1994 Fiscal Year Final Research Report Summary
Basic Researches on Snowmelt Processes in a Subalpine Region
| Project/Area Number |
05660153
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
林学
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| Research Institution | Iwate University |
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Principal Investigator |
OHTA Takeshi Iwate Univ., Fac.Agriculture, Associated Professor, 農学部, 助教授 (20152142)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAYAMA Kenichi Iwate Univ., Fac.Technology, Professor, 工学部, 教授 (10001140)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Subalpine region / Snowmelt / Heat balance / Temporal variation / Spatial variation |
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| Research Abstract |
Snowmelt characteristic in a subalpine region were investigated from a viewpoint of a heat balance. New interpretations obtained by this project are as follows ; (1) Ratios of net radiation in snowmelt energy decreased as time passed, because latent heat transfer caused a condensation in the latter half of the melting seasons. The condensation accelerates snowmelt. On the other hand, evaporation occurred in the first half and restrains snowmelt. (2) Differences of snowmelt rates between a slope and a flat place were caused by variations of net radiation at the two study point, when latent heat transfer was negative values and evaporation occurred. The influence of turbulent flux on differences of snowmelt caused by a slope angle was not ignored, when condensation occurred. Differences of snowmelt between a slope and a flat place increased with the increase of differences of wind speed between them. (3) Snowmelt rates were larger at a lower place than at a higher place in the first half of the melting seasons. But snowmelt at the higher place was accelerated during the latter half. Radiative energy was always larger at the lower site than at the higher site, and turbulent heat transfer increased at the higher site as time passed, especially on warm and windy days.
Variabilities of turbulent heat transfer are very important on snowmelt characteristics at a subalpine region, because melting seasons are very long.
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