The demise of the Aral Sea in central Asia was caused primarily by the diversion of the inflowing Amu Dar’ya and Syr Dar’ya rivers to provide irrigation water for local croplands. These diversions dramatically reduced the river inflows, causing the Aral Sea to shrink by more than 50%, to lose two-thirds of its volume, and to greatly increase its salinity. At the current rate of decline, the Aral Sea has the potential to disappear completely by 2020 (Pidwirny, 1999).
In 1963, the surface of the Aral Sea measured 66,100 km2, with an average depth of 16 m and a maximum depth of 68 m. The salt content was 1%. During the 1960s, upstream irrigation schemes for growing rice and cotton consumed 90% of the natural flow of water from the Tian Shan Mountains.
By 1987, 27,000 km2 of former sea bottom of the Aral Sea had become dry land; about 60% volume had been lost, its depth had declined by 14 m, and its salt concentration had doubled.
Today, about 200,000 tonnes of salt and sand are carried by the wind from the Aral Sea region every day, and dumped within a 300 km radius. The salt pollution is decreasing the available agriculture area, destroying pastures, and creating a shortage of forage for domestic animals. The number of domestic animals in the region has become so low that the government has issued a decree to reduce the slaughter of animals for food.
Fishing in the Aral Sea has ceased completely, while shipping and other water-related activities have declined; the associated economic changes have taken a heavy toll on agricultural production. Rising unemployment has led to a major exodus from the region. In Aralsk Rayon, for example, the population has dropped from 82,900 to 72,500 people in the past 10 years (Okda, 2001).
The quality of drinking water has continued to decline due to increasing salinity, bacteriological contamination, and the presence of pesticides and heavy metals.
Diseases like anaemia, cancer and tuberculosis, and the presence of allergies, are on the rise. The incidence of typhoid fever, viral hepatitis, tuberculosis and throat cancer is three times the national average in some areas (DLR, 2002; LEAD, 1997; Okda, 2001).
Recent measures have been taken to change this disastrous state, through the International Fund for Saving the Aral Sea (UNEP, GRID Arendal, IFAS, 1997). If all measures are adhered to, a substantial recovery might be achieved within 20 years, although it is doubtful that the Aral Sea will ever be restored to the conditions that existed before the large-scale diversion of its inflowing rivers.