Author(s): Kyung Soo Jun; Yi Joon Hwang; Jin Soo Kim
Linked Author(s): Kyung Soo Jun
Keywords: No Keywords
Abstract: A looped-network unsteady flow model is developed that allows variable roughness coefficient for each computational point according to its spatial position and the discharge. A step function or a power function can be used for functional relation between the discharge and Manning’s roughness coefficient. The model is applied to the Han River in South Korea, and model parameters are estimated by optimization. Estimated parameters of both the step function and the power function model show that Manning’s roughness coefficient decreases as the discharge increases. Stages calculated by the variable roughness coefficient model agree better with the observed values than those by the conventional single parameter model. Spatial variation of the roughness coefficient for the Han River appears to be more significant than the variation with discharge.