Effect of sediment supply on geometry of wave ripples: preliminary results of flume experiment

• Published in: Journal of the Sedimentological Society of Japan Vol. 80; no. 1-2; pp. 3 - 9
• Main Authors: Sekiguchi, Tomohiro, Yamaguchi, Naofumi, Taki, Toshifumi
• Format: Journal Article
• Language: English; Japanese
• Published: Matsumoto The Sedimentological Society of Japan 28.02.2022; Japan Science and Technology Agency
• Subjects: Accretion; Flumes; Grain size; laboratory experiment; Lamination; Morphology; oscillatory flow; Particle size; Ripples; Sediment; sediment supply; sedimentary structures; Sediments; Water depth; Wave height; Wave period; wave ripple marks
• ISSN: 1342-310X; 1882-9457
• DOI: 10.4096/jssj.80.3

In order to examine the effects of sediment supply on wave-ripple morphology, we conducted flume experiments under similar hydraulic conditions with three different sediment supply rates. In a case with relatively low sediment supply rate, the wave-ripple morphology was maintained. As the sediment supply rates increased, the initial wave ripples flattened over a larger area. Under the hydraulic conditions and sediment grain size in the present experiments (water depth: 0.3 m, wave period: 1.0 s, wave height: 76-78 mm and sediment grain size: 0.20 mm), flattening of wave ripples was observed at bed aggradation rate of 32 mm/min. This result suggests that the previous formation models of wave-ripple lamination, in which wave ripples are unaffected by sediment supply, do not necessarily hold when the sediment supply rate is high.