Development of chemical weathering index to build innovative landslide monitoring

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K18785
• 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: Fukushima University
• Principal Investigator: KAWAGOE SEIKI 福島大学, 共生システム理工学類, 教授 (30548467)
• Co-Investigator(Kenkyū-buntansha): 藪崎 志穂 総合地球環境学研究所, 研究基盤国際センター, 上級研究員 (60447232)
• Project Period (FY): 2021-07-09 – 2024-03-31
• Keywords: 化学的風化指標 / 土砂災害発生予知 / 化学成分 / 被災回避 / 基底流 / 花崗岩類

Outline of Final Research Achievements

The goal of this study was to establish scientific technology that can provide specific information that can lead to avoidance of damage in advance, which is more effective for disaster prevention than emergency evacuation. We worked to develop scientific techniques to determine the degree of geological weathering using the chemical composition of the water quality of base flow runoff from a watershed. We collected examples from granitic areas in the Japanese archipelago where mass movements were frequent, and proceeded with sampling of basement flows in the watersheds. The water chemistry of the sampled samples was compared to obtain chemical properties that can identify the degree of weathering of the granitic geology. From these characteristics, a chemical weathering index was obtained and an attempt was made to derive risk from the mass movement.

Free Research Field

防災工学

Academic Significance and Societal Importance of the Research Achievements

気候変動に基づく豪雨頻発の危惧より，災害対策の高度改良だけでなく，多岐の科学技術を導入した安全な社会構築に向けての防災効果の高い革新的な防災技術の開発が急務である．本課題では，人的被害を引き起こしやすい土砂災害の発生予知と事前の被災回避を目的にして，花崗岩類の流域の基底流の化学成分を広域で比較することで風化度を同定をはかり「化学的風化指標」と「指標を用いたモニタリング」に寄与できる防災技術の開発に取り組んだ．「緊急避難」よりも防災効果の高い「風化進行が活発であり，安全のために早急に移転する必要がある」等の「事前の被災回避」に繋がる具体的な情報を提供できる科学技術の基盤情報を求めている．