STUDY ON SNOWMELT RUNOFF MODEL IN THE COLD AND SNOWY REGION WITH FROZEN SOIL
2001 Volume 45 Pages 67-72
Details
2001 Volume 45 Pages 67-72
In Hokkaido, we have often experienced ground surface freezing during the winter. The Tomisato dam experiment basin was set up to clarify the effects of frozen soil on the snowmelt runoff. It is possible in snowmelt season to occur the overland flow at the hillslopes because of reducing infiltration capacity of ground surface by soil freezing. By analyzing observed data, it was pointed out that the swell of long wavelength of hydrograph occurred in the early snowmelt season.
To make clear the effects of frozen soil on the snowmelt runoff, we reconstruct 4×3 zoned tank model, which can consider the spatially distributed frost depth and snow depth at this site, by including the frost dept prediction model. By multiple regression analysis, the frost depth is good relationship between freezing index, snow depth and melting index, and the max value of frost depthis dependent upon the accumulate rainfall at autumn season. As a result, it shows that this improvement is effective to estimate the snowmelt runoff in the coldand snowy region with the frozen soil.
