Hydraulic and Thermal Dynamics at Various Permafrost Sites on the Qinghai-Tibet Plateau

• Main Author: Pan, Xicai
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2011
• Subjects: 550; 550 Earth sciences; permafrost
• Online Access: https://archiv.ub.uni-heidelberg.de/volltextserver/11934/; https://archiv.ub.uni-heidelberg.de/volltextserver/11934/1/2011_Pan_Xicai.pdf; https://doi.org/10.11588/heidok.00011934; https://nbn-resolving.org/urn:nbn:de:bsz:16-opus-119346

Heat transfer mechanisms governing the permafrost-atmosphere interaction are essential to understand present permafrost degradation. Hydraulic and thermal dynamics of various active layers at four di erent permafrost sites on the QTP were investigated with various geophysical methods and soil-weather monitoring stations. Complex eld data were detected and processed with appropriate methods. The principal physical processes controlling the active-layer thermal regime were characterized with a surface energy balance method at Chumaer, Qumahe and Tianshuihai. As a geophysical tool for characterizing soil properties, multi-channel GPR was further explored. Through Monte Carlo uncertainty analysis and eld tests, the accuracy of the multi-channel GPR method and its capability of quantifying eld-scale hydraulic properties and processes was validated at a non-permafrost sandy site. Based on precise soil temperature and soil water content data, heat transfer in various active layers were characterized with a transfer function method. Given the characteristics of ground heat transfer at the study sites, an inverse method for seasonal thermal conductivity parameterization was tested. Combining the transfer function method and the multi-channel GPR, a eld-scale thermal conductivity parameterization was proposed at the end.