Modeling Regional and Local-scale Permafrost Distribution in Qinghai-Tibet Plateau Using Equivalent-elevation Method

Key words: 
• equivalent-elevation method /
• permafrost distribution /
• permafrost lower limit (PLL) /
• Gaussian curve /
• platform function /
• Qinghai
  -Tibet Plateau

Abstract: This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional
and local-scale permafrost distribution in the Qinghai-Tibet Plateau, and to model the general permafrost-distribution patterns in regional
and local-scale area. It is found that the Gaussian curve―an empirical model describing the relation between variations of altitudinal
permafrost lower limit (PLL) and latitude in the Northern Hemisphere―could be applied in regional- and local-scale areas in the Qinghai-
Tibet Plateau in a latitude-sensitive interval of 30°–50°N. The curve was then used to evaluate the latitudinal effect on permafrost
distribution through transforming the latitudinal effect into a kind of altitudinal difference of PLL. This study then calculated the local
equivalent-elevation value by overlaying the altitudinal difference of PLL onto real elevation at a certain location. The equivalent-
elevation method was verified in an experimental subwatershed of the Qinghai-Tibet Plateau. However, feasibility of the method should be
further tested in order to extend for future studies. The use of equivalent-elevation values can build a platform for comparing the regional
general permafrost distribution in the plateau, and for basing further evaluations of local factors′ effects on regional permafrost
distribution.