This video utilizes the Emriver Em2 Stream Table to demonstrate meander evolution in a simulated alluvial river. One of the meander bends is armored with riprap to protect a home while other bends are free to migrate in response to the river’s flow. This video shows how meanders will change through time and demonstrates some of the unintended consequences of the “hard” approach to stabilizing river banks. Approximately 20 minutes lapsed during the simulation.

Suggestions for educators:

Before watching the video with your students, it might be a good idea to review some of the key terms used in the video. Feel free to direct students to https://www.ausableriver.org/programs... for definitions of these key terms:

Cut Bank
Eddy
Meander
Meander neck
Meander cutoff (also see Chute cutoff)
Riprap
Spring sapping

Questions to consider:

How did the riprap affect erosion on the meander bend? Upstream and downstream of the riprap?

How did the bend with riprap behave differently than the natural bend?

The slope or steepness of a river channel is equal to the change in elevation divided by distance. Water moves at a higher velocity and has more energy to move sediment in rivers with steep slopes. Explain why a meandering channel has lower energy than a straight channel flowing through the same valley.