Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway
文献类型:期刊论文
作者 | Jin Huijun; Zhao Lin; Wang Shaoling; Jin Rui |
刊名 | SCIENCE IN CHINA SERIES D-EARTH SCIENCES
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出版日期 | 2006-11-01 |
卷号 | 49期号:11页码:1170-1183 |
关键词 | QTP QTH permafrost ground temperatures degradation modes geothermal gradients |
ISSN号 | 1006-9313 |
DOI | 10.1007/s11430-006-2003-z |
通讯作者 | Jin Huijun(hjjin@lzb.ac.cn) |
英文摘要 | Permafrost on the Qinghai-Tibet Plateau (QTP) is widespread, thin, and thermally unstable. Under a warming climate during the past few decades, it has been degrading extensively with generally rising ground temperatures, the deepening of the maximum summer thaw, and with lessening of the winter frost penetration. The permafrost has degraded downward, upward and laterally. Permafrost has thinned or, in some areas, has totally disappeared. The modes of permafrost degradation have great significance in geocryology, in cold regions engineering and in cold regions environmental management. Permafrost in the interior of the QTP is well represented along the Qinghai-Tibet Highway (QTH), which crosses the Plateau through north to south and traverses 560 km of permafrost-impacted ground. Horizontally, the degradation of permafrost occurs more visibly in the sporadic permafrost zone in the vicinity of the lower limit of permafrost (LLP), along the margins of taliks, and around permafrost islands. Downward degradation develops when the maximum depth of seasonal thaw exceeds the maximum depth of seasonal frost, and it generally results in the formation of a layered talik disconnecting the permafrost from the seasonal frost layer. The downward degradation is divided into four stages: 1) initial degradation, 2) accelerated degradation, 3) layered talik and 4) finally the conversion of permafrost to seasonally frozen ground (SFG). The upward degradation occurs when the geothermal gradient in permafrost drops to less than the geothermal gradients in the underlying thawed soil layers. Three types of permafrost temperature curves (stable, degrading, and phase-changing transitory permafrost) illustrate these modes. Although strong differentiations in local conditions and permafrost types exist, the various combinations of the three degradation modes will ultimately transform permafrost into SFG. Along the QTH, the downward degradation has been proceeding at annual rates of 6 to 25 cm, upward degradation at 12 to 30 cm, and lateral degradation in the sporadic permafrost zone at 62 to 94 cm during the last quarter century. These rates exceed the 4 cm per year for the past 20 years reported for the discontinuous permafrost zone in subarctic Alaska, the 3 to 7 cm per year reported in Mongolia, and that of the thaw-stable permafrost in subarctic Yakutia and Arctic Alaska. |
收录类别 | SCI |
WOS研究方向 | Geology |
WOS类目 | Geosciences, Multidisciplinary |
语种 | 英语 |
WOS记录号 | WOS:000242923300005 |
出版者 | SCIENCE CHINA PRESS |
URI标识 | http://www.irgrid.ac.cn/handle/1471x/2555814 |
专题 | 寒区旱区环境与工程研究所 |
通讯作者 | Jin Huijun |
作者单位 | 1.Chinese Acad Sci, State Key Lab Frozen Soils Engn, Cold & Arid Reg Environm & Engn Res Inst, Lanzhou 730000, Peoples R China 2.Chinese Acad Sci, Cryosphere Stn Qinghai Tibet Plateau, Cold & Arid Reg Environm & Engn Res Inst, Lanzhou 730000, Peoples R China |
推荐引用方式 GB/T 7714 | Jin Huijun,Zhao Lin,Wang Shaoling,et al. Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway[J]. SCIENCE IN CHINA SERIES D-EARTH SCIENCES,2006,49(11):1170-1183. |
APA | Jin Huijun,Zhao Lin,Wang Shaoling,&Jin Rui.(2006).Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway.SCIENCE IN CHINA SERIES D-EARTH SCIENCES,49(11),1170-1183. |
MLA | Jin Huijun,et al."Thermal regimes and degradation modes of permafrost along the Qinghai-Tibet Highway".SCIENCE IN CHINA SERIES D-EARTH SCIENCES 49.11(2006):1170-1183. |
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来源:寒区旱区环境与工程研究所
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