Performance evaluation study and hydrologic and productive analysis of irrigation systems at the Qazvin irrigation network (Iran)

The objective of this work is to develop a combined approach for performance evaluation of different irrigation practices based on the classical and neoclassical concept of irrigation efficiency, preliminary water accounting and water productivity. For this purpose, 2000 ha of land under Qazvin irrigation network in Iran with various types of irrigation systems were selected. Classical irrigation efficiency for furrow irrigation system was found 5.9% and 27.8% in primary and middle growth stages, respectively. The lowest classical efficiency for sprinkler systems was for linear-move system (11.8% and 45.6% in primary and middle growth stages, respectively). The values of effective efficiency were less than net efficiency in all studied irrigation systems in both evaluation stages. Obtained results showed that effective efficiency could define irrigation management at farm scale, whereas net efficiency considered the concept of beneficial reuse at larger scales. The total beneficial fraction in all sprinkler irrigation systems was higher than in furrow irrigation system. Overall, the values of depleted beneficial fraction were lower for the furrow irrigation system, which was due to large deep percolation values. The maximum and minimum values of net water productivity were for the center pivot with height-regulated sprinklers (9652 Rials m−3) and furrow irrigation system (1391.4 Rials m−3).