Dzungarian Plain

(also Dzungarian Basin, or Dzungaria), a plains region in northwestern China. Area, approximately 700,000 sq km; average elevation, 600-800 m. In the north, Dzungaria is bounded by the Mongolian Altai, and in the south, by the eastern Tien-Shan ranges. The average elevation of the surrounding ranges is approximately 3,000 m. The Dzungarian Plain was formed as a result of young subsidences that were accompanied by the accumulation of sediments. The plain is composed of a thick cover of ancient and recent friable deposits and has major oil reserves. The surface of the Dzungarian Plain is broken by low mountain ridges and a hillocky area. The piedmont shelf that adjoins the mountains is usually stony and is devoid of vegetation in places. Below, on the loamy surfaces with shallow ground-water, there is a strip of oases that gives way to solonchaks. The large central part of the Dzungarian Plain is occupied by deserts (Dzosotyn Elisun, Kurbantongut, Karamaili, Kobbe, and others), with areas of barchan and ridgy sands.

The climate is moderately continental, with hot dry summers and cold dry winters (mean temperature in January ranges from -20° to -25°C, and in July from 20° to 25°C) and with sharp temperature fluctuations during a 24-hour period. Strong winds are frequent. Annual precipitation is 150-200 mm, and in the mountains up to 800 mm. The river network is sparse. The rivers irrigate only the peripheral regions of the Dzungarian Plain, where numerous oases are concentrated, and then disappear in the sands. The largest rivers are the Manas and Urungu; in the northern part of the Dzungarian Plain lie the headwaters of the Irtysh. The channels of many rivers are filled with water only during torrential rains. In the west, which is the direction of the runoff, there are several large lakes (Ebi Nor, Manas, and Uliungur).

The vegetation cover of the Dzungarian Plain, where it exists, is of the desert type and is very thin. In the sandy deserts, saxaul, tamarisk, Calligonum, and ephedra predominate, and in the solonchak deserts there is saltwort. In the western part of the Dzungarian Plain, there are arid steppes combined with wormwood-saltwort and wormwood-gramineous semideserts. In the lake basins are thickets of sedge and reed. There is pasture livestock raising. In the oases along the edges of the Dzungarian Plain, there is also irrigation farming. (Wheat, millet, cotton, and koaliang are raised.)