The influence of mountain topography on the evolution of alpine permafrost was studied under Southern Yakutia conditions using a two-dimensional finite difference thermal model. The altitudinal zonality in the mean annual ground surface temperature distribution and the spatial heterogeneity of thermal properties and water content of rocks were included in the model. It has been recognized that 100 Kyr, 33 Kyr, 1.5 Kyr and 208 years’ oscillation periods affect permafrost thickness’ dynamics. Following modeling results has demonstrated that the permafrost in the valley depression is more stable than the one on the watershed. During the warm periods in the Holocene, the open taliks were periodically developed in this region on mountaintops and upland plateaus. During the cold periods permafrost developed in the divides as well as in the valleys. The actual taliks arose in this region at the end of historical period. The surface waters sink into these taliks during the summertime and enlarge ground water resources and river water discharge during the winter. This also has a significant impact on portioning precipitations between evaporation and ground water discharge. Further climate warming and related permafrost degradation will substantially increase the area of taliks distribution in the Southeast part of the Lena River basin.
Alpine permafrost, permafrost thickness, talik, ground water, climate change, numerical modeling