Abstract
Due to the influence of topographic drops, a large elevation difference often occurs in the middle and lower sections of the main pipe of a gravity-driven irrigation pipe network (GDIPN) system. This elevation difference must be reduced appropriately through pressure reduction facilities (pressure-regulating ponds (PRPs) or pressure-reducing valves (PRVs)). The number and locations of PRPs are crucial factors in regulating and balancing the pressure head of the main pipe of a GDIPN system as well as in reducing the project cost. However, there are few studies on the optimization of this kind of pipe network system. In this paper, first, we generalize such type of GDIPN system, and a simplified mathematical model for such system optimization was established. A genetic algorithm based on a fixed proportion and direct comparison (GA-FPDC) was introduced to solve the model. Two existing projects were tested by the proposed method. The results show that the presented method not only improved the design efficiency and rationality but also greatly decreased the project cost. The presented method is effective and efficient to address optimization design of such GDIPN system problems.