2019 - 2021
Quantifying Geomorphological Response to Climate-Change Induced River Piracy, Yukon, Canada
2019 - 2020
Abstract: Understanding landscape response to current climate-driven change is a vital component for assessing the future state of the environment. As sensitive regions around the world undergo variations in streamflow, precipitation, and, air temperature, adjustments are being made. What are these changes, what rate of change is occurring, and most importantly, are these changes permanent? Glacial and fluvial systems are at high risk of these drastic and potentially permanent changes. To assess landscape response, we have analyzed a nearly instantaneous event resulting in river capture due to glacier retreat. In May 2016, river capture occurred in southwest Yukon due to the retreat of Kaskawulsh Glacier in Kluane National Park, Yukon, redirecting flow from Ä’äy Chù to Kaskawulsh River. To evaluate the planform geomorphic response of these two rivers, we quantified changes in channel complexity and alluvial fans pre and post river capture. Through satellite remote sensing, we mapped the braiding intensity of each river approximately biweekly from May – September (2013-2020) and measured the areas of 9 alluvial fans within Ä’äy Chù and 6 in Kaskawulsh River from 2013-2020, and normalized them to 2015 extents. River capture resulted in an increase in discharge to Kaskawulsh River causing braiding intensity to rapidly increase and alluvial fan area to reduce. Discharge rapidly decreased to Ä’äy Chù causing braiding intensity to decrease and marginally affected alluvial fans. This event has allowed us to identify how a sensitive landscape has responded to a climate-driven change and the extent of its effects.
Fluvial Response Over 50-70 Years
This is the second portion of my master's thesis. I have selected nine study sites throughout North America where there has been the formation of a proglacial lake due to glacial retreat. Over the past 50-70 years, as these proglacial lakes are forming, fluvial systems are undergoing major changes in discharge and sediment transport.
How have these proglacial rivers evolved over the past 5-7 decades as glaciers rapidly retreat?