Irrigation expansion and dynamics of desertification in the Circum-Aral region of Central Asia

The aim of this paper is to examine the causes and dynamics of desertification in one of the world's worst disaster areas, the Aral Sea region. During the 1960s, a large-scale irrigation campaign aimed at achieving independence in cotton production was launched in soviet Central Asia. From 1960, ever-increasing water withdrawal from the two inflowing rivers-the Amudarya and Syrdarya-has resulted in the dramatic decline of the level, area and volume of the sea. Desiccation was accompanied by the development and further acceleration of various desertification processes. The study reveals that, for different reasons, the predominant, direction and trends of desertification have been changing during each of the four identified periods from 1961 to 1995. The main desertification processes recorded in the Circum-Aral region ('Priaraliye' in Russian) were a decline in the groundwater level, increased mineralization and chemical pollution of watercourses, soil salinization, the spread of xerophytic and halophytic vegetation, and deflation and aeolian accumulation, with the development of salt storms. Recent improvements in the situation are also discussed, along with their causes. Zonation of Priaraliye is carried out and an outlook for the future is given. (C) 2000 Published by Elsevier Science Ltd.