This paper concerns with the general theory of steady behaviours of open channel flows by means of the one dimensional procedures of analysis. The theory described herein is essentially formed by the transitional characteristics of steady flows in channel transitions and controls, and it can provide the unified treatment for hydraulic behaviours of gradually varied flows, which mainly treat with the determination of surface profiles of water, and of rapidly varied flows, which are counterpart of gradually varied flows and deal with local variations of flow behaviours occured by sudden changes in channel characteristics
