Japan Geoscience Union Meeting 2024

Presentation information

Print

[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS11] Mountain Science

Mon. May 27, 2024 3:30 PM - 4:45 PM 201B (International Conference Hall, Makuhari Messe)

convener:Yoshihiko Kariya(Department of Environmental Geography, Senshu University), Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Chiyuki Narama(Niigata University, Program of Field Research in the Environmental Sciences), Motoshi Nishimura(Interdisciplinary Cluster for Cutting Edge Research, Institute for Mountain Science, Shinshu University), Chairperson:Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Chiyuki Narama(Niigata University, Program of Field Research in the Environmental Sciences)

4:15 PM - 4:30 PM

[MIS11-09] Denudation process of rock slope at Mt. Shakushi in the Hakuba mountain range

*Hirotaka Sugiyama1, Chiyuki Narama2 (1.Graduate School of Science and Technology, Niigata Univ., 2.Niigata Univ.)

Keywords:Rock slope failure, Joint density, Denudation process, Gravitational deformation, Alpine belt

To clarify the denudation process of the rock slope at Mt. Shakushi in the Hakuba mountain range, we investigated the recent changes (1976-2023) of the rock slope that caused the rock slope failure in 2005 using a multi-year 3D topographic model created from SfM-MVS software with aerial photographs and UAV images. As the result, we found that denudation occurred frequently on rock walls with high joint density. Two clacks were observed in the head area of the rock wall before the collapse in 2005. The collapse occurred along the clack of the valley side. The other remaining clack has expanded during 2019-2023, and rock wall is in an unstable state. In this study, in addition to the observed denudation process due to joint density dependence, crack expansion along the dominant joint was also observed, indicating that gravitational deformation plays an important role in the denudation process.