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Permafrost in the Qinghai-Tibet Plateau (QTP) is highly sensitive to climate change, but its evolution over past century remains unclear. Based on the QTP climate change analysis since the 20th century, our study employed machine learning technique with field observations to construct permafrost simulation models, clarify its evolution processes, and reveal its changes on vertical zonation and sunny-shady slope distribution under climate warming. The results indicated that the QTP air temperature trends included initial warming (1900-1940 s, 0.13 degrees C/10a), cooling (1950-1960 s, - 0.20 degrees C/10a), and warming again (1970s to 2010s, 0.21 degrees C/10a). Precipitation patterns showed a slight decrease (- 0.33 mm/10a), rapid decrease (- 6.75 mm/10a), and gradual increase (6.57 mm/10a). Correspondingly, significant permafrost changes were recorded during the periods of 1900s, 1940s, 1960s, and 2010s, with the permafrost areas of 1.28, 1.19, 1.30, and 1.10 x 106 km2, respectively, and average mean annual ground temperature (active layer thickness) were - 2.82 +/- 1.93 degrees C (1.89 +/- 0.72 m), - 2.58 +/- 1.91 degrees C (2.21 +/- 0.78 m), - 2.86 +/- 1.94 degrees C (2.10 +/- 0.79 m), and - 2.26 +/- 1.72 degrees C (2.23 +/- 0.75 m) (mean +/- standard deviation), respectively. The southern Qiangtang Plateau and Three Rivers Source region exhibited significant permafrost changes during both the warming and cooling stages. Climate warming over the past 50 years has raised the average permafrost distribution altitude by 43 m, and accelerated its degradation on sunny slopes. These findings exhibit new knowledges on the QTP permafrost evolution and provide scientific references for permafrost degradation research under climate warming.

来源平台：CLIMATE DYNAMICS