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Tuesday, May 27, 2008 - 10:15 AM
140
Watershed hydrology and solute fluxes in catchments underlain with discontinuous permafrost in interior Alaska: An end-member mixing analysis
Jeremy B. Jones, Kelly L. Balcarczyk, Amanda J. Rinehart, and Emily E. Schwing. Institute of Arctic Biology, University of Alaska Fairbanks, 902 N. Koyukuk Drive, Fairbanks, AK 99775-7000
Hydrologic flowpaths through watersheds plays a central role in determining solute fluxes in streams. In the boreal forest of interior Alaska, watersheds are underlain with discontinuous permafrost, which has a dominant control on groundwater infiltration and catchment flowpaths. We studied watershed hydrology and the associated solute fluxes in a series of subcatchments which varying in extent of underlying permafrost in the Caribou Poker Creeks Research Watershed in Alaska. Watershed flowpaths were modeled using an end-member mixing analysis and five conservative solutes (Ca2+, Mg2+, Na+, SO4= and HCO3-). Stream flow in the watershed with the greatest extent of underlying permafrost was fed by three end members, with a sizable proportion of stream discharge derived from a shallow, soil flowpath. In the lower permafrost catchments, watershed hydrology was more complex with four major source waters contributing to stream flow and a greater proportion of stream flow from deeper source waters. Coupled to these patterns in flow, streams draining higher permafrost watersheds tend to have lower base cations and higher dissolved organic carbon concentrations compared with streams draining lower permafrost watersheds. With climatic warming and permafrost thaw, solute fluxes will change in response to altered watershed hydrology.
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)