Improved criterion for plunge of reservoir turbidity currents

It is important to investigate the condition of turbidity current formation in reservoir sediment management. Previous criteria for turbidity current plunge are not applicable to hyperconcentrated turbidity currents. The governing equations for the motion of a turbidity current are refined, and an improved criterion for predicting the plunge of turbidity currents is derived based on the refined equations, with the effect of sediment concentration being included explicitly. The proposed criterion is calibrated using laboratory experimental data, which indicates that this improved criterion could be applicable to hyperconcentrated turbidity currents with sediment concentrations less than 400 kg/m³ as a kind of Newtonian fluid, and the plunging depth would be in direct proportion to the unit discharge to the power of 2/3 and would be in inverse proportion to the volumetric sediment concentration to the power of 1/4. The improved criterion is then verified using another three datasets, including measurements obtained from the prototype and model of the Xiaolangdi reservoir, and these verified results indicate that the predicted plunging depths agree well with the observed values, with a comprehensive correlation coefficient of 0·94. Therefore, the improved criterion can be used to predict the plunge of turbidity currents in the Xiaolangdi reservoir.