关键词: 多年冻土, 活动层, 地下冰, 热融灾害, 区划

Abstract:

Qinghai-Tibet Plateau permafrost region is the largest region in low latitude regions in the world. Climate warming could leads mean annual ground temperature to rise, the ground ice to melt and permafrost to degrade, and so on. By supporting of ARCGIS software the changes of ground ice content and active layer thickness are calculated by using ground ice model and Stefan equation under different climate change scenarios. The results show that: the distribution of permafrost will not have a significant change in the next few decades but a large-scale changes will take place at the end of this century.The main permafrost degradation types are the melting of ground ice and converted the low-temperature to high-temperature permafrost. The large-scale changes will accompany with the thermal hazards such as thermokarst and thermal slump. Thermal hazards are zoned on the Qinghai-Tibet Plateau permafrost region according to the modified Nelson model. The greatest danger zone distributed in the south of the West Kunlun Mountains mainly, Middle of Qingnan Valley, and southern foot of Gangdise Mountains, Nyainqentanglha Mountains, and the Himalayas Mountains. Thermal hazards will be exacerbated in future several decades.

Key words: permafrost, active layer, ground ice, thermal hazards, zoning