A Sensitivity Analysis of Total-Load Prediction Parameters in Standard Sediment Transport Equations1

Abstract

The lack of a well-defined, strong correlation between sediment transport load and the dominant variable selected for the development of a sediment transport equation is one of the fundamental reasons for discrepancies between computed and measured results under different flow and sediment conditions. Although several scholars have suggested different parameters, they unfortunately could not yet solve the problem. Twenty-three total-load equations for noncohesive particles were studied by providing insight into the relative strengths, weaknesses, and limitations. Three hundred parameters were investigated individually by using sensitivity analysis to pinpoint the key physical properties that control the errors. It is found that, the most influential parameter for the total-load sediment flux equations used in alluvial rivers for the sand particles is the gravitational power due to Shields’ parameter with an energy slope. For the gravel particles, the most influential parameter is the universal stream power due to critical Shields’ parameter with an energy slope. Several graphs are presented to emphasize the effect of these parameters that were either directly used or were embedded within those equations. Recommendations and guides are also presented for the researchers working in this field.