ABSTRACT
Flume experiments were conducted under unsteady hydrograph flows with sediment feed and no-sediment feed conditions specified at the upstream boundary. Bedload transport data were collected and analysed to investigate the effects of sediment supply on sediment transport characteristics in terms of bedload transport rates and hysteresis, as well as total bedload yields over the hydrograph duration. Higher sediment transport rates, and consequently 4-19% higher total bedload yields were found during no-sediment feed tests, as compared to equivalent sediment feed tests. Clockwise hysteresis was dominant during the no-sediment feed tests, while a frequent counter-clockwise hysteresis was observed during sediment supply tests. The results showed that hysteresis pattern had changed dramatically from counter-clockwise to clockwise during no sediment feed tests. These findings highlight the importance of sediment supply in laboratory investigations and differentiate the expected sediment transport characteristics in alluvial and supply-limited river channels.
