The main regularities of dust-salt transference in the desert zone of Kazakhstan

Abstract

The area of Kazakhstan is 272.3 mln.ha. The major part of the territory is represented by plain (93.0%), fringed only in the south, and southeast by the Tyan Shan, Tarbagatai and Altai mountains (7.0%).

The climate is very arid. The soils of saline series are rather widely spread in the structure of the soil cover of all geographical zones. Solonchaks account for more than 8.5 mln.ha (zones of brown and grey-brown soils) of the total area of Kazakhstan. Solonetzes and solonetz-like soils occupy more than 70 mln.ha (especially in the dry-steppe and desert-steppe zones). Maximum participation (51%) of saline soils in soil cover is observed in the light-chestnut soils of the dry desert steppe (semi deserts) where the sum of participation per year makes up 200- 230 mm under an evaporation of 800-1,000 mm. Mainly solonetz-like complexes with participation of solonetzes themselves prevail here constituting from 10 to 30% of soil cover. In the desert zone of brown, grey-brown and takyr-like soils, where precipitation is 120-170 mm per year and evaporation is over 1,000 mm per year, the quantity of solonchaks makes up 15% of soil cover and the quantity of solonchaks in complexes makes up 16% of soil cover (Borovsky & Uspanov, 1971). Solonchaks of different variants are especially widely spread in the deltas of rivers in the desert zone of southern Kazakhstan – the Syr Darya, Talas, Assy, Ili and the lower reaches of the Ural river. Vast areas of solonchaks are located in small and large reservoirs: the Myertvy Kultuk near the Caspian Sea, the saline coasts of the Aral and Balkhash seas and some other places serve as examples. The content of easily soluble salts in crusty-swelling solonchaks ranges from 150 to 400 t/ha in the upper 1 m layer.