Numerical analysis of the morphological changes by sediment supply at the downstream channel of Youngju dam
Ki-Ho Kanga Jeong Bin Kimb Gi Han Leec Kwansue Jungd,*
aK-water Yeongju Dam Construction Office bDept. of Civil Engineering, Korea National University of Transportation cDept. of Civil Engineering, Kyungpook National University dDept. of Civil Engineering, Chungnam National University
In this study, the effects of sediment supply on the downstream of a large dam are investigated using a numerical model. The model simulation shows a good agreement with laboratory experiment results of sediment transport and diffusion from sediment pulses. The water surface changes from the various sediment bed elevations are also simulated using the model. The site which has a relatively stiff bed slope and meandering of a channel is selected as an appropriate location for sediment supply because of its shear stress enough to supply the sediment downstream. The model simulation shows the decrease of channel bed elevation through the simulation period with time. The well-deposition of sediment supplied from the downstream of dam is found in the location where the flow rate is relatively low. A bed relief index is increased with time and it is relatively greater in downstream compared to upstream. The channel bed variability increases as flow rate increases with a greater bed relief index. The results of this study demonstrate the importance of increasing water discharge of a large dam to increase the dynamic of channel bed and thus to enhance the efficiency of channel bed restoration by sediment supply.