Departure from Existing Condition

Existing conditions were measured in earlier FGM Module Sections using Rosgen Level I and II analysis. Low Stream stability and Stream departure from its Rosgen classification type can be estimated at least three ways.

1. Estimated by comparing Rosgen Level II and III geomorphological data to data sets of known stable channels to see whether certain data values are beyond characteristic values.
2. Estimated by invoking trend analysis using comparisons to a base level condition of known type for that channel.
3. Estimated by longitudinal study, where departure if often shown to travel upstream or downstream.

This illustration demonstrates various bank failure pathways, however the FGM Module does not train in channel and watershed restoration methods for returning channels to their most probable form.

Image courtesy of Rosgen