Long-term hydrological change of the Gwich'in Settlement Area, Mackenzie River Basin - ArcticNet P51.

The Mackenzie River Basin (MRB) is experiencing warming surface temperatures. Warmer temperatures may be affecting water levels/flows, causing warmer/drier winters, thinning ice, thawing permafrost, and changes to the surrounding ecosystems and to large-scale biogeochemical cycling. To address the knowledge gap on the drivers of changes in water quantity and quality in the MRB, six peat cores/monoliths were collected from the Gwichin Settlement Area (GSA) of the MRB and two from outside of the MRB, but near the same latitude, to reconstruct the long-term hydrological changes. A combined paleoecological and Traditional Knowledge approach will create new knowledge on past climate variability and water quantity in the MRB that will improve the understanding of how climate affects hydrology of the MRB. The peat cores were sliced at 5 mm or 1 cm intervals throughout their depth, and then sub-sampled for various analyses, including: 1) testate amoebae, palynology and microscopic charcoal, plant macrofossil and macroscopic charcoal analysis to reconstruct changes in vegetation, fire history, and hydrology over time; 2) radiometric dating to date the cores; 3) elemental (including Hg) geochemical analyses; and 4) HAWK pyrolysis to provide information on organic matter preserved in the peats. Cores and monoliths from peatlands were collected for the purpose of reconstructing hydrological change over past centuries to millennia. WHY the study took place: to reconstruct long-term changes in water quality and quantity to elucidate if and which synoptic scale drivers of climate change (e.g., the Pacific Decadal Oscillation) are affecting water resources in the Gwich'in Settlement Area, this information is needed for accurate modelling of future trajectories of water quality and quantity for the region; WHAT the study was about: this study aims to reconstruct long-term changes in water quality and quantity in the Gwich'in Settlement Area using a combination of western science and Traditional Knowledge for the purposes described above; WHY the data collection took place in the locations that it did: with air support provided by ArcticNet, the Gwich'in Renewable Resources Board were able to land at several peatlands and sampled peat cores and peat samples and other measurements, such as depth to water table, from a variety of peatland types and microforms. A variety of sampling locations is needed to understand the spatial variability in changes in water quantity.