1997 Fiscal Year Final Research Report Summary
Study on water and heat cycle in forest areas with snow cover
| Project/Area Number |
07306006
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
林学
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| Research Institution | Faculty of Agriculture, Iwate University |
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Principal Investigator |
OHTA Takeshi Faculty of Agriculture., Iwate Univ.Associate Professor, 農学部, 助教授 (20152142)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAI Yuichiro FFPRI.Hokkaido office Researcher, 北海道, 研究員
KOMINAMI Yuji FFPRI.Kansai office Researcher, 関西, 研究員
KUBOTA Jumpei Faculty of Agriculture, Tokyo Univ.of Agriculture and Technology Associate Profe, 農学部, 助教授 (90195503)
KODAMA Yuji Inst.Low. Temp.Science, Hokkaido Univ.Associate Professor, 低温科学研究所, 助手 (70186708)
ISHIKAWA Nobutaka Inst.Low Temp.Science, Hokkaido Univ.Associate Professor, 低温科学研究所, 助教授 (70002277)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Forest / Snow cover / Canopy condition / Energy balance |
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| Research Abstract |
The intensive observations were carried out in February 1996 and 1997 at a ash tree forest which was deciduous. The results obtained by these observations were compared to those gotten at evergreen forests. The followings are the new interpretation by this study. (1) Net radiation and sensible heat on the ash tree forest were similar to those on the evergreen forests though there were clear distinctions about canopy conditions. (2) Upward long-wave radiation at the was smaller at the ash tree forest than at the evergreen forest, so differences of albedo among the three forest were set off. Consequently, there was no remarkable difference on net radiation. (3) Zero plane displacement in the ash tree forest was very low and a large part of the canopy layr was effective for heat exchange with atmosphere. Moreover, roughness length was higher at the ash tree forest than at the evergreen forests, so mixing was accelerated. This might be a reason for the fact that sensible heat was similar to each other.
About interception on canopies, some new interpretaions were gotten. The followings are the results obtained in Hokkaido. (1) Evaporation was larger in February than during a melting season, because a snow covered period of a canopy was longer. (2) The daily mean values was 0.8 mm/day, and this is twice as large as the values was obtained at an open area. Other results obtained in Tokamachi town where was a warmer and snowy region. (1) The mean interception rate was 2.7-4.2 mm/day. This rate was twice as large as net radiation was. (2) Differences of water equivalent of snow between at a forest and at an open site were mainly caused by snow interception.
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