Item: Observation of fingering flow and lateral flow development in layered dry snowpack by using MRI
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Title: Observation of fingering flow and lateral flow development in layered dry snowpack by using MRI
Proceedings: International Snow Science Workshop Proceedings 2018, Innsbruck, Austria
Authors:
- Takafumi Katsushima [ Forestry and Forest Product Research Institute, Tohkamachi Experimental Station, Tohkamachi City Niigata, Japan ]
- Satoru Adachi [ National Research Institute for Earth Science and Disaster Resilience, Shinjo Cryospheric Environment Laboratory, Shinjo City Yamagata, Japan ]
- Satoru Yamaguchi [ National Research Institute for Earth Science and Disaster Resilience, Snow and Ice Research Center, Nagaoka City Niigata, Japan ]
- Toshihiko Ozeki [ Hokkaido University of Education, Sapporo Campus, Sapporo city Hokkaido, Japan ]
- Toshiro Kumakura [ Nagaoka University of Technology, Nagaoka City Niigata, Japan ]
Date: 2018-10-07
Abstract: Fingering flow develops due to the infiltration of snow meltwater or rain water into dry snowpack. The width, spacing, and areal coverage of the fingering flow path and occurrence of capillary barriers have been demonstrated using dye tracer experiments that were conducted at the field and in cold laboratories. However, the initial shape and temporal development of fingering and lateral flows are unclear because a vertical or horizontal section of snow is needed to observe them. To examine this, we carried out non-destructive observations of fingering flow development and capillary barriers in layered snow in a cold laboratory using Magnetic Resonance Imaging (MRI) via 3-dimensional rapid imaging method. μCT was also used to associate the water flow phenomena with the snow microstructure. The snow column was directly sampled in the vertical direction using the infiltration column from a natural snow-pack without breaking the layered structure of the snow. The experimental results showed that fingering flows developed in all of the snow samples. Fingering flow path increased and lateral flow developed 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. These results showed that the persistence of a fingering flow path and an increase in the number of flow paths are important phenomena in understanding the infiltration of water into dry snow, which are needed develop snowpack models that include water moving processes. Detailed information on the heterogeneity of pore distribution and snow microstructures in layered snowpack are needed to understand the water flow phenomena in a natural snowpack.
Object ID: ISSW2018_P10.22.pdf
Language of Article: English
Presenter(s):
Keywords: Fingering flow, Lateral flow, Capillary barrier, MRI, μCT
Page Number(s): 971-975
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