Experimental Investigation and Numerical Simulation of Morphological Changes in Natural Channel Bend

Sediment transport is an important process in maintaining balance of the form of river. The transport of bed load particles affects the processes of aggradation and degradation of the riverbed significantly. To predict the evolution process of the river morphology, the numerical model is considered as a useful tool. This study developed a two-dimensional (2D) depth-averaged model for the morphological change in the river bend. The flow module is represented by the shallow water equations, and the river morphological changes are represented by the sediment continuity equation. The sediment transport module treats bed load as mixtures of multiple grain-size sediments. A finite difference method was applied to solving the governing equations. The developed model was applied to predict bed-load transport rate on one set of the laboratory experiment. A field study was further applied to demonstrate the capability of the developed model in predicting morphological change in the curved river section in South Korea. The simulation results of the developed model were in good agreement with field data both laboratory experiment and natural channel bend.