Author(s): Norio Harada; Ichiro Kimura; Yoshifumi Satofuka
Linked Author(s): Ichiro Kimura, Norio HARADA
Keywords: Backwater experiments field survey sediment and flooding damage
Abstract: The frequent occurrence of sediment discharge and flooding at river confluences in Japan, exacerbated by localized heavy rainfall due to climate change, has become a growing concern. Intensive countermeasures to address these issues are urgently needed. This study examined the mechanisms underlying structural damage caused by sediment discharge and flooding based a literature review and field survey. Sediment deposition was experimentally investigated in tributaries upstream of confluences, focusing on water level fluctuations in the main river downstream. The results suggest that intense rainfall events and downstream water level increases during a flooding disaster contribute to significant sediment production and backwater effects. Flume experiments conducted to verify the impact of water level fluctuations in the main river on tributaries revealed the formation of a sediment delta, typically observed in reservoir areas, immediately upstream of the confluence when the water level of the main river increased.
Year: 2025