Risk evaluation of rock fall and Yukishiro (Slush avalanche and lahar) disaster in Mount Fuji and its public awareness activity

2017 Fiscal Year Final Research Report

• Project/Area Number: 26350477
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Natural disaster / Disaster prevention science
• Research Institution: Teikyo Heisei University
• Principal Investigator: KOMORI Jiro 帝京平成大学, 現代ライフ学部, 講師 (10572422)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 非噴火時 / 斜面災害 / スラッシュ雪崩 / 登山道 / 発生予測

Outline of Final Research Achievements

This study shows following results,
Related phenomena of Yukishiro consist 1) wet-snow surface-layer avalanche, 2) slush avalanche, 3) slush flow, 4) slush lahar and 5) debris flow without avalanche. In this study period, Yukishiro event was less frequent than before 2014. Even the spring in 2014 after record snowfall, remarkable event had never occurred. Snow structure may holds the key of the outbreak condition. Underground surveying radar detects the boundary of Yukishiro sediment, air-fall deposit and lava. Unexperienced and tragic Yukishiro event occurred from shallow valley in March 2018. There is the possibility that the valley is located on the northern scarp of Gotenba debris avalanche. Rock falls can be divided into 4 types; failures of massive rock wall, detachment of rock from agglutinated outcrops, rework of fallen rock and man-made rock fall. For safety of mountain tourist, change the ascending route at the 9.5 station of the Fujinomiya trail is urgently required.

Free Research Field

自然災害科学，地学教育