Performance evaluation and optimization of water delivery schedule in the Zarinehroud irrigation network

Restoration of the Urmia Lake requires an increase of water productivity in irrigation networks. This research was aimed to evaluate the performance of water delivery in the Zarinehroud irrigation network, the Urmia Lake Basin, and to provide with an optimization plan. An intensive survey was carried out in the area under left main canals of the network duringSummer 2015.The water demand for irrigation was computed in each unitfor different courses of the year,and compared with the allocated water by the network authority. The four performance indicators of Molden-Gates were computed. Results indicated that the efficiency index with mean value of 56% represents a poor condition. While the adequacy index, with mean value of 97%,shows a good condition; the corresponding durability index (with mean value of 38%), and equity index (with mean value of 50%) represent the lack of balance between water supply and demand in the study area. The non-uniform distribution of surface water has lead to an increase in water depth and groundwater salinity in the lowland areas, and water logging in parts of upland areas. In this study, water delivery schedule for current crop pattern in the region was optimized using PSO algorithm. Accordingly, the four network indices (i.e. efficiency, adequacy, dependability and equity) could be upgraded to 65, 100, 8, and 60 percent, respectively. The results confirm the potential of great improvement in water productivity, even by continuing the traditional crop pattern used in the Zarinehroud irrigation network.