This study aims to develop an economical tool for pipe size (diameter) design, i.e. a model, by using optimization techniques
for agricultural irrigation systems. The developed model is validated through applications to an actual target region
(Saemangeum reclamation area, zone 6). A newly developed metaheuristic optimization algorithm, termed a proportional genetic
harmony search algorithm (PGHSA), is proposed in this study. To evaluate the optimization results of pipe diameters for
the target region, the cost and hydraulic results of the initial and optimal designs are investigated by means of a comparison.
Spatial equalization of nodal pressure and the economic velocity of each pipe are used as indicators for evaluating the hydraulic
stability of the irrigation system. The results indicate that the proposed optimal design model can save construction cost
considerably, by 1?11%, in comparison to the original plans
