Original papersScenarios for improvement of water distribution in Doroodzan irrigation network based on hydraulic simulation

- Using a Hydraulic-Numerical model (SOBEK) to assess the gravity irrigation networks.
- Assessment a part of large scale irrigation network (Doroodzan in Iran).
- Proposing operation methods based on water user's attitude and hydraulic simulation.
- Choosing the best operation scenario based on water distribution indices.

Considering the value of water and the high cost of its acquisition and distribution, goal-oriented utilization of water resources is necessary. One of the problems of water resources development in developing countries is the low-yield use of water in irrigation networks downstream of dams. Despite vast investments on construction of these networks in Iran, enough attention is not paid to the right method of their operation, which guarantees the success in achievement of primary goals of networks' construction. Therefore, most of irrigation networks are operated through experimental methods, without any scientific and planned basis. Considering the complex hydraulics of water conveyance and distribution in open networks as very extensive infrastructures, studying them with the aim of determination of a suitable and reliable operation method is not possible with the physical tests in laboratories or experimental approaches, and the mathematical models must be utilized. In the present study SOBEK hydrodynamic model was employed for provision of a suitable operation method for Doroodzan irrigation network, located downstream of Doroodzan dam in Iran. The best operation scenario, based on water distribution assessment indicators was offered after calibrating the model and vast study of available scenarios. In the present operation method water is distributed in the network with a steady distribution and a fixed discharge, and in the proposed method water is distributed through a continual distribution with variable discharge in each 15 days, to provide the water requirement for the present cropping pattern.