Author(s): M. Muste; H-C. Ho; H. Zhang

Linked Author(s): Marian Muste

Keywords: Hysteresis; Unsteady; Rating curve; LSPIV; Flood

Abstract: The typical procedure to estimate stream discharges entails constructing a one-to-one relationship (a. k. a rating curve) based on set of direct discharge measurements. The direct measurements are typically acquired several times over the year. The one-to-one rating curve is only valid for steady flows. For unsteady flows, such as flood wave propagation, this relationship takes the shape of a loop curve. The advent of modern instrumentation allows acquiring discharge measurements at a considerably faster pace than with conventional instruments. The paper reports direct discharge measurements taken during an epic flood using an image-based technique for quantifying the velocity at the free surface. Velocities were acquired simultaneously with depth measurements with a temporal resolution commensurate with the travel time of flood such that the loop curve was successfully captured. The paper illustrates the differences between the discharges estimated with the one-to-one rating curve and those obtained with direct discharge measurements

DOI:

Year: 2011