Flood Waves in Prismatic Channels

Abstract

An examination of the Forcheimer equation for crest subsidence, as applied to prismatic channels reveals the great dependence of flood wave classification on the magnitude of the bed slope. It is also shown that a flood crest will subside provided that slope terms other than So are significant. The rate of subsidence increases with the channel storage available for a given depth, and reduces as the exponent of R in the resistance formula increases. Although the results parallel those of Forcheimer somewhat, there is subsequent divergence. A critical examination of discharge in unsteady flow produces improved equations.