Item: The hydrological importance of avalanche snow, kaghan valley, himalaya mountains, pakistan
Title: The hydrological importance of avalanche snow, kaghan valley, himalaya mountains, pakistan
Proceedings: 1988 International Snow Science Workshop, Whistler, October 12-15
Authors: Fes de Scally and Jim Gardner
Abstract: Spring snowmelt is a significant runoff component in the tributaries of the Indus River located on the south side of the Himalayan crest line. Part of this snowmelt component derives from avalanche transported snow. This paper addresses the processes and relative importance of avalanche snow transport and water yield in the hydrology of the Kunhar River in Kaghan Valley, Pakistan. Three main issues are discussed: the prediction of avalanche snow masses on individual paths; the proportion of slope area in the Kunhar basin affected by avalanching; and the measurement and modelling of avalanche snow melting and disappearance compared to undisturbed snow. Results indicate that both the magnitude of individual avalanches and the proportion of slope area prone to avalanching exceed that in other mountain ranges. Ablation of avalanche snow is driven by vertical fall which determines the air temperature increase, and the concentration factor of the avalanche path which determines the surface area of the snow deposit exposed to atmospheric energy exchanges. On many larger paths in Kaghan a high concentration factor outweighs the rise in temperature resulting from a large vertical fall. As a result avalanching retards snowmelt and delays meltwater inputs so that they overlap monsoon rain inputs later in the summer.
Keywords: snow, avalanche, transport, predication, melting, vertical fall
Digital Abstract Not Available