3:00 PM - 3:15 PM
[HDS11-04] Comparing magnitudes of tephra-mantled slope failures triggered by the 2016 Kumamoto earthquake and those triggered by rainfalls before and after the earthquake in the post-caldera central cones of Aso volcano, southwestern Japan
Keywords:Aso volcano, Post-caldera central cones, tephra-mantled slope, landslide depth, area-volume relationship, 2016 Kumamoto earthquake
The Airborne LiDAR (Light Detection and Ranging) measurement has been conducted four times around the Aso volcano as follows: before and after the rainfall event in July 2012 (April 2010 and January 2013), just after the 2016 Kumamoto earthquake (late April 2016), after the rainfall event in late June 2016 (August 2016). We developed multi-temporal Digital Elevation Models (DEMs) with high-resolution (0.5-1 m grid) based on these LiDAR data, and measured the depth and volume of individual slope failures by computing elevation changes between each pair of DEMs for the above three events. In this report, we examine 1) how the difference of triggering factors (earthquake vs. rainfall) among the three events effects on the depth and volumetric characteristics of tephra-mantled slope failures, and 2) whether the characteristics vary considerably between the two rainfall events (before vs. after the earthquake).