NRW105: 7.5 Aral Sea Environmental Disaster

Overview of the Aral Sea

• The Aral Sea is located east of the Caspian Sea between Uzbekistan and Kazakhstan in Central Asia.
• It lies within the Turkestan desert, the world's fourth largest desert, formed by Afghanistan's mountains creating a rain shadow.
• The climate is arid and seasonally hot, leading to significant evaporation.
• Summer temperatures can reach up to 60°C (140°F).
• The primary water sources were the Amu Darya and Syr Darya rivers, fed by snowmelt from mountainous regions.

Diversion of Rivers

• In the early 1960s, the Soviet Union diverted the Amu Darya and Syr Darya rivers to irrigate dry areas for the production of rice, melons, cereals, and especially cotton.
• The Soviets aimed to make cotton a major export.
• Uzbekistan is now one of the world's largest cotton exporters.
• The diversion essentially stopped river inflow to the Aral Sea, leading to its near disappearance.

Shrinking of the Aral Sea

• In 1960, the Aral Sea was the fourth largest inland water body, after the Caspian Sea, Lake Superior, and Lake Victoria.
• It has shrunk progressively due to evaporation and lack of river recharge.
• Before 1965, it received 2060 km³ of fresh water annually, but by the early 1980s, this ceased.
• By 2007, the Aral Sea had shrunk to about 10% of its original size.

Environmental Impact

• Salinity increased from about 1% to 10% dissolved salt, making it three times saltier than seawater.
• The once-thriving fishing industry collapsed, and 24 fish species could not adapt to the increased salinity and died.
• Shorelines are now tens of kilometers away from former fishing towns and ports, with fishing boats stranded in dried-up lakebeds.
• Irrigation canals were poorly constructed, leading to water leakage and evaporation.
• An increasing number of dust storms carry salt, pesticides, and herbicides into nearby towns, causing respiratory illnesses, including tuberculosis.

Consequences and Restoration Efforts

• Wetlands of the river deltas and associated ecosystems have disappeared.
• The regional climate became drier with greater temperature extremes because of the reduced moisture.
• In 2003, restoration work began in the northern part of the Aral Sea, raising water levels and reducing salinity.
• The southern part has not seen any relief and remains nearly completely dry.
• The destruction of the Aral Sea is considered one of the planet’s biggest environmental disasters, caused entirely by humans.
• Other lakes affected: Lake Chad, the Dead Sea, Lake Manchar, and Owens and Mono Lakes.