Rosgen Classification by Pattern, Profile and Dimension

Rosgen classification can be simplified to pattern, profile, and dimension graphical analysis, as shown in this figure without identification of bed material.

Pattern is shown in the plan view, illustrating relatively straight channels on the left, increasingly sinuous and wider channels next, followed by threaded and braided channels in the center, and then highly sinuous channels, wider channels, and narrow relatively channels.

Dimension is shown in the cross section view, which illustrates water surface in blue at Bankfull Elevation, and a dashed line at two-times Bankfull or the flood prone Elevation. The ratio of these two lines gives the entrenchment of the channel. On the left the chart begins with a relatively low Entrenchment Ratio which denotes highly entrenched channels. In the center, the Entrenchment Ratio increases, indicating moderate entrenchment.

Profile is shown in the dominant slope range view, which plots average or typical longitudinal slopes along the Bankfull water surface. On the left, type A and B Streams have steep slopes, while in the center slopes are gentle. On the far right, for G Streams, slopes once again are typically higher.

Image courtesy of Rosgen