ABSTRACT: Assessing the influence of melting permafrost on streamflow in discontinuous permafrost catchments.

CGRG Bibliography of Canadian Geomorphology
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There is a growing body of literature exploring the role permafrost plays in hydrological and biogeochemical cycling, and how recent changes in permafrost has affected these cycles. For example, over the last 40 years, the Yukon River has seen changes in both the timing, magnitude and quality of streamflow, which are attributed to permafrost melt. As near-surface permafrost degrades, deeper subsurface flow pathways are activated, and the nature of biogeochemical reactions change. However, large-scale studies do not explicitly link streamflow response to direct observations of catchment processes. This talk will explore the role of frozen ground on water and biogeochemical cycling in discontinuous permafrost alpine headwater catchments of the Yukon River. Results from the Wolf Creek Research Basin near Whitehorse, Yukon, will be utilized to show that where permafrost is present, it enhances runoff due to restricted drainage, which also limits dissolution and increases DOC flux due to the ubiquitous nature of surface organic soils. However, in discontinuous permafrost environments, there is considerable intra- and sub-permafrost groundwater that supplies ion-rich waters to streams throughout the year. By using current differences in permafrost disposition as an analogy for future changes, it is possible to hypothesize what hydrometric and/or biogeochemical indicators we expect to respond first. Furthermore, a decade of research suggests that large inter-annual variability and water and chemical fluxes will make change detection from infrequent synoptic samplings schemes challenging.

Bibliography of Canadian Geomorphology