Assessing Groundwater-Driven Advective Heat Transport and Its Influence on Permafrost Stability in Alaska

Author: Santosh Ranabhat , University of Alaska, Fairbanks

Poster

Video Presentation

Abstract

Subsurface thermal and hydrological processes have a significant impact on permafrost deterioration in cold climates; traditional geotechnical modeling techniques mainly take into consideration conductive heat transfer and frequently ignore advective heat transport related to groundwater movement. The objective of this study is to assess the amount of influence of groundwater movement on permafrost degradation. A statewide DRASTIC Index is developed to quantify the potential for groundwater infiltration and associated advective heat flux into the subsurface. The index incorporates key parameters, including depth to groundwater, recharge, aquifer characteristics, soil properties, topography, vadose zone conditions, and hydraulic conductivity. To evaluate the relationship between groundwater-driven processes and permafrost dynamics, the DRASTIC index is compared with long-term observations from Circumpolar Active Layer Monitoring (CALM) stations distributed across Alaska. These stations provide multi-decadal measurements of ground temperature and active layer thickness, enabling assessment of permafrost response to varying hydrogeological conditions. Statistical and spatial analyses are employed to examine correlations between DRASTIC-derived vulnerability and observed active layer changes. The results highlight the significance of groundwater-mediated heat transport in influencing permafrost stability and demonstrate the applicability of hydrogeological indices as proxies for advective thermal processes.

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