Methods of Seepage Estimation in Canals and Evaluation of Seepage and Distribution Efficiency in Doroodzan Irrigation System

Because of limited water resources in Iran, decrease the water seepages and increase the water are necessary. Water productivity and the management conditions of irrigation and drainage systems shows that more attention should be paid to this subject. Doroodzan irrigation and drainage network is one of Iranian modern irrigation and drainage networks. This network irrigates Marvdasht plain fertile farms. There are not enough field studies about seepage losses in the related irrigation canals. In this study the previous experiences on seepage estimation is mentioned. The seepage losses were measured in 12 tertiary irrigation canals located on the four main irrigation districts in Dorooodzan irrigation network. Seepage values were measured using inflow outflow method using a flow velocity meter. The values of seepage and evaporation losses was about 488500 and 335900 cubic meter per day, with and without considering the canals continued to the left and right bank canals. The average distribution efficiency in tertiary and quaternary canals was about 81 percent. About 15 percent of the delivered water in the beginning of the system was wasted in tertiary and quaternary canals due to seepage and evaporation losses. Therefore, it is suggested to use these seepage and distribution efficiency rates to raise the water delivery performance in Doroodzan irrigation system.