Effects of climate change and human activities on environment and area variations of the Aral Sea in Central Asia

This study aims to gain a better understanding of how climatic and anthropogenic factors have affected the Aral Sea Area (ASA). The dynamic changes of the ASA from 1920 to 2020 were investigated, and then the relationship between the water area and its drivers was evaluated using different regression analyses. The results demonstrate that the water surface area exhibited minor fluctuations with an upward trend of 0.04 km(2)/year from 1920 to 1960. Since then, the water area decreased dramatically. It reduced by 88% in 2020 compared to that in 1920, and the decreasing rate slowed significantly after 2010. The multi-factor analysis determined that human activities are the root cause of declining in water area. The multiple stepwise regression results suggest that the water withdrawals from rivers (dam capacity > domestic water consumption > agricultural water consumption) could be responsible for most of the variation in ASA, and 82% of total withdrawal water was used for agricultural consumption. The diversion of rivers (for irrigation) that historically fed the Aral Sea, resulting in a decrease in inflow entering the sea, is another cause of the ASA's shrinkage.