The Role of Minimum Variance Theory in Defining the Regime Characteristics of the Lower Namoi‐gwydir Drainage Basin¹

While minimum variance theory appears to offer an explanation for the hydraulic behaviour and regularity among channel systems it is not entirely successful in predicting the regime of a channel system. In the case of the Namoi‐Gwydir river system the hydraulic variables velocity, depth, width, slope, friction, and shear appear to govern the behaviour and, hence regime of the channels. The significance of sediment load in determining regime could not be assessed.