Characteristics of Snowmelt Induced Peak Flows in a Small Northern Basin

Abstract

Six years' runoff data from Bensbyn Research Watershed (BRW) in northern Sweden is discussed. BRW is 1.6 km2, out of which 0.5 km2 is a large meadow and the remaining area consists of a dense coniferous forest. In the runoff analysis, runoff contribution from the meadow is separated from that from the forest. Peak flows are related to snowmelt from each separate area, and to rain events. The snowmelt generated runoff hydrographs are compared to those from rain events. The diurnal fluctuations of the snowmelt-induced runoff are analyzed in order to determine to what extent the stream flow originates from overland flow or subsurface flow. The highest flow recorded, 1.25 mm/h, was the result of a major rain storm of 60 mm occurring two weeks after all snow had disappeared. The peak runoff generated by snowmelt only was 0.78 mm/h. Overland flow is shown to take place from the meadow, but the runoff contribution from the forest is mainly due to subsurface flow. The peak flows from BRW are compared with observations reported in the recent literature.