Meandering and braiding of rivers

The origin of meandering and braiding of alluvial rivers is re-analysed in terms of stability theory. The flow is described by a two-dimensional model, and the transportation of sediment is separated into bed-load transport and transport of suspended sediment, by use of the improved knowledge of sediment transport mechanisms achieved in recent years. The paper explains why it is important to distinguish between the sediment transported as bed load and that in suspension. The analysis is able to predict whether a river remains stable or tends to meander or braid. The results of the stability analysis are compared with laboratory experiments and data from natural rivers, and the agreement is satisfactory.