Aral Sea

The Aral Sea lies in the arid interior of Central Asia, with Kazakhstan along its northern side and Uzbekistan to the south. Despite its name, it is an inland saltwater lake. Before its rapid shrinkage, it was one of the world’s largest inland bodies of water; in 1960 its surface covered about 68,000 square kilometres. Its main sources of river inflow were the Amu Darya, which entered from the south, and the Syr Darya, which flowed in from the northeast. In the region’s dry climate, river inflow was crucial to balancing water lost through evaporation.

From the 1960s, Soviet irrigation projects diverted increasing quantities of water from the Amu Darya, Syr Darya and their tributaries to farmland, including cotton-growing areas. Less river water reached the lake, while evaporation continued. The resulting water loss caused the shoreline to retreat and salinity to rise. By the late 1980s or around 1990, the receding waters had separated the lake into a northern and a larger southern part. The southern basin later divided further into eastern and western lobes. Satellite observations documented substantial year-to-year changes in the southern basin; its eastern lobe was dry in 2014.

As the lake contracted, salinity and pollution increased and fisheries that had supported shoreline communities collapsed. Ports once situated beside the water became separated from it by newly exposed land. Winds can lift salt and agricultural chemicals from the dry lakebed and carry the dust into surrounding areas, posing environmental and public-health risks and contributing to soil degradation. The loss of a large body of water also weakened its local moderating influence: NASA describes colder winters and hotter, drier summers as part of the regional changes associated with the shrinking lake. These effects varied across a large basin shared by several countries.

Kazakhstan completed the Kok-Aral dike and dam in 2005, separating the North Aral Sea from the lower southern basin and retaining more water in the north. NASA satellite observations showed a rapid rise in the North Aral’s water level after the dam’s completion, and the agency reports that northern fisheries rebounded. A World Bank account published in 2008 also documented lower salinity and increased fish harvests in the North Aral during the first years of the restoration project. These gains were local rather than a restoration of the whole former lake: the dam also limits water flowing from the north to the south, whose eastern portion has experienced severe drying. The broader basin’s future depends on water use and cooperation among the countries that share its rivers.