South Aral Sea
A shrinking lake formed from the divided Aral Sea.
Wikipedia / Wikimedia Commons
The South Aral Sea is a lake that emerged in 1987 when the original Aral Sea split into two, a result of rivers being diverted for farming. In 2003, this southern part divided further into an eastern and a western basin, linked by a narrow channel at an elevation of 29 meters that kept water levels even but prevented mixing. A dam built on the North Aral Sea in 2005, intended to save its fisheries, cut off the only remaining water supply to the southern lakes. By 2008, the eastern basin had split again, and by May 2009 it had nearly vanished, leaving only the small, intermittent Barsakelmes Lake between the northern and western seas and expanding the Aralkum desert. Meltwater partially refilled it in 2010, but it was dry again by 2014. The West Aral Sea receives some groundwater from the Ustyurt plateau in the northwest.
The Aral Sea began shrinking in the 1960s, when the Soviet Union redirected the Amu Darya and Syr Darya rivers to irrigate cotton and food crops in Kazakhstan and Uzbekistan. By 1987, the sea had split into northern and southern parts.
In 2007, the western basin had a salinity of 70 grams per liter, and the eastern basin 100 grams per liter. If water levels drop below the connecting channel, salinities will likely diverge further. Under current conditions, the eastern basin may get water from the Amu Darya in wet years, causing salinity to fluctuate and flooding up to 4,500 square kilometers to a depth of about one meter, which would prevent any economic activity there, while the western basin grows saltier. Diverting water from the Amu Darya directly into the deeper western basin could lower its salinity enough to restart local fisheries, while letting the eastern basin dry out almost completely and avoiding flood problems.
The West Aral Sea is expected to stabilize at 2,700 to 3,500 square kilometers, with a mean depth of 14 to 15 meters and a maximum depth of 37 to 40 meters, assuming groundwater discharge of 2 cubic kilometers per year. The Eastern Sea dried up entirely in the summer of 2009, except for the small, now intermittent Barsakelmes Lake. It received some snowmelt in spring 2010 and is expected to alternate between complete summer desiccation and occasional floods from the Amu Darya or spillover from the Kokaral Dam, though a planned second dike may reduce such spillover. In 2015, the Western Sea began splitting into two as
- formed
- 1987
- split_into_eastern_and_western_basins
- 2003
- eastern_basin_salinity_2007
- 100 g/L
- western_basin_salinity_2007
- 70 g/L
- western_basin_expected_stable_area
- 2,700–3,500 km²
- western_basin_expected_mean_depth
- 14–15 m
- western_basin_expected_maximum_depth
- 37–40 m
Lore & Background
The South Aral Sea originated in 1987 when the Aral Sea split into northern and southern parts due to accelerated water loss from river diversion for irrigation. In 2003, the South Aral Sea itself divided into eastern and western basins, the Eastern Sea and the West Aral Sea, connected by a narrow channel at an elevation of 29 m that balanced surface levels but prevented mixing. In 2005, the North Aral Sea was dammed to protect its fisheries, cutting off the only remaining inflow to the southern lakes.
By 2008, the Eastern Sea split again, and in May 2009 it had almost completely dried out, leaving only the small, intermittent Barsakelmes Lake between the Northern and Western Seas and increasing the Aralkum desert. In 2010, it was partially refilled by meltwater, but by 2014 it was once again dry. The West Aral Sea receives some replenishment from groundwater in the northwest from the Ustyurt plateau.
In 2015, the Western Sea began splitting into two as the connecting channel grew skinnier, and by 2018 the split was complete. The eastern basin may receive water from the Amu Darya in wet years, fluctuating in salinity and flooding up to 4500 km² to a depth of about one meter, precluding economic activity, while the western basin becomes increasingly saline.
Reader's Guide
The South Aral Sea represents a dramatic example of anthropogenic environmental change, resulting from the diversion of the Amu Darya and Syr Darya rivers for cotton and food crop irrigation in Kazakhstan and Uzbekistan. Its formation in 1987 and subsequent fragmentation illustrate the accelerating loss of the Aral Sea, once one of the world's largest lakes. The repeated desiccation of the Eastern Sea and the expansion of the Aralkum desert highlight the ecological and economic consequences of water mismanagement, including the collapse of fisheries and the creation of a salt- and dust-prone landscape.
The West Aral Sea, sustained partly by groundwater from the Ustyurt plateau, is expected to stabilize at a reduced size, but its increasing salinity limits its utility. Proposals to divert water from the Amu Darya directly to the deeper western basin could lower salinity enough to allow fisheries to resume, while allowing the eastern basin to desiccate almost entirely and avoid flooding problems. The South Aral Sea's history serves as a cautionary tale about the long-term impacts of large-scale water diversion and the challenges of restoring degraded ecosystems.
Did You Know?
- The South Aral Sea formed in 1987 when the Aral Sea split into northern and southern parts.
- In 2003, the South Aral Sea itself split into eastern and western basins connected by a narrow channel at an elevation of 29 m.
- The Eastern Sea dried out almost completely by May 2009, leaving only the intermittent Barsakelmes Lake.
- The West Aral Sea receives some groundwater replenishment from the Ustyurt plateau.
Frequently Asked Questions
What is the South Aral Sea?
The South Aral Sea is a remnant lake that came into existence in 1987 after the original Aral Sea fractured into two separate bodies of water. Its creation was driven by the large-scale diversion of inflowing rivers toward agricultural irrigation, which starved the sea of freshwater and caused it to collapse into distinct basins.
How did the South Aral Sea split into eastern and western basins?
In 2003 the southern portion divided into an eastern and a western basin linked by a narrow channel sitting at roughly 29 meters elevation. That channel equalized water levels between the two sides but blocked any meaningful mixing, producing different salinity profiles—around 100 g/L in the east versus 70 g/L in the west by 2007.
What happened to the South Aral Sea after the 2005 dam was built?
A dam constructed on the North Aral Sea in 2005 to protect its remaining fisheries severed the last freshwater inflow feeding the southern lakes. Without that supply the eastern basin fragmented further by 2008 and had almost completely vanished by May 2009, leaving only the tiny, intermittent Barsakelmes Lake.
Why is the South Aral Sea important to study?
It stands as a stark, documented case of how upstream water-management decisions can reshape an entire ecosystem within a single generation. Its rapid shrinkage, basin fragmentation, and shifting salinity make it one of the most cited examples of anthropogenic lake loss on Earth.
What is the expected long-term future of the western basin?
Projections suggest the western basin will stabilize at roughly 2,700 to 3,500 square kilometers with a mean depth of about 14 to 15 meters. That area represents only a small fraction of the original Aral Sea, yet it is expected to persist as a permanent, highly saline water body.
More in Straits, Channels, And Seas 1-24
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