At present, only the Colby function contains a correction for fines in SAM. In
HEC-6, the Colby correction factor is applied to all sediment transport equations
except Toffaleti, when Toffaleti is not combined with other equations.
Importance of Bed-material Gradation Designation
In the calculation of sediment transport, the designated bed gradation controls
the calculated sediment discharge. The rate of transport increases exponentially
as the grain size decreases, as shown in Figure 3.1. Therefore, bed-material