| 講演要旨(和文) | | 地すべり発生の要因である地すべり面や地下水の分布を面的に理解するためには、斜面下の地下構造を物理探査などにより把握することが必要である。本研究ではケーススタディーとして、長期間の地すべり観測が実施されている斜面（徳島県三好市）において比抵抗トモグラフィーを実施した。その結果、現在クリープを起こしている地層は相対的に低比抵抗であることが示された。本発表では、地すべり面や地すべり履歴と地下比抵抗構造の関係について議論を行う。 |
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| | 講演要旨(英文) | | Spatial distribution of slip plane at landslide has been characterized by geophysical explorations. For example, electrical resistivity tomography (ERT) often indicates low resistivity zones along the slip plane. However, the resistivity boundary (between conductive surface and resistive basement) is also found along the slip plane. For delineate the complex feature, we conducted the ERT along the well-studied landslide are in Miyoshi City, Tokushima prefecture, as a case study. Two profiles on the slope are characterized as past slope failure and ongoing creep, possible related to the future failure, respectively. In the inversion results, conductive layers are commonly found below the two profiles, however, the resistivity value below the creeping part is much lower. Also, the surface layer below the creeping part is lower. In conclusion, low resistive zone is possibly related to the slip plane, and becomes vague below the slope with past failures. |
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