Author(s): Takayuki Tanaka; Takuro Fukatsu; Yasuko Yamamoto

Linked Author(s): Takayuki Tanaka

Keywords: Hybrid groyne; Riverboat ADCP; River survey; River environment; River bed material

Abstract: The Aizuma River, which flows through Aichi Prefecture in Japn, meanders to the left after its confluence, three groynes are installed vertically in the downstream direction on the right bank about 300m downstream from the confluence of the Aizumame River and the Aizumao River. This groynes are formed by mixing impermeable stone groyne and permeable groyne with pile sill. However, the effect of these groynes on river flow has not been investigated. In this study, we use Riverboat ADCP to grasp the flow structure around the groynes and examine the effect of the groynes on the flow. All three groynes of the Aizuma River are installed about 22m apart. Each groyne is about 11 to 12m in total length, 60% of which is impermeable and 40% is permeable. The permeable groyne consists of two rows of 16 wooden piles facing the main stream. When observing water depth, flow velocity, discharge, and channel shape, survey lines L-1 to L-13 were set around the Aizuma River groyne. A riverboat equipped with an ADCP (Acoustic Doppler Current Profiler) was used for observation, and the riverboat was moved from the left bank to the right bank. As a result of observation, by combining permeable and impermeable groynes, it was confirmed that the resistance to water flow was increased and the effect of preventing erosion and flooding of the outer bank was confirmed.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0059-cd

Year: 2023