Development of nondestructive observation method using magnetic resonance imaging and numerical simulation model of preferential flow in dry snowpack.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K12860
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: KATSUSHIMA Takafumi 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)
• 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)
• Research Collaborator: Yamaguchi Satoru ; KUMAKURA Toshiro
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 水みち / フィンガー流 / 止水面 / MRI / X線µCT / インベーション・パーコレーション

Outline of Final Research Achievements

We tried to a challenging research that unraveling a developing process of a preferential flow inside of snowpack. We succeeded to visualize a development of the preferential flow by using MRI system that implemented a three-dimensional rapid imaging method. The experimental results showed that the preferential flow path has a dimension of a several mm and its number increased through the continuing water supply. The small discontinuity of pore size and snow density in the vertical direction acted as capillary barriers and induced a lateral flow. We also succeeded to develop a new pore-scale mathematical model of the water movement into dry snow.

Free Research Field

雪氷学

Academic Significance and Societal Importance of the Research Achievements

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理論と技術の両面において研究基盤の萌芽に成功したと考える．これらの理論と技術を更に発展・応用することで，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が期待できる．