The Karez Well System in Xinjiang Uyghur Autonomous Region
The Karez System in the Xinjiang Uyghur Autonomous Region of China (East Turkestan) was built approximately 2000-2500 years ago.1 The name of Karez given by Uyghurs to water channel systems. In Iran, these systems are known as Qanat or Kariz, and in northern Africa as Fuqara. Similar systems are known from more than 34 countries in the world.2
The Karez Wells system was recognized as one of three major ancient engineering projects, along with the Great Wall and the Beijing-Hangzhou Grand Canal. The People’s Republic of China restored the channels for tourism in 2005. The channels have been recognized by UNESCO as World Heritage Sites in 2008.3
Besides tourism, the channels still active and transport water to the region for agriculture. According to Ayse Suberker, (TRT Turk TV, presenter of Uyghur Karez Channels Documentary) 1784 channels have been identified and 614 of these channels are still active. In a year, 301 million cubic meters of water is transported from the mountains to the city. The source of the transported water by the Karez System is the snow that melts in the Xinjiang Tianshan Mountain. The channels’ length is 500 kilometers. The waters transported by the channels cross the 60 km desert and reach the city of Turpan. Turpan has a warm climate. Therefore, the channels were built 100 meters below the ground to prevent water evaporation.4
According to Camille Jetzer, today 545 channels are active but 200 of them are working properly. Uyghurs believe that the channels are named after the owner of the channels and they say that the first names of channels are known.5 Nowadays, the question of who built the channels is disputed by the Uyghur Turks and Chinese. The construct date indicates that the Karez system was built by the Turks or the Chinese.
According to Jetzer’s study, Karez channels directly impressed the Uyghurs’ songs, poems, and lifestyles and they became part of the national identity of Uyghurs.6 The thesis supporting that the Chinese built the Karez system reference a claim that the Turks’ didn’t have an architectural knowledge to build it. Ibn-i Fadlan cited a story about the city built by Turks in his travel book.7
Ali Ibn Sahl Rabban Al Tabari8:
The most beautiful city established in the world is in one of the Turk’s state. There was a bogland in the state. The Turk’s Khan had the direction of the river changed. By order of the Khan, the workers dug a widely foundation (40 cubits9 approximately 30 meters), then they built two walls by using brick and lime. The width of each wall was 10 cubits and there was a distance of 20 cubits between the two walls. When the walls reached the ground level they filled the gap between the walls with sand and mud. After the walls rose 50 cubits, they established the city and built palace and houses. They surrounded the city with a ditch and gave water to the ditch. Not long after, around a year, the bogland became as a huge forest. After the city established, the Khan lived in the city with his family and brought the state treasury. This is the most beautiful city established in the world.
As a result, there is no information about the city, which Tabari mentions, or when the city was founded. As Tabari lived in Tabaristan, where Turks founded states throughout history (It is located in Northern Iran, nowadays.), what he told could be the truth.
On the other hand, there is no other structure similar to the Turpan Karez Channels in China. Therefore, the possibility that the Turpan Karez water channels were built by the Turks is more likely than the possibility that they were built by the Chinese.
 Chunliang Cui, Shalamu Abudu, Zhuping Sheng, Donghai Guan, The Karez System in China’s Xinjiang Region, Online Link: https://www.mei.edu/publications/karez-system-chinas-xinjiang-region#_ftn1, Accessed Date: 20.09.2020
 Abudu S., Sheng Z., King J.P., Ahn SR. (2019) A Karez System’s Dilemma: A Cultural Heritage on a Shelf or Still a Viable Technique for Water Resiliency in Arid Regions. In: Yang L., Bork HR., Fang X., Mischke S. (eds) Socio-Environmental Dynamics along the Historical Silk Road. Springer, Cham.
 Unesco, Online Link: http://whc.unesco.org/en/tentativelists/5347/ Accessed Date: 21.05.2017
 Ayse Suberker, Trt Turk Tv, Uyghur Karez Channels Documentary, Online Link: https://www.youtube.com/watch?v=G5H1-u5Sx8o, Accessed Date: 22.05.2017
 Camille Jetzer, Water at the Boundaries Conserving the Karez in Turpan, Northwest China, Oxford, 2015, page 20-26
 Camille Jetzer, same study, page 41
 Ibn Fadlan, Ibn-i Fadlan Seyahatnamesi, page 51, (The book was translated English by Paul Nunde as the name of “Ibn Fadlan and the Land of Darkness: Arab Travellers in the Far North”)
 Tabari is the physician of the Khalifa el-Mutevekkil. He was Jewish before he accepted Islam. Firdevs el-Hikme is the famous work of him. He died around 860 years.
 Cubit: It is a unit of length used by Turks in the past.
 Image 2: https://link.springer.com/chapter/10.1007/978-3-030-00728-7_22#citeas