The qanat is a collection and conveyance system for groundwater that was developed in Persia. A qanat, illustrated in Fig. 1.3 Consists of an underground tunnel which uses gravity to convey water from the water table (or springs) at higher elevations to the surface of lower lands. Qanats also have a series of vertical shafts that were used
Fig. 1.2 Compartmented wheel with saqiya gear (Description de L Egypte, 1822)
Fig. 1.3 Qanat, foggara, falaj, or karez
For excavation of the tunnel and provided air circulation and lighting. The oldest qanats have been found in the northern part of Iran and date back to around 3,000 years ago when the Arians (Aryans) settled in present day Iran (Javan et al., 2006). The longest (71 km with 2,115 vertical shafts) and oldest (over 3,000 years) is to the ancient city of Zarch. Qanat comes from the Semitic word meaning “to dig” (Moosavi, 2006). Presently there are about 33,000 operational qanats in Iran (Javan et al., 2006).
From 550-331 B. C. Persian rule extended from the Indus to the Nile, during which time qanat technology spread. As this technology transferred to other civilizations, it was known by different names: karez (Afghanistan and Pakistan), kanerjing (China), falaj (United Arab Emirates), and foggara and fughara (North Africa). Qanats were constructed to the west of Persia from Mesopotamia to the Mediterranean and southward into parts of Egypt. Qanats were also constructed to the east of Persia in Afghanistan, in the Silk Route oases settlements of central Asia and to Chinese Turkistan. The Persians introduced qanats to Egypt around 500 B. C.
World History
