Investigate the relationships between the Aral Sea shrinkage and the expansion of cropland and reservoir in its drainage basins between 2000 and 2020

The Aral Sea crisis is considered one of the most severe ecological tragedies from the 1960s in Central Asia. The reasons for this crisis, especially in the twenty-first century, are still scientific disputes. This study investigated the relationship between land cover change in the Aral Sea related basins and the Aral Sea crisis from 2000 to 2020 by employing the GlobeLand30 dataset with 30 m resolution. Results showed that the cultivated land in the Aral Sea basin increased by 2,291 km2, and 75.4% of it occurred in the region of Karakum Canal, the largest water conservancy project for irrigation in the world. The water surface area of reservoirs increased by 1,183.5 km2 during the same period. Coincident with this change, the Aral Sea further shrank from 26,280.8 km2 in 2000 to 9,285.2 km2 in 2020, mainly occurred in the first decade of the twenty-first century. These imply that the Aral Sea crisis is persistent in the twenty-first century and is likely driven by water competition among different regions within the basin for agricultural irrigation. Strengthening the coordination and cooperation of cross-boundary water resource management is still the most important management strategy choice to address the crisis from a broader perspective.