are called ''rotors'' and are driven by a ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial circle. Guns are similar to rotors, except that they generally operate at very high pressures of 275 to 900 kPa (40 to 130 psi) and flows of 3 to 76 L/s (50 to 1200 US gal/min), usually with nozzle diameters in the range of 10 to 50 mm (0.5 to 1.9 in). Guns are used not only for irrigation, but also for industrial applications such as dust suppression and
logging.
Sprinklers can also be mounted on moving platforms connected to the water source by a hose. Automatically moving wheeled systems known as ''traveling sprinklers'' may irrigate areas such as small farms, sports fields, parks, pastures, and cemeteries unattended. Most of these use a length of polyethylene tubing wound on a steel drum. As the tubing is wound on the drum powered by the irrigation water or a small gas engine, the sprinkler is pulled across the field. When the sprinkler arrives back at the reel the system shuts off. This type of system is known to most people as a "waterreel" traveling irrigation sprinkler and they are used extensively for dust suppression, irrigation, and land application of waste water.
Other travelers use a flat rubber hose that is dragged along behind while the sprinkler platform is pulled by a cable.
Center pivot
![Crop Triangle South Africa](https://upload.wikimedia.org/wikipedia/commons/3/34/Crop_Triangle_South_Africa.jpg)
Center pivot irrigation is a form of sprinkler irrigation utilising several segments of pipe (usually galvanized steel or aluminium) joined and supported by
truss
A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure.
In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assembl ...
es, mounted on wheeled towers with sprinklers positioned along its length.
The system moves in a circular pattern and is fed with water from the pivot point at the center of the arc. These systems are found and used in all parts of the world and allow irrigation of all types of terrain. Newer systems have drop sprinkler heads as shown in the image that follows.
most center pivot systems have drops hanging from a U-shaped pipe attached at the top of the pipe with sprinkler heads that are positioned a few feet (at most) above the crop, thus limiting evaporative losses. Drops can also be used with drag hoses or bubblers that deposit the water directly on the ground between crops. Crops are often planted in a circle to conform to the center pivot. This type of system is known as LEPA (Low Energy Precision Application). Originally, most center pivots were water-powered. These were replaced by hydraulic systems (''
T-L Irrigation'') and electric-motor-driven systems (Reinke, Valley, Zimmatic). Many modern pivots feature
GPS
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
devices.
Irrigation by lateral move (side roll, wheel line, wheelmove)
A ''series of pipes, each with a wheel'' of about 1.5 m diameter permanently affixed to its midpoint, and sprinklers along its length, are coupled together. Water is supplied at one end using a large hose. After sufficient irrigation has been applied to one strip of the field, the hose is removed, the water drained from the system, and the assembly rolled either by hand or with a purpose-built mechanism, so that the sprinklers are moved to a different position across the field. The hose is reconnected. The process is repeated in a pattern until the whole field has been irrigated.
This system is less expensive to install than a center pivot, but much more labor-intensive to operate – it does not travel automatically across the field: it applies water in a stationary strip, must be drained, and then rolled to a new strip. Most systems use 100 or 130 mm (4 or 5 inch) diameter aluminum pipe. The pipe doubles both as water transport and as an axle for rotating all the wheels. A drive system (often found near the centre of the wheel line) rotates the clamped-together pipe sections as a single axle, rolling the whole wheel line. Manual adjustment of individual wheel positions may be necessary if the system becomes misaligned.
Wheel line systems are limited in the amount of water they can carry, and limited in the height of crops that can be irrigated. One useful feature of a lateral move system is that it consists of sections that can be easily disconnected, adapting to field shape as the line is moved. They are most often used for small, rectilinear, or oddly-shaped fields, hilly or mountainous regions, or in regions where labor is inexpensive.
Lawn sprinkler systems
A lawn sprinkler system is permanently installed, as opposed to a hose-end sprinkler, which is portable. Sprinkler systems are installed in residential lawns, in commercial landscapes, for churches and schools, in public parks and cemeteries, and on
golf course
A golf course is the grounds on which the sport of golf is played. It consists of a series of holes, each consisting of a tee box, a fairway, the rough and other hazards, and a green with a cylindrical hole in the ground, known as a "cup". ...
s. Most of the components of these irrigation systems are hidden under ground, since aesthetics are important in a landscape. A typical lawn sprinkler system will consist of one or more zones, limited in size by the capacity of the water source. Each zone will cover a designated portion of the landscape. Sections of the landscape will usually be divided by
microclimate
A microclimate (or micro-climate) is a local set of atmospheric conditions that differ from those in the surrounding areas, often with a slight difference but sometimes with a substantial one. The term may refer to areas as small as a few squ ...
, type of plant material, and type of irrigation equipment. A landscape irrigation system may also include zones containing drip irrigation, bubblers, or other types of equipment besides sprinklers.
Although manual systems are still used, most lawn sprinkler systems may be operated automatically using an
irrigation controller, sometimes called a clock or timer. Most automatic systems employ electric
solenoid valve
A solenoid valve is an electromechanically operated valve.
Solenoid valves differ in the characteristics of the electric current they use, the strength of the magnetic field they generate, the mechanism they use to regulate the fluid, and the ty ...
s. Each zone has one or more of these valves that are wired to the controller. When the controller sends power to the valve, the valve opens, allowing water to flow to the sprinklers in that zone.
There are two main types of sprinklers used in lawn irrigation, pop-up spray heads and rotors. Spray heads have a fixed spray pattern, while rotors have one or more streams that rotate. Spray heads are used to cover smaller areas, while rotors are used for larger areas. Golf course rotors are sometimes so large that a single sprinkler is combined with a valve and called a 'valve in head'. When used in a turf area, the sprinklers are installed with the top of the head flush with the ground surface. When the system is pressurized, the head will pop up out of the ground and water the desired area until the valve closes and shuts off that zone. Once there is no more pressure in the lateral line, the sprinkler head will retract back into the ground. In flower beds or shrub areas, sprinklers may be mounted on above ground risers or even taller pop-up sprinklers may be used and installed flush as in a lawn area.
Hose-end sprinklers
There are many types of hose-end sprinklers. Many of them are smaller versions of larger agricultural and landscape sprinklers, sized to work with a typical garden hose. Some have a spiked base allowing them to be temporarily stuck in the ground, while others have a sled base designed to be dragged while attached to the hose.
Subirrigation
Subirrigation
Subirrigation also known as seepage irrigation, is a method of irrigation where water is delivered to the plant root zone. The excess may be collected for reuse.
Subirrigation is used in growing field crops such as tomatoes, peppers, and sugar ...
has been used for many years in field crops in areas with high
water table
The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated.
T ...
s. It is a method of artificially raising the water table to allow the
soil
Soil, also commonly referred to as earth or dirt
Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty.
Common types of dirt include:
* Debri ...
to be
moistened from below the plants'
root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...
zone. Often those systems are located on permanent grasslands in lowlands or river valleys and combined with drainage infrastructure. A system of pumping stations, canals, weirs and gates allows it to increase or decrease the water level in a network of ditches and thereby control the water table.
Subirrigation is also used in the
commercial
Commercial may refer to:
* a dose of advertising conveyed through media (such as - for example - radio or television)
** Radio advertisement
** Television advertisement
* (adjective for:) commerce, a system of voluntary exchange of products and s ...
greenhouse production, usually for
potted plants. Water is delivered from below, absorbed by upwards, and the excess collected for recycling. Typically, a solution of water and
nutrients floods a container or flows through a trough for a short period of time, 10–20 minutes, and is then pumped back into a holding
tank
A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and good battlefield mobility provided by tracks and a powerful engi ...
for reuse. Sub-irrigation in greenhouses requires fairly sophisticated, expensive equipment and management. Advantages are water and nutrient conservation, and labor savings through reduced system maintenance and
automation
Automation describes a wide range of technologies that reduce human intervention in processes, namely by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines ...
. It is similar in principle and action to subsurface basin irrigation.
Another type of subirrigation is the self-watering container, also known as a
sub-irrigated planter
Sub-irrigated planter (SIP) is a generic name for a special type of planting box used in container gardening and commercial landscaping. A SIP is any method of watering plants where the water is introduced from the bottom, allowing the water to s ...
. This consists of a planter suspended over a reservoir with some type of wicking material such as a polyester rope. The water is drawn up the wick through capillary action. A similar technique is the
wicking bed A wicking bed is an agricultural irrigation system used in arid countries where water is scarce, devised by Australian inventor Colin Austin. It can be used both in (arid) fields as in containers. Besides use in fields/containers outdoors, it can ...
; this too uses capillary action.
Efficiency
Modern irrigation methods are efficient enough to supply the entire field uniformly with water, so that each plant has the amount of water it needs, neither too much nor too little.
Water use efficiency in the field can be determined as follows:
* Field Water Efficiency (%) = (Water Transpired by Crop ÷ Water Applied to Field) x 100
Increased irrigation efficiency has a number of positive outcomes for the farmer, the community and the wider environment. Low application efficiency infers that the amount of water applied to the field is in excess of the crop or field requirements. Increasing the application efficiency means that the amount of crop produced per unit of water increases. Improved efficiency may either be achieved by applying less water to an existing field or by using water more wisely thereby achieving higher yields in the same area of land. In some parts of the world, farmers are charged for irrigation water hence over-application has a direct financial cost to the farmer. Irrigation often requires pumping energy (either electricity or fossil fuel) to deliver water to the field or supply the correct operating pressure. Hence increased efficiency will reduce both the water cost and energy cost per unit of agricultural production. A reduction of water use on one field may mean that the farmer is able to irrigate a larger area of land, increasing total agricultural production. Low efficiency usually means that excess water is lost through seepage or runoff, both of which can result in loss of crop nutrients or pesticides with potential adverse impacts on the surrounding environment.
Improving the efficiency of irrigation is usually achieved in one of two ways, either by improving the system design or by optimising the irrigation management. Improving system design includes conversion from one form of irrigation to another (e.g. from furrow to drip irrigation) and also through small changes in the current system (for example changing flowrates and operating pressures). Irrigation management refers to the scheduling of irrigation events and decisions around how much water is applied.
Challenges
Environmental impacts
Negative impacts frequently accompany extensive irrigation.
Some projects which diverted surface water for irrigation dried up the water sources, which led to a more extreme regional climate.
[ McNeill 2000 pp.164-165.] Projects that relied on groundwater and pumped too much from underground aquifers created
subsidence and
salinization. Salinization of irrigation water in turn damaged the crops and seeped into drinking water.
Pests and pathogens also thrived in the irrigation canals or ponds full of still water, which created regional outbreaks of diseases like
malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...
and
schistosomiasis. Governments also used irrigation schemes to encourage migration, especially of more desirable populations into an area.
[ Visser 2018] Additionally, some of these large nationwide schemes failed to pay off at all, costing more than any benefit gained from increased crop yields.
[ McNeill 2000]
Overdrafting
Overdrafting is the process of extracting groundwater beyond the equilibrium yield of an aquifer. Groundwater is one of the largest sources of fresh water and is found underground. Groundwater depletion is comparable to a bank account in which mor ...
(depletion) of underground
aquifers
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...
: In the mid-20th century, the advent of diesel and electric motors led to systems that could pump
groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...
out of major
aquifer
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteris ...
s faster than
drainage basin
A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...
s could refill them. This can lead to permanent loss of aquifer capacity, decreased water quality, ground subsidence, and other problems. The future of food production in such areas as the
North China Plain, the
Punjab region
Punjab (; Punjabi: پنجاب ; ਪੰਜਾਬ ; ; also romanised as ''Panjāb'' or ''Panj-Āb'') is a geopolitical, cultural, and historical region in South Asia, specifically in the northern part of the Indian subcontinent, comprising a ...
in India and Pakistan, and the
Great Plains of the US is threatened by this phenomenon.
Technical challenges
Irrigation schemes involve solving numerous engineering and economic problems while minimizing negative environmental consequences.
[ILRI, 1989, Effectiveness and Social/Environmental Impacts of Irrigation Projects: a Review. In: Annual Report 1988, International Institute for Land Reclamation and Improvement (ILRI), Wageningen, The Netherlands, pp. 18 – 34 . On line]
/ref> Such problems include:
* Ground subsidence (e.g. )
* Underirrigation or irrigation giving only just enough water for the plant (e.g. in drip line irrigation) gives poor soil salinity control
Soil salinity control relates to controlling the problem of soil salinity and reclaiming salinized agricultural land. The aim of soil salinity control is to prevent soil degradation by salination and reclamation of already salty (saline) soil ...
which leads to increased soil salinity with consequent buildup of toxic salts on soil surface in areas with high evaporation. This requires either leaching
Leaching is the loss or extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). and may refer to:
* Leaching (agriculture), the loss of water-soluble plant nutrients from the soil; or applying a small amou ...
to remove these salts and a method of drainage
Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic condition ...
to carry the salts away. When using drip lines, the leaching is best done regularly at certain intervals (with only a slight excess of water), so that the salt is flushed back under the plant's roots.
* Drainage front instability, also known as viscous fingering, where an unstable drainage front results in a pattern of fingers and viscous entrapped saturated zones.
* Overirrigation because of poor distribution uniformity Distribution uniformity or DU in irrigation is a measure of how uniformly water is applied to the area being watered, normally expressed as percentage, and not to be confused with efficiency. The distribution uniformity is often calculated when pe ...
or management
Management (or managing) is the administration of an organization, whether it is a business, a nonprofit organization, or a Government agency, government body. It is the art and science of managing resources of the business.
Management includ ...
wastes water, chemicals, and may lead to water pollution
Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. ...
.
* Deep drainage (from over-irrigation) may result in rising water tables which in some instances will lead to problems of irrigation salinity requiring watertable control Watertable control is the practice of controlling the height of the water table by drainage. Its main applications are in agricultural land (to improve the crop yield using agricultural drainage systems) and in cities to manage the extensive under ...
by some form of subsurface land drainage.
* Irrigation with saline or high-sodium water may damage soil structure owing to the formation of alkaline soil
Alkali, or Alkaline, soils are clay soils with high pH (greater than 8.5), a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico ...
.
* Clogging of filters: algae can clog filters, drip installations, and nozzles. Chlorination, algaecide, UV and ultrasonic methods can be used for algae control in irrigation systems.
*Complications in accurately measuring irrigation performance which changes over time and space using measures such as productivity, efficiency, equity and adequacy.
Social aspects
* Competition for surface water right
Water right in water law refers to the right of a user to use water from a water source, e.g., a river, stream, pond or source of groundwater. In areas with plentiful water and few users, such systems are generally not complicated or contentiou ...
s.
* Assisting smallholders in sustainably and collectively managing irrigation technology and changes in technology.
History
Ancient history
Archaeological investigation has found evidence of irrigation in areas lacking sufficient natural rainfall
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
to support crops for rainfed agriculture. Some of the earliest known use of the technology dates to the 6th millennium BC in Khuzistan
Khuzestan Province (also spelled Xuzestan; fa, استان خوزستان ''Ostān-e Xūzestān'') is one of the 31 provinces of Iran. It is in the southwest of the country, bordering Iraq and the Persian Gulf. Its capital is Ahvaz and it covers ...
in the south-west of present-day Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
. The site of Choga Mami, in Iraq on the border with Iran, is believed to be the earliest to show the first canal irrigation in operation at about 6000 BCE.
Irrigation was used as a means of manipulation of water in the alluvial plains of the Indus valley civilization, the application of which is estimated to have begun around 4500 BC and drastically increased the size and prosperity of their agricultural settlements. The Indus Valley Civilization developed sophisticated irrigation and water-storage systems, including artificial reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contro ...
s at Girnar
Girnar is an ancient hill in Junagadh, Gujarat, India.
Geology
Mount Girnar is a major igneous plutonic complex which intruded into the basalts towards the close of the Deccan Trap period. The rock types identified in this complex are ga ...
dated to 3000 BCE, and an early canal
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flo ...
irrigation system from 2600 BCE. Large-scale agriculture was practiced, with an extensive network of canals used for the purpose of irrigation.
Farmers in the Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the ...
n plain used irrigation from at least the third millennium BCE.
They developed ''perennial irrigation'', regularly watering crops throughout the growing season by coaxing water through a matrix of small channels formed in the field.
Ancient Egyptians practiced ''basin irrigation'' using the flooding of the Nile
The flooding of the Nile has been an important natural cycle in Egypt since ancient times. It is celebrated by Egyptians as an annual holiday for two weeks starting August 15, known as ''Wafaa El-Nil''. It is also celebrated in the Coptic Church ...
to inundate land plots which had been surrounded by dykes. The flood water remained until the fertile sediment had settled before the engineers returned the surplus to the watercourse
A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams a ...
.[''p19'' Hill] There is evidence of the ancient Egyptian pharaoh
Pharaoh (, ; Egyptian: '' pr ꜥꜣ''; cop, , Pǝrro; Biblical Hebrew: ''Parʿō'') is the vernacular term often used by modern authors for the kings of ancient Egypt who ruled as monarchs from the First Dynasty (c. 3150 BC) until the ...
Amenemhet III in the twelfth dynasty
The Twelfth Dynasty of ancient Egypt (Dynasty XII) is considered to be the apex of the Middle Kingdom by Egyptologists. It often is combined with the Eleventh, Thirteenth, and Fourteenth dynasties under the group title, Middle Kingdom. Some ...
(about 1800 BCE
Common Era (CE) and Before the Common Era (BCE) are year notations for the Gregorian calendar (and its predecessor, the Julian calendar), the world's most widely used calendar era. Common Era and Before the Common Era are alternatives to the or ...
) using the natural lake of the Faiyum Oasis
The Faiyum Oasis ( ar, واحة الفيوم ''Waḥet El Fayyum'') is a depression or basin in the desert immediately to the west of the Nile, or just 62 miles south of Cairo in Egypt. The extent of the basin area is estimated at between 1,270 ...
as a reservoir to store surpluses of water for use during dry seasons. The lake swelled annually from the flooding of the Nile
The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest ...
.
The Ancient Nubians developed a form of irrigation by using a waterwheel-like device called a ''sakia
A sāqiyah or saqiya ( ar, ساقية), also spelled sakia or saqia) is a mechanical water lifting device. It is also called a Persian wheel, tablia, rehat, and in Latin tympanum. It is similar in function to a scoop wheel, which uses buckets, ...
''. Irrigation began in Nubia some time between the third and second millennia BCE. It largely depended upon the flood waters that would flow through the Nile River and other rivers in what is now the Sudan.
In sub-Saharan Africa irrigation reached the Niger River
The Niger River ( ; ) is the main river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in south-eastern Guinea near the Sierra Leone border. It runs in a crescent shape through ...
region cultures and civilizations by the first or second millennium BCE and was based on wet-season flooding and water harvesting.
Evidence of ''terrace irrigation'' occurs in pre-Columbian America, early Syria, India, and China. In the Zana Valley of the Andes Mountains in Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = National seal
, national_motto = "Firm and Happy f ...
, archaeologists have found remains of three irrigation canal
Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flo ...
s radiocarbon-dated from the 4th millennium BCE
The 4th millennium BC spanned the years 4000 BC to 3001 BC. Some of the major changes in human culture during this time included the beginning of the Bronze Age and the invention of writing, which played a major role in starting recorded history. ...
, the 3rd millennium BCE and the 9th century CE. These canals provide the earliest record of irrigation in the New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...
. Traces of a canal possibly dating from the 5th millennium BCE
The 5th millennium BC spanned the years 5000 BC to 4001 BC (c. 7 ka to c. 6 ka). It is impossible to precisely date events that happened around the time of this millennium and all dates mentioned here are estimates mostly based on geological an ...
were found under the 4th-millennium canal.
Ancient Persia
The history of Iran is intertwined with the history of a larger region known as Greater Iran, comprising the area from Anatolia in the west to the borders of Ancient India and the Syr Darya in the east, and from the Caucasus and the Eurasian Step ...
(modern day Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
) used irrigation as far back as the 6th millennium BCE to grow barley in areas with insufficient natural rainfall. The Qanat
A qanat or kārīz is a system for transporting water from an aquifer or water well to the surface, through an underground aqueduct; the system originated approximately 3,000 BC in what is now Iran. The function is essentially the same across ...
s, developed in ancient Persia
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
about 800 BCE, are among the oldest known irrigation methods still in use today. They are now found in Asia, the Middle East and North Africa. The system comprises a network of vertical wells and gently sloping tunnels driven into the sides of cliffs and of steep hills to tap groundwater. The noria
A noria ( ar, ناعورة, ''nā‘ūra'', plural ''nawāʿīr'', from syr, ܢܥܘܪܐ, ''nā‘orā'', lit. "growler") is a hydropowered '' scoop wheel'' used to lift water into a small aqueduct, either for the purpose of irrigation or to s ...
, a water wheel with clay pots around the rim powered by the flow of the stream (or by animals where the water source was still), first came into use at about this time among Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*'' Epistle to the Romans'', shortened to ''Romans'', a lette ...
settlers in North Africa. By 150 BCE the pots were fitted with valves to allow smoother filling as they were forced into the water.
Sri Lanka
The irrigation works of ancient Sri Lanka, the earliest dating from about 300 BCE in the reign of King Pandukabhaya, and under continuous development for the next thousand years, were one of the most complex irrigation systems of the ancient world. In addition to underground canals, the Sinhalese were the first to build completely artificial reservoirs to store water. These reservoirs and canal systems were used primarily to irrigate paddy fields, which require a lot of water to cultivate. Most of these irrigation systems still exist undamaged up to now, in Anuradhapura
Anuradhapura ( si, අනුරාධපුරය, translit=Anurādhapuraya; ta, அனுராதபுரம், translit=Aṉurātapuram) is a major city located in north central plain of Sri Lanka. It is the capital city of North Central ...
and Polonnaruwa
Poḷonnaruwa, ( si, පොළොන්නරුව, translit=Poḷonnaruva; ta, பொலன்னறுவை, translit=Polaṉṉaṟuvai) also referred as Pulathisipura and Vijayarajapura in ancient times, is the main town of Polonnaruwa Dis ...
, because of the advanced and precise engineering. The system was extensively restored and further extended during the reign of King Parakrama Bahu (1153–1186 CE).
China
The oldest known hydraulic
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ...
engineers of China were Sunshu Ao (6th century BCE) of the Spring and Autumn period and Ximen Bao
Ximen Bao was a Chinese hydraulic engineer, philosopher, and politician. He was a government minister and court advisor to Marquis Wen of Wei (reigned 445–396 BC) during the Warring States period of ancient China. He was known as an early ratio ...
(5th century BCE) of the Warring States
The Warring States period () was an era in ancient Chinese history characterized by warfare, as well as bureaucratic and military reforms and consolidation. It followed the Spring and Autumn period and concluded with the Qin wars of conquest ...
period, both of whom worked on large irrigation projects. In the Sichuan
Sichuan (; zh, c=, labels=no, ; zh, p=Sìchuān; alternatively romanized as Szechuan or Szechwan; formerly also referred to as "West China" or "Western China" by Protestant missions) is a province in Southwest China occupying most of the ...
region belonging to the state of Qin of ancient China, the Dujiangyan Irrigation System
The Dujiangyan () is an ancient irrigation system in Dujiangyan City, Sichuan, China. Originally constructed around 256 BC by the State of Qin as an irrigation and flood control project, it is still in use today. The system's infrastructure deve ...
devised by the Qin Chinese hydrologist and irrigation engineer Li Bing was built in 256 BCE to irrigate a vast area of farmland that today still supplies water. By the 2nd century AD, during the Han Dynasty
The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...
, the Chinese also used chain pumps which lifted water from a lower elevation to a higher one.[Needham, Joseph (1986). ''Science and Civilization in China: Volume 4, Physics and Physical Technology, Part 2, Mechanical Engineering''. Taipei: Caves Books Ltd. Pages 344–346.] These were powered by manual foot-pedal, hydraulic waterwheels, or rotating mechanical wheels pulled by oxen.[Needham, Volume 4, Part 2, 340–343.] The water was used for public works
Public works are a broad category of infrastructure projects, financed and constructed by the government, for recreational, employment, and health and safety uses in the greater community. They include public buildings ( municipal buildings, sc ...
, providing water for urban residential quarters and palace gardens, but mostly for irrigation of farmland
Agricultural land is typically land ''devoted to'' agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with bo ...
canals and channels in the fields.[Needham, Volume 4, Part 2, 33, 110.]
Korea
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...
, Jang Yeong-sil
Jang Yeong-sil (; ; 1390 – after 1442) was a Korean mechanical engineer, scientist, and inventor during the Joseon Dynasty (1392–1897). Although Jang was born as a peasant, King Sejong allowed Jang to work at the royal palace. Jang's inven ...
, a Korean engineer of the Joseon Dynasty
Joseon (; ; Middle Korean: 됴ᇢ〯션〮 Dyǒw syéon or 됴ᇢ〯션〯 Dyǒw syěon), officially the Great Joseon (; ), was the last dynastic kingdom of Korea, lasting just over 500 years. It was founded by Yi Seong-gye in July 1392 and r ...
, under the active direction of the king, Sejong the Great, invented the world's first rain-gauge, ''uryanggye'' (Korean
Korean may refer to:
People and culture
* Koreans, ethnic group originating in the Korean Peninsula
* Korean cuisine
* Korean culture
* Korean language
**Korean alphabet, known as Hangul or Chosŏn'gŭl
**Korean dialects and the Jeju language
** ...
: 우량계) in 1441. It was installed in irrigation tanks as part of a nationwide system to measure and collect rainfall for agricultural applications. With this instrument, planners and farmers could make better use of the information gathered in the survey.
North America
The earliest agricultural irrigation canal system known in the area of the present-day United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
dates to between 1200 B.C. and 800 B.C. and was discovered by Desert Archaeology, Inc. in Marana, Arizona (adjacent to Tucson) in 2009. The irrigation-canal system predates the Hohokam culture by two thousand years and belongs to an unidentified culture. In North America, the Hohokam were the only culture known to rely on irrigation canals to water their crops, and their irrigation systems supported the largest population in the Southwest by AD 1300. The Hohokam constructed an assortment of simple canals combined with weirs
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of l ...
in their various agricultural pursuits. Between the 7th and 14th centuries they built and maintained extensive irrigation networks along the lower Salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...
and middle Gila Rivers that rivaled the complexity of those used in the ancient Near East, Egypt, and China. These were constructed using relatively simple excavation tools, without the benefit of advanced engineering technologies, and achieved drops of a few feet per mile, balancing erosion and siltation. The Hohokam cultivated varieties of cotton, tobacco, maize, beans and squash, as well as harvesting an assortment of wild plants. Late in the Hohokam Chronological Sequence, they also used extensive dry-farming systems, primarily to grow agave
''Agave'' (; ; ) is a genus of monocots native to the hot and arid regions of the Americas and the Caribbean, although some ''Agave'' species are also native to tropical areas of North America, such as Mexico. The genus is primarily known for ...
for food and fiber. Their reliance on agricultural strategies based on canal irrigation, vital in their less-than-hospitable desert environment and arid climate, provided the basis for the aggregation of rural populations into stable urban centers.
South America
The oldest known irrigation canals in the Americas are in the desert of northern Peru in the Zaña valley near the hamlet of Nanchoc. The canals have been radiocarbon
Carbon-14, C-14, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and c ...
dated to at least 3400 B.C. and possibly as old as 4700 B.C. The canals at that time irrigated crops such as peanut
The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible seeds. It is widely grown in the tropics and subtropics, important to both small and ...
s, squash
Squash may refer to:
Sports
* Squash (sport), the high-speed racquet sport also known as squash racquets
* Squash (professional wrestling), an extremely one-sided match in professional wrestling
* Squash tennis, a game similar to squash but pla ...
, manioc
''Manihot esculenta'', commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively cultivated ...
, chenopods, a relative of Quinoa
Quinoa (''Chenopodium quinoa''; , from Quechua ' or ') is a flowering plant in the amaranth family. It is a herbaceous annual plant grown as a crop primarily for its edible seeds; the seeds are rich in protein, dietary fiber, B vitamins, a ...
, and later maize
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...
.
Modern history
In the 20th century, global anxiety specifically about the American cotton monopoly fueled many empirical irrigation projects: Britain began developing irrigation in India
Irrigation in India includes a network of major and minor canals from Indian rivers, groundwater well based systems, tanks, and other rainwater harvesting projects for agricultural activities. Of these groundwater system is the largest. In 2013 ...
, the Ottomans in Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
, the French in Algeria
)
, image_map = Algeria (centered orthographic projection).svg
, map_caption =
, image_map2 =
, capital = Algiers
, coordinates =
, largest_city = capital
, relig ...
, the Portuguese
Portuguese may refer to:
* anything of, from, or related to the country and nation of Portugal
** Portuguese cuisine, traditional foods
** Portuguese language, a Romance language
*** Portuguese dialects, variants of the Portuguese language
** Portu ...
in Angola
, national_anthem = " Angola Avante"()
, image_map =
, map_caption =
, capital = Luanda
, religion =
, religion_year = 2020
, religion_ref =
, coordina ...
, the Germans
, native_name_lang = de
, region1 =
, pop1 = 72,650,269
, region2 =
, pop2 = 534,000
, region3 =
, pop3 = 157,000
3,322,405
, region4 =
, pop4 = ...
in Togo
Togo (), officially the Togolese Republic (french: République togolaise), is a country in West Africa. It is bordered by Ghana to the west, Benin to the east and Burkina Faso to the north. It extends south to the Gulf of Guinea, where its c ...
, and Soviets
Soviet people ( rus, сове́тский наро́д, r=sovyétsky naród), or citizens of the USSR ( rus, гра́ждане СССР, grázhdanye SSSR), was an umbrella demonym for the population of the Soviet Union.
Nationality policy in ...
in Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
.
American West
Irrigated land in the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
increased from 300,000 acres in 1880 to 4.1 million in 1890, then to 7.3 million in 1900. Two thirds of this irrigation sources from groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...
or small ponds and reservoirs
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including control ...
, while the other one third comes from large dam
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...
s. One of the main attractions of irrigation in the West was its increased dependability compared to rainfall-watered agriculture in the East. Proponents argued that farmers with a dependable water supply could more easily get loans from bankers interested in this more predictable farming model. Most irrigation in the Great Plains region derived from underground aquifer
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteris ...
s. Euro-American farmers who colonized the region in the 19th century tried to grow the commodity crops that they were used to, like wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...
, corn, and alfalfa, but rainfall stifled their growing capacity. Between the late 1800s and the 1930s, farmers used wind-powered pumps to draw groundwater. These windpumps had limited power, but the development of gas-powered pumps in the mid-1930s pushed wells deep into the Ogallala Aquifer
The Ogallala Aquifer () is a shallow water table aquifer surrounded by sand, silt, clay, and gravel located beneath the Great Plains in the United States. One of the world's largest aquifers, it underlies an area of approximately in porti ...
. Farmers irrigated fields by laying pipes across the field with sprinklers at intervals, a labor-intensive process, until the advent of the center-pivot sprinkler after WWII, which made irrigation significantly easier. By the 1970s farmers drained the aquifer ten times faster than it could recharge, and by 1993 they had removed half of the accessible water.
Large-scale federal funding and intervention pushed through the majority of irrigation projects in the West, especially in California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
, Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
, Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
, and Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
. At first, plans to increase irrigated farmland, largely by giving land to farmers and asking them to find water, failed across the board. Congress passed the Desert Land Act
The Desert Land Act is a United States federal law which was passed by the United States Congress on March 3, 1877, to encourage and promote the economic development of the arid and semiarid public lands within certain states of the Western state ...
in 1877 and the Carey Act
The Carey Act of 1894 (also known as the Federal Desert Land Act)Carey Act in Idaho http://www.gchshome.org/careyact.htm. allowed private companies in the U.S. to erect irrigation systems in the western semi-arid states, and profit from the sales ...
in 1894, which only marginally increased irrigation. Only in 1902 Congress passed the National Reclamation Act
The Reclamation Act (also known as the Lowlands Reclamation Act or National Reclamation Act) of 1902 () is a United States federal law that funded irrigation projects for the arid lands of 20 states in the American West.
The act at first covere ...
, which channeled money from the sale of western public lands, in parcels up to 160 acres large, into irrigation projects on public or private land in the arid West. The Congressmen who passed the law, as well as their wealthy supporters, supported Western irrigation because it would increase American exports, ‘reclaim’ the West, and push the Eastern poor out West in search of a better life.
While the National Reclamation Act was the most successful piece of federal irrigation legislation, the implementation of the act did not go as planned. Originally, the Reclamation Service planned to construct a small number of projects that would allow engineers to learn from the process, but President Roosevelt chose instead push as many irrigation projects through as fast as possible. The Reclamation Service also chose to push most of the Act’s money toward construction rather than settlement, so the Service overwhelmingly prioritized building large dams like the Hoover Dam. Over the 20th century Congress and state governments grew more frustrated with the Reclamation Service and the irrigation schemes in general. Frederick Newell, head of the Reclamation Service, proving uncompromising and difficult to work with, falling crop prices, resistance to delay debt payments, and refusal to begin new projects until the completion of old ones all contributed. The Reclamation Extension Act of 1914, transferring a significant amount of irrigation decision-making power regarding irrigation projects from the Reclamation Service to Congress, was in many ways a result of an increasing political unpopularity of the Reclamation Service.
In the lower Colorado Basin of Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
, Colorado
Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...
, and Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
, the states derive irrigation water largely from rivers, especially the Colorado River
The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...
, which irrigates more than 4.5 million acres of land, with a less significant amount coming from groundwater. In the 1952 case Arizona v. California, Arizona sued California for increased access to the Colorado, under the grounds that their groundwater supply could not sustain their almost entirely irrigation-based agricultural economy, which they won. California, which began irrigating in earnest in the 1870s in San Joaquin Valley
The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven ...
, had passed the Wright Act of 1887 permitting agricultural communities to construct and operate needed irrigation works. The Colorado also irrigates large fields in California’s Imperial Valley
, photo = Salton Sea from Space.jpg
, photo_caption = The Imperial Valley below the Salton Sea. The US-Mexican border runs diagonally across the lower left of the image.
, map_image = Newriverwatershed-1-.jpg
, map_caption = Map of Imperial ...
, fed by the National Reclamation Act-built All-American Canal.
Soviet Central Asia
When the Bolsheviks
The Bolsheviks (russian: Большевики́, from большинство́ ''bol'shinstvó'', 'majority'),; derived from ''bol'shinstvó'' (большинство́), "majority", literally meaning "one of the majority". also known in English ...
conquered Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
in 1917, the native Kazakhs, Uzbeks
The Uzbeks ( uz, , , , ) are a Turkic ethnic group native to the wider Central Asian region, being among the largest Turkic ethnic group in the area. They comprise the majority population of Uzbekistan, next to Kazakh and Karakalpak mino ...
, and Turkmens
Turkmens ( tk, , , , ; historically "the Turkmen"), sometimes referred to as Turkmen Turks ( tk, , ), are a Turkic ethnic group native to Central Asia, living mainly in Turkmenistan, northern and northeastern regions of Iran and north-weste ...
used minimal irrigation. The Slavic immigrants pushed into the area by the Tsarist government brought their own irrigation methods, including waterwheels, the use of rice paddies
A paddy field is a flooded field of arable land used for growing semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in southern China, associated with pre-Au ...
to restore salted land, and underground irrigation channels. Russians dismissed these techniques as crude and inefficient. Despite this, in absence of other solutions, tsarist officials maintained these systems through the late 19th century.[ Peterson 2016.]
Before conquering the area, the Russian government accepted a 1911 American proposal to send hydraulic experts to Central Asia to investigate the potential for large-scale irrigation. A 1918 decree by Lenin
Vladimir Ilyich Ulyanov. ( 1870 – 21 January 1924), better known as Vladimir Lenin,. was a Russian revolutionary, politician, and political theorist. He served as the first and founding head of government of Soviet Russia from 1917 to 1 ...
then encouraged irrigation development in the region, and development began in the 1930s. When it did, Stalin
Joseph Vissarionovich Stalin (born Ioseb Besarionis dze Jughashvili; – 5 March 1953) was a Georgian revolutionary and Soviet political leader who led the Soviet Union from 1924 until his death in 1953. He held power as General Secretar ...
and other Soviet leaders prioritized large-scale, ambitious hydraulic projects, especially along the Volga River
The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchme ...
. The Soviet irrigation push stemmed largely from their late 19th century fears of the American cotton monopoly and subsequent desire to achieve cotton self-sufficiency. They had built up their textile manufacturing industry in the 19th century, requiring increased cotton and irrigation, as the region did not receive enough rainfall to support cotton farming.
The Russians built dams on the Don
Don, don or DON and variants may refer to:
Places
*County Donegal, Ireland, Chapman code DON
*Don (river), a river in European Russia
*Don River (disambiguation), several other rivers with the name
*Don, Benin, a town in Benin
*Don, Dang, a vill ...
and Kuban Rivers for irrigation, removing freshwater flow from the Sea of Azov and making it much saltier. Depletion and salinization scourged other areas of the Russian irrigation project. In the 1950s Soviet officials began also diverting the Syr Darya and the Amu Darya
The Amu Darya, tk, Amyderýa/ uz, Amudaryo// tg, Амударё, Amudaryo ps, , tr, Ceyhun / Amu Derya grc, Ὦξος, Ôxos (also called the Amu, Amo River and historically known by its Latin name or Greek ) is a major river in Central Asi ...
, which fed the Aral Sea. Before diversion, the rivers delivered 55km3 of water to the Aral Sea per year, but after they only delivered 6km3 to the Sea. Because of its reduced inflow, the Aral Sea covered less than half of its original seabed, which made the regional climate more extreme and created airborne salinization, lowering nearby crop yields.
By 1975, the USSR used eight times as much water as they had in 1913, mostly for irrigation. Russia’s expansion of irrigation began to decrease in the late 1980s, and irrigated hectares in Central Asia capped out at 7 million. Mikhail Gorbachev killed a proposed plan to reverse the Ob and Yenisei for irrigation in 1986, and the breakup of the USSR in 1991 ended Russian investment in Central Asian cotton irrigation.
Africa
Different irrigation schemes with a variety of goals and success rates have been implemented across Africa in the 20th century, but have all been influenced by colonial forces. The Tana River Irrigation Scheme in eastern Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
, completed between 1948 and 1963, opened up new lands for agriculture, and the Kenyan government attempted to resettle the area with detainees from the Mau Mau uprising. Libya’s underground water resources were discovered by Italian oil drillers during the Italian colonization of Libya
The Italian colonization of Libya began in 1911 and it lasted until 1943. The country, which was previously an Ottoman possession, was occupied by Italy in 1911 after the Italo-Turkish War, which resulted in the establishment of two colonies: It ...
. This water lay dormant until 1969, when Muammar al-Gaddafi
Muammar Muhammad Abu Minyar al-Gaddafi, . Due to the lack of standardization of transcribing written and regionally pronounced Arabic, Gaddafi's name has been romanized in various ways. A 1986 column by ''The Straight Dope'' lists 32 spellin ...
and American Armand Hammer
Armand Hammer (May 21, 1898 – December 10, 1990) was an American business manager and owner, most closely associated with Occidental Petroleum, a company he ran from 1957 until his death. Called "Lenin's chosen capitalist" by the press, ...
built the Great Man-Made River to deliver the Saharan water to the coast. The water largely contributed to irrigation but cost four to ten times more than the crops it produced were worth.
In 1912, the Union of South Africa
The Union of South Africa ( nl, Unie van Zuid-Afrika; af, Unie van Suid-Afrika; ) was the historical predecessor to the present-day Republic of South Africa. It came into existence on 31 May 1910 with the unification of the Cape, Natal, Tran ...
created an irrigation department and began investing in water storage infrastructure and irrigation. The government used irrigation and dam-building to further social goals like poverty relief, both by creating construction jobs for poor whites and by creating irrigation schemes to increase white farming. One of their first major irrigation projects was the Hartbeespoort Dam
Hartbeespoort Dam (also known as ''Harties'') is an arch type dam situated in the North West Province of South Africa. It lies in a valley to the south of the Magaliesberg mountain range and north of the Witwatersberg mountain range, about 35 kil ...
, begun in 1916 as a mechanism to elevate the living conditions of the ‘poor whites’ in the region and eventually completed as a ‘whites only’ employment opportunity. The Pretoria
Pretoria () is South Africa's administrative capital, serving as the seat of the executive branch of government, and as the host to all foreign embassies to South Africa.
Pretoria straddles the Apies River and extends eastward into the foot ...
irrigation scheme, Kammanassie project, and Buchuberg irrigation scheme on the Orange River
The Orange River (from Afrikaans/Dutch: ''Oranjerivier'') is a river in Southern Africa. It is the longest river in South Africa. With a total length of , the Orange River Basin extends from Lesotho into South Africa and Namibia to the north ...
all followed in the same vein in the 1920s and 30s.
In Egypt, modern irrigation began with Muhammad Ali Pasha
Muhammad Ali Pasha al-Mas'ud ibn Agha, also known as Muhammad Ali of Egypt and the Sudan ( sq, Mehmet Ali Pasha, ar, محمد علي باشا, ; ota, محمد علی پاشا المسعود بن آغا; ; 4 March 1769 – 2 August 1849), was ...
in the mid-1800s, who sought to achieve Egyptian independence from the Ottomans through increased trade with Europe—specifically cotton exportation. His administration proposed replacing the traditional Nile basin irrigation, which took advantage of the annual ebb and flow of the Nile, with irrigation barrages in the lower Nile which better suited cotton production. Egypt devoted 105,000 ha to cotton in 1861, which increased fivefold by 1865. The majority of their exports were shipped to England, and the United-States-Civil-War-induced cotton scarcity in the 1860s cemented Egypt as England’s cotton producer. As the Egyptian economy became more dependent on cotton in the 20th century, it became more important to control even small Nile floods. Cotton production was more at risk of destruction than more common crops like barley
Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley p ...
or wheat. After the British occupation of Egypt in 1882, the British intensified the conversion to perennial irrigation with the construction of the Delta Barrage
The Delta Barrage is barrage-type dam that was constructed intermittently beginning in 1833 to its initial completion in 1862. Its purpose was to improve irrigation and navigation along the main Rosetta and Damietta branches of the Nile downstre ...
, the Assiut Barrage
The Assiut Barrage is a dam on the Nile River in the city of Assiut in Upper Egypt (250 miles to the south of Cairo). It was completed in 1903.
Background
It was designed by the famous British engineer Sir William Willcocks who also concurrentl ...
, and the first Aswan Dam
The Aswan Dam, or more specifically since the 1960s, the Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. Its significance largely eclipsed the previous Aswan L ...
. Perennial irrigation decreased local control over water and made traditional subsistence farming or the farming of other crops incredibly difficult, eventually contributing to widespread peasant bankruptcy and the 1879-1882 ‘Urabi revolt.[ Ross 2017 p. 37-38.]
Examples by country
Gallery
Center-pivot irrigation.jpg, upThe hub of a center-pivot irrigation system
Irrigation drip leaks.jpg, Leaks in micro-irrigation
Micro-irrigation, also called Micro-spray,localized, low-volume, low-flow, or trickle irrigation, is an irrigation method with lower water pressure and flow than a traditional sprinkler system. Low-volume irrigation is used in agriculture for r ...
drip lines
Irrigated blueberries4046.jpg, Sprinkler irrigation of blueberries in Plainville, New York
Plainville is a hamlet on NY Route 370, approximately 4.5 miles west of Baldwinsville in Onondaga County, New York, United States.
It is noted for the extensive Plainville Turkey Farms, which remained in the same family from 1835 until the busi ...
, United States
Peanuts irrigation.jpg, Irrigation in Tamil Nadu, India
Tamil Nadu (; , TN) is a state in southern India. It is the tenth largest Indian state by area and the sixth largest by population. Its capital and largest city is Chennai. Tamil Nadu is the home of the Tamil people, whose Tamil language— ...
Irrigation ditch in Montour County, Pennsylvania.JPG, upIrrigation ditch in Montour County, Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
, USA
Sigiriya WaterGardens.JPG, Water gardens in Sigiriya
Sigiriya or Sinhagiri (''Lion Rock'' si, සීගිරිය, ta, சிகிரியா/சிங்ககிரி, pronounced see-gi-ri-yə) is an ancient rock fortress located in the northern Matale District near the town of Dambull ...
, Sri Lanka
Sprinkler Irrigation - Sprinkler head.JPG, Micro-sprinkler
See also
* Deficit irrigation
* Gezira Scheme
The Gezira Scheme ( ar, مشروع الجزيرة) is one of the largest irrigation projects in the world. It is centered on the Sudanese state of Al Jazirah, just southeast of the confluence of the Blue and White Nile rivers at the city of Kha ...
* Irrigation management
* Irrigation statistics
* Leaf Sensor
* Lift irrigation scheme
* List of countries by irrigated land area
* Surface irrigation
Surface irrigation is where water is applied and distributed over the soil surface by gravity. It is by far the most common form of irrigation throughout the world and has been practiced in many areas virtually unchanged for thousands of years.
S ...
* Tidal irrigation
Tidal irrigation is the subsurface irrigation of levee soils in coastal plains with river water under tidal influence. It is applied in (semi) arid zones at the mouth of a large river estuary or delta where a considerable tidal range (some 2 ...
* Water use in alluvial fans
*
References
Sources
*
*
*
*
*
*
*
*
*
*
*
*
External links
International Commission on Irrigation and Drainage (ICID)
Irrigation
at the Water Quality Information Center, U.S. Department of Agriculture
AQUASTAT
FAO's global information system on water and agriculture
{{Authority control
Agricultural soil science
Agronomy
Environmental issues with water
Land management
Water management