Guest editor's note

Authors: EL KADI ABDERREZZAK, KAMAL - Electricite De France (EDF); ABAD, JORGE - University Of Pittsburgh; Langendoen, Eddy

Submitted to: Journal of Hydro-environment Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2014
Publication Date: 6/1/2014
Publication URL: http://handle.nal.usda.gov/10113/63313
Citation: El Kadi Abderrezzak, K., Abad, J.D., Langendoen, E.J. 2014. Guest editor's note. Journal of Hydro-environment Research. 8(2):75-76.

Interpretive Summary: Sediment transport processes in rivers are of great concern in many practical studies ranging from large-scale problems such as reservoir management and design of restoration works, to small-scale problems such as local bed scour around bridge piers. Scientists and engineers use various approaches to study sediment transport processes: fieldwork; mathematical, conceptual and numerical modeling; and experimental and physical scale models. Each approach has its advantages and limitations. Many processes that occur in nature (e.g., bank failure, grain sorting, bed forms, vegetation effects on flow and sediment transport) are too complex to be accurately described in numerical models or investigated through continuous or event-based field monitoring. Unfortunately, numerical modeling has replaced laboratory experimentation to study or predict the very complex processes because they are cheaper to setup and operate. Scientists at the USDA, ARS, National Sedimentation Laboratory in collaboration with researchers at the French National Hydraulics Laboratory and the University of Pittsburgh have brought together a select group of internationally renowned scientists to discuss the need for physical modeling and laboratory experimentation in order to understand complex sediment transport processes and to study in sufficient detail the interaction between the flow and the erosion, transport and deposition of sediments in many practical applications. The discussion has been facilitated by Elsevier's Journal of Hydro-Environment and Research, which published key, state-of-the-art papers by these scientists. The synergy between physical modeling, laboratory experiments, field monitoring and numerical modeling is the key to advance our knowledge of the fluvial environment, and to provide a sound scientific basis for guiding engineering applications. The combined efforts of the contributors will stimulate further progress and interest in the topic of physical and laboratory experimental movable bed models. New or ongoing lines of research include, among others, such topics as the assessment of scale effects, formation of bed forms (i.e., ripples, dunes, bars, meandering and braided channels), interaction between sediment transport and large wood, development of advanced instrumentation, as well as improvement of operational procedures.

Technical Abstract: Sediment transport processes in rivers are of great concern in many practical studies ranging from large-scale problems such as reservoir management, dam removal, and design of restoration works to small-scale problems such as local bed scour around intakes, outfalls and piers. Within the discipline of fluvial geomorphology several approaches are used to study sediment transport processes: fieldwork; mathematical, conceptual and numerical modeling; and experimental and physical scale models. Each approach has its advantages and limitations. Many processes that occur in nature (e.g., bank failure, grain sorting, bed forms, vegetation effects, transport of widely graded sediments over partially armored beds, debris-sediment interaction) are too complex to be accurately described in numerical models or investigated through continuous or event-based field monitoring. The use and application of movable bed physical models and laboratory experimentation are therefore recognized as powerful tools for solving practical problems. Laboratory experimental works have considerably advanced our knowledge of many complex fluvial processes, and have enabled the incorporation of realistic processes in numerical models and the validation of the accuracy of the computational results. We believe that, notwithstanding the increasing power and use of computational models, physical modeling and laboratory experimentation are still needed to understand complex sediment transport processes (mainly three dimensional in character), and to study in sufficient detail the interaction between the flow and the erosion, transport and deposition of sediments in many practical applications (e.g., design of restoration works, scour at water intakes, energy dissipaters, and piers). The synergy between physical modeling, laboratory experiments, field monitoring and numerical modeling is the key to advance our knowledge of the fluvial environment, and to provide a sound scientific basis for guiding engineering applications. We sincerely hope that the combined efforts of all the contributors will stimulate further progress and interest in the topic of physical and laboratory experimental movable bed models. New or ongoing lines of research include, among others, such topics as the assessment of scale effects, formation of bed forms (i.e., ripples, dunes, bars, meandering and braided channels), interaction between sediment transport and large wood, development of advanced instruments, as well as improvement of operational procedures.