Snow accumulation, albedo and melt patterns following road contruction on permafrost, Inuvik-Tuktoyaktuk Highway, Canada

Abstract. Roads constructed on permafrost can have a significant impact on the surrounding environment, potentially inducing permafrost degradation. These impacts arise from factors such as snow accumulation near the road, which affects the soil’s thermal and hydrological regime and road dust that decreases the snow’s albedo, altering the timing of snowmelt. However, our current understanding of the magnitude and the spatial extent of these effects is limited. In this study we addressed this gap by usingremote sensing techniques to assess the spatial effect of the Inuvik to Tuktoyaktuk Highway (ITH) in Northwest Territories, Canada, on snow accumulation, snow albedo and snowmelt patterns. We quantified the snow accumulation at road segments in the Trail Valley Creek area using digital elevation model differencing. We found increased snow accumulation up to 36 m from the road center. The magnitude of this snow accumulation was influenced by the prevailing wind direction and the height of the embankment. Furthermore, by analysing 43 Sentinel-2 satellite images between February and May 2020 we observed reduced snow albedo values within 500 m of the road, resulting in a twelve days earlier onset of snowmelt within 100 m from the road. We examined snowmelt patterns before, during and after the road construction using the normalized difference snow index from Landsat-7 and Landsat-8 imagery. Our analysis revealed that the road affected the snowmelt pattern up to 600 m from the road, even in areas which appeared undisturbed. In summary, our study improves our understanding of the spatial impact of gravel roads on permafrost on snow cover accumulation, snow albedo and snowmelt patterns. Our study underscores important contribution that remote sensing can provide to improve our understanding of the effects of infrastructure development on permafrost environments.