Chapter index
Previous section
Next section
Search Meanders

As downcutting streams begin to approach base level, the erosional action begins to act more laterally than vertically. The stream begins to meander with respect to the straight stream course. Meanders often begin as a result of existing topographic control, but as the stream velocity and the position of maximum turbulence change, the banks of the stream undergo differential erosion which leads to meandering.

The maximum flow and erosion occurs on the outside of the meander while minimum erosion and deposition occur on the inside of the meander where point bars form. A helical flow, which develops across the channel cross section, transports material off the bottom upward to be deposited on the inside of the meander loop. The resulting deposits tend to be somewhat loose. During the high water stage, the path of maximum turbulence may follow a straighter course through the meander loops.

Thread of Maximum Velocity
Thread of Maximum Velocity
Galloway, W. E. and D. K. Hobday.
Terrigenous Clastic Depositional Systems.
Springer-Verlay New York, Inc., New York, 1983.
Thread of Maximum Velocity  Distribution of Turbulence  Gradients of sed. size and load, velocity, sinuosity  Meandering stream: erosion and deposition  Meandering Yampa River in mature stage with well developed flood plain, Colorado.  Meandering stream showing cut bank and flood plain, Grand County, Colorado.  Meandering stream and flood plain.  Aerial view of a river showing oxbow development, Near Gunnison Colorado. 

Term index