THEORIES ON THE CAUSE OF CHANNEL PATTERNFORMATION
河型成因的各种理论及其间关系

The approaches for studying channel pattern used by various investigators have been classified according to their theoretical basis in this paper, such as hypothesis on geomorphic thresholds, extremal hypothesis on energy dissipation rate, theory of stability, theory of stochastic analysis and method of statistic analysis. The advantages and shortcomings of each theory and the internal relations among those approaches have been exhaustively discussed. It was pointed out that the general tendency of those approaches is to find out thmost probable, equilibrium or extremal state of the natural rivers, even though the methods used are quite different. It was concluded that in studying the cause of channel pattern formation, study on the mechanism in the process of river pattern development and study on the geomorphic thresholds due to various boundary conditions of rivers should be emphasized and combined with each other. The importance of establishment of more reliable constitutive relationships of water and sediment motion and the experimental study in laboratory are also stressed.