Author(s): Chang-Lae Jang; Minseok Kang; Hyo Hwang; David Oh

Linked Author(s): Chang-Lae Jang

Keywords: Vegetation; Laboratory experiments; Numerical model; Sediment transport; Bed load

Abstract: This study analyzed bed load transport and channel changes in the vegetation zone through laboratory experiments and numerical simulations. To examine the effect of the vegetation zone in the laboratory experiment, artificial vegetation zones made of acrylic sticks were installed in the experimental channel, and discharge conditions were adjusted to observe bed load transport and channel changes in the vegetation zone. Numerical simulations were performed using the Nays2D model, a two-dimensional numerical model, with the same conditions as the laboratory experiment, and the applicability of the numerical model was examined by comparing the results with those of the laboratory experiment. A numerical model was used to examine bed load transport and channel changes according to changes in vegetation density. The results of the laboratory experiment and numerical model showed similar trends when examining bed load transport and channel changes in the vegetation zone under different discharge conditions. As the discharge increased, bed load from the upper stream was deposited inside the vegetation zone. On the other hand, on the opposite side of the vegetation zone, the flow was concentrated, resulting in erosion. Additionally, the extent of erosion increased downstream. Upon examining the transport of bed load and channel changes in relation to changes in vegetation density, it was observed that as vegetation density increased, the bed load from the upper stream was deposited inside the vegetation zone. Conversely, due to the higher vegetation density, the flow was concentrated on the opposite side of the vegetation zone, resulting in erosion.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p1774-cd

Year: 2023