Relationship between Slope Failure and the Active Fault based on Kumamoto Earthquake in 2016 and following Heavy Rainfall Induced Disaster

Abstract

The slope sediment related disaster caused by the Kumamoto earthquake in April 2016, there were six types of natural slope failure and artificial slope failure. The slope failures occur within 10 km on both sides of the active strike slip fault, especially large slope failures occurred in vicinity of the active fault. The slope failure value pattern of separate length from the active strike slip fault is found to be located between the active reverse fault and active normal fault in almost the same magnitude.

The expansion of the slope failures due to the earthquake and the new slope failures in the rainfall catchment topography are caused by the torrential rain in couple of months after the earthquake. And about half of the slope failures caused debris flow.