Publication Date:
2012-11-15
Description:
Research on large northern rivers suggests that as permafrost thaws, deeper groundwater flowpaths become active, resulting in greater baseflow, increased concentrations of weathering ions and reduced concentrations of dissolved organic carbon in the streamflow. In contrast, at the headwater-catchment scale, where understanding of groundwater/surface-water interactions is developed, inter-annual variability in climate and hydrology result in complex hydrological and chemical responses to change. This paper reports on a 4-year runoff investigation in an alpine discontinuous permafrost environment in Yukon, Canada, using stable isotopes, major dissolved ions and hydrometric data, to provide enhanced insight into the inter-annual-variability runoff-generation processes. Stable isotope results suggest that pre-event (old) water stored within the catchment dominates the snowmelt hydrograph, and dissolved ion results reveal that groundwater pathways occur predominantly in the near-surface during freshet. Dissolved organic carbon varies inter-annually, reflecting changing melt patterns, whereas weathering ions generated from deeper flowpaths become diluted. The total snow-water equivalent does not have a major influence on the fraction of snowmelt water reaching the stream or the runoff ratio. Results from multiple years highlight the considerable variability over short time scales, limiting our ability to detect climate-change influences on groundwater at the headwater scale. Content Type Journal Article Category Paper Pages 1-11 DOI 10.1007/s10040-012-0920-9 Authors Sean K. Carey, School of Geography and Earth Sciences, McMaster University, 1280 Main St. W, Hamilton, ON L8S 4K1, Canada Jessica L. Boucher, Department of Geography and Environmental Studies, Carleton University, 1125 Colonel By Dr., Ottawa, ON K1S 5B6, Canada Celina M. Duarte, Department of Geography and Environmental Studies, Carleton University, 1125 Colonel By Dr., Ottawa, ON K1S 5B6, Canada Journal Hydrogeology Journal Online ISSN 1435-0157 Print ISSN 1431-2174
Print ISSN:
1431-2174
Electronic ISSN:
1435-0157
Topics:
Geosciences
