Conjunctive use of surface water and grounwater for optimal water allocation of reservoir dam under water resources shortage (Case Study: Yamchi Reservoir dam, Ardabil)

In this research, a deterministic algorithm based on the Genetic Optimization (GA) method was used to optimal water allocation from surface and underground resources between different uses in the operation of Yamchi reservoir dam in Ardabil province. The objective function in the optimized model was to maximize the profit of water allocated to the agricultural sector according to the selected cropping pattern, so that the supply of drinking and environmental requirements was considered as a constraint in the optimal model. The rainfall and inflow to the reservoir are discretized due to their non-deterministic property, and then for different values of the initial volume of the reservoir at the beginning of the operation period and any logical combination of rainfall and inflow to the reservoir (under the three scenario: minimum, normal and maximum), the optimal model was implemented. The results showed that in the minimal and normal scenario with increasing initial volume of the reservoir, the profit was increased, but in maximum scenario, the initial volume of the reservoir had no effect on the profit. The smaller the initial volume of the reservoir had the lower the relative yield of the products, which is most evident in the minimum scenario. Also, the amount of water allocated from groundwater resources to agricultural sector varies from 3.1 to 7.9 MCM, which corresponds to the potential for extracting water through utilization wells.