Abstract
Abstract. Soil moisture and ground thaw state are both indicative of a hillslope's ability to transfer water. In cold regions, in particular, it is widely known that the depth of the active layer and wetness of surface soils are important for runoff generation, but the diversity of interactions between ground thaw and surface soil moisture themselves has not been studied. To fill this knowledge gap, detailed shallow soil moisture and thaw depth surveys were conducted along systematic grids at the Baker Creek Basin, Northwest Territories. Multiple hillslopes were studied to determine how the interactions differed along a spectrum of topological, typological and topographic situations across the landscape. Overall results did not show a simple link between soil moisture and ground thaw as was expected. Instead, correlation was a function of wetness. The interaction between soil moisture and ground thaw was more dependent at wetter sites. This indicates that interactive soil moisture and thaw depth behaviour on hillslopes in cold regions changes with location and cannot necessarily be lumped together in hydrological models. To explore further why these differences arise, a companion paper (Guan et al., 2010) will examine how the hydrological and energy fluxes influenced the patterns of moisture and thaw among the study sites.
Highlights
Over 50% of Canada is underlain with discontinuous or continuous permafrost (Wolfe, 1998)
A large portion of this area remains thoroughly frozen for at least six months each year and this duration increases with latitude. It is only in the spring and summer months when the mean daily air temperature remains above 0 ◦C can there be substantial ground thaw – either entirely at locations with only seasonal frozen ground or partially at locations underlain by permafrost
Work at a continuous permafrost site found soil moisture to be affected by intrinsic water retention and transmission properties of frozen and thawed soil; the hydrological processes operating outside of the soil column, including precipitation and meltwater runoff; and the thermal and hydrological processes occurring in the active layer that redistribute moisture (Woo and Marsh, 1990)
Summary
Over 50% of Canada is underlain with discontinuous or continuous permafrost (Wolfe, 1998). A large portion of this area remains thoroughly frozen for at least six months each year and this duration increases with latitude. It is only in the spring and summer months when the mean daily air temperature remains above 0 ◦C can there be substantial ground thaw – either entirely at locations with only seasonal frozen ground or partially at locations underlain by permafrost. Studies have suggested a strong link between soil moisture and frost table dynamics, especially at wet locations
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call