The process of channel movement in a meander system involves rotation and translation of meander loops and an increasing path length. The amount of path-length increase is directly proportional to the impulse supplied by discharge and is inversely proportional to the silt-clay percentage of the material composing the channel perimeter.
Comparable paths have been obtained by standardizing measurements with a sine-generated curve and a moving reference axis. Analysis of previous investigations and time-of-travel data indicates that the discharge effective in channel formation consists of the range beginning just higher than the average and continuing throughout all higher discharges. Of six field sites investigated, three meander systems had path-length increases of sufficient magnitude to correlate with above-average discharge volume, one had no discernible change over a 30-year period, and two had changes which were too small for correlation owing to the short period of time covered by the available data.
Because of the consistency of yearly above-average discharge volumes, it was possible to develop a general relation between path-length increase per thousand cubic-feet-per-second-days per square mile of drainage area above average discharge and the width-depth ratio of the channel. Little progress was made toward defining relationships for rotation and translation.
