• Introduction
• Watershed importance
• Stream classification
  • Method 1
  • Method 2
  • Method 3
  • Method 4
• Stream mechanics
  • Energy
  • Natural vs Man-made
  • Stability
• Laterial Stability
• Vertical Stability
• Stream Changes
• Summary
• Interactive Exercises
• Do it yourself

Streams and Watersheds - Stable versus Unstable Streams

All streams are dynamic, but not all streams are unstable.

Stable Stream =
A stable stream - over the course of time - remains in equilibrium with the amount of water and sediment the stream has to carry.

Unstable Stream =
An unstable stream, on the other hand, is "out of balance" in that it can no longer do what is required of it.

One of the difficulties in determining stability and instability is that nature does not always operate on our time scale. Thus, it is sometimes difficult to determine exactly when a change in the system reflects dynamic variation within a long time frame or instability resulting from short term impacts (Figure 1-11).