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Aral Sea Basin

Executive Committee, International Fund for saving the Aral Sea, 2010

Located in the heart of Central Asia, the Aral Sea Basin consists of the drainage area of the two major rivers, Amudarya and Syrdarya. The rivers descend from the slopes of the Tien Shan Mountains and the Pamirs. They run through Afghanistan, Tajikistan, Kyrgyzstan, Turkmenistan, Uzbekistan and Kazakhstan.


The Amudarya is in the south of the basin and has a mean annual flow of about 70-80 km3/year. The river is 2,540 km long, with a basin area of more than 300,000 km2. Most of the Amu Darya flow (74%) is formed on the territory of Tajikistan, 13.9% in Afghanistan and 8.5% in Uzbekistan.


The Syrdarya runs in the north of the basin. Its annual flow is half of the Amudarya. It is the longest river in Central Asia and ranks second with regard to water flow. It is 2,790 km long, with a basin area of almost 300,000 km2. Most of the Syrdarya flow (75.2%) is formed within Kyrgyzstan, Uzbekistan contributing 15.2%, Kazakhstan 6.9%, and Tajikistan 2.7%. 


The delta of the Amudarya is located in the northwestern part of Uzbekistan, while the delta of the Syrdarya is in the mid-western part of Kazakhstan.


Until 1960, the Aral Sea area was about 67,000 square km in size. This made the Aral Sea the world's fourth largest inland water body. Now, the Aral Sea is not a single water body any more.  Its northern part is separated by a dam and is sustained by the Syr Darya River. The remaining part is a residual water body with saline water. It comprises a shallow central part and a deeper narrow part stretching along the meridian of the Ustyurt Plateau escarpment.


For Central Asia, water is the key for development. Land has been irrigated for many centuries, with the local people enjoying a centuries-old tradition of cultivating agricultural crops in the harsh dry climate. The Soviet Union doubled the area under irrigation, from around 4 million hectares to 8 million hectares, with irrigated land becoming a major water consumer. Diversion of water for irrigation purposes accounts for more than 90% of the total intake from all water sources.

According to SIC ICWC, in 1960 the total water diversion in the Aral Sea Basin was 60.6 cubic km, while by 1994 it had grown to 116.3 cubic km. From 1960 to 2008, the basin population more than doubled to an estimated figure of almost 60 million today. Increased population and increased irrigated land, as well as deteriorating water infrastructures, have led to what is known worldwide as ‘the Aral Sea catastrophe’. This includes health problems, high rates of child mortality, desiccation of the Aral Sea, biodiversity degradation, salt-dust transport from the dry bed of the Sea, and a loss of pastures, fisheries and wetlands.


Under the current conditions the Aral Sea cannot be restored to its former level. However, there is no doubt that greater efficiency in the use and management of water could significantly improve the situation and the trend towards a complete dry-out of the Aral Sea could be reversed. 


Information about the Aral Sea Basin water resources - asb-water-resources-information.pdf [177,08 Kb] (downloads: 79)


More detailed information about the water resources use in the Aral Sea Basin, water resources management, including issues on transboundary water resources management:


Portal of Knowledge for Water and Environmental Issues in Central Asia


CARNet Environment and Sustainable Development in Central Asia and Russia 


Regional Research Network "Central Asian Water"


Regional Environmental Centre for Central Asia


GRID Arendal, UNEP


Regional Water Intelligence Report Central Asia. Baseline Report, UNDP, Stockholm International Water Institute (SIWI), 2010


Interstate Commission for Water Coordination of IFAS


Global Water Partnership of Central Asia and Caucauses


Climate Impact Assessment on water resources of Central Asia. Sectoral Report, EDB, Regional Centre of Hydrology (RCH), 2009


Climate change in Central Asia, ZOI Environment Network, 2007


International Network of Basin Organizations


UN Water

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