Sensitivity and Applicability of Bed Mixing Algorithms

The selection of a bed mixing approach influences sediment routing computations of graded materials. This aspect of sediment modeling has been notoriously empirical and difficult to simulate. A wide variety of mixing algorithms exist to handle this process, but little work has been done to compare the sensitivity and relative merits of the different approaches. Several of these methods were implemented in a developmental version of the sediment transport capabilities of HEC-RAS. A range of methods were applied to a series of scenarios with distinct bed gradation and transport characteristics to investigate sensitivity, applicability and numerical stability.