On ancient agriculture in arid regions of Central Asia: the case of the Uvs Nuur basin

The Uvs Nuur Basin is one of the largest arid basins in southern Siberia and Central Asia. Local economy is based on pastoralism. Small-scale irrigation farming is practiced in river valleys. Satellite images of the basin reveal traces of ancient farming, which was much more extensive than that practiced at present. In the central part of the basin, in the Tes-Khem valley, dense irrigation networks are observed, along with numerous associated and hitherto unknown ancient settlements. Presumable remains of an ancient city surrounded by a network of irrigation canals were discovered on the west coast of Lake Uvs Nuur. Field studies confirmed the results of image analysis. Parts of ancient irrigation systems, ruins of the city and separate settlements were documented on the ground. For the first time, paleobotanical studies of buried soils and peatlands on ancient fields in the central Uvs Nuur Basin revealed seeds of Triticum sp. Remains of trees and grasses found in the same associations suggest that parts of the basin that are now deserted were covered by forest-steppe landscapes, and the climate was milder at the time when agriculture was practiced. Tentative results of radiocarbon dating suggest that the city existed during the High Middle Ages. Our results point to a higher role of agriculture at that time as compared to the present.