Driving-response mechanism of waterway regulations in a complex braided channel

The meandering and branching channels frequently appear in the middle and lower reaches of the Yangtze River, China. Various waterway regulations projects have been performed to provide favorable navigable conditions for inland water transport. Owing to the complex driving and response mechanisms, the relationship between regulation strategies and hydrodynamics has not yet been revealed. Thus, a case study is presented in Dongliu channel, characterized as a complex braided river. The relationship between river shaking force and geometry is evaluated in terms of channel and riverbed stability index. The results indicate that the waterway conditions are generally improved although a few negative variations have been observed at the inlet of Laohu Shoal and Xigang. In the light of hydrograph, the stability index of Dongliu channel is evaluated considering river bank protections, flow conditions and river configurations. Meanwhile, human activities would alter the river bathymetry and hydrodynamic conditions, thus should be carefully considered during developing a waterway regulation program. The present study could provide a guidance for waterway regulations in complex braided rivers.