Emriver channelization, large meanders, packed sediment
This is a time-lapsed Emriver channelization demonstration in which a meander loop is cut off. In this case the channel length between two points is more than halved, so slope would increase by a factor of 2+. The playback speed varies and is noted on the video.
Note the relative stability of the system before channelization, in which a small amount of sediment is moving through the reach, but there is little bank erosion and by one definition - sediment in = sediment out - the system is very stable. A moving circle and the words “uniform bedload transport” illustrate this.
After the channelization note bank failures both up and downstream, and that the channel slowly reestablishes a meandering form so that its overall length is about the same as before the channelization. Graphics show how bedload transport greatly increases due to incision and bank erosion upstream of and within the reach.
During the remeandering process, note that there is a net export of sediment—
you can see this by visually comparing sediment movement into the reach versus
that out of it.
File 19077 is a 8.6MB Flash Video
Uploaded: Dec21 09
Last Modified: 2011-02-17 08:09:28