LHASA, May 9 (Xinhua) -- Scientists have identified three distinct periods over the past four decades that feature notably different variations of lake area and volume on the Qinghai-Tibet plateau.

Zhang Guoqing, a researcher with the Chinese Academy of Sciences (CAS) Center for Excellence in Tibetan Plateau Earth Sciences, was part of a team of domestic and foreign scientists that examined annual changes in lake area, level and volume from 1970s to 2015.

The team found that the three indexes changed at similar rates. They saw a slight decline from 1970s to 1995, followed by a rapid increase from 1996 to 2010, and then a recent deceleration during the period from 2011 to 2015.

They also found that increased precipitation contributed the most to lake volume increases, followed by glacier mass loss and the melting of ground ice due to permafrost degradation.

These results suggest that the hydrological cycle on the plateau has intensified remarkably during recent decades.

The study was published in the U.S. journal Geophysical Research Letters on May 2.