| Summary: | A fundamental understanding of how river morphology interacts with permafrost is needed to understand the role of Arctic rivers as indicators and drivers of landscape change and their linkages to pan-Arctic feedback systems. Given the ecological role of rivers, projected changes in surface air temperatures, permafrost degradation, and hydrologic regimes, an investigation into the fundamental geomorphic dynamics of Arctic rivers and how those dynamics might be affected in the future is needed. For these reasons, the purpose of this study is to investigate the morphological characteristics of Arctic and sub-Arctic meandering river bends using remote sensing technology to determine whether the observed patterns have any relation to the areal extent of permafrost. A morphometric analysis using the bend and chord length, sinuosity, absolute average curvature, and asymmetry index of approximately 600 Arctic and sub-Arctic river bends indicates that bends from the continuous permafrost zones, discontinuous permafrost zones, and high-latitude non-permafrost regions are morphometrically different from one another at a half-meander bend scale. Results show that bends from the continuous permafrost zone, when compared to other bends from Arctic or sub-Arctic rivers, are statistically more likely to be 1) smaller in size (via chord and bend length), 2) have a lower chance of being upstream skewed (via asymmetry index) and 3) on average have sharper bends and sharp transition zones between bends (via absolute average curvature). However, the combination of the half-meander bend morphometrics when transformed via PCA, are alone not enough to delineate between river bends of different permafrost zones. This analysis reveals the unique morphometric signature of Arctic river bends and moves us closer towards understanding the control of permafrost on rivers.
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