Note on boundary effects on stream meandering



This paper provides some additional evidence supporting the necessary (but insufficient) condition for the formation of stream meandering proposed by Nakagawa:


where Me is a non-dimensional parameter, τs, and τb are the average bank and bed shear stress respectively, ps and pb are the average bank and bed wetted perimeter of a half-channel respectively, and K≃0.2 is the critical value of the parameter estimated from experimental data.

Provided the criterion is satisfied, the main thread of the stream meanders in the non-erodible channel, and the maximum amplitude amax, the angle a between the channel central axis and oblique crest line of the surface wave, and the mean wavelength L of the main thread decrease as the non-dimensional parameter Me increases.