A[VG1][VG2][H3] GLANCE AT HISTORICAL QANATS IN IRAN WITH AN EMPHASIS ON VAZVAN QANAT IN ISFAHAN

Qanat is a way of conveyance of underground water to ground surface for irrigation and drinking. This is a technology born and developed in Iran and extended to other countries in the East and the West over the time. The total number of Iranian Qanats is 18000 and their total discharge is about 7.4 billions cubic meters. Among the Iranian Qanats some of them are specific from the point of view of mother well depth, length, rate of flow, oldness and attractiveness. Keikhosrow Qanat in Gonabad (Khorasan Province) has the deepest mother well, that is 400 meters. One of the Yazd Qanats has the largest tunnel that is 116 kilometers. The most flow rate Qanat is Payekam Qanat in Bam suburb which is 312 lit/s. From innovation and talent point of view, there are few historical Qanats in Isfahan such as Moon Qanat in Ardestan in which the tunnel has two parallel floors and Vazvan Qanat in which flowing water is collected beyond an underground dam for a period for irrigation purposes over the following year. There are a large number of benefits resulted from Qnanats, and few disadvantages as well, but the benefits are more. If the idle Qanats are repaired and renewed, then the rate of available water will be 1.7 billions lit/s, i.e. 4 times of Karroon River in Iran or ¾ of Nile River in Egypt. But from author’s point of view, this is not possible, because of shortage of rainfall and falling water level tables which had been happened due to huge number of dug wells.