Author(s): Luiz Eduardo Domingos De Oliveira; Carlo Gualtieri; Johannes Gerson Janzen

Linked Author(s): Carlo Gualtieri

Keywords: Lateral cavity; Vegetation; Geometric shape; Sediment transport; Large Eddy Simulation (LES)

Abstract: Lateral cavities, in the context of rivers, are regions connected to the main channel by a single interface. The presence of vegetation in lateral cavities modifies the flow, mass and sediment transport. Similarly, the shape of the lateral cavity also impacts on these metrics. In this study, the impact of both shape and vegetation density on the hydrodynamics, mass and sediment transport were investigated with a numerical model. The vegetation density was distributed from 0 to 10.65% in four cases for each geometry. Mass transport was investigated with the washout procedure using an inert tracer and sediment transport was investigated through the Rouse number, Hjulstrom, and Shields diagrams. The trapezoidal geometry could retain non-null velocities in denser vegetation scenarios compared to the rectangular. Furthermore, the mass exchange in the trapezoidal geometry was generally faster. Finally, neither shape nor vegetation played a significant role in sediment transport as the stronger mechanism remained the sediment particle diameter.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0043-cd

Year: 2023