Increasing temperatures and changing precipitation patterns are global consequences of climate change, which are amplified in northern environments. Cold environments are particularly sensitive to warming due to the importance of sub-zero temperatures, which influence frozen ground status and precipitation type. The objective of this research is to evaluate the controls on the timing, rate, and volume of the major hydrological fluxes within the Wolf Creek Research Basin (WCRB), Yukon Territory and to identify any long-term changes. WCRB is a long-term hydrological observatory established in 1993 to evaluate cold region hydrological processes. Within WCRB, three long-term meteorological stations at different elevations with total precipitation measurements and several stream gauges allow a long-term (26 year) evaluation of water balance components. Increases in temperature and precipitation magnitude are consistent with climate models including CIMP6 models. There has also been a significant increase in the number of high intensity precipitation days (primarily in June, July, and August). Fall and winter discharge increased and there was an increase in mean annual baseflows. The proportion of discharge output during freshet (April 1st – July 1st) has not changed, but the timing of peak flow has shifted from late-May to mid-June. This research provides a unique opportunity to study long-term change while recognizing short-term natural variability in hydrologic data. Understanding the mechanisms within catchments will allow for a stronger interpretation of the response of catchments to changing climate regimes which can have diverse impacts on local ecosystems and prevailing geohazards in northern environments. / Thesis / Master of Science (MSc) / Increasing temperatures and changing precipitation patterns are global consequences of climate change, which are amplified in northern environments. This research looks at a long-term hydrologic dataset of the Wolf Creek Research Basin (WCRB), located near Whitehorse, Yukon. Three hydrologic variables were evaluated: air temperature, precipitation, and discharge. Each variable plays a critical role in a watershed’s response to climate change. From 1993 to 2019, there was a significant increase in winter precipitation across the basin. Mean annual temperature also increased at the two lower elevation sites at a rate comparable to the rest of Yukon. Mean annual discharge has also increased, most notably in fall and winter which is reflective of an increase in groundwater contributions to the stream. This research increases our understanding of the relationships and drivers behind hydrometric changes which allows for a stronger interpretation of the response of catchments to climate change.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/26959 |
| Date | January 2021 |
| Creators | Chapman, Fiona M. |
| Contributors | Carey, Sean K. |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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