2002 Fiscal Year Final Research Report Summary
Study on Generalization of the Snowmelt Runoff Estimating Methods
| Project/Area Number |
12660213
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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 |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | Iwate University |
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Principal Investigator |
KURASHIMA Eiichi Iwate University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (30178082)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Toru Miyagi Agricultural College, Professor, 教授 (70070224)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Experimental Watershed / Snowmelt Runoff / Bottom Snowmelt / Shock Front / Water Equivalent of Snow / Global Warming |
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| Research Abstract |
When planning irrigation and other water utilization, it is very important to grasp the process of snowmelt, and to understand how the snowmelt affects river runoff. For this purpose the experimental watershed was set up and factors concerned the snow melt were observed.
Snowmelt which is caused by heat transfer across the snow-soil interface is called bottom snowmelt. It is very important to reflect the influence of bottom snowmelt on research regarding the mechanism of snowmelt runoff. But there have been very few examples of estimating the amount of bottom snowmelt during snow-covered period. In order to improve this situation 11 points where ranging from Hokkaido to Tohkai Regions were selected as research subjects and amount of bottom snowmelt was estimated and a comparison was conducted.
In the other hand in the melt season, most snowmelt phenomenon occurs at the surface of the snowpack. Meltwater percolates to the ground surface with time lag. To forecast snowmelt runoff, it is necessary to understand the mechanism of meltwater percolation in snow cover. Thus, meteorological factors used in estimating surface melt and meltwater at the ground surface were measured. The percolation model, proposed for glacial area, was improved, then using this method, ground arrival amount was estimated from surface melt amount. As a result, it was determined that by applying the method, preferable reproducibiilty could be achieved for the time after the peak time of the graph, while there was amount loss regarding formation of shock front.
As a part of the study program, water equivalent of snow was estimated at several watersheds and effects of global warming on spring river flow was tested.
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