Secondary sediment movements and secondary sediment disasters caused by rainfalls after the Kumamoto Earthquake in April 2016

Abstract

After the Kumamoto Earthquake in April 2016, a lot of secondary sediment movements were induced by rainfall and secondary sediment disasters were caused by them from April 16th to the end of July in Kumamoto prefecture, especially in the Aso volcanic range. Hence, field investigations and reconnaissance were conducted four times by the Japan Society of Erosion Control Engineering to clarify the actual conditions of the phenomena of secondary sediment movements and secondary sediment disasters. The various results and information obtained through those investigations were reported as the secondary report concerning characteristics of rainfall after the earthquake, distribution of secondary sediment movements, geologic-geomorphologic characteristics of secondary sediment movements, features of secondary disasters, and the efficiency of Sabo facilities in these disasters.