DISCHARGE ESTIMATION METHODS FOR STEADY COMPOUND CHANNEL FLOWS

Abstract

This study evaluates various alternatives to account for flood plain conveyance in steady compound channel flows. Evaluations are based on applying several traditional discharge estimation methods to a steady, uniform flow laboratory data set. Many of the applied techniques overestimate compound channel discharge. Six interface and two other standard methods for computing discharge in open channels were compared. Each interface method uses a particular arrangement of imaginary interface planes to artificially sub-divide the compound flow field into homogeneous zones. These methods are named for the particular interface plane arrangement adopted. The two standard methods do not involve interface planes. In general, among the methods tested, the outward-facing diagonal interface plane method and the vertical interface plane method produced the most accurate simulations.