Factors limiting snowmelt runoff in a permafrost environment

Snowmelt runoff has long been recognized as a major component of streamflow in permafrost environments. Due to the cold snow cover and soil in these regions, a number of processes combine to both delay and limit runoff from snow cover. In more temperate climates these processes are often ignored, but in northern areas they take on added importance and must be considered when calculating runoff. These processes include: reducing the cold deficit of the snow, soil heat flux, refreezing of soil infiltration, and the growth of basal ice. A field study of these processes was carried out in a lake basin in the Mackenzie Delta, N.W.T. During the 1986 snowmelt period, the cold content of the snow and the strong negative soil heat flux delayed the arrival of meltwater at the snow cover base, and most of the melt water infiltrated the soil. As a result there is little immediate runoff from snow cover to the lake. This has important implications to the hydrology of these Delta lakes.