Airbus Defence and Space

The shrinking Aral Sea – as witnessed by satellite

The Aral Sea, straddling Kazakhstan and Uzbekistan in Central Asia, is dying.

What was the world’s fourth largest inland body of water has been shrinking at a dramatic rate over the last 50 years, and it is now expected that by 2020 its whole southern section will disappear entirely. In 1963, the lake had an average depth of 16 metres and covered 66,457 square kilometres, but then, in what that UN’s Food and Agriculture Organisation has described as a ‘textbook example of unsustainable development’, the Soviet government decided to divert two rivers that fed the sea – Syr Darya to the north, Amu Darya to the southwest – to provide irrigation to Kazakh and Uzbek cotton farmers.

As the water flow dropped off, the Aral Sea began to dry up. By 1987, 27,000 square kilometres – an area just under the size of Belgium – were no longer covered by water, the depth had dropped to 14 metres in the parts that remained and the water’s salinity had doubled. Three years later, so much of the sea had dried up that it split into two – the Large Aral to the south and the Small Aral to the north. By 1997, the Large Aral was considered biologically dead due to the rise in salt levels. Today, a 300-kilometre radius around the sea is blighted by the 200,000 tonnes of salt and sand carried by the wind daily. Salt pollution has reduced – and continues to reduce – the area available for agriculture, destroying grazing land and poisoning the region’s inhabitants: tuberculosis and throat cancer rates are three times the national average in certain areas around the sea. While it is generally agreed that the Aral Sea will never return to its 1960s level, international efforts are now underway to stop the situation deteriorating further.

These images, taken by the European Space Agency’s eco-monitoring satellite Envisat, trace the sea’s retreat – and sound a clarion call for action.