2016 Fiscal Year Final Research Report
Risk determination of debris flow disaster from the viewpoint of time-related disaster prevention studies integrated by carbon dating and paleographic analysis
Project/Area Number |
26560185
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Research Category |
Grant-in-Aid for Challenging Exploratory Research
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Allocation Type | Multi-year Fund |
Research Field |
Natural disaster / Disaster prevention science
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Research Institution | Yamaguchi University |
Principal Investigator |
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Research Collaborator |
Sakaguchi Kazuyuki アジア航測株式会社, 理事・フェロー
Matsugi Hiroaki 復建調査設計株式会社, 地盤防災課長
Hanno Mitsumasa NPO法人山口県防災・砂防ボランティア協会, 理事長
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Project Period (FY) |
2014-04-01 – 2017-03-31
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Keywords | 土石流 / 年代測定 / 歴史 / リスク / 発生頻度 / 花崗岩 |
Outline of Final Research Achievements |
During the heavy rainfall in 21 July 2009, many slope failures and debris flows occurred around Hofu City, Yamaguchi Prefecture. In this area, debris flow cones have progressively formed due to past debris flows. Therefore, it is important to assess the long-term risk of sediment disaster and its recurrence period in order to prevent any disasters in the future. In this research, the radiocarbon dating was conducted on carbides collected from previous debris flow deposits. The distribution of measured values was compared with the disaster events recorded in the historical archives. As a result, it is clear that debris flows of similar magnitude occurred nine times or more since 600 A.D. and the interval of debris flow occurrence was estimated to be between 100 and 200 years. The proposed research approach is effective and useful to inspect the history of past disasters in areas where the weathered granite is widely distributed.
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Free Research Field |
地盤防災学
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