微地形から解析される地すべりの移動過程：北海道日高幌内川岩盤すべりを例に

抄録

Micro-landforms formed by mass movement reflect their process. In this study, classification and its arrangement of micro-landforms were examined subjecting to the Hidakahoronaigawa rockslide induced by the 2018 Hokkaido Eastern Iburi Earthquake, using precise topographical maps based on DTM with 0.5 m grid, aero photos and satellite images before and after the earthquake. The descending, disruptive and arresting processes of the deplete mass and the mode of movement were analyzed based on the arrangement and the relationship of the classified micro-landforms. The landslide movement launched as a translational slide immediately after shallow tephra layer slide. And then the movement continued as rotational slides and rock avalanches in sequence while in the depositional area. Finally, shallow slides, debris flows occurred in various places. The precise topographic maps and satellite images before and after the earthquake were very useful for recognizing the landform formation by this landslide.