2022 Fiscal Year Final Research Report
Development of a new infiltration calculation scheme based on the theory of the formation of preferential flow in snowpack revealed by using MRI
Project/Area Number |
19K04960
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 25030:Disaster prevention engineering-related
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Research Institution | Forest Research and Management Organization |
Principal Investigator |
Takafumi Katsushima 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (00611922)
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Co-Investigator(Kenkyū-buntansha) |
安達 聖 国立研究開発法人防災科学技術研究所, 雪氷防災研究部門, 特別研究員 (80719146)
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Project Period (FY) |
2019-04-01 – 2023-03-31
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Keywords | MRI / 選択流 / フィンガー流 / 積雪モデル / 浸透計算 / Invasion percolation |
Outline of Final Research Achievements |
We have investigated and modeled the formation process of preferential flow inside snowpacks caused by rainfall or snowmelt to improve prediction technology on hazards caused by melting snow. Non-destructive measurement technique by using MRI visualized the formation and development of the preferential flow and the deformation of the snow due to infiltrated water. When differences in capillary forces existed in the vertical direction within the snow layer, the significant differences of it tended to produce a wider horizontal spread of the preferential flow. We have developed a method to directly simulate pore-scale infiltration phenomena based on invasion percolation, which models the fluid replacement process by another fluid in a porous material. The formation of preferential flow and the spread of it observed in MRI-based infiltration experiments were reproduced approximately by the simulation.
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Free Research Field |
雪氷学
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Academic Significance and Societal Importance of the Research Achievements |
積雪内部の浸透現象と,それによりもたらされる積雪の内部構造の急激な変化は,積雪研究の実解決問題の1つである.積雪内部の選択流の物理過程を解明し,選択流の可視化技術,シミュレーション技術を開発したことは,積雪内部の浸透現象の全体像を示す可能性のある成果であり,融雪期の積雪現象の理解を大きく前進させる.これらの成果は,これまで予測が困難であった春先の急激な融雪や積雪への降雨による湿雪雪崩,融雪洪水,地すべりなどの融雪災害の予測精度の向上に資するものと考える.
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