Unified Nondimensional Formulation for Open Channel Flow

The specific force, specific energy, and a Chezy-resistance solution for gradually varied flow in wide open channels are presented on a single nondimensional diagram with a common depth ordinate. The gradually varied flow solution appears as isopleths of length along the channel, from a specified initial depth, on axes of normal depth and flow depth. Lines on the diagram representing normal depth, critical depth, and transitional depth produce a natural division of water surface profiles into M, S, C, and H categories. The unified approach represented by this general open channel diagram should prove useful in the understanding and preliminary estimation of both rapidly and gradually varied steady flows in open channels.