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[HTT08-04] High-definition topography applied to landslide hazard assessment around Aso Volcano
Keywords:shallow landslide, UAV, SfM-MVS photogrammetry
We obtained ortho-rectified photographs and DSMs with spatial resolutions of 4 cm and 10 cm, respectively. In the Saishigahana area, 20 landslides (20–4,600 m2) occurred. The ratio of the total landslide area reached 30% of the area. These landslides tended to occur specifically on 40-degree slopes. The landslide depth was ca. 1.0 m. The estimated total landslide volume was 1.5–2.8×105 m3/km2. In the Sensuikyo area, 300 landslides (10–10,000 m2) occurred. The estimated total landslide volume was 1.1–1.4×105 m3/km2. In the Sensuikyo area, the landslide distribution was not uniform. Our results indicate that topography and past landslide history affected these landslide occurrences. Additional studies must be conducted to detect temporal changes of topography and vegetation around shallow landslides based on multi-temporal ortho-photographs and DSMs.