Monitoring of landslide deformation on the E slope of Mt.Takabi in Yamagata Prefectrue, Japan using ALOS-2 and ariborne LiDAR data

Mt.Takabi (869.4m) is underlain by basalt lava, sandstone and mudstone in Miocene. Seismisity around the mountain is low currently; however, intermittent landslide deformation has been observed on site and once an earthquake occur, the deformation may become remarkable. Therefore, continuous monitoring of the deformation is important. In this study, detection of the deformation were compared between airbone LiDAR data observed in 2013 and 2021 and time-series ALOS-2 data observed between April 2016 and January 2025. And the detecting results were evaluated by on-site data. As a result, it was found that the deformation near the ridge was sharply detected by both data; however, though the deformation at the foot of the mountain was detected by the LiDAR, the deformation was not detected by the ALOS-2 data. It is concluded that direction of the deformation near the ridge is E and sensitively detected by the ALOS-2 data but direction of the deformation at the foot of the mountain is S and unsensitively detedted by the ALOS-2 data.