Recent advances from research on meandering and directions for future work

Abstract

This paper presents a review of the present understanding of the kinematics of meandering flow, and its relationship to bed deformation as well as downstream migration and lateral expansion of meander loops. Taking into account the conditions prevailing in natural, low-land alluvial meandering rivers, the paper focuses primarily on the behaviour of streams having “large” values of width-todepth ratio. The present review is preceded by a brief description of meandering defining geometric characteristics, as these are invoked throughout this manuscript. The paper is also used as an opportunity to outline future directions for research. These involve matters related to the topics under consideration that remain obscure and which, in the writer’s view, constitute subjects particularly worthwhile as future research topics for their scientific as well as practical significance. More specifically, these concern the nature and analytical formulation of meander wavelength; the value of width-to-depth ratio beyond which the effect of cross-circulation becomes of secondary importance where the meandering bed deformation is concerned; and, finally, the unification of present methods of determination of meandering planimetric evolution with the principle of self-formation of alluvial streams as expressed by regime theory.