摘要：An understanding of bedload transport processes is an essential
research goal for better prediction of river morphology and morphodynamics
as well as the transport and fate of sediment-bound materials in river systems.
Passive tracer particles have been used widely to monitor bedload transport
processes in rivers by measuring the spatiotemporal distribution of the
bedload tracers. Here, we propose a numerical model for reproducing the
transport of bedload tracers in river systems, more specifically, the
behaviours of bedload tracers under the influence of complex river
morphodynamics. A two-dimensional morphodynamic model is combined
with a flux-based bedload tracer model with use of the active layer approach.
The model is applied to a laboratory experiment that demonstrates the
transport processes within the channel of bedload tracers supplied from the
floodplain. The numerical model effectively reproduces the main features of
the experiment, namely, the bedload tracers supplied from the floodplain due
to bank erosion deposit onto sand bars developed within the channel.
Because the sand bars cause a very long residence time of the bedload tracers
within the bed, the transport speed of the tracers is slowed significantly
under the influence of bar formation and channel migration.
其他摘要：An understanding of bedload transport processes is an essential research goal for better prediction of river morphology and morphodynamics as well as the transport and fate of sediment-bound materials in river systems. Passive tracer particles have been used widely to monitor bedload transport processes in rivers by measuring the spatiotemporal distribution of the bedload tracers. Here, we propose a numerical model for reproducing the transport of bedload tracers in river systems, more specifically, the behaviours of bedload tracers under the influence of complex river morphodynamics. A two-dimensional morphodynamic model is combined with a flux-based bedload tracer model with use of the active layer approach. The model is applied to a laboratory experiment that demonstrates the transport processes within the channel of bedload tracers supplied from the floodplain. The numerical model effectively reproduces the main features of the experiment, namely, the bedload tracers supplied from the floodplain due to bank erosion deposit onto sand bars developed within the channel. Because the sand bars cause a very long residence time of the bedload tracers within the bed, the transport speed of the tracers is slowed significantly under the influence of bar formation and channel migration.
