Rosgen Classification by Bed Material

Cross sectional, or dimension, views of the Rosgen Reach classes are shown in this diagram. Note that the bedrock and coarser sediment types are not represented in the D, DA, and E channels.

Dimension illustrations reveal how the various substrate material, along with the channel Reach type, tend to influence the cross section shape. Some substrates create more angular shapes, while other substrates allow for more curvilinear features. Typical values and ranges for entrenchment, width to depth, Sinuosity, and slope are also given. It should be noted that field measured FGM values may depart from this illustration.

Image courtesy of Rosgen