The Tibetan Plateau and its surroundings, with an area of 5 million km2 and an average elevation of over 4000 m, are not only the source region of major Asian rivers but also hosts more than 1000 lakes with a total lake area of 46,000 km2 in its interior. During the past half century, this region experienced significant warming at a rate of 0.3-0.4 ℃ /decade, which is about twice the rate of global average.
Accompanying the warming is the moistening, wind stilling, and cryosphere degradation. These climate changes have significantly altered the water cycle in the Tibetan Plateau. In the periphery of the Plateau, the water cycle change can be observed from discharge data of large rivers. However, in its interior, there is no long-term observation of hydrology, which limits our understanding on the changes in water cycle. Nevertheless, there are more than 1000 closed lakes in the interior Tibetan Plateau. Their dynamic including water area and water level is a good indicator of regional climate and hydrological changes.
Since the 1970s, these lakes have been monitored by different satellites, which give us very important information about long-term lake area/level changes. Since the late 1990s, most closed lakes in the interior Tibetan Plateau have expanded and deepened rapidly. These changes have considerably affected the local residence, basin management and infrastructure (such as roads and bridges) planning. Causes for the lake expansion can be (1) glacier melting acceleration, as indicated by the retreating and thinning of most glaciers in the Tibetan Plateau, (2) permafrost degradation, as characterized by deepening active layer of permafrost, and (3) increasing precipitation amount. A recently publish paper provides a review on the lake dynamics in the Plateau during the past four decades and an analysis of the contribution of the main factors that are related to lake water budget.
Kindly contributed by Yanbin Lei.