|Channel typing is used for much the same reasons why biologists classify organisms - to establish a common vocabulary amongst researchers, and to organize them into related groups.
of classification include increased communication, more critical analysis of stream morphology, and the ability to monitor and predict the natural evolution of stream types as well as evolution resulting from human impact.
While accurate classification is dependent upon experience, one of the benefits of Rosgen's classification system is that it is based upon measurable (quantifiable) characteristics.
Initially, streams are grouped by water surface slope, entrenchment, width/depth ratio, and sinuosity into categories A - G.
Streams are then further divided into categories 1 - 6 based upon dominate channel materials (D50).
The resulting value is given as an alpha-numeric combination, such as C4. A stream categorized as C4 thus has certain describable properties, whether it is located in California, Siberia, or Costa Rica.
Level 3 characterizations would include information on riparian vegetation, fish habitat, and debris.
Level 4 would include specific measurements of bank erosion, sediment transport, and fish biomass.
For a more complete description of stream channel typing and its uses in monitoring and restoration, visit Wildland Hydrology, Dave Rosgen's consulting company.