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Abe, O., Nakamura, T., Lang, E.T. and Ohnuma, T.,
: Comparison of simulated runout distances of
snow avalanches with those of actually observed
events in Japan. IAHS Publication, , .
Gubler, H., : Measurement and modeling of snow
avalanche speeds. IAHS Publication, , .
:
pp.
Issler, D., : Experimental information on the dy-
namics of dry-snow avalanches. Dynamic re-
sponse of granular and porous materials under
large and catastrophic deformations. Lecture
notes in applied and computational mechanics, ,
Berlin, Germany, Springer Verlag, .
Johnson, Jr., R.C., Ramey, G.E. and O’Hagan, D.S.,
: Wind induced forces on trees. Journal of Flu-
ids Engineering, , .
:
.
Kern, M., Bartelt, P., Sovilla B. and Buser O., :
Measured shear rates in large dry and wet snow
avalanches. Journal of Glaciology, , .
:
pp.
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AKEUCHI ORITA ISHIMURA AKAMOTO
AGINO OTO URAKAMI NDO
. :
: .
. Takeuchi, Y., Yamanoi, K., Endo, Y., Murakami, S.
pp. and Izumi, K., : Velocities for the dry and wet
: snow avalanches at Makunosawa valley in
. Myoko, Japan. Cold Region Science and Technol-
Nishimura, K. and Ito, Y., : Velocity distribution ogy, , .
in snow avalanches. Journal of Geophysical Re-
search, , No. B , . Evgeniy Podolskiy
: :
.
: .
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Yukari T , Hiroyuki T , Koichi N , Tomoki S ,
Hiroaki H , Yoshiaki G , Shigeki M and Yasoichi E
: A large-scale dry slab avalanche occurred at the Makunosawa valley in Myoko on
February , , which damaged many trees in the valley. We investigated the extent of damage
to the artificial cedar forest. We also estimated the decrease in avalanche velocity in the forest. Our
aim is to verify the role of forests in reducing the avalanche velocity. We found that the cedar trees
were broken by the bending stress. The damage was most near the upper edge of the forest. The
number of damaged trees decreased gradually in the forest. On the basis of these observation
results, we estimated the avalanche velocity from the bending stress of the broken cedar trees. We
considered two cases in the calculations: ( ) only the suspension layer of avalanche flowing into the
cedar forest and ( ) two layers of avalanche, consisting of a suspension layer (density: kg m ) and
a dense-flow layer (density: kg m ), flowing into the forest. In result, the avalanche was
estimated to flow into the cedar forest at the velocity of m s with a m high suspension
layer and a dense-flow layer less than m in height. The calculation result showed that the
avalanche slowed down in the forest and stopped around m from the upper edge of the forest.
This result is consistent with the observations.
) Tohkamachi Experimental Station, Forestry and Forest Products Research Institute,
Tatsu-otsu , Tohkamachi
) Hokkaido Forestry Research Institute, Koshunai-cho, Biei
) Graduate School of Environmental Studies, Nagoya University,
Furo-cho, Chikusa-ku, Nagoya
) Forestry and Forest Products Research Institute,
Matsunosato, Tsukuba
) Kyushu Research Center, Forestry and Forest Products Research Institute,
Kurokami, Kumamoto
) Ken’s-house , Honcho , Tohkamachi
Abstract
Study of extent of damage to cedar forest by large-scale slab avalanche, and
estimation of the avalanche velocity at Makunosawa, Myoko, Japan
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