To overcome the difficulty in providing upstream boundary conditions in traditional depth-averaged models for turbidity currents, a one-dimensional numerical model was proposed for predicting the coupled processes of open channel flow and turbidity current in reservoirs under a two-step calculation mode.The calculations of the open channel flow and the turbidity current alternated with each other, the relationship between the Froude number and the volumetric sediment concentration at the plunge point was used to determine the location of the upstream boundary for the turbidity current and to specify the corresponding boundary conditions,and the method for calculating the limiting height of aspiration was adopted to evaluate the outflow discharge of the current.The whole processes of two turbidity current events in the Sanmenxia Reservoir from formation to recession were simulated.The predicted plunge point locations were in agreement with the measurements,with the arrival times of the current front being satisfactorily predicted.The calculated sediment concentrations and elevations of interface between the clear-water layer and turbidity current layer agreed with the field measurements, and the simulation results indicated that the sediment delivery ratio was reduced considerably when a muddy reservoir was formed.The proposed model provided a viable tool for simulating turbidity current events and designing procedures for sediment routing.
