Estimating a Stream Restoration Design Discharge

Abstract

A primary assumption of the natural channel design method for stream restoration is that the bankfull design discharge is the channel forming or dominant discharge. Dominant discharge is defined as the theoretical discharge that if constantly maintained in an alluvial stream over a period of time will produce the same channel geometry that is produced by the long-term hydrograph. The dominant discharge appears typically in three different forms, effective discharge, bankfull discharge, and as a specified return period discharge. The bankfull discharge is the most commonly used form in stream restoration projects. The selection of an appropriate design discharge that best approximates the dominant discharge is critical to the natural channel design methodology and will dictate the success of restoration projects in improving channel stability and water quality. In this paper, we present existing methods of estimating dominant discharge, including methodology, assumptions, limitations, and appropriate applications. The goal of this paper is to offer the stream restoration community a single reference to aid in the selection of an appropriate design discharge for restoration projects.

Suspended sediment transport in the Magdalena River (Colombia, South America): Hydrologic regime, rating parameters and effective discharge variability

“…The effective discharge and its respective return interval were calculated as follows: (i) suspended sediment transport was determined using a frequency histogram (e.g., Mckee, 2002;Crowder et al, 2005;Huang Ma, 2010) and (ii) magnitude-frequency was determined using lognormal (e.g., Wolman and Miller 1960;Nash, 1994) and normal distribution probabilities (e.g., Goodwin 2004, West et al, 2006. To calculate effective discharge and analyze its temporal variability, the data were divided into two study periods, 1990-1999 and 2000-2010.…”

How to determine the effective discharge and its return period in a semi-arid basin? The case of the Wadi Sebdou, Algeria (1973–2004)

“…The curve h has a unique maximum reached at the effective rate QD ( fig.1), whose analytical expression is solution of the derived function, h'(Q)=0. For more precision and in order to deal with different flow regimes, the analytical solution of the dominant discharge has been established for probability distributions other than the log-normal distribution, such as the normal, exponential or log-Pearson III distributions (Goodwin 2004;West and Niezgoda 2006;Quader et al, 2008;Higgins et al 2015).…”

Empirical and analytical methods to characterize the efficiency of floods to move sediment in a small semi-arid basin

“…1), whose analytical expression is the solution of the derived function, h (Q) = 0. For more precision and in order to deal with different flow regimes, the analytical solution of the dominant discharge has been established for probability distributions other than the log-normal distribution, such as the normal, exponential or log-Pearson III distribu-tions (Goodwin, 2004;West and Niezgoda, 2006;Quader et al, 2008;Higgins et al, 2015).…”