Numeric simulation of permafrost degradation in the eastern Tibetan Plateau

Rates of permafrost degradation at both the permafrost table and the base of permafrost were simulated using a prescribed rate of increase in mean annual air temperatures of 0.04°C/a for a site in continuous permafrost near Changshitou Mountain, eastern Tibetan Plateau. The results indicate that over 110 years, the permafrost table descends from a depth of 1.20 m to 1.48 m, and that the base of permafrost rises from the initial value of 55.0 m to 15.2 m. The predicted rate of basal permafrost degradation in low moisture content bedrock reaches a peak of 0.58 m/a after 60 years, assuming a constant thermal gradient at the base of 0.018°C/m. The permafrost is persistent due to the ice‐rich nature of the near‐surface soil layers. Copyright © 2008 John Wiley & Sons, Ltd.