Throughout the arid regions of Iran, agricultural and permanent settlements are supported by the ancient qanat system of tapping alluvial aquifers at the heads of valleys and conducting the water along underground tunnels by gravity, often over many kilometres. The eleven qanats representing this system include rest areas for workers, water reservoirs and watermills. The traditional communal management system still in place allows equitable and sustainable water sharing and distribution. The qanats provide exceptional testimony to cultural traditions and civilizations in desert areas with an arid climate.Qanats are constructed as a series of well-like vertical shafts, connected by gently sloping tunnels. Qanats efficiently deliver large amounts of subterranean water to the surface without need for pumping. The water drains by gravity, typically from an upland aquifer, with the destination lower than the source. Qanats allow water to be transported over long distances in hot dry climates without much water loss to evaporation.
It is very common for a qanat to start below the foothills of mountains, where the water table is closest to the surface. From this source, the qanat tunnel slopes gently downward, slowly converging with the steeper slope of the land surface above, and the water finally flows out above ground where the two levels meet. To connect a populated or agricultural area with an aquifer, qanats must often extend for long distances.
Qanats are sometimes split into an underground distribution network of smaller canals called kariz. Like qanats, these smaller canals are below ground to avoid contamination and evaporation. In some cases water from a qanat is stored in a reservoir, typically with night flow stored for daytime use. An ab anbar is an example of a traditional Persian qanat-fed reservoir for drinking water.
The qanat system has the advantage of being resistant to natural disasters such as earthquakes and floods, and to deliberate destruction in war. Furthermore, it is almost insensitive to the levels of precipitation, delivering a flow with only gradual variations from wet to dry years. From a sustainability perspective, qanats are powered only by gravity, and thus have low operation & maintenance costs once built. Qanats transfer freshwater from the mountain plateau to the lower-lying plains with saltier soil. This helps to control soil salinity and prevent desertification.The Persian Qanat was inscribed on the world heritage list of UNESCO in 2016 .
Collection Of Persian Ganat :
1- Ghasabe Gonabad in Khorasan Razavi province
2- Baladeh Ferdows in Khorasan Razavi province
3- Hasan Abad in Mehriz of Yazd province
4- Zarch in Yazd province
5- Ebrahim Abad in Arak province
6- Mozdabad in Meymeh of Isfahan province
7- Vazvan in Isfahan province
8- Moon in Ardestan of Isfahan province
9- Goharriz in Jopar of Kerman province
10- Akbarabad in Kerman province
11- ghasemabad in Kerman province