Role of snow in the hydrology of a High Arctic riparian wetland

摘要

Riparian wetlands are narrow strips of saturated and vegetated ground forming critical links between dry ground and waterways. The hydrology of a riparian wetland situated within a polar oasis landscape near Eastwind Lake, Ellesmere Island, Nunavut (80°80'N, 85°35'W) was investigated in 2006 using a combination of fieldwork and modelling. Supplemental information from 2005 was also employed. This study showed that deep snow in the nearby stream channel does not promote a period of extended over-bank flooding but instead initially serves as a dam blocking most streamwater from entering and flooding the wetland. It was not until the snow dam melts and disintegrates in response to favourable weather conditions that the wetland becomes flooded and fully recharged. This was a delay of three weeks from the previous year. For the remainder of the 2006 growing season, contributions of meltwater from late-lying snow beds located within and adjacent to the stream channel and near the headwaters were essential for maintaining saturated conditions in the wetland.