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Streams & Watersheds
Functions and Conditions
Grazing the Landscape
Grazing Riparian Areas
Grazing Management
Management Plan
Supplemental Material


Page 12 of 16
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Streams and Watersheds - Vertical Instability

The other type of instability occurs when a stream cuts deeper into its bed material. This is referred to as vertical instability, downcutting, or incisement (Figure 1-13).

Figure 1-13
Downcutting is most likely in systems which experience intense high flows over short periods of time.

Vertical Instability =
Downcutting may be caused by natural circumstances, but it is more often the result of human activities. Of the two types of instability, vertical instability is more significant because it is more likely to lead to a fundamental change in the riparian area due to a lowering of the water table and subsequent changes in plant communities.

Once begun, downcutting is often more difficult to control than lateral cutting.