BACKGROUND AND OBJECTIVES: The
Aral Sea disaster is widely recognized as one of the worst human-caused environmental catastrophes of the twentieth century. The study objectives were to provide a comprehensive ecological assessment of the dried Aral Sea-bed in Kazakhstan to support
phytomelioration planning.METHODS: Field work was carried out from ۲۴ April to ۲۰ May ۲۰۲۳, covering an area of ۱,۰۷۱,۹۶۷ hectares. The study combined climate analysis (۱۹۹۱-۲۰۲۴ data), groundwater surveys (۲۷ observation wells), soil studies (۶۸ soil pits, ۳۴۸ samples), and vegetation mapping (۹۳ plots) using geographic information system and remote sensing tools. By December ۲۰۲۳, laboratory analyses had been finalized. The mapping of
ecological risk zones was conducted through the application of weighted overlay analysis with six parameters.FINDINGS: The study documented extreme desert conditions with only ۱۲۰ millimeters of annual rainfall and a humidification coefficient K = ۰.۲۰. By the year ۲۰۵۰, it is anticipated that the average annual air temperature will rise by ۲.۰-۲.۸ degrees Celsius in comparison to the current climate. The groundwater exhibited a high salinity level, varying from ۳۷.۶ to ۱۰۴.۶ grams per liter, depths of ۱.۲ to ۵.۲ meters. Soils were mostly solonchaks with surface salt content reaching ۳۵.۹ percent. A total of ۳۶۸ plant species were recorded, and black saxaul (Haloxylon aphyllum) plantations exhibiting survival rates ranging from ۲۲ percent and ۱۰۰ percent. Four distinct classes of forest site conditions were established: favorable (۷ percent), marginally favorable (۳۴ percent), unfavorable (۲۷ percent), and unsuitable (۳۲ percent).CONCLUSION: Using six weighted parameters, four
ecological risk zones were mapped: low (۷ percent), moderate (۳۷ percent), elevated (۲۵ percent), and high (۳۱ percent). The high-risk regions align with bare solonchaks and migrating dunes, identified as the principal contributors to salt-dust storms. The four-tier forest site classification system developed in this study, specifically calibrated for groundwater salinity levels up to ۱۰۴.۶ grams per liter, provides a preliminary scientific foundation for
phytomelioration planning under Kazakhstan's National Afforestation Program.