THE ELUSIVENESS OF SEDIMENT TRANSPORT PREDICTIONS

There are inherent uncertainties in both the measurement and the prediction of sediment transport rates and morphological simulations. This paper discusses the various types and sources of uncertainty. In the first part, a framework and a terminology are established, and a number of well-controlled laboratory experiments of suspended sediment concentrations are analysed to dissect the variability observed in sediment concentration measurements. We introduce a scatter parameter and categorise variability into predictable, unpredictable but explainable and unexplainable. The second part introduces the concept of robustness in sediment transport and morphodynamic modelling, and discusses practical implications.