Analytical and Numerical Modeling at High Sediment Concentrations

Methods for classifying sediment-water mixtures according to material concentration and rheologic properties are discussed. Results from laboratory and field measurements show that bed material load increases several orders of magnitude when fine sediment concentration is greatly increased. Results from field measurements at Mount St. Helens are used to develop a modified B.R. Colby relationship for total bed material discharge that is applicable for hyperconcentrated flow conditions.