By the analysis of the field data of gravel bedload rate, it is found that the gravel bedload rate has a distinct stochastic nature and turbulence intensity of bedload rate is closely related to the sampling duration. The deviation, diversity coefficient，dimensionless turbulence intensity and dimensionless ultimate difference of bedload rate per unit width, all decrease with the increase of sampling duration. The maximum value of dimensionless ultimate difference of bedload rate per unit width is about 8.0. As the sampling duration t≥600 s, the dimensionless ultimate difference Z≤4.0. As the sampling duration t≥2400 s, the dimensionless ultimate difference Z≤2.0. The deviation coefficient of bedload rate per unit width has a maximum value of 2.0. As the sampling duration t≥1200 s, the deviation coefficient Cv≤1.0. As the sampling duration t≥3000 s, the deviation coefficient Cv≤0.5. The dimensionless turbulence intensity of bedload rate per unit width has a maximum value of 10.0. As the sampling duration t≥1200 s, the dimensionless turbulence intensity E′≤5.0. As the sampling duration t≥3600 s, the dimensionless turbulence intensity E′≤2.0.
