Irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

covers 89,930 km² making it the fifth ranked country in terms of irrigated area.

Tidal irrigation at Abadan island, Iran

The Abadan Island (Fig. 1) in

Khūzestān Province Khuzestan province () is one of the 31 Provinces of Iran. Located in the southwest of the country, the province borders Iraq and the Persian Gulf, covering an area of . Its capital is the city of Ahvaz. Since 2014, it has been part of Iran's ...

is situated between the Arvand and

Bahmanshir The Bahmanshir channel (, ) is a secondary estuary of the Karun River that parallels the Shatt al-Arab/Arvand Rud waterway on the far side of the Abadan Island, Iran, for 70 miles before emptying into the Persian Gulf. The Bahamanshir served ...

rivers. The Arvand river (in Arabic:

Shatt al-Arab The Shatt al-Arab () is a river about in length that is formed at the confluence of the Euphrates and Tigris rivers in the town of al-Qurnah in the Basra Governorate of southern Iraq. The southern end of the river constitutes the Iran– ...

) forms the boundary between

and

Iraq Iraq, officially the Republic of Iraq, is a country in West Asia. It is bordered by Saudi Arabia to Iraq–Saudi Arabia border, the south, Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq border, the east, the Persian Gulf and ...

and collects the waters from the

Euphrates The Euphrates ( ; see #Etymology, below) is the longest and one of the most historically important rivers of West Asia. Tigris–Euphrates river system, Together with the Tigris, it is one of the two defining rivers of Mesopotamia (). Originati ...

and

Tigris The Tigris ( ; see #Etymology, below) is the eastern of the two great rivers that define Mesopotamia, the other being the Euphrates. The river flows south from the mountains of the Armenian Highlands through the Syrian Desert, Syrian and Arabia ...

rivers. On the island

orchards An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit- or nut-producing trees that are generally grown for commercial production. Orchards are also sometimes a feature of lar ...

date palm ''Phoenix dactylifera'', commonly known as the date palm, is a flowering-plant species in the palm family Arecaceae, cultivated for its edible sweet #Fruits, fruit called dates. The species is widely cultivated across North Africa, northern A ...

are found on tidal irrigation in the

desert climate The desert climate or arid climate (in the Köppen climate classification ''BWh'' and ''BWk'') is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert ...

, although many date palms were destroyed during the

Iran–Iraq War The Iran–Iraq War, also known as the First Gulf War, was an armed conflict between Iran and Iraq that lasted from September 1980 to August 1988. Active hostilities began with the Iraqi invasion of Iran and lasted for nearly eight years, unti ...

Palm tree belt

The palm tree belt stretches along the Arvand River from Abadan south-east over a distance of about 40 km and is bounded in the interior by a road.

Tidal canals

A sketch of the system of tidal canals is shown in figure 2. They are 2 to 6 km long depending on the topography and spaced at 50 to 60 m. The tidal canals cut through and serve the ''levee soils'' along the river (Fig. 3) and they stop where the ''basin soils'' of the

backswamp In geology, a backswamp is a type of depositional environment commonly found in a floodplain. It is where deposits of fine silts and clays settle after a flood A flood is an overflow of water (list of non-water floods, or rarely other flui ...

s begin. ''Field channels'' originate from the lateral ditches at a spacing of 10 to 12 m and the date palms are planted along these (Fig. 4).

Soil properties

The typical properties of the ''levee soils'' are shown in figure 5.

Simulation tidal propagation

The tidal movements are 2 m on average. A simulation of tidal fluctuations in the ditches is shown in figure 6 for an average and a high river discharge at various distances from the sea. The simulations were made with the Duflow model.

Gallery

Image:TidalCanals.GIF, Fig. 2. A tidal canal stretches from the river inland and distributes the water over the lateral ditches Image:TidalCrossSection.GIF, Fig. 3. Longitudinal section of a tidal canal and cross-section through the river levee Image:LateralDitches.GIF, Fig. 4. The field channels run between the lateral ditches Image:TidalSoils.GIF, Fig. 5. An impression of soil properties Image:TidesAbadan.JPG, Fig. 6. Simulated tidal movements in canals at different river discharges and at various distances from the sea, assuming a normal tidal range

Irrigation of the Garmsar alluvial fan

Reference: ''Irrigation, groundwater, drainage and soil salinity control in the alluvial fan of Garmsar'' The

irrigation system Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has be ...

for the

alluvial fan An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to Semi-arid climate, semiar ...

of Garmsar is quite well developed (Fig. G1, below), to the extent that lined canals have been made and a belt-canal crosses the fan through its middle. An estimated average annual water balance is shown in Fig. G2 (below). It is seen that the storage of irrigation losses in the

aquifer An aquifer is an underground layer of water-bearing material, consisting of permeability (Earth sciences), permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The s ...

plays an important role. In the

dry season The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The t ...

the

groundwater Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...

is used for irrigation by pumping from deep wells. A cross-section of the groundwater situation is shown in Fig. G3 (below). The

water rights Water right in water law is 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 contentious. In o ...

are expressed in ''sang'', a measure of continuous flow of about 10 L/s, but in practice it varies from 10 to more than 15 L/s. The water is delivered to about 100 tertiary units (often a village), within which the water is distributed by 12-day rotations amongst the farmers who each are entitled to receive the authorized ''sangs'' for a fixed number of hours during each rotation period. The village communities are, at the same time, water-user associations who take care of the water-distribution within the tertiary unit and they maintain the tertiary canals. At present, the distribution of surface irrigation water to the villages is determined by the Garmsar Water Authority on the basis of the water rights and verbal agreements and communications with the water users in the absence of a written manual. The fair distribution of the irrigation water is not an easy job as the average annual river discharge is quite variable in the range of 5 to 20 m3/s (see graph at the right). The deep tube-wells are privately owned. The drilling of wells is subject to

license A license (American English) or licence (Commonwealth English) is an official permission or permit to do, use, or own something (as well as the document of that permission or permit). A license is granted by a party (licensor) to another part ...

. Recently, the licensing has stopped for fear of

over-exploitation Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable t ...

of the aquifer. It appears that no operational rules are applied to the wells. In the fringe lands, the water table is shallow. To stabilize the agriculture in the fringe lands, which are threatened by soil salinization, a method of strip-cropping (Fig. G4) can be recommended for

soil salinity control Soil salinity control refers to controlling the process and progress of soil salinity to prevent soil degradation by salination and land reclamation, reclamation of already salty (saline) soils. Soil reclamation is also known as soil improvement ...

. Image:GarmsarMap.JPG, Fig. G1. Map of the Garmsar area showing irrigation systems Image:GarmsarWatBal.JPG, Fig. G2. Irrigation and groundwater balances, estimated annual average in MCM Image:GarmsarAquifer.JPG, Fig. G3. Cross-section through the aquifer showing the geohydrologic conditions Image:StripCropping.jpg, Fig. G4. Principle of strip-cropping and sacrifice of the permanently unirrigated strips to where the soil salinization is directed.

Transfer from Persian Gulf

As of 2021,

Pipeline transport A pipeline is a system of Pipe (fluid conveyance), pipes for long-distance transportation of a liquid or gas, typically to a market area for consumption. The latest data from 2014 gives a total of slightly less than of pipeline in 120 countries ...

lines links (using

desalination Desalination is a process that removes mineral components from saline water. More generally, desalination is the removal of salts and minerals from a substance. One example is Soil salinity control, soil desalination. This is important for agric ...

techniques)

Persian Gulf The Persian Gulf, sometimes called the Arabian Gulf, is a Mediterranean seas, mediterranean sea in West Asia. The body of water is an extension of the Arabian Sea and the larger Indian Ocean located between Iran and the Arabian Peninsula.Un ...

Yazd Yazd (; ) is a city in the Central District of Yazd County, Yazd province, Iran, serving as capital of the province, the county, and the district. At the 2016 census, its population was 529,673. Since 2017, the historical city of Yazd is rec ...

in central Iran. Other similar projects have been launched linking Isfahan, Mashhad or Zahedan to littoral water sources.

Project to transfer Caspian Sea water to central regions

According to the plan, water will be transferred from

Sari A sari (also called sharee, saree or sadi)The name of the garment in various regional languages include: * * * * * * * * * * * * * * is a drape (cloth) and a women's garment in the Indian subcontinent. It consists of an un-sti ...

to the city of Semnan within 24 months (starting April 2012). The plan aims to provide

central provinces The Central Provinces was a province of British India. It comprised British conquests from the Mughals and Marathas in central India, and covered parts of present-day Madhya Pradesh, Chhattisgarh and Maharashtra states. Nagpur was the primary ...

with water for industrial and agricultural purposes at a cost of $1.5 billion. Once the plan comes on stream, some 500 million cubic meters of water will be transferred per annum. After

at the point of origin in the

Caspian Sea The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...

, it will be transported through a pipeline to the central Kavir desert, bringing about 200 million cubic meters (7,062 cubic feet) of water per year. Nearly 14 percent Iran's territory is desert and suffers from prolonged droughts. The Caspian Sea is shared by Iran, Russia, Kazakhstan, Azerbaijan and Turkmenistan. Its salinity is about a third of that of sea water.

References

{{Irrigation by country