Shrinking Aral Sea

In the 1960s, the Soviet Union undertook a major water diversion project on the arid plains of Kazakhstan, Uzbekistan, and Turkmenistan. The region’s two major rivers, fed from snowmelt and precipitation in faraway mountains, were used to transform the desert into fields for cotton and other crops.

Although irrigation made the desert bloom, it devastated the Aral Sea. This series of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite documents the changes throughout the past decade. At the start of the series in 2000, the lake was already a fraction of its 1960 extent (black line). The Northern Aral Sea (sometimes called the Small Aral Sea) had separated from the Southern (Large) Aral Sea. The Southern Aral Sea had split into eastern and western lobes that remained tenuously connected at both ends.

By 2001, the southern connection had been severed, and the shallower eastern part retreated rapidly over the next several years. Especially large retreats in the eastern lobe of the Southern Sea appear to have occurred between 2005 and 2009, when drought limited and then cut off the flow of the Amu Darya. Water levels increased in 2010 after the drought broke and then began to dwindle again in 2011.

In a last-ditch effort to save some of the lake, Kazakhstan built a dam between the northern and southern parts of the Aral Sea. Completed in 2005, the dam was basically a death sentence for the southern Aral Sea, which was judged to be beyond saving. All of the water flowing into the desert basin from the Syr Darya now stays in the Northern Aral Sea. Between 2005 and 2006, the water levels in that part of the lake rebounded significantly and very small increases are visible throughout the rest of the time period. The differences in water color are due to changes in sediment.