Stochasticity in the estuarine sediment erosion processes

Stochasticity in sediment erosion signifies the randomness that under the same hydraulic condition, some sediment is erodible while the other is not. It is crucial in the erosion processes of the estuarine seabed, but its mechanism is not yet clear. In this study, three methods (in-situ data analysis, Gust erosion microcosm system (GEMS) experiments, and numerical experiments) were used to analyze the stochastic effects on Type Ia erosion (limited erosion in the thin surface layer). The in-situ data analysis revealed that the relationship between the stochastic parameters μ (mean velocity) and σ (standard deviation of velocity) of the bottom current varied within a limited range, rather than being linear. The stochasticity in both the shear stress and the critical shear stress was found to have significant effects on the erosion processes. Our study highlights the need to consider the stochasticity for detailed study in sediment erosion processes. •The relationship between μ and σ of turbulent velocity lies in an area with limited range instead of being linear.•Both stochastic parameters of μ and σ have significant effects on the distribution of shear stress.•The stochasticity shear stress and critical shear stress has important effects on the erosion behavior of sediments.