Water, water … somewhere

Changes in global surface water distribution over the past 30 years were mapped at high-resolution in a paper published in Nature.

Researchers in Italy and Switzerland analysed more than 3,000,000 Landsat images, taken between 1984 and 2015, to quantify month-to-month changes in surface water at a resolution of 30 metres. 

Over the past 32 years, permanent surface water has disappeared from an area of almost 90,000 square kilometres, roughly equivalent to that of Lake Superior, with 70% of that loss occurring in the Middle East and Central Asia.

But they also show that new permanent surface water has formed elsewhere, covering an area about double that from which water was lost (184,000 square kilometres), and that all continental regions show a net increase in permanent water except Oceania, which experienced a 1% net loss.

The map above shows the upper stretches of the Yenisei River (Река Енисей) in Russia and captures the spatial and temporal patterns in surface water. Dark blue colours are areas of permanent water and the pink colours show areas of where water occurs less often.