INVESTIGATIONS OF THE BEDLOAD SEDIMENT TRANSPORT IN A NATURAL RIVER USING IC-TAG MONITORING TECHNIQUE AND NUMERICAL SIMULATIONS

Abstract

Sediment transport is a most important piece of controlling the morphological evolution of the bed in rivers, however, it is generally hard to understand the transport processes, in particular, in natural streams because of the difficulties of monitoring and modelling. In this study, we first perform a monitoring of the transport process of sediment (more specifically, gravels transported as bedload) in a natural river using an IC-tag technique. The bedload transport caused by a bankfull-scale discharge of the river is measured by tracking a hundread of IC tag-embedded gravels. We then conduct numerical simulations to reproduce the monitored bedload transport and depositional patterns of gravels using an Euler-based bedload tracer transport model coupled with a 2D morpholodynamic model. The results show that the model reasonably predicts the monitored distribution of the gravels deposited in the river, suggesting that proposed model can be used to quantify the bedload transport processes in field-scale rivers.