Planning for a Hydro-Secure Future: Using Water Isotope Tracers to Characterize Hydrology of the Regulated Yukon River

English Abstract:

The Yukon River, which drains 832,700 km², is a key water resource that supports traditional Northern activities. The river is also the primary source of Yukon’s energy – it provided 99.6% of the territory’s energy in 2014. Researchers from the Yukon Research Centre (YRC) are involved in two projects that integrate the use of water isotope tracers to assess Yukon River hydrology. Both projects support responsible decision-making around water resource management in the watershed in the context of a changing climate.

Yukon River discharge dynamics are of key interest to Yukon Energy Corporation (YEC). In order to ensure sound planning for a hydro-secure future, YEC has partnered with the YRC to build hydrological and glacial models for the headwaters region. To complement this work, isotope hydrology studies focusing on δ¹⁸O and δ²H have been initiated. To date, samples from the glaciated headwaters of the Yukon River, including terminal ponds, fresh snow, and the glacial outlet have been collected, as well as a suite of samples collected during a synoptic sampling campaign in the broader headwater region. Results have been analyzed, and preliminary interpretations will be presented via this contribution. YRC researchers are also leading an isotope-focused project that partners with the Yukon River Intertribal Watershed Council (YRITWC), an indigenous organization focused on the protection of the Yukon River watershed. YRITWC’s Indigenous Observation Network has been collecting water samples from locations along the Yukon River, from the Canadian headwaters to the Alaskan mouth, for a suite of analyses since 2006. Many samples have been analyzed for δ¹⁸O and δ²H, although results have never been interpreted. Here, we will present results from the isotope data collected via this unique sampling network, and will discuss how integration of results from both projects contributes to understandings of regional hydrology, and implications for resource management.