Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

M (Multidisciplinary and Interdisciplinary) » M-GI General Geosciences, Information Geosciences & Simulations

[M-GI25] Environmental changes in mountainous area

Tue. May 22, 2018 10:45 AM - 12:15 PM A08 (Tokyo Bay Makuhari Hall)

convener:Keisuke Suzuki(Department of Environmental Sciences, Faculty of Science, Shinshu University), Yoshihiko Kariya(Department of Environmental Geography, Senshu University), Chiyuki Narama(新潟大学理学部理学科, 共同), Akihiko SASAKI(Department of Geography and Environmental Studies, Kokushikan University), Chairperson:Narama Chiyuki(新潟大学)

11:30 AM - 11:45 AM

[MGI25-10] Altitudinal distribution characteristics of snow water equivalent at snow-clad volcanoes where cyclonic snowfall dominates

★Invited Papers

*Katsuhisa Kawashima1, Tsutomu Iyobe2, Takane Matsumoto1, Kyoko S. Kataoka1, Atsushi Urabe1, Akihiko Sasaki3, Keisuke Suzuki3 (1.Research Institute for Natural Hazards and Disaster Recovery, Niigata University, 2.Graduate School of Engineering, Kyoto University, 3.Faculty of Science, Shinshu University)

Keywords:snow-clad volcano, snow water equivalent, volcanic mudflow due to snowmelt

Eruptions at snow-clad volcanoes bring about intensive snowmelt, which may cause enormous damage by the occurrence of volcanic mudflow. Assessments of the risk associated with volcanic mudflows due to snowmelt require the understanding of temporal and spatial distribution of snow water eqivalant (SWE) on the slope of volcanoes. Because of the insufficient knowledge of the altitudinal distribution characteristics of SWE at snow-clad volcanoes where cyclonic snowfall dominates, we conducted snow surveys at Ontake volcano, Azuma Adatara volcanoes, and Kusatsu-Shirane (Motoshirane) volcano since the snow season of 2014/15. Consequently, snow surveys revealed that SWE depends on altitude (H) approximately linearly, which is given by SWE=a・H+b, where the proportional coefficient a means the rate of increase in SWE per unit height. Obtained values of increasing rate a range from 0.3 to 1.1 mm/m, indicating that the increasing rate is much smaller at snow-clad volcanoes where cyclonic snowfall dominates in comparison with those where snowfall by winter monsoon dominates. The present paper discusses the influence of snowfall processes and meteorological conditions on altitudinal distribution characteristics of SWE.