[H-DS17] [JJ] Geohazards in humid, tectonically active countries and their precursors

2:30 PM - 2:45 PM JST(5:30 AM - 5:45 AM UTC)

[HDS17-04] Study on landslide-susceptible slopes by heavy rain in the Aso Caldera, Southwest Japan

*Daisuke Higaki¹, Xueqiang Li², Ikuima Hayashi¹ (1.Faculty of Agriculture and Life Science, Hirosaki University, 2.Japan Conservation Engineers Co. Ltd.)

Keywords:

landslide,tephra,Aso Mountains

The Aso Caldera located in Kyushu, Southwest Japan has been affected by concentrated occurrences of surfacial landslides in the tephra layers in the recent decade. This study aims to propose the detection of slopes with landside susceptibility by heavy rain based on interpretation of LiDAR-based high-resolution topographical maps. Remnants of past landslides are widely distributed on the tephra-covered slopes. Analysis on the locations of recent landslide occurrence indicates that surrounding slopes of remnants of surficial landslides and steep valley side slopes are prone to landslides by heavy rain. Inside of past landslide slopes partially covererd with collapsed materials also may become susceptible after time of tephra deposition.