On the definition of solid discharge in hydro-environment research and applications

Abstract

Various forms of mass balance equations are commonly used in sediment transport studies and applications. However, the quantities involved in such equations are not always clearly defined, with sediment flux (or solid discharge) as a typical example. Starting with the fundamental definitions, this paper provides a general and consistent framework for integral (Eulerian) mass balances and gives scale-consistent definitions for instantaneous and time-averaged variables. In particular, alternative expressions for the instantaneous and averaged solid discharge are proposed and compared with the existing formulations. Conceptual developments of this study are illustrated using sediment transport data from laboratory experiments.

• Bedload
• fluvial hydraulics
• sediment transport
• solid discharge

Funding

The authors thank Alessio Radice and Jenny Campagnol for providing access to experimental data used in this research, Andrea Marion for fruitful discussions, and Aurora Luzzi for editorial work with the manuscript. The insightful comments and suggestions of Christopher Ancey, David Jon Furbish and two anonymous reviewers have been gratefully incorporated in the final version.