(TibetanReview.net, Mar09’25) – While lakes in many parts of the world have lost water over the past three decades, leading to severe droughts, the number and size of those in the northern part of the Tibetan Plateau, referred to as the “roof of the world”, have risen sharply, according to a NASA survey spanning three decades published in 2024. Researchers have examined the current and anticipated effects of these expanding lakes, warning of “widespread societal and ecological impacts”.
New images published this week by the American space agency, NASA, within the framework of its Earth Observatory program, show two different sides of a same area on the Tibetan plateau. The first image, taken on Aug 1, 1994, shows an almost desert area, with two larger lakes and another handful of small or medium lakes.
The second image, taken after 30 years on Aug 11, 2024, shows the same frame, only this time, the light brown color of the ground is splashed by an infinity of small and medium-sized lakes. The two larger lakes extend by a larger surface, and are accompanied by others also of considerable size.
The images show part of the counties of Nyima in Tibet’s Nagchu City and Qiemo in East Turkestan (under the administration of the Bayin’gholin Mongol Autonomous Prefecture, Xinjiang), said the earthobservatory.nasa.gov.
Several generations of Landsat satellites have been observing the earth from orbit. According to NASA, since the 1970s, these satellites capture images of the region every 16 days. This series of images has allowed scientists to detect this unique change in the geography of the region.
Several recent studies have verified changes in the region. In 2023, a study published in the Science magazine revealed that, in a global context in which the dominant trend was the opposite, the Tibetan Plateau lakes were accumulating water, said ruetir.com Mar 8, reporting on the NASA report.
A subsequent study, published in ISPRS Journal of Photogrammetry and Remote Sensing, was stated to have quantified this proliferation in the region. The report said the Lagos count indicated that the bodies of water of more than 0.1 km² in the region went from 4,385 units in 1991 to 6,159 in 2023. And the surface covered by lakes went from 37,471 km² to 53,267 km².
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The Tibetan plateau is stated to be an endorheic basin, with the implication that the water flowing in it does not go to the ocean. Its only output is infiltration or evaporation. For water to accumulate, therefore, it has to flow at a greater pace than evaporation.
Factors such as precipitation levels, the rate of evaporation, and the intensity of seasonal thawing of frozen soils and melting of glacial ice are thus stated to play key roles in controlling the number and size of the plateau’s lakes.
Other researchers have looked at the current and anticipated effects of these expanding lakes. One team was stated to have reported in Nature Geoscience that projected lake expansion by the year 2100 could lead to “widespread societal and ecological impacts,” noting that hundreds of kilometers of roads, hundreds of settlements, and 10,000 square kilometers of grasslands, wetlands, and croplands could be submerged.
“The dramatic increases in lake area are flooding people’s homes, displacing livestock, and making some glacial lakes vulnerable to outburst flooding,” Fangfang Yao, a researcher at the University of Colorado Boulder and lead author of the study in Science, has said.
“The Tibetan Plateau is a very remote, harsh environment. Satellites like Landsat are the only way to observe changes across numerous lakes and long time periods.”