INVESTIGATION OF RIVER STRUCTURES DAMAGED AT CHIKUMA RIVER DUE TO TYPHOON NO. 19, OCTOBER 2019

Abstract

 Typhoon 19, which landed on the Japanese Islands on October 12, 2019, brought record-breaking heavy rain to the Kanto-Koshin and Tohoku regions. In the Chikuma River basin of the Shinano River system, severe damage to bridges and large-scale inundation occured due to a levee breach occurred. On October 23 and 24, 2019, about 10 days after the disaster, we carried out a field survey at the damaged sites of river structures in the Chikuma River. The investigation techniques used field exploration and aerial photography by Unmanned Aerial Vehicle (UAV). This paper reports the damage situations obtained from the field survey at the sites where the abutment backfills were washed away and the levee breach occurred. It also cites issues for future consideration.