Variations in the northern permafrost boundary over the last four decades in the Xidatan region, Qinghai–Tibet Plateau Variations in the northern permafrost boundary over the last four decades in the Xidatan region, Qinghai–Tibet Plateau

最小化 最大化

Vol15 No.4: 765-778

Title】Variations in the northern permafrost boundary over the last four decades in the Xidatan region, Qinghai–Tibet Plateau

Author】LUO Jing1*; NIU Fu-jun1,2*; LIN Zhan-ju1; LIU Ming-hao1; YIN Guo-an1

Addresses】1 State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; 2 South China Institute of Geotechnical Engineering, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China

Corresponding author】LUO Jing; NIU Fu-jun

Citation】Luo J, Niu FJ, Lin ZJ, et al. (2018) Variations in the northern permafrost boundary over the last four decades in the Xidatan region, Qinghai–Tibet Plateau. Journal of Mountain Science 15(4). https://doi.org/10.1007/s11629-017-4731-2

DOI】10.1007/s11629-017-4731-2

Abstract】The distribution and variations of permafrost in the Xidatan region, the northern permafrost boundary of the Qinghai-Tibet Plateau, were examined and analyzed using ground penetrating radar (GPR), borehole drilling, and thermal monitoring data. Results from GPR profiles together with borehole verification indicate that the lowest elevation limit of permafrost occurrence is 4369 m above sea level in 2012. Compared to previous studies, the maximal rise of permafrost limit is 28 m from 1975 to 2012. The total area of permafrost in the study region has been decreased by 13.8%. One of the two previously existed permafrost islands has disappeared and second one has reduced by 76% in area during the past ~40 years. In addition, the ground temperature in the Xidatan region has increased from 2012 to 2016, with a mean warming rate of ~0.004°C a−1 and ~0.003°C a−1 at the depths of 6 and 15 m, respectively. The rising of permafrost limit in the Xidatan region is mainly due to global warming. However, some non-climatic factors such as hydrologic processes and anthropic disturbances have also induced permafrost degradation. If the air temperature continues to increase, the northern permafrost boundary in the Qinghai-Tibet Plateau may continue rising in the future.

Keywords】Qinghai-Tibet Plateau; Permafrost; Climate warming; Permafrost limit; Ground penetrating radar; Thermal monitoring.