Author(s): Chang-Lae Jang; Yasuyuki Shimizu; Ickhwan Ko
Linked Author(s): Chang-Lae Jang, Yasuyuki Shimizu
Keywords: Braided river; Bank erosion; Numerical model; CIP method; Moving boundary-fitted coordinate system
Abstract: Understanding the process and mechanism of morphological behavior in braided river is very important for river engineering purposes to manage hydraulic structures and prevent disaster from flood, and environmental purposes to maintain river ecosystem and landscape. A two-dimensional numerical model was developed to simulate braided river with erodible bed and banks composed of well sorted-sandy materials. A generalized coordinate system was employed to calculate water flow, bed change, and bank erosion. CIP (Cubic Interpolated Pseudo-particle) method was used to calculate flow, which introduced little numerical diffusion. Sediment transport equation in the streamline and transverse wise, considering the secondary flow, was used to estimate bed and bank evolution in time. Bank erosion was simulated by following the procedure proposed by Shimiz (2002). Braided river in laboratory was reproduced for verifying the numerical model in the channel filled with nearly uniform sandy materials. Comparison of numerical results and experimental data has shown relatively good agreements.