The study of Otrar oasis late medieval irrigation technique

The irrigation detachment of the South Kazakhstan complex archaeological expedition studied the late medieval irrigation technique of the Otrar oasis based on the surviving remains of the Temir-Aryk irrigation system (15th-17th centuries). As the survey showed, the head sections of Temir-Aryk consisted of three canals of various lengths with a width of about 9 m. The main canals were located on the concave side of the Arys bank and departed from the river at an angle of 60-70 °. The total length of the central canal is about 40 km, and its route follows the main slope of the terrain from the southeast to the northwest. The width of the central channel varies from 20 m in the idle part to 12 m in the middle position. The length of the water run in Temir-Aryk is 10 km. The central canal had bilateral command. Every 500-700 m from it, at a distance of 5-10 km, distribution channels depart at an acute angle. The width of command distributors is from 5 to 7 m. District distributors have a 1 km to 3 km with a channel width of 3 to 5 m. Irrigators, as a rule, are equal to the length of the irrigation site; their width is from 1 to 1.5 m.

The irrigation technique used in irrigated agriculture in the late Middle Ages in the Otrar oasis was diverse. This is irrigation along furrows, strips and floods. Traces of various irrigated land layouts are visible on aerial photographs of the studied areas. In percentage terms, it should be noted that the bulk of the irrigated land was occupied by fields of grain crops, from which horizontal platforms have been preserved, adapted for flood irrigation. A small share is occupied by melons, vineyards, garden and park plots, which were mainly located within the city and nearby environs. During this period, in the irrigation technology of the Otrar oasis, ceramic water distributors and aqueducts and water-lifting structures - chigirs were widely used. This is evidenced by the finds of water pipes on the remains of chigir pits. In the late medieval period, along with ceramic chigir vessels, iron objects' share in chigir installations sharply increased. Finds of numerous iron fragments and a whole iron block discovered during the clearing of one of the chigir pits clearly confirm this.