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

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 degrees-50 degrees 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.