Chapter 9 - The Dynamics of Meandering Rivers

Summary

This chapter examines the dynamics of meandering rivers, including the initiation of meandering in straight channels; the development of bar units; and the relation of these units to pools, riffles, and point bars. It reviews theories of pool-riffle development and maintenance; flow through meander bends, including the influence of channel curvature and the point bar on flow structure; and the relation of the spatial pattern of shear stress in curved channels to patterns of erosion and deposition, to the development of bar unit topography, and to patterns of bank erosion. Mechanisms of bank erosion are introduced, emphasizing that bank erosion occurs in different types of rivers. Modes of planform deformation on meandering rivers are explored, as well as the factors that influence planform migration dynamics in meandering rivers. The discussion includes a basic introduction to numerical models of meandering rivers and attempts to integrate models of flow and sediment transport in curved channels with models capable of simulating bank erosion and lateral migration of meandering rivers. The chapter also briefly discusses meandering of mixed bedrock-alluvial rivers.