Development of compact exploration equipments for MT method for predictive detection of landslide disasters

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K04950
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: Kyushu University
• Principal Investigator: Tanaka Toshiaki 九州大学, 工学研究院, 助教 (90294892)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 土砂災害 / 地下水分布 / 比抵抗 / 電磁探査 / 探査装置

Outline of Final Research Achievements

In steep slope areas, the risk of landslides increases when groundwater levels rise rapidly due to heavy rainfall. To detect rising groundwater levels at the ground surface, a compact MT method exploration equipment was developed, focusing on the change in the resistivity of the ground. The exploration equipment was emphasized for its portability and light weight. A prototype of the equipment was developed and its basic functions were tested in the laboratory and in the field. In the MT method, which measures electric and magnetic fields, noise from power lines can be an obstacle to measurement in both urban and mountainous areas. Therefore, based on the results of noise evaluation, an appropriate noise reduction circuit was added to the exploration equipment. As a result, it was confirmed that the electric and magnetic fields can be accurately measured.

Free Research Field

物理探査学

Academic Significance and Societal Importance of the Research Achievements

急傾斜地などで発生する土砂災害は、地盤中の地下水の増加が原因の一つとして知られている。地下水の分布は、観測孔に設置した地下水位計などにより測定されることが多い。しかし、広範囲な地下水位変化をモニタリングするためには、多数の観測孔が必要になり、コストと労力が必要になる。そこで、地下水の分布によって変化する地下の比抵抗分布を地表からMT法により測定する。しかし、MT法の探査装置は一般に高価であるため小型の探査装置を開発した。その結果、多数の探査装置を同時に利用することで、精度良く地下水の分布の推定が可能となり、減災の一助となりうる。