Saltwater, endorheic, relic lake.
Once the fourth largest lake in the world, located on Turan Basin in Central Asia on the border of Kazakhstan and Uzbekistan. Since the second half of 20th century as a result of shifting feeding rivers Amu Darya and Syr Darya the lake has been losing its area and water leading to an environmental disaster on an unprecedented scale.
The climate in the Aral Sea area is continental and very dry with high amplitude of temperatures, with cold winter and hot summer. Scanty rainfall, with sum of about 100mm a year, only slightly compensates evaporation. The main factors determining the water balance are feeding by rivers and evaporation which formerly had equal value.
In the ‘60s water table of the Aral Sea was 53 meters above sea level, and the lake covered 68 thousand square kilometers. The sea stretched on about 435 km in the North-South axis and about 290 km in the East-West axis. The average depth was 16 meters, and the depth in the deepest places came up to 69 meters.
Due to numerous islands the lake was called Aral Sea, which in the language of the indigenous people means "sea of Islands".
Aral Sea Disapperance
Since about ‘60s the Aral Sea water level has begun to decreased systematically and dramatically. It was caused by returning the rivers Amu Darya and Syr Darya for fields irrigation purposes. The Soviet Union authorities changed wastelands of Uzbekistan, Kazakhstan and Turkmenistan into farmlands. As a result of these measures the amount of water reaching the lake constantly decreased. From the ‘80s during summer months Amu Darya and Syr Darya dried up before they reached the lake, which left with no feeding rivers began to shrink.
At the end of the 80s the Aral Sea split into two parts creating „Large Aral” on the South and „Small aral” on the North. Each of the lakes had salinity three times higher than in the 50s.
In 1992 the total area of both lakes shrank to about 33,8 thousand square kilometers, and water lever lowered by 15 meters.
Governments of Central Asia counties tried to introduce water saving agriculture policy to let more water from Amu Darya and Syr Darya and stabilize water level of the Aral Sea. The policy resulted in a reduction of water consumption but it wasn’t enough to affect the amount of water flowing into the lake.
In 1994 Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan created a common committee to manage efforts to save the Aral Sea. Unfortunately, difficulties in coordinating any projects between the member countries prevented progress.
At the turn of the Millennium the Aral Sea split into three separate lakes. "Large Aral" split into narrow West Lake and bigger East Lake, while the “Small Aral” remained on the North. The volume of water dropped by three quarters in relation to 1960. Waters of the Amu Darya and Syr Darya didn’t reach the remains of the lake.
At the beginning of the 21st century the eastern part of the Lake has experienced the most violent disappearance reducing by 4/5 between 2006 and 2009.
With the World Bank financing the barrier protecting the northern part of the Lake, a total loss of its southern part is expected by 2020.
Effects of the Aral Sea Disappearance
The rapid disappearance of the Aral Sea has led to many environmental problems in the region. In the late ‘80s the Lake lost more than half its volume. For this reason, drastically increased the concentration of salts and minerals in the water, leading to the extinction of the once rich fauna in the region and, in particular, many species of fish.
Fishing industry, which the region was famous for, was virtually destroyed. Ports - Aralsk in the North and Muynak in the South – are now many kilometers from the shore. Along with the economic degradation the region suffered a gradual depopulation.
Disappearance of the Aral Sea has led to a noticeable tightening of the climate and an increase in the amplitude of temperature.
In the late 1990s Rebirth Island became the main concern. At that time only 10 km of water separated the island from the mainland. Increasing availability of the island represented a particular problem because Rebirth Island was a Center for research on biological weapons during the cold war. The island was also used to store hundreds of tons of anthrax bacteria, which still alive was discovered there in the 1990s. Scientists feared that the connection of the island with the mainland will enable the spread of anthrax on inhabited areas.
Living conditions in the region started to significantly deteriorate. The community of Karakalpaks living in the area on the South of the Aral Sea suffered the most.
Discovered bottom of the Lake is a source of sand storms spreading all over the region, carrying toxic dust containing salts, fertilizers and pesticides.
The result of abovementioned toxins are health problems occurring on an unprecedented scale – from larynx cancer to anemia and kidney diseases. Also infant mortality in the region belongs to the world's most significant.
Dust from the Aral Sea was also discovered in glaciers of Antarctica, which is a proof of the huge impact of the disappearance of the Lake on the global ecosystem.