巴颜喀拉山是较典型的高海拔多年冻土区。南、北坡迥异的气候、土壤及地表景观控制和影响其多年冻土空间分布。2008~2012年冻土调查及测温资料表明,该山以高温冻土(〉-1℃)为主。海拔是冻土主要影响因素。年均地温随海拔升高而降低的高程递减率在北坡6℃/km,南坡4℃/km。北坡查拉坪及巴颜喀拉山口一带,活动层厚度约1m,活动层随海拔降低而增厚;南坡活动层厚度受局地因素影响较大,与海拔无明显相关。
Permafrost on the Qinghai-Tibet Plateau (QTP) is elevational, where the permafrost accounts for approximately 75% of the elevational permafrost in the Northrn hemisphere. Located in the transition zone from the Qinghai-Tibet Plateau higher than 4 500 m a. s. 1. to the Loess Plateau at less than 2 000 m a. s. 1., the Bay- an Har Mountains (BHM) have typical alpine permafrost. The intensive uplifts of the BHM have resulted in a great variety in climate, permafrost and landscapes on the north and south slopes. Based on field investigations and ground temperature measurements between 2008-2012, the distributive features and controlling/influenc- ing factors of permafrost in the BHM are revealed in detail in this paper. Most permafrost in the BHM is warm (〉-1 ~C), except that at some mountain tops such as Chalaping and the Bayan Har Mountain Pass. The ground temperature in the BHM is principally controlled by elevations. The lowest MAGT of-l.8℃ and the thickest permafrost of 74 m are found at Chalaping higher than 4 700 m a. s. 1. The lapse rate of MAGT with rising elevation is 6℃/kin on the north slopes and 4℃/kin on the south slopes, respectively. The MAGTs are -0.2℃ in Borehole YNG-1 at the north-slope toes, and +0.3℃ in Borehole QSH-1 at the south-slope toes. Permafrost thins rapidly downwards at both slope toes. The MAGTs are lower than -0.5 ℃ at elevations above 4 570 m a. s. 1. on the south slopes and above 4 527 m a. s. 1. on the north slopes. The MAGTs are lower.than -1 ℃ at eleva- tions above 4 670 m a. s. 1. on the south slopes and above 4 615 m a. s. 1. on the north slopes. The zone boundaries of-0.5℃ in mean annual ground temperatures largely coincide with the lower limits of sporadic (discontinuous) permafrost, and zone boundaries of-1 ℃ correspond to the lower limits of continuous permafrost. The active layer thickness, which usually affected by the lithology (soil types) and moisture conditions, is about 1 m at the Bayan Har Mountain Pass and Chalaping on the n