17 January 2019

Tibetan lakes as indicator of climate change

The Tibetan Plateau is the site of gigantic lakes that inexplicably and rapidly change in size and volume. Many of these lakes are isolated and are therefore a perfect indicator of climate change. Hydrologists at Utrecht University have received a grant from NWO to conduct research using satellite images, models and measurements to discover which processes cause these changes.

Lake Puma Yumco is 32 km long and covers an area of 280 km2. Image: NASA

The Tibetan Plateau plays an essential part in supplying water to the main Asian river systems. It is the largest and highest mountain plateau in the world and is therefore the driving force behind the Asian monsoon and various other global circular processes. The plateau is suffering greatly due to climate change, which is causing an imbalance in the water cycle and therefore in the lives of millions of people.

Fluctuations in water volume

The gigantic lakes – dozens of kilometres in diameter – on the Tibetan Plateau are not connected to the river systems and yet they are subject to enormous fluctuations in water volume. Because of the lakes’ isolated position, these fluctuations can only be explained by climate change, which makes them a perfect indicator of such change.

Ambitious plan

Hydrologists Dr Walter Immerzeel and Prof Marc Bierkens of Utrecht University are keen to discover the driving forces behind these fluctuations in water level. To do so, they are examining changes in precipitation and evaporation and the increased rate at which glaciers and the permafrost are melting. They combine satellite images with measurement data from Tibet and computer models. “New satellite data and powerful computer models enable us to put our ambitious plan into action,” says Immerzeel. “Never before has it been possible to integrate all these techniques in this smart way. This innovative approach ensures that we can gain a better understanding of what the drivers are for these types of major climate-related changes. Our findings will also be able to be applied to other high, cold areas all over the world.”