Water flow and sediment transport in a 90° channel diversion: an experimental study

This paper reports the results of an experimental series carried out to study flow and sediment distribution in a 90° channel diversion. Each experiment is performed letting the system evolve until an equilibrium state is achieved. The obtained results confirm that sediment tends to move into the lateral branch as suggested in previous studies. The experiments also show a dependence of the phenomenon on the total water discharge and the bed topography evolution in the diversion area. These results have not been previously reported. Over a threshold value of momentum flux ratio, a depression is formed in the main branch that acts as a blocking mechanism for sediment, capturing and directing it towards the lateral branch. This study highlights the importance of interrelations at fluvial diversions between the evolution of bed topography, flow characteristics and sediment distribution.