Assessing Changes in Arctic River Migration in a Warming Climate: are Frozen Rivers Ready to Let it Go?

Keywords: Rivers, Arctic, Migration, Climate Change
Session Type: Virtual Paper
Day: Thursday
Session Start / End Time: 4/8/2021 11:10 AM (Pacific Time (US & Canada)) - 4/8/2021 12:25 PM (Pacific Time (US & Canada))
Room: Virtual 3

Abstract

Anthropogenic climate change has resulted in widespread changes to landscapes with many negative implications across the globe, especially in thermally sensitive areas like the arctic and subarctic. Melting glaciers and permafrost, for example, result in enhanced sediment production in watersheds that could trigger a chain of reaction to neighbouring and related landscape systems. In particular, river migration rates might change in response to increases in discharge and sediment availability due to the climatic changes that are ongoing and predicted in cold regions across the globe. This study aims to identify fluctuations in migration rates of arctic rivers in response to such changes, focused on meandering reaches of the Yukon (Alaska, USA) and Mackenzie (NT, CA) Rivers and their tributaries. We use recently published software packages to identify river centrelines, movement trends, and sediment erosion/deposition of river channel banks derived from multitemporal satellite imagery (LANDSAT) obtained between the 1980s and 2018. Our results show an overall increase in channel movement and erosional/depositional responses with time when averaged over the study sites. While significant spatial and temporal complexity exists, these results suggest there is a measurable connection between climatic shifts and rates of morphologic changes in cold-region meandering rivers. The datasets produced in this study can serve as a physical marker of climate change and an initial step in modelling the effects of climate change on cold-region river morphology.