Long-term hydrological dynamics of Canada's largest watershed: climate controls on water quantity and quality of the Mackenzie River Basin
Canada’s Mackenzie River Basin (MRB) is one of the world’s largest and most important freshwater ecosystems and is at risk due to climate change and resource development. The MRB is of global importance due to its biodiversity and unique role in carbon storage, climate processes, and health of Arctic terrestrial and marine ecosystems. Warming temperatures in the MRB have led to widespread permafrost thaw and are affecting the hydrological cycle. People living in communities in the basin report decreased water levels and water flows, drying conditions, warmer temperatures, and thinning ice. Although water quantity monitoring of rivers in the MRB has been conducted since 1970s, the brevity of instrumental records makes them inadequate for understanding multi-decadal cycles and trends associated with long-lived climate phenomena such as the Pacific Decadal Oscillation (PDO) that may influence the hydrology of the MRB. The objectives of this multi-disciplinary research project are to reconstruct hydrological change of MRB of the past ~4000 years with a focus on the Mackenzie River in the Gwich’in Settlement Area. We will collect and analyze lake sediments and peats to provide information on past climate variability and water quantity in the MRB. Traditional Knowledge will also be used to better understand long-term changes in water levels in the basin. Our approach will permit recognition of cycles and trends that have impacted water levels of the MRB. Information on drivers of water quantity change are needed for strategic management of Canada’s water resources. Through a multi-disciplinary network federal and territorial governments, communities, and academia we will develop currently non-existent data on long-term climate fluctuations that affect the MRB and how these have impacted water quantity of the basin. This knowledge will serve as a benchmark against which to understand water resource trajectories under 21st c. climate forcing and using this knowledge we will generate hydrological models to predict future trajectories of climate variability and water quantity change in the MRB.