Introduction to Karez: Kaner, meaning well hole, is a special irrigation system in desert areas; it is common in Turpan, Xinjiang, China. Karez, the Great Wall and the Beijing-Hangzhou Grand Canal are known as the three major projects in ancient China. There are nearly a thousand karez in Turpan, with a total length of about 5,000 kilometers. The structure of the karez is generally composed of four parts: vertical shafts, underground channels, surface channels and "waterlogging dams" (small reservoirs). Bogda Mountain in the north of the Turpan Basin and Kalawucheng Mountain in the west have four parts in spring and summer. A large amount of snow and rainwater flows down the valley and dives under the Gobi Desert. People took advantage of the slope of the mountain and cleverly created karez to divert underground water to irrigate farmland. Kaner does not evaporate a lot of water due to heat and strong winds, so the flow rate is stable, ensuring gravity irrigation. Karez was recorded as early as "Historical Records" and was called "Jingqu" at that time. Most of the existing karez in Turpan were built successively since the Qing Dynasty. Today, large oasis fertile fields are still watered. Wudaolin Karez and Wuxing Township Karez on the outskirts of Turpan are available for sightseeing. Different provinces in mainland China have different names; for example, it is called "Jingqu" in Shaanxi, "Shuixiang" in Shanxi, "Hundred Eyes of String Wells" in Gansu, and in some places it is called "underground channel."