Author(s): Eun-Kyung Jang; Myeonghui Ahn; Un Ji; Inhyeok Bae
Linked Author(s): Myeonghui Ahn, Un Ji, Un Ji
Keywords: Flow Roughness; Flow Velocity; Numerical Calibration; Stream-scale Experiment; Vegetated Channel
Abstract: The impact of climate change has increased the frequency of extreme floods, necessitating a more precise analysis of flood level changes. A problem arises because the frequency of floods increases with the rapid increase in the number of dry days. The inflow of vegetation not only has an impact on flood levels, but also on the river system in general, including the effect of velocity decrease on sediment transport. Therefore, it is necessary to carefully analyze the changes in flow caused by vegetation and utilize the results for flow analysis. However, accurate analysis of the effects of vegetation is difficult because they are influenced by numerous factors including vegetation species, range, density, and form. In addition, it is difficult to immediately identify the effect of vegetation on the flow because existing studies are mainly based on the reproduction of two- dimensional images or laboratory research. Therefore, in this study, a two-dimensional numerical model was used for a more accurate estimation of flow resistance in a stream-scale channel. To this end, theoretical flow resistance estimations using relations proposed by Chezy and Baptist are compared with the velocity measured by Acoustic Doppler Velocimetry (ADV). This can be used to estimate vegetation flow resistance more accurately for application to the numerical model for flow resistance.
Year: 2020