Bed load transport over a broad range of timescales: Determination of three regimes of fluctuations

This paper describes the relationship between the statistics of bed load transport flux and the timescale over which it is sampled. A stochastic formulation is developed for the probability distribution function of bed load transport flux, based on the Ancey et al. (2008) theory. An analytical solution for the variance of bed load transport flux over differing sampling timescales is presented. The solution demonstrates that the timescale dependence of the variance of bed load transport flux reduces to a three-regime relation demarcated by an intermittency timescale (t(I)) and a memory timescale (t(c)). As the sampling timescale increases, this variance passes through an intermittent stage (