Numerous Simulation of Permafrost Degradation under the Influence of Thaw Lake on the Qinghai-Tibet Plateau
详细信息
- 责任者：Lin Zhanju (State Key Laboratory of Frozen Soil Engineering ; Research Institute of Cold and Arid Regions Environmental and Engineering ; Chinese Academy of Sciences ; Lanzhou 730000 ; China) ; Niu Fujun
- 刊名：Acta Geologica Sinica
- 出版年：2013
- 卷期：87(5)
- 关键词：多年冻土 ; permafrost ; 青藏高原 ; Qinghai-Tibetan Plateau
- 页码：p.737-746
- 图表：illus., 5 tables, 15 refs.
- 分类号：1400
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
Under rectangular coordinate system, a heat transfer model with phase change was used to predict the influence of thaw lake on permafrost degradation in the Beiluhe Basin on the Qinghai-Tibet Plateau.The results show that the presence of a water body constitutes a heat source and releases heat energy to the permafrost beneath and around lake,giving rise to the significant changes in ground temperature regime.For the same deep lakes, the mean annual lake-bottom temperature is one of the important factors that decide whether the lake has impacted on the permafrost.The higher annual average lake-bottom temperature occurs at the lake-bottom, the more obviously thermal disturbance may happen in permafrost beneath and around it. When the mean annual lake bottom temperature equals to 0℃, talik (perennial thaw layer) is impossible occurrence beneath and around lake-bottom, however the ground temperatures would gradual increase. When the mean annual lake bottom temperature is higher than 0℃, temperature of permafrost will increase and upper limit will decrease. Talik will develop, finally resulting in the thawing of the permafrost. The higher temperature at the lake-bottom, the quicker ground temperature increases in permafrost, and the shorter the time for the permafrost to melt. Under conditions of the same annual mean temperatures at bottom of the lake, difference of water depths has no distinct influence on the permafrost degradation.