 This irrigation system of special connected wells has been claimed to originate in Iran (e.g., the qanat system), to have originated indigenously, or to have been invented in other parts of China .Both historical and archaeological research convincingly point to the origins of this technology as arriving from more western regions along with indigenous innovations.In Xinjiang, the greatest number of karez wells are in the Turpan Depression, where today there remain over 1100 karez wells and channels having a total length of over .