Iran: Agriculture Using Underground Irrigation Canals in Inland Dry and Semi-dry Zones
SUBMITTED ORGANISATION :
United Nations University Institute for the Advanced Study of Sustainability (UNU-IAS); Japan Wildlife Research Center (JWRC)
DATE OF SUBMISSION :
This study was commissioned to be included in the publication “Socio-ecological Production Landscapes in Asia”. This chapter provides an overview of the qanat water management and irrigation system in Iran.
Drylands, water management, qanat, irrigation
Japan Wildlife Research Center (JWRC)
The summary sheet for this case study is available here.
[Note: this case study originally appeared in the publication Socio-ecological Production Landscapes in Asia.]
The term “qanat” refers to technology that has been developed to use groundwater for agriculture and the lives of people in dry zones (Jomehpour, 2009). The origin of qanats is not certain, but it is believed that they have a history of some 3,000 years since tradition says that some of them were built in 1200 BC (Balali et al., 2009). There is also a view that qanats were originally not facilities to supply water but technology to remove water at the time of mining (Hosseini et al., 2010), but it is said that this technology spread to various places from Iran along with the Islamic faith (Balali et al., 2009). Today, technology similar to Iranian qanats is found in more than 34 countries around the world, and has a local name in each country (Jomehpour, 2009; Hussain et al., 2008). For example, it is called “Kariz” in Afghanistan, Tajikistan, China and also in Iran, “Falaj” in Oman, “Foggara” in Libya, Tunisia, and Algeria, “Galeria” in Spain, “Khotara” in Morocco, and “Auon” in Saudi Arabia and Egypt. However, in recent years, qanats are being concentrated and the number of qanats is decreasing in most countries.
Iran faces the Caspian Sea to the north and the Persian Gulf to the south. While the Alborz mountains stretch from east to west, the Zagros mountains run from northwest to southeast. The inland area surrounded by these mountains consists of dry zones 500-1,000 meters above sea level. Dry and semi-dry zones account for about 75% of the country and have an average annual precipitation of about 242 mm. This is about one third of the world’s average annual precipitation of 860 mm (Hosseini, 2010). There is relatively high rainfall from winter to early spring, but during the summer season, there is little rain, and large amounts of water evaporate because it is hot. The inland area has an average annual precipitation of 100-500 mm, but 500 mm or more falls on the mountains. Water brought by rivers that rise in the mountains flows toward the inland basin and disappears into vast stretches of alluvial or diluvial beds in the basin or into salt lakes located at the center of the basin. These alluvial and diluvial beds consist mainly of unconsolidated gravel, sand, and silt, all of which makes it easy for river water to permeate into the ground (Moritani, 1969).
In the dry zones in Iran, people have used qanats, the only source of water supply, to overcome the obstacle to development of water shortages for centuries, creating the characteristic Qanat Civilization (Jomehpour, 2009). It has unique cultural, socioeconomic, and politic characteristics, and in this civilization the Iranians developed the wisdom to think how to coexist with the deserts by using irrigation water, performing agricultural work jointly, and taking other measures (Jomehpour, 2009; Salih, 2006). Qanat water is used for agriculture and drinking water (Photo 1; Hussain et al., 2008) and today it is even supplied to urban areas (Jomehpour, 2009).
Photo 1. Drinking water tank (The water comes through the underwater canal) (Photo: Vafadarimehrizi Kazem)
Characteristics of Qanat System
Structure and Construction of Qanats
According to the Iranian Ministry of Jihade- Agriculture, there are 37,490 qanats nationwide with their tunnels extending for 30,000 km and the amount of water supplied by them totals 38,000,000 m3 (Hosseini et al., 2010). There are two types of qanats: the mountain type and the plain type. While mountain-type qanats draw water from aquifers filled with rainwater and snowmelt and channel it from the mountains to settlements through canals (Figure 1), plain-type ones bring the water from rivers (Jomehpour, 2009; Hussain et al., 2008; Salih, 2006).
In general, a qanat is composed of gently sloping horizontal ducts 50-80 cm in width and 90-150 cm in depth, which continue from the headspring to the irrigated land, and wells perpendicular to the ducts, which are drilled for the construction of the qanat and the removal of the excavated earth. After the construction of the qanat, these wells are used for ventilation (Jomehpour, 2009). In addition, the structure of qanats is largely affected by the climate of the area where they are constructed (Jomehpour, 2009; Hussain et al., 2008). If much rain falls, the ducts of the qanats are short, and their wells are shallow. If precipitation is low, on the other hand, the ducts are long, and the wells are deep. Cultivated land and settlement sites are situated downslope from the point where the water surfaces, and the people use the water from the qanats.
Qanats are constructed by experts called “Muqanni (or Moghannis)” (Balali et al., 2009; Salih, 2006). Muqanni first install a winch and put the earth that is dug up when constructing the qanat into buckets and pull them up to the ground. Thus vertical holes about 90 cm in width are first dug. In this work, one worker uses a mattock (pickax), and others employ a short-handled spade (Balali et al., 2009). Muqanni are highly regarded in Iranian society (Jomehpour, 2009) and their techniques are handed down from father to son. Muqanni, who belong to a management organization of Qanat called Buneh (described below), are supplied with agricultural products for repairing qanats and making other contributions throughout the year even if they are not engaged in agricultural work (Balali et al., 2009).
Figure 1. The structure of a typical qanat (mountaintype) (Source: Salih, 2006, modified)
Qanat Management Organization: Buneh
Qanats are constructed and maintained by an organization called a “Buneh” (Mohmmoud et al., 2009). The Buneh also manages the water use, as well as the production of agricultural products, the development of agricultural land, and related socioeconomic systems as described below (Jomehpour, 2009; Balali et al., 2009). Agricultural production by individuals is disadvantageous compared to a Buneh-based one due to the lack of capital and labor required for the construction and maintenance of qanats. In addition, Buneh play a role in efficiently developing agricultural land, and it can therefore be said that Buneh raise the socioeconomic position of tenant farmers compared to agricultural production by individuals (Balali et al., 2009).
In the Buneh-based collective system, the landowner stands at the top of the hierarchy and is mainly responsible for investments in qanats, irrigation, shortterm loans to purchase seeds, and the provision of cash to tenants during the winter season (Jomehpour, 2009). A Buneh usually consists of 10-15 tenants (Jomehpour, 2009). From among these tenants, the landowner chooses the one who has experience and technical skills in agriculture as the Buneh’s leader called a “Sarbuneh” (or “Abyar”). The Sarbuneh then selects two assistants, called “Varbuneh,” from among his or her friends and relatives. Other members comprise sharecroppers without any official position. A member’s share of the agricultural products is determined by his or her position in the Buneh (Balali et al., 2009). As described above, the structure of a Buneh reflects the socioeconomic position of its members in the village (Jomehpour, 2009).
Distribution of Agricultural Land and Water Distribution
The distribution of agricultural land among Buneh organizations in a village is determined at a meeting convened by the village’s Sarbuneh at the beginning of the agricultural season each year. Agricultural land is ranked in three grades (good, average, and bad) depending on its fertility, and when agricultural land is distributed, ingenuous plans are used to ensure that all grades of land are included in the package of land allotted to each Buneh. Each Buneh lets certain tracts of land lie fallow (Jomehpour, 2009). Once the distribution of land to each Buneh is determined, the Sarbuneh demarcates the lots in the Buneh, adjusts the types of cereals cultivated in each lot, the irrigation, and the periods of sowing, defines the roles of the members, concludes contracts with seasonal workers, mediates between the landowner and the tenants, and performs other duties (Balali et al., 2009). Qanat water is used according to each individual’s water rights. Usually, depending on the hour, water rights are distributed at a rate of several minutes to several hours a year. In this way, the size of each tenant’s agricultural land and the amount of cereals he/she grows are determined by his/her water rights (Photo 2). For this reason, in each Buneh, a balance has to constantly be made between water rights and agricultural land. These water rights have been handed down from generation to generation, and this balance has also been maintained (Jomehpour, 2009).
Photo 2. Qanat irrigation canal (Photo: Vafadarimehrizi Kazem)
Major Qanat-related Land Uses
As mentioned above, the agricultural land below the qanats and the water available from them are distributed among the tenants who work within the range of the land and water distributed. In this region, land can generally be cultivated twice a year, spring and autumn. In early spring, the tenants sow the seeds of tomatoes, eggplants, cucumbers, onions, watermelons, and other vegetables, and encourage them to sprout by moistening the earth moderately through qanat irrigation (Photo 3). Subsequently, they irrigate the fields roughly every three to four days, although the interval between irrigation varies slightly according to the crops, maintain a sufficient amount of water to stimulate the growth of crops, and harvest the crops around August. In autumn, the seeds of wheat, barley, and other cereals are planted from September to October. In winter, irrigation water is not used due to the relatively large amount of rainfall, but the fields are irrigated from early April to around early June. Tenants do not cultivate land in the same pattern in order to prevent it from becoming sterile. They use it for spring crop planting and autumn crop planting and then let it lie fallow, and repeat this pattern in a three-year cycle.
Functions and Benefits
Qanats fulfill a wide range of functions. The following section discusses four of these functions.
(a) Multiple uses
Qanats can be used for multiple purposes such as irrigation water, drinking water, and systems to discharge groundwater at times of flooding (Jomehpour, 2009; Hussain et al., 2008). In particular, drinking water from qanats is supplied to both rural and urban areas. The groundwater discharge systems play the role of preventing the groundwater level from rising when flash floods occur, a phenomenon peculiar to dry zones (Jomehpour, 2009). An existing example is Hassanabad Qanat that provides drinking water for Yazd city. In Mehriz city located in south of Yazd city, people have been using a small fish in the qanat as an indicator of water quality and changes in the population of this fish can indicate possible problems with qanat water over time.
(b) Source of energy
One example is that hydroelectric power is generated using sloping water supply pipes and flour is milled using water wheels (Jomehpour, 2009; Hussain et al., 2008). In Iran, even today, there are cities where water wheels remain with high potential for tourism applications and potential for livelihood diversification in the local community (Hussein et al., 2008).
(c) Ecological Functions
Qanats prevent excessive water collection, ensuring sustainable water supplies, since they can only provide as much water as the aquifers can naturally replenish (Mohammad, 2009; Hussein et al., 2008). If precipitation decreases, the volume of water running through qanats also decreases. On the other hand, pump wells tend to constantly collect the required amount of water irrespective of the precipitation and the amount of water existing in the aquifers, and the water is therefore not supplied in a sustainable way (Jomehpour, 2009; Hussain et al., 2008).
In addition, since the ground is dug as deep as the solid subsoil when qanats are built, the qanats are less wet and prevent a rise in the groundwater level, inundation, evaporation, and other undesirable phenomena, reducing the concentration of salts in the water, which prevents agricultural land from being ruined by salination (Jomehpour, 2009).
(d) Social Functions
Qanats are closely related to the local communities. The management of qanats is decentralized and involves the local residents. This unites local residents and generates their allegiance to the local community (Hussain et al., 2008). The social status of people is determined by the extent of the water rights for qanats that they have (Jomehpour et al., 2009; Hussain et al., 2008). Muqanni, experts in qanat construction, have a high social status, and the social status of people living in urban areas is determined by whether their place of residence is located upstream or downstream from a qanat as well as the distance to it (Jomehpour, 2009).
Qanats are also closely related to the social and cultural traditions of the area where they are located (Jomehpour, 2009). Qanat water is considered sacred, and a ceremony called a “Qanat wedding” is often held. In this ceremony, a woman purified with qanat water pours special soup into the qanat. It is believed that by holding such a ceremony, local people can continue to use qanat water in the following year (Foltz, 2002).
Challenges and Responses
Where the Problems Lie
In recent years, the proportion of qanat water to the total water supply has decreased. It was 70% before 1950 but fell to 50% in 1950 and to 10% in 2000 (Hosseini et al., 2010). The reasons for this decrease in the number of qanats include urbanization (Hosseini et al., 2010) and the introduction of modern pump wells (Balali et al., 2009; Jomehpour, 2009; Hussain et al., 2008). If, due to urbanization, a new city was planned to be built in an area where qanats were located, the qanats have been filled in with earth. Buildings were constructed on the vertical holes of qanats, and there are many cases in which it is no longer known where the qanats existed (Hosseini et al., 2010). In addition, agricultural reforms, which began in 1962, accelerated the introduction of modern pump wells. These agricultural reforms promoted the redistribution of land ownership rights from feudal landowners and absentee landlords to tenant farmers (Yokoyama et al., 2007). With these reforms, the relationship between the landowners and Buneh, both of whom had up to then been responsible for the management of the qanats, ceased to exist. Since it was difficult for individuals to manage qanats, modern pump wells came to be more favored. Another reason for these changes was that there were scholars who underestimated qanat technology and argued for a shift to modern pump systems (Balali et al., 2009).
The recent growth in the population is also cited as the reason for the shift to modern pump wells. Qanats have been replaced by pump wells because they could not meet the growing demand for water as the population grew (Hussain et al., 2008). It takes less time to dig a pump well than to construct a qanat. While it takes two to three years to expand the horizontal ducts of qanats when it becomes necessary to increase the amount of water discharged, pump wells are more convenient mainly because all that needs to be done is to replace the existing ducts with ones that have a larger diameter. For this reason, farmers have gradually come to favor pump wells (Balali et al., 2009).
Moreover, it is pointed out that there is a shortage of labor for qanat construction as people have changed their jobs from primary industries to other areas, and a lack of understanding of qanats affects policy making. The government overlooked the social functions of qanats such as efficient agricultural production by Buneh and as a result pushed forward with such policies as agricultural modernization using pump wells and industrialization (Hussain et al., 2008).
Today, however, qanats are attracting worldwide attention (Hussain et al., 2008). Up to now, when the world was faced with water shortages due to population growth, it has found solutions in technological innovation. But at the Second World Water Forum, which took place in the Dutch city of the Hague in 2000, participants pointed out that water crises had occurred due to failures in water management rather than water shortages (Balali et al., 2009). In this context, traditional water use and management systems like qanats have attracted attention as sustainable systems (Balali et al., 2009). Some experts point out the need to take such measures as establishing laws to protect qanats and integrating qanats into modern irrigation systems in the future (Hussain et al., 2008). Others urge the need to gather information on qanats, evaluate the cost benefits of pump wells compared to qanats, and ensure worldwide information sharing, for example. The Iranians position qanats as something that connects people to nature, creates ecological awareness, and prompts people to take ecologically conscious actions. For this reason, activities aimed at connecting people to nature are carried out at mosques and other facilities in connection with the Islamic religion in which water plays an important role (Balali et al., 2009).
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