Geometry of river channels: Discussion by William W. Emmett and Luna B. Leopold

For many years river engineers and geomorphologists have sought a rationale for the general similarity that can be observed among river channels from various environments. Some aspects of this general comparability were noted a century ago by Playfair, and other aspects were examined in a more quantitative way approximately 10 yr ago by R. E. Horton. Such similarities with respect to the channel cross section and the associated hydraulic parameters and their changes downstream were studied by some of the engineers who attained prominence for their work on the self-adjusting irrigation canals of India, especially G. Lacy,¹⁵ C. Inglis,¹⁶ and T. Blench.¹⁷ Among these men, canal characteristics were the principal objects of investigation, although natural river channels assumed an increasing share of the attention of the students of "regime analysis," especially Blench. L. B. Leopold and T. Maddock¹⁸ developed a scheme by which the average relationships among form and hydraulic parameters could be easily described, this description being the one on which the author chose to elaborate.