| Project/Area Number |
11680522
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental dynamic analysis
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| Research Institution | Hokkaido University |
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Principal Investigator |
ISHII Yoshiyuki Hokkaido Univ., Inst. of Low Temp. Sci., Assi. Prof., 低温科学研究所, 助手 (40222955)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Daiji Hokkaido Univ., Inst. of Low Temp. Sci., Prof., 低温科学研究所, 助手 (30001655)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | snowy cold region / basin water balance / inter-annual variation / snow water storage / water balance model / material cycle / 流域水收支 / 水收支モデル |
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| Research Abstract |
During the past 15 years, hydrological and meteorological observations have been continued in good condition in a snowy mountainous watershed (1.15 km^2) of northern Hokkaido. Annual basin water balance was calculated every water year using these data sets, and inter-annual variations of basin water storage were evaluated. Moreover, a conceptual mathematical model for the basin water balance was proposed. Air temperature was assumed only one variable parameter within the model, and an effect of the changes of snow water storage on the basin water balance due to the winter warming was examined by this model calculation. Recently, it is said that the snowy region in Japan has warm winter and the snowpack amount is decreasing remarkably. We have studied what kinds of influence would be caused by these trends in the basin water balance of the non-anthropogenic watershed. Following results were obtained through our study : 1) the wide range of inter-annual variation in snow water storage depended on not only winter precipitation but also air temperature in the beginning of snow accumulation and ablation periods, 2) snow water storage did not affect so much on the drought flow after the snowmelt season.
Water and material budgets were examined at the same watershed during the whole snowmelt season in 1999. Runoff process of the subsurface flow component on the hillslope was analyzed using chemical constituent as a tracer. Stream hydrograph separation by the three components model (snowmelt water, groundwater and those mixed water) showed that groundwater contribution to the stream discharge was almost 40 % of total flow during the whole snowmelt season. This leads to the excessive output of chemical constituent as compared with the total input in the snowpack.
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