The aral sea

Irrigation canals

Further information: Great Plan for the Transformation of Nature

Cotton picking near Kyzyl-Kala, Karakalpakstan.

Timeline of shrinking

Satellite images show the changing water levels in the Aral Sea from 2000 to 2018.

In the early 1960s, as part of the Soviet government plan for cotton, or "white gold", to become a major export, the Amu Darya river in the south and the Syr Darya river in the east were diverted from feeding the Aral Sea to irrigate the desert in an attempt to grow cotton, melons, rice and cereals. This temporarily succeeded, and in 1988, Uzbekistan was the world's largest exporter of cotton. Cotton production is still Uzbekistan's main cash crop, accounting for 17% of its exports in 2006.

Large scale construction of irrigation canals began in the 1930s and was greatly increased in the 1960s. Many canals were poorly built, allowing leakage and evaporation. Between 30 and 75% of the water from the Qaraqum Canal, the largest in Central Asia, went to waste. It was estimated in 2012 that only 12% of Uzbekistan's irrigation canal length was waterproofed. Only 28% of interfarm irrigation channels, and 21% of onfarm channels have anti-infiltration linings, which retain on average 15% more water than unlined channels. Only 77% of farm intakes have flow gauges.

By 1960, between 20 and 60 km3 (4.8 and 14.4 cu mi) of water each year was going to the land instead of the Aral Sea and the sea began to shrink. From 1961 to 1970, the Aral's level fell an average of 20 cm (7.9 in) per year. In the 1970s the rate nearly tripled to 50–60 cm (20–24 in) per annum, and in the 1980s to 80–90 cm (31–35 in) per annum. The amount of water taken for irrigation from the rivers doubled between 1960 and 2000. In the first half of the 20th century prior to the irrigation, the sea's water level above sea level held steady at 53 m. By 2010 the large Aral was 27 m and the small Aral 43 m above sea level.

The disappearance of the lake was no surprise to the Soviets, they expected it to happen long before. As early as 1964, Aleksandr Asarin at the Hydroproject Institute pointed out that the lake was doomed, explaining, "It was part of the five-year plans, approved by the council of ministers and the Politburo. Nobody on a lower level would dare to say a word contradicting those plans, even if it was the fate of the Aral Sea."

The reaction to the predictions varied. Some Soviet experts apparently considered the Aral to be "nature's error", and a Soviet engineer said in 1968, "it is obvious to everyone that the evaporation of the Aral Sea is inevitable." On the other hand, starting in the 1960s, a large-scale project was proposed to redirect part of the flow of the rivers of the Ob basin to Central Asia over a gigantic canal system. Refilling of the Aral Sea was considered one of the project's main goals. However, due to its staggering costs and the negative public opinion in Russia proper, the federal authorities had abandoned the project by 1986.

From 1960 to 1998, the sea's surface area shrank by 60%, and its volume by 80%. In 1960, the Aral Sea had been the world's fourth-largest lake with an area of 68,000 km2 (26,000 sq mi) and a volume of 1,100 km3 (260 cu mi). By 1998, it had dropped to 28,687 km2 (11,076 sq mi) and eighth largest. Its salinity increased, by 1990 it was at 376 g/L. (By comparison, seawater is typically 35 g/L, and the Dead Sea between 300 and 350 g/L.)

In 1987, the lake split into two separate bodies of water, the North Aral Sea (the Lesser Sea, or Small Aral Sea) and the South Aral Sea (the Greater Sea, or Large Aral Sea). In June 1991, Uzbekistan gained independence from the Soviet Union. Craig Murray, UK ambassador to Uzbekistan in 2002, attributes the shrinkage of the Aral Sea in the 1990s to president Islam Karimov's cotton policy. The enormous irrigation system was massively wasteful, crop rotation was not used, and huge quantities of pesticides and fertilizer were applied. The runoff from the fields washed these chemicals into the shrinking sea, creating severe pollution and health problems. As demand for cotton increased the government applied more pesticides and fertilizer to the monoculture and depleted soil. Forced labor was used and profits siphoned off by the powerful and well-connected.

In 2003, the South Aral further divided into eastern and western basins. The waters in the deepest parts of the sea were saltier and not mixing with the top waters, so only the top of the sea was heated in the summer and it evaporated faster than had been predicted. A plan was announced to recover the North Aral Sea by building Dike Kokaral, a concrete dam separating the two halves of the Aral Sea.

In 2004, the sea's surface area was 17,160 km² (6,630 sq mi), 25% of its original size, and a nearly fivefold increase in salinity had killed most of its flora and fauna. Dike Kokaral was completed in 2005 and, as of 2006, some recovery of sea level had been recorded