Stochastic Analysis of Dune Bed Profiles

Application of stochastic models of bed-load transport and dispersion requires a knowledge of the probability distributions of the step lengths and the rest periods of the particles. The probability distributions of the rest periods, the elevation of particle deposition, and the elevation of particle erosion were obtained in a large flume from a continuous record of bed elevation at a fixed point as a continuous function of time. The probability distribution of the step lengths was obtained from a series of instantaneous longitudinal bed profiles and the distribution of the elevation of particle deposition and erosion. Using an existing transport equation, the total sediment transport in the flume was predicted for three flow conditions. The errors in the predicted total sediment transport rates were -3.0%, +3.5%, and +80.1%.