2008 Volume 52 Pages 781-786
Field observations on characteristics of discharge were conducted in an urban tidal river, the Horikawa River. Velocity distributions and discharges on various cross sections were measured by acoustic Doppler profiler (ADP). The longitudinal distribution of maximum discharge caused by tidal flow was revealed. The velocity structures in a falling stage were different from those in a rising stage. In the falling stage, the surface-layer velocity is higher and the lower-layer velocity is lower than the log-law profile. In the rising stage, the medium-layer velocity indicates maximum value. In a concavity zone of the tidal river, horizontal vortices were observed in both the falling and rising stages. The flow structures in the concavity zone indicate three-dimensional feature. The surface vortex structures were different between falling and rising stage.
