Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau
文献类型：期刊论文
| 作者 | Wu JiChun; Sheng Yu; Wu QingBai; Wen Zhi |
| 刊名 | SCIENCE CHINA-EARTH SCIENCES
 |
| 出版日期 | 2010 |
| 卷号 | 53期号:1页码:150-158 |
| 关键词 | Qinghai-Tibet Plateau permafrost degradation process degradation stage degradation mode |
| ISSN号 | 1674-7313 |
| DOI | 10.1007/s11430-009-0198-5 |
| 通讯作者 | Sheng Yu(sheng@lzb.ac.cn) |
| 英文摘要 | Climate warming must lead the mainly air temperature controlled permafrost to degrade. Based on the numerical simulation, the process of permafrost degradation can be divided into five stages, i.e., starting stage, temperature rising stage, zero geothermal gradient stage, talic layers stage, and disappearing stage, according to the shape of ground temperature profile. Permafrost on the Qinghai-Tibet Plateau (QTP) is generally considered a relic from late Pleistocene, and has been degenerating as a whole during Holocene. According to spatial-temporal compensation, the present thermal state discrepancy of permafrost in different areas on the QTP may correspond with their degradation stages. On the QTP, permafrost in the high and middle mountains belongs to temperature rising stage, the permafrost thermal state is transiting from late rising temperature stage to zero geothermal gradient stage that is distributed in the middle-low-mountains. Permafrost that is in a zero gradient stage mainly appears in the high plateau and valley, whereas the transition from zero gradient stage to talic layers stage of permafrost is located in the vicinity of the lower limit of permafrost, and permafrost is disappearing from margin of perennially frozen ground. There are two modes of perennially frozen ground thawing, thawing from top to bottom and thawing from bottom to top respectively. During the temperature rising stage, when the heat flux in the perennially frozen soil layer is less than that in the unfrozen soil underlying frozen soil layer, the geothermal flux is partly used to thaw the base of permafrost, and permafrost thaws from bottom to top. With the decrease of thermal gradient in the perennially frozen ground, the heat that is used to thaw permafrost base increases, and geothermal heat will be entirely consumed to thaw the base of permafrost until the temperature gradient reaches zero thermal gradient state. On the other hand, the disappearance of permafrost may be delayed by "thermal offset" and "seasonal offset" effects in the upper of permafrost layer. When ground surface temperature rises to the level that can counteract the thermal offset effect, heat accumulation in the active layer would start, and the thickness of the active layer increases until a talic layer to appear. This process can be intensified by the "seasonal anti-offset effect". |
| 收录类别 | SCI |
| WOS关键词 | CLIMATE-CHANGE ; HIGHWAY ; CHINA ; PREDICTION ; RAILWAY ; GEOLOGY |
| WOS研究方向 | Geology |
| WOS类目 | Geosciences, Multidisciplinary |
| 语种 | 英语 |
| WOS记录号 | WOS:000276546600015 |
| 出版者 | SCIENCE PRESS |
| URI标识 | http://www.irgrid.ac.cn/handle/1471x/2556349 |
| 专题 | 寒区旱区环境与工程研究所 |
| 通讯作者 | Sheng Yu |
| 作者单位 | Chinese Acad Sci, State Key Lab Frozen Soil Engn, Cold & Arid Reg Environm & Engn Res Inst, Lanzhou 730000, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wu JiChun,Sheng Yu,Wu QingBai,et al. Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau[J]. SCIENCE CHINA-EARTH SCIENCES,2010,53(1):150-158. |
| APA | Wu JiChun,Sheng Yu,Wu QingBai,&Wen Zhi.(2010).Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau.SCIENCE CHINA-EARTH SCIENCES,53(1),150-158. |
| MLA | Wu JiChun,et al."Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau".SCIENCE CHINA-EARTH SCIENCES 53.1(2010):150-158. |
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来源：寒区旱区环境与工程研究所
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