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.

泥沙侵蚀的随机性是指在相同的水力条件下，有的泥沙可蚀，有的泥沙不可蚀的随机性。它在河口海床的侵蚀过程中至关重要，但其机制尚不清楚。本研究采用原位数据分析、阵风侵蚀微观系统（GEMS）实验和数值实验三种方法分析Ia型侵蚀（薄表层中的有限侵蚀）的随机效应。原位数据分析表明，随机参数μ（平均速度）与σ之间的关系（速度的标准偏差）在有限的范围内变化，而不是线性的。发现剪切应力和临界剪切应力的随机性对侵蚀过程具有显着影响。我们的研究强调需要考虑对沉积物侵蚀过程进行详细研究的随机性。