Author(s): Fumiya Yagi; Tastuhiko Uchida; Yoshihisa Kawahara
Linked Author(s): Tatsuhiko Uchida, Yoshihisa Kawahara
Keywords: Bottom velocity computation (BVC) method; Bank erosion; Turbulence energy; Seno River; Misasa River
Abstract: A river channel curves in various ways and generates a three-dimensional flow, which causes riverbank erosion at the bends and is a major cause of damage to river structures. To reduce the damage caused by riverbank erosion, it is essential to establish a method that can be used to calculate the risks of riverbank erosion. The purpose of this study is to develop such a method to clarify the three-dimensional flow in a two-dimensional framework and to establish a method for evaluating riverbank erosion. Turbulence energy was used as an indicator of the risk of riverbank erosion, and we clarified that it could be assessed using quasi-threedimensional analysis. As a result, it was found that turbulent energy could be estimated at erosion danger points regardless of the erosion mode. In addition, the value of the turbulent energy k1/2 at the location at which the riverbank erosion occurred exceeded 0.4–0.5m/s.
Year: 2020