CGRG Bibliography of Canadian Geomorphology
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Author : Harms, P.L.; Adam, M.E.; Mongeon, C.L.; Sokal, M.A.; Brock, B.E.; Wolfe, B.B.; and Hall, R.I.
Date : 2007.
Title : Multi-proxy paleolimnological reconstructions of river discharge and lake water balance in the Slave River Delta, NWT.
Publication : CANQUA Ottawa 2007. Canadian Quaternary Association Conference, June 4-8, 2007. Carleton University, Ottawa, Ontario, Canada.
Issue :
Page(s) :
Abstract
The Slave River Delta (SRD), located at the mouth of the Slave River where it enters Great Slave Lake from the south, is a highly productive ecosystem supporting a wide variety of wildlife and numerous riparian plant communities. Biological productivity and diversity in the SRD are closely linked to the hydrology of the Slave River, which supplies water and nutrient-rich sediment during flood events that are thought to sustain extensive shoreline habitat and overall vitality of this northern freshwater ecosystem. In recent years, increased recognition of the potential impacts of various stressors on SRD hydroecology, including river regulation, resource development and climate variability, have raised concerns regarding the current state of the ecosystem which has implications for management of the delta and the community of Fort Resolution. To develop better understanding of the role of the Slave River and climate on the hydroecology of the SRD, lake sediment cores have been collected from several basins and analyzed using a broad suite of chemical and biological techniques. Multi-proxy analysis of a 50-cm sediment core from a basin adjacent to the Slave River has produced a high-resolution, ~90-year record of flood frequency that closely corresponds to intervals of high Slave River spring discharge over the 45-year period in which gauged records exist. At another more elevated basin, paleohydrological reconstruction of a 28-cm sediment core has revealed strong, climate-driven variability in lake water balance over the past ~250 years. Longer sediment cores will be obtained from these and other key delta basins using a Russian peat corer and a vibra-corer in March 2007 to examine past hydrological variability within a broader climatic context. Paleohydrological reconstructions will be derived from analyses of organic carbon and nitrogen elemental and stable isotope composition, cellulose oxygen isotope composition, magnetic susceptibility, and diatom and plant macrofossil assemblages, temporally constrained using 210Pb, 137Cs and 14C techniques. Results will be used to define relationships between variability in Slave River discharge, climate and delta hydroecology, in order to anticipate potential impacts from continued warming, declining snowpacks in the headwater region and reduced river discharge.
Bibliography of Canadian Geomorphology