ASSESSMENT OF A LAND COVER DRIVEN TTOP MODEL FOR MOUNTAIN AND LOWLAND PERMAFROST USING FIELD DATA, SOUTHERN YUKON AND NORTHERN BRITISH COLUMBIA, CANADA

Alexandre Bevington, Antoni G. Lewkowicz

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

Session: Physical and Numerical Modelling in Cold Regions / Modélisation physique et numérique en régions nordiques

ABSTRACT: Air, ground surface and top of permafrost temperatures (TTOP) were measured at 55 sites in three areas of Yukon and northern British Columbia in order to explore relationships between climate-permafrost transfer functions and environmental variables and to assess and validate the TTOP model. The strongest factors controlling climate-permafrost transfer functions are elevation and land cover, though slope, aspect, topographic position and surficial geology were also investigated. In 1000 iterations of the model using randomly-generated equally possible scenarios, 64% of the TTOP model predictions were within ±1°C of measured values, a result that is 6% better than applying a uniform 3°C total offset to the mean annual air temperature. A sensitivity analysis confirmed that the TTOP model is most sensitive to changes in the freezing n-factor, thermal conductivity ratio of the ground, and summer air temperatures.

RÉSUMÉ: trois secteurs du Yukon et du nord de la Colombie-Britannique afin d'étudier les relations entre les fonctions de transfert climat-pergélisol et certaines variables environnementales avec pour but d'évaluer le modèle TTOP (Smith et Riseborough, 1996, 2002). Les variables environnementales les plus importantes pour les fonctions de transfert climat-pergélisol sont l'élévation et la couverture terrestre, bien que la pente, la direction de la pente, la position topographique et la géologie de surface aient également été étudiées. Lors de 1000 itérations du modèle, en utilisant des scénarios aléatoires tous sensibilité confirme que le modèle TTOP est plus sensible aux changements du facteur-n de gel, du coefficient de conductivité thermique des sols et de la température de l'air pendant l'été.

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Cite this article:
Alexandre Bevington; Antoni G. Lewkowicz (2015) ASSESSMENT OF A LAND COVER DRIVEN TTOP MODEL FOR MOUNTAIN AND LOWLAND PERMAFROST USING FIELD DATA, SOUTHERN YUKON AND NORTHERN BRITISH COLUMBIA, CANADA in GEO2015. Ottawa, Ontario: Canadian Geotechnical Society.

@article{724,author = Alexandre Bevington; Antoni G. Lewkowicz,title = ASSESSMENT OF A LAND COVER DRIVEN TTOP MODEL FOR MOUNTAIN AND LOWLAND PERMAFROST USING FIELD DATA, SOUTHERN YUKON AND NORTHERN BRITISH COLUMBIA, CANADA,year = 2015}