Abstract
To examine effects of forest cutting on snowmelt runoff, a total of 52.2 % of tree areas in the No.1 Stream Watershed of the Takaragawa Forest Watershed Experiment Station was cleared in several strips along contours. After cutting the period of snowmelt runoff was 8 days longer on average and the runoff percentage during snowmelting has increased by 6.4 % to 70.9 %, along with the decrease in depletion curve gradient during the recession period after snow melting. Daily peaks in hydrographs showed about 2 hrs delay after air temperature or radiation maximums when the initial runoff was small, while it was 40 min when the initial runoff was large. In the strip-cut areas the snowcover absorbs more solar radiation than wooded areas, so the snowmelting is accelerated and the snow properties become changeable. Open areas in the forest is apt to pile more snow than wooded areas and the snow is shaded by surrounding trees, so the melting may delay in comparison with that from clear cut areas.
