Author(s): Kevin Flora; Ali Khosronejad

Linked Author(s): Kevin Flora

Keywords: No Keywords

Abstract: High-fidelity numerical modeling of natural rivers can provide valuable insight for many engineering purposes; however, the many complexities in the riverine environment require simplifying assumptions to facilitate the numerical simulations. Our study explores how complex vegetation along the banks can impact the hydrodynamic results in rivers using large eddy simulations (LESs) by incorporating trees into the model using two approaches: (1) discrete modelling of individual tree-like structures and (2) extraction of momentum from tree regions using a vegetation model. The results from both approaches demonstrated that trees redistributed the flow within the river. The unit flow rate was significantly reduced along the banks and increased in the center of the river when compared to simulations which omitted bankline trees. Likewise, the bed shear stress was redistributed in the simulations with trees which can impact morphological predictions such as bank erosion and sediment transport potential in rivers. In addition, both vegetation approaches showed reductions in TKE within the tree regions but increases in TKE immediately adjacent to the banks due to shear layers. The two vegetation approaches did differ, however, with respect to near-bank turbulent structures.

DOI:

Year: 2022