Karez

A karez is an ancient horizontal water collection structure for the collection of groundwater. This type of structure is used on piedmonts and alluvial fans where people can tap groundwater for irrigation and daily consumption. Karez are mainly distributed in the Turpan Basin in Xinjiang Province, where there are nearly a thousand with a total length of approximately 5,000 km. A karez is composed of a shaft, an underground channel, a surface channel and a ‘waterlogging dam’ (a small storage pool). At Bogda (Bogeda) Mountain in the northern Turpan Basin and Kalawucheng Mountain in the western Turpan Basin, abundant meltwater and rainwater flow down to the valleys in the spring and summer and then into the aquifer under the Gobi Desert. The Xinjiang people developed the skill to make use of the natural gradient of the proluvial fans and diverted the groundwater via the karez for farm irrigation (Fig. 2).

Fig. 2

Karez in Turpan