Estimating sediment storage rate in mountainous river channel by LiDAR data

Kenji MIWA, Jiro OURA, Kenji TAKETOSHI, Tadashi KUMAKI, Yoshiaki KASHIWABARA,
Kosuke YOSHINO and Nao KINOSHITA

Abstract

It is thought that a large amount of sediment produced during a flood in the mountainous river channel will once stay in the river channel and will flow secondarily at the time of the subsequent flooding. But there are few examples of estimating sediment storage rate in mountainous river channel in Japan. On the other hand, use of LiDAR data is advanced in terrain measurement. In the Kinugawa watershed, remarkable sediment transport occurred due to collapse of hillside and debris flow during the September 2015 torrential rains in the Kanto and Tohoku region. Therefore, We tried to grasp the sediment storage rate on the mountainous river channel by differential analysis of the LiDAR data of before and after the September 2015 torrential rains in the Kanto and Tohoku region. The obtained sediment storage rate was about equivalent to the past report.

Key words

sediment storage rate, LiDAR data, differential analysis, Kinugawa watershed