Influence of Increasing Wasteway Sill Elevation on Discharge Changes in Doroodzan Irrigation Network

The low efficiency and weak performance of Doroodzan irrigation and drainage network¡ and other irrigation and drainage networks in Iran¡ make researchers to evaluate and solve the problems. Water distribution and management of related structures are important research subjects. In Doroodzan irrigation network¡ radial gates and constant head orifices¡ control and deliver water to farms. Complexity of the radial gates hydraulic algorithms¡ and farmers interference in gates regulating¡ cause problems for water distribution. In the present study¡ the influence of weir elevation setting on offtaking discharge change was evaluated. The selected radial gate was closed about 20¡ 50¡ and 80% of the initial gate opening¡ and elevation of the external wasteway was raised about 7¡ 14¡ and 20 centimeter. Results showed that raising elevation of external wasteways to an elevation higher than internal wasteways¡ decreases the wastewater and the discharge changes in offtakes¡ and leads to easier management of the system.