A simplifed approach to optimizing the design of waterways

The methods and formulations used for optimizing waterways are presented and discussed in this article. Special attention is given to the discharge duration coefficient β. The β coefficient represents the effect of different operating fluctuations of the discharge through the waterways. By using this one coefficient, the formulation becomes simple and clear. The formulation is then used to optimize the diameter of various types of waterways, GRP pipes, unlined tunnels, and open canals. The result is presented as an optimum velocity for various design discharges and three values of the duration coefficient β. In addition, the formulations are used to identify the minimum slope that is economical to utilize as an increment lengthening of planned waterways. Finally, a simple method for sensitivity analysis of the optimum velocity is presented simply by adjusting the β coefficient.