the development of meandering of stream channels

There is a close relationship between braided stream and meanders.Example:-The ana branches of a braided stream definitely meanders.On the basis of the works by European engineers,Lelivesky(1955) concluded that meanders are the result of helical flow.Although this mechanism has been important but it isn't clear how helical flow is related to the width,curvature and length of the meanders.

                                According to Matthes,bank cutting and orderly transfer of sediment to it's place of deposition on the point bars were simple requirements for the meandering Friendkin's concept is essentially identical.

    A meander can't exist if the banks were unerodible or if they were completely unstable.The meander pattern of melt water channels on the surface of glaciers have nearly identical geometry to the meander bends in rivers yet these meandering channels on the ice are formed without any sediment load or point bar construction by sediment deposition.

                    Hjulstrom has tried to explain meanders oscillatory motion expressed in gravity wave in terms of a seiche having a fetch equal to the width of the meander belt and the water depth equal to that of the river.He considered wave celerity to be the mean down valley velocity of the river.

                     The forces determined by velocity distribution including helical circulation can account for the shape of the cross section in a meander.the change from meandering to the non-meandering has a high degree of improbability.the existence of meanders on the glaciers implies that erosion and deposition are collateral rather than governing principles of the meander development and movement.Other conditions being equal ,the additional frictional loss due to channel curvature leads to formation of meandering stream steeper than a non-meandering stream.The pool in the meander in stream tends to coincide with the zone of maximum curvature.The effect of the meander is then is to introduce the flow resistance  due to curvature in just such a way that the stepped profile of the straight reach is replaced by a uniform utilization of energy throughout the whole length of the meander reach.In this way the meandering approaches closely to the condition of equilibrium aa defined by the entropy concept.

     In the absence of any dynamic theory or principle to explain the development of meanders attempts has been made to explain it at least qualitatively.