Geological Structure and Timing of Landslide Occurred in Volcanic Rock Area, by the 2017 Northern Kyushu Heavy Rain Disaster

Abstract

Geological field survey and hearing at landslide time, analysis of radar rainfall of three Landslides sites, which occurred by North Kyushu heavy rainfall of July 2017 in volcanic rock area. The results of the investigation are as follows：（1） large-scale landslide site formed a structure that facilitated the storage of the groundwater by the fault perpendicular to the slope,（2） medium-scale landslide site was a gentle dip slope structure,（3） shallow landslide site was cap lock structure it seems that the supply of groundwater caused by rainwater was delayed.

As a result of reflecting such geological structure, it became clear that landslide occurred in the order of large-scale landslide, medium-scale landslide, and shallow landslide.