|Budget Amount *help
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1988: ¥1,500,000 (Direct Cost: ¥1,500,000)
Generally, in snowmelt runoff analysis, empirical formula in which atmospheric temperature is taken as index, is widely used for the calculation of amount of snowmelt.
On the other hand, in studies which are dealing with heat balance of snowpack, it has been made clear that considerable portion of total snowmelt in one day is attributed to absorbed net radiations of short-wave and long-wave, and so-called quantity of snow thawed by air temperature which is caused by heat transfer from atmosphere, show increase in propotional to wind speed.
There, in present study, 4 kinds of snowpack-snowmelt models which are adopted or suggested in Japan, were compared and examinations were conducted concerning their applicability, using values of water equivalent of snow cover or snow density which were measured at 8 spots in districts of Hokkaido, Tohoku and Hokuriku, and pointed out problem and subject of improvement.
Together with above subjects, in present study, field observations of amount of snowmelt and meteorological factors were carried out over 3 years, and the actual conditions of snowmelt in surface of snow cover and surface of ground were made clear, and heat balance of snowpack in snowmelt season was investigated. In addition, utilizing the results of investigation, relative importances of meteorological factors on snowmelt were considered.
The information above suggest the necessity of taking the mechanisms of cooling, temperature and heat tranfer of snowpack into the construction of snowmelt model, and is expected to make much contribution to studies in the future.