Terrestrial water storage in the Tibetan Plateau shows spatial differences: study

Regional averaged terrestrial water storage in the Tibetan Plateau has increased during the years from 2002 to 2012, and then declined since then, a recent study showed.

The study, based on Gravity Recovery and Climate Experiment (GRACE) data of terrestrial water storage (TWS) across the Tibetan Plateau from April 2002 to December 2016, found that regional averaged TWS has increased by 0.20 mm per month during the 2002–2012 period, but decreased by 0.68 mm per month from May 2012 to December 2016.

TWS is defined as vertically integrated water of all forms above and below the Earth’s surface, including surface water, soil moisture, groundwater, and snow and ice. It is not only a key control of global water, energy, and biogeochemical cycles but also provides an integrated indicator of water availability and uses.

TWS variations in the TP also showed significant spatial differences. “A declining trend was clearly evident in the seasonal variability of TWS anomalies in the south Tibetan Plateau, but increasing in the inner Plateau,” said CHEN Yaning, leading researcher of the study from Xinjiang Institute of Ecology and Geography of the Chinese Academy of Sciences.

Global warming in the recent decades has seen glacial recession in the Tibetan Plateau, melting of snowpack, and deepening of tundra active layer. “Glacial retreat and lake area expansion explain the spatial differences in TWS,” said CHEN.

Precipitation increases and lake area expansion drove increasing TWS in the Inner Tibetan Plateau during the 2002–2016 period; temperature increases and glacial retreat drove decreasing TWS in southern Plateau, according to the study.

Results of the study were published on Climatic Change, entitled “Understanding the spatial differences in terrestrial water storage variations in the Tibetan Plateau from 2002 to 2016”.

Contact: LIU Jie, Xinjiang Institute of Ecology and Geography

E-mail: liujie@ms.xjb.ac.cn