Evaluation of Qazvin Plain Irrigation Systems Through an Assessment of Classical vs Neoclassical Irrigation Efficiencies

One of the most important performance indicators in as evaluation of the irrigation systems is the efficiency. The objective followed in this study was to evaluate surface and sprinkler irrigation systems with the neoclassical concept of efficiency, net efficiency and effective efficiency, and to compare the results with those of evaluation through systems of classical approach. Two thousand ha of land under Qazvin irrigation network (equipped with various types of irrigation systems) were selected. Evaluation of the systems was performed in two stages, of initial and mid-crop growth during the summer season of 2012. The results of the evaluation, using classical approach for furrow irrigation system were recorded as 5.9 and 27.8% for primary vs middle growth stages, respectively. The lowest efficiency for sprinkler systems was related to Linear-move system (11.8 and 45.6 % within the primary vs middle growth stages, respectively). The most conspicuous difference between neoclassical vs net efficiency was related to furrow irrigation system (41.2 and 44.9 % for primary vs middle growth stages, respectively). The values of effective efficiency were less than those of net efficiency, for all the irrigation systems and for both stages of the evaluation. The differences for furrow irrigation system were obtained as 22.2 and 37.1% within the primary vs middle growth stages, respectively. The results obtained finally indicated the concept that the effective efficiency presents a suitable expression regarding irrigation management and method at a farms, scale whereas net efficiency considers the concept of the reuse of waste water on spatial scales, larger than the field size.