Recent multi-year streamflow regimes and water budgets of hillslope catchments in the Canadian High Arctic: evaluation and comparison to other small Arctic watershed studies

摘要

This study evaluates whether a recent decline in snowcover extent for circumpolar regions is matched by changes in the seasonal streamflow regime of several small hillslope catchments on Bathurst and Melville islands. This includes shifts in the timing of initiation, peak discharge and impacts on the spring-summer water budgets. Paired catchments (West and East} at the Cape Bounty Arctic Watershed Observatory (CBAWO) on Melville Island (74.9°N, 109.5°W) have been studied from the pre-snowmelt season to early August since 2003. They are low-rolling tundra catchments between 8.0 and 11.6 km~2 in area. Likewise, within the Polar Bear Pass (PBP) watershed, Bathurst Island (75.7°N 98.7°W), two hillslope basins. Windy Creek (4.2 km~2) and Landing Strip Creek (0.2 km~2) have been investigated since 2007. Detailed snow surveys were conducted each spring and streamflow estimates were made using the mid-section velocity method. Nival regimes continue to dominate in these basins but runoff ratios are variable between catchments, across islands, and from year-to-year, In comparison to earlier streamflow studies across the Queen Elizabeth Islands (QEIs), an earlier response to peak discharge and start of flow for these hillslope streams is confirmed, Water budgets for PBP, CBAWO differ from other small Arctic watersheds.