2019 Fiscal Year Final Research Report

High accuracy risk assessment of sediment disaster considering paleoclimate and social change in the last millennium

Research Project

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Project/Area Number	17K18954
Research Category	Grant-in-Aid for Challenging Research (Exploratory)
Allocation Type	Multi-year Fund
Research Field	Social systems engineering, Safety engineering, Disaster prevention engineering, and related fields
Research Institution	Yamaguchi University
Principal Investigator	Suzuki Motoyuki 山口大学, 大学院創成科学研究科, 教授 (00304494)
Co-Investigator(Kenkyū-buntansha)	楮原京子山口大学, 教育学部, 准教授 (10510232) 川島尚宗山口大学, 大学情報機構, 助教 (10650674) 江口毅山口大学, 大学情報機構, 助教 (20783773) 赤松良久山口大学, 大学院創成科学研究科, 准教授 (30448584) 進士正人山口大学, 大学院創成科学研究科, 教授 (40335766) 高橋征仁山口大学, 人文学部, 教授 (60260676) 森下徹山口大学, 教育学部, 教授 (90263748)
Project Period (FY)	2017-06-30 – 2020-03-31
Keywords	土石流 / 年代測定 / 古気候 / 遺跡 / 洪水 / ハザードマップ / リスク / リモートセンシング
Outline of Final Research Achievements	The purpose of this study is to improve the accuracy of long-term risk assessment of sediment disaster. Therefore, we tried to clarify unrecognized disaster events in history by adding the information of paleoclimate and social changes to the disaster chronology created from the occurrence dates of past debris flows and the disaster archives. Next, we made disaster risk maps by analyzing ruins of villages and temples, collapse sites, debris flow paths, flood areas, and then considered where people in each age were seeking safe places. As a result of this research, the measurement results of oxygen isotope ratios for tree rings collected in this area were consistent with the heavy rainfall disaster records in the neighboring areas. Furthermore, the positional relationship between people's living place and the zone where there is a risk of debris flow or floods damage was clarified.
Free Research Field	地盤工学
Academic Significance and Societal Importance of the Research Achievements	本研究により、研究対象地域における災害の発生傾向や防災上の弱点が時・空間的に理解された。また、先人の安全意識や居住地等の選定基準をある程度推定することができた。この成果は、長期間にわたる災害事実を考慮したハザードマップの開発に活用することができ、さらに、地域住民の災害に対する慣習的誤解の解消に寄与するものと期待される。