Uploaded January 2007 | Updated September 2026, 2 weeks ago

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The amount of turbulence in a flow dramatically affects sediment transport. In this video, I review the Reynolds number and the characteristics of the flow near the boundary layer. For a beautiful example of a video showing the change in Reynolds number with depth in the flow, watch: youtube.com/watch?v=cUTkqZeiMow

Please note that this is a very simplified description of the boundary layer in a smooth channel with a low turbulence flow. Real rivers have irregular sides and rough beds that disrupt the boundary layer, complicating the picture substantially.

You can also see my lecture notes on this topic in the second half of this blog posting: dawnssedstrat.blogspot.com/2011/01/lecture-2-walthers-law-and-fluid-flow.html