INVESTIGATION ON THE SOIL THERMAL CONDUCTIVITY OF DIFFERENT UNDERLYING SURFACES IN THE NORTHERN QINGHAI-TIBETAN PLATEAU, CHINA

Ren Li, Tonghua Wu, Lin Zhao, Changwei Xie, Yao Xiao, Guojie Hu, Yizhen Du

In the proceedings of: GeoQuébec 2015: 68th Canadian Geotechnical Conference & 7th Canadian Permafrost Conference

Session: In Situ Testing, Instrumentation, and Monitoring in Cold Regions / Essais insitu et instrumentation en milieu nordique

ABSTRACT: Several numerical methods are applied and compared in the calculation of soil thermal conductivity (STC) in the Kekexili (QT01), Beiluhe (QT02), Kaixinling (QT05), and Tongtianhe (QT06) regions in the northern Qinghai-Tibetan Plateau based on data from January 2004 to December 2013. The results show that the STC of the active layer in the study region exhibited marked seasonal variations: it was low during the cold season but high in the warm season. Averagely, the mean value was 1.080 Wm-1K-1, ranging from 0.752 to 1.371 Wm-1K-1. In the frozen state (FS), STC was 0.955 W.m-2.K-1 while in the unfrozen state (UFS), it was 1.204 W.m-2.K-1. STC increased with increasing soil bulk density but decreased with increasing vegetation cover of the land surface; STC of alpine frost meadow soil was greater than that of alpine frost steppe soil; fine-grained soil with low unfrozen water content and a low saturation degree resulted in low STC in the cold season; and monthly mean STC can be well expressed as a function of conventional meteorological data. Verification results further ensured that the proposed model accurately predicts monthly STC values.

RÉSUMÉ: Plusieurs méthodes numériques sont appliquées et comparées dans le calcul de la conductivité thermique des sols (STC) dans les régions Kekexili (QT01), Beiluhe (QT02), Kaixinling (QT05), et Tongtianhe (QT06) dans le nord du plateau Qinghai- Tibet en se basant sur les données de janvier 2004 à décembre 2013. Les résultats montrent que la saison froide, mais haut durant la saison chaude. En moyenne, la valeur était de1.080 Wm-1K-1, pour un intervalle de données allant de 0.752 à 1.371 Wm-1K--2.K-non-gelé elle était de 1.204 W.m-2.K-te du sol, gelée était plus élevée que celui de la steppe alpine gelée; les sols à grains fins ayant un faible contenu en eau non-gelée et un faible degré de saturation ont une STC basse dans la saison froide; et la moyenne mensuelle des STC peut être exprimée comme une fonction de données météorologiques conventionnelles. Les résultats de la vérification ont assuré que le modèle proposé prédit précisément les valeurs de STC mensuelles.

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Cite this article:
Ren Li; Tonghua Wu; Lin Zhao; Changwei Xie; Yao Xiao; Guojie Hu; Yizhen Du (2015) INVESTIGATION ON THE SOIL THERMAL CONDUCTIVITY OF DIFFERENT UNDERLYING SURFACES IN THE NORTHERN QINGHAI-TIBETAN PLATEAU, CHINA in GEO2015. Ottawa, Ontario: Canadian Geotechnical Society.

@article{548,author = Ren Li; Tonghua Wu; Lin Zhao; Changwei Xie; Yao Xiao; Guojie Hu; Yizhen Du,title = INVESTIGATION ON THE SOIL THERMAL CONDUCTIVITY OF DIFFERENT UNDERLYING SURFACES IN THE NORTHERN QINGHAI-TIBETAN PLATEAU, CHINA,year = 2015}