The Vegetation instruments on Spot-4 and Spot-5 have been performing monitoring of Earth's land surfaces since 1998, capable of tracking long-term trends such as the drying up of Asia's inland Aral Sea. The Aral Sea was once the world’s fourth-largest inland body of water, but it has been steadily shrinking over the past 50 years since the rivers that fed it were diverted for irrigation projects.
By the end of the 1980s, it had split into the Small Aral Sea (north), located in Kazakhstan, and the horse-shoe shaped Large Aral Sea (south), shared by Kazakhstan and Uzbekistan. The sea’s entire southern section is expected to dry out completely by 2020, but efforts are underway to save the northern part.
By 2000, the Large Aral Sea had split into two – an eastern and western lobe. As the Aral Sea evaporated, it left behind a 40 000 sq km zone of dry, white salt terrain now called the Aral Karakum Desert. Each year violent sandstorms pick up at least 150 000 tonnes of salt and sand from the Aral Karakum and transport it across hundreds of km, causing severe health problems for the local population and making regional winters colder and summers hotter. In an attempt to mitigate these effects, vegetation that thrives in dry, saline conditions is being planted in the former seabed.