CGRG Bibliography of Canadian Geomorphology
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Author : Dery, S.; Stahl, K.; Moore, D.; Whitfield, P.; Menounos, B.; and Burford, J.
Date : 2008.
Title : Detection of runoff timing changes in pluvial, nival and glacial rivers of Western Canada.
Publication : Water, Weather, and Climate: Science Informing Decisions. Canadian Meteorological and Oceanographic Society 2008 Congress. May 25-29, 2008, Kelowna, British Columbia.
Issue :
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Abstract
Changes in temperature, precipitation and, in some cases, glacial runoff affect the timing of river flow in watersheds of western Canada. This talk presents a robust method to detect streamflow phase shifts in pluvial, nival and glacial rivers. The nonparametric Mann-Kendall test yields monotonic trends in standardized pentad values of runoff in nine river basins of western Canada over the period 1955-2006. In comparison to trends in the timing of the date of annual peak flow and the center of volume, two other metrics often used to infer streamflow timing changes, our approach reveals more detailed structure on the nature of these changes. For instance, it is shown that changes toward an earlier occurrence of the centre of volume are not only sensitive to the earlier spring melt but also to higher late fall and winter flows and the seasonal snow accumulation. In contrast, the Mann-Kendall test yields evidence of an extension of the warm hydrological season in nival and glacial rivers of western Canada. This feature is marked by an earlier onset of the spring melt, statistically-significant decreases in summer streamflow, and a delay in the onset of enhanced autumn flows. This novel approach therefore provides critical information on streamflow timing changes throughout the entire hydrological year, enhancing results from previous methods to assess climate change impacts on the hydrological cycle.
Bibliography of Canadian Geomorphology