OPTIMIZATION OF IRRIGATION WATER DISTRIBUTION USING THE MGA METHOD AND COMPARISON WITH A LINEAR PROGRAMMING METHOD

Abstract

Optimization of irrigation water distribution is an important item for water management in irrigation networks. A linear programming model can have problems, for example when the objective function is based on only one goal. So some methods, for example modelling to generate alternatives (MGA), can improve results. This study presented a schedule for distributing irrigation water as well as an optimal cultivation pattern aiming at maximizing net profit on one side and water productivity (WP) on the other. Since the production function is the most important part of water distribution models, the best available production functions were checked and calibrated. The obtained results revealed that WP could be enhanced by 20–40% using the MGA technique. However, investigation of water shortage conditions showed that a 30–35% water deficit could result in an increase of WP by 54%. Thus, it could be argued that the most important matter in water management in irrigation networks is the simultaneous study of WP and water economic productivity (WEP). Considering both factors, a deficit of 30%, which results in a decrease of profit by 10%, was selected as the best alternative for the economic enhancement of WP in the Qazvin Plain. Copyright © 2014 John Wiley & Sons, Ltd.