Explanation of the Pfankuch-Rosgen Stability Exercise

Exercise Objective

Exercise Explanation

1. The described C3 river received the following Pfankuch-Rosgen scores:

   • Upper Banks: Landform slope of 6, Mass wasting of 6, Debris jam potential of 3, Vegetative bank protection of 12.
   • Lower Banks: Channel capacity of 2, Bank rock content of 4, Obstructions to flow of 4, Cutting of 4, Deposition of 8
   • Bottom: Rock angularity of 3, Brightness of 2, Consolidation of particles of 4, Bottom size distribution of 12, Scouring and Deposition of 12, and Aquatic vegetation of 3.

2. The Pfankuch-Rosgen numeric total score from the right hand column is 85.
3. Conversion of Pfankuch-Rosgen numeric score to a C3 Reach condition resulted in a ranking of good, but at the outer limit and nearing fair.

Image modified courtesy of Rosgen