New water in the Aral Sea, although much remains dry

What remains of the Aral Sea is a fraction of what it was in the 1950s and 60s. In those years, the government of the former Soviet Union diverted so much water from the Amu Darya and Syr Darya—the regions’s two major rivers—to irrigate farmland, that it pushed the hydrologic system beyond the point of sustainability. During subsequent decades, the fourth largest lake in the world shrank to roughly a tenth of its former size and divided into several smaller bodies of water.

The image above, captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terrasatellite, shows the Aral Sea in Central Asia on August 22, 2017. While the lake was much smaller in August 2017 than it was in the 1960s, some growth in the eastern lobe of the South Aral represents an improvement over August 2014, when that lobe was completely dry.

Instead of pooling in one large basin, water flowing down the two rivers now ends up in either the North Aral Sea (fed by the Syr Darya) or the South Aral Sea (fed by Amu Darya). The Kok-Aral dike and dam, finished in 2005, separates the two water bodies and prevents flow out of the North Aral into the lower-elevation South Aral. The dam has actually led fisheries in the North Aral Sea to rebound, even as it has limited flow into the South basin.