Risk assesment of sediment disasters by multispectral imagery

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18790
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 25:Social systems engineering, safety engineering, disaster prevention engineering, and related fields
• Research Institution: Shizuoka University
• Principal Investigator: Imaizumi Fumitoshi 静岡大学, 農学部, 教授 (80378918)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 土石流 / 分光反射特性 / 撹乱

Outline of Final Research Achievements

Aim of this study is to clarify relationship between the sediment transport history and spectral reflection characteristics in the debris flow torrents. Field monitoring of the debris flow, analysis of debris flow records, and UAV photography of multi-spectral images were conducted in the Ohya landslide, north Shizuoka, central Japan. Our study clarified temporal changes in the reflection characteristics after occurrence of debris flow, mainly affected by the recovery of vegetation.We also demonstrated that grain size in the debris flow torrent can be automatically detected using high-resolution UAV images. UAV photogrammetry was also conducted in other large-scale landslides with different sediment transfer characteristics and geology. We conducted disciplinary studies with researchers from many academic fields such as spatial information science, geomorphology, and remote sensing science.

Free Research Field

砂防学

Academic Significance and Societal Importance of the Research Achievements

本研究により，地表面の分光反射特性が，土石流発生後の経過年数とともに変化することを示した。この研究成果は学際的な研究と，土石流の発生頻度が極めて高い流域で行った現地観測の結果得られたものであり，国際的にみても新規性が高い。この知見を用いれば，渓流の過去の土石流の発生履歴を１回のドローンを用いた調査により，推定することができるようになる。そのため，土砂災害への対策を立案するための調査への活用が期待される。