Recent (1999–2003) Canadian research on contemporary processes of river erosion and sedimentation, and river mechanics

Abstract

Abstract:Contributions by Canadian fluvial geomorphologists between 1999 and 2003 are discussed under four major themes: sediment yield and sediment dynamics of large rivers; cohesive sediment transport; turbulent flow structure and sediment transport; and bed material transport and channel morphology. The paper concludes with a section on recent technical advances. During the review period, substantial progress has been made in investigating the details of fluvial processes at relatively small scales. Examples of this emphasis are the studies of flow structure, turbulence characteristics and bedload transport, which continue to form central themes in fluvial research in Canada. Translating the knowledge of small-scale, process-related research to an understanding of the behaviour of large-scale fluvial systems, however, continues to be a formidable challenge. Models play a prominent role in elucidating the link between small-scale processes and large-scale fluvial geomorphology, and, as a result, a number of papers describing models and modelling results have been published during the review period. In addition, a number of investigators are now approaching the problem by directly investigating changes in the system of interest at larger scales, e.g. a channel reach over tens of years, and attempting to infer what processes may have led to the result. It is to be expected that these complementary approaches will contribute to an increased understanding of fluvial systems at a variety of spatial and temporal scales.

Recent Canadian Research on Fluvial Sediment Transport and Morphology, 2003-2007

“…Research in Canada on fine-sediment processes was reviewed in detail by De Boer et al (2005). Recent contributions include microscopic analysis of the relationship between floc structure, floc strength and sediment dynamics (Droppo, 2004) and an assessment of the requirements for development and testing of numerical models of fine-sediment transport incorporating all the known phenomena associated with the process (Willis and Krishnappan, 2004).…”

Influence of bed clusters and size gradation on operational time distribution for non‐uniform bed‐load transport

“…Sediment transport along river beds is one of the major hydrological processes that can affect river restoration and geomorphology (Rosgen, ; Sear, ; de Boer et al, ; Abad et al, ; Bravard et al, ). Bed‐load transport is known as a random process, likely because of the multi‐scale heterogeneity and complex interactions within a river system, motivating the development of various stochastic models such as the well‐known Poisson model (Einstein, ; Habersack, ), the stochastic saltation model (Niño and García, ), the birth‐death Markov model (Ancey, ), the neuro‐fuzzy model for rolling particles (Valyrakis et al, ), and the probabilistic inter‐particle collision model for saltating grains (Bialik, ), among many others.…”