| Summary: | Climate change affects High Arctic hydrological and biogeochemical processes by increasing air and soil temperatures and altering precipitation patterns, leading to permafrost degradation and increased surface-subsurface water connectivity. In polar desert regions, wetlands serve as critical biogeochemical hotspots, impacting watershed-scale biogeochemical and hydrological processes. Since polar desert wetlands form where reliable water sources are available, spatial variations in water sources and geomorphology can result in spatial differences in wetland biogeochemistry, allowing for the classification of wetlands based on hydrogeomorphic position. Despite past studies acknowledging spatial variations in High Arctic wetland water chemistry due to landscape variations, no studies have explored the influence of hydrogeomorphology, specifically water source and landscape position, on wetland water chemistry. This thesis aims to fill this knowledge gap by evaluating the seasonal and spatial dynamics of water chemistry for hydrogeomorphically distinct wetlands throughout the growing season. We classified 15 wetland sites into five wetland types based on their hydrogeomorphic position following Woo & Young’s (2003) wetland classification in Qausuittuq (Resolute Bay), Nunavut. Water samples and ground thaw measurements were collected throughout the growing season to assess wetland water chemistry’s response to thaw progression and analyze spatial variations linked to hydrogeomorphology. Moisture content, vegetation cover, topography, geology, and thaw depth were compared between sites to understand the influence of landscape position on wetland water chemistry. Results indicate that, in the first half of the season, ion concentrations were strongly linked to thaw depths irrespective of hydrogeomorphic setting. In the second half of the season, ion concentrations were less influenced by thaw depth and more controlled by landscape factors such as moisture content, vegetation, ground ice, permafrost history, and ...
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