Applicability of Dam‐Break Flood Wave Models

Abstract

Mathematical models based on the Saint‐Venant equations for open channel flow often encounter serious difficulties when applied to natural channels. On the other hand, the approximate flood routing models used in practice may yield results which are in gross error. In this work five mathematical models are constructed based on equations ranging from the complete dynamic system to a simple normal‐depth kinematic wave equation. The results of the models are compared between themselves and with experimental data, in the form of free‐surface profiles and stage hydrographs. The models are then converted to dimensionless form, which reduces the number of independent parameters controlling their solution. The results of these calculations are presented in the form of dimensionless plots of maximum flood depth and time vs. distance along the channel, for various levels of truncation of the open‐channel flow equations. Estimates for the permissible range of application of the simplified routing models are given, and recommendations are made for their judicious application.