Performance Assessment of a Water Delivery Canal to Improve Agricultural Water Distribution

Abstract

The performance of an irrigation water delivery canal located in northern Iran, which supplies water to 5,514 ha of paddy fields through ten secondary canals, was investigated. Throughout the rice growing season in the region, two performance measures, the measure of adequacy (PA) and the measure of equity (PE), were calculated for the system. It was observed that the canal, in its current physical and operational condition, is unable to distribute available water among all upstream and downstream users adequately. While 46.7 % of the total area is experiencing significant water scarcity, the amount of water received by 51.4 % of the area is approximately three times more than required. To improve the performance of the canal, structural and non-structural modifications were proposed and assessed using the SOBEK hydrodynamic model. The results showed that implementing the proposed modifications would decrease the measure of equity by 71.7 %, meaning that the overall performance of the canal could be reasonably improved.