2017年九州北部豪雨災害による斜面災害の特徴

Abstract

The 2017 Northern Kyushu Rainstorm induced numerous numbers of landslides, which heavily damaged forest, roads, rivers, and houses with 37 fatalities and 4 missing. We investigated landslides using air photographs and high-resolution digital elevation models. Landslides occurred mainly in areas with over 200 mm/3 hr of rainfall. Landslide densities were higher in granodiorite and pelitic schist areas than in areas of volcanic rocks. Landslides were mostly shallow but large landslides occurred in at least two locations, where landslide dams were made. Huge volume of tree logs yielded with rock debris and soil, enlarging the disaster.