Channel Development in Snow-Filled Valleys, Resolute, N. W. T., Canada

In the Canadian High Arctic, the bulk of annual streamflow occurs during the period when valleys are choked with snow. A study was carried out near Resolute, Northwest Territories, to examine the manner in which meltwater runoff carves channels in the valley snowpacks. Major factors controlling channel development include snow distribution and snow characteristics which in turn are related to local topography and the prevailing direction of winter snow drift. Channel development begins with a saturation of the valley snowpack, followed by water movement within or on the surface of the snow. Several processes then take place including the ponding and subsequent release of water behind snow-dams formed by drifts, the formation and collapse of snow tunnels, the vertical incision and lateral shifting of channels in the snowpack, the abandonment of channels due to flow diversion, and a disintegration and decay of the snow in the valleys. Based on the close relationship between topography, snow accumulation patterns and the recurrence of channel development processes, a qualitative model was formulated to predict the sequence of channel development events.