Abstract: A 2-D horizontal model with generalized curvilinear coordinates was applied to simulate flow and sediment transports in the Tianxingzhou reach of the Yangtze River. The model was first calibrated and verified using field data. The variations in the velocity distribution and water surface level were then simulated for the conditions of different flow discharges and different depths of sand mining. The model was also used to forecast the change of the reach and the sedimentation efficiency in mining areas after sand mining through selected typical flow and sediment conditions. The results provide necessary information for quantifying effects of sand mining at different scales.

Key words: sand mining depth, braided channel, water distribution, sediment resilt, 2-D horizontal flow and sediment model, sand mining depth, braided channel, water distribution, sediment resilt