| 講演要旨(和文) | | 豪雨災害により発生した深層崩壊地周辺において空中物理探査を実施し,地上電気探査やボーリング調査,空中写真判読等の結果と共に深層崩壊危険地の抽出を試みた.空中物理探査結果からは,地上電気探査結果およびボーリング調査結果と検討することにより風化岩盤と新鮮な岩盤との境界を示唆する比抵抗値を推定した.さらに,この比抵抗値の断面的な分布と空中写真判読を比較することにより,深層崩壊発生域の斜面土層および地質構造の特性を明らかにした.これらの結果から,新鮮な岩盤の傾斜や風化岩盤の層厚と深層崩壊発生区域との関係に関し,いくつかの知見を得た. |
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| | 講演要旨(英文) | | We carried out airborne geophysical survey for deep collapse site that occurred by heavy rain disaster at Mt. Wanitsuka, Miyazaki prefecture in 2005. The resistivity distribution that suggests the border between instable layer and stable ground was estimated by inspecting the results from vertical electric survey and drilling survey. In addition, characteristics of slope and geological structure at deep collapse area were determined by comparing the vertical distribution of resistivity with the aerial photo-interpretation. Based on these results, angle of stable ground and thickness of instable layer were estimated, and potentially deep collapse area was extracted with surface slope angle. |
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