Principles of Graphical Gradually Varied Flow Model

Any gradually varied flow computation requires the solution of the energy and continuity equations. To this end, many techniques are available. For prismatic channels, the Direct Step Method gives a result without requiring iteration. However, for nonprismatic channels, it is necessary to resort to some variation of the Standard Step Method, thereby requiring some iterative procedure. A graphical solution, using a simple program to construct a set of curves, can eliminate iteration as well as retain flexibility with regard to flow variations along the reach. To accomplish this, a graphical solution of the energy equation is presented using hydraulic transform graphs for river cross sections along a reach.