Reservoir operation in assigning optimal multi-crop irrigation areas

A mathematical model is developed for the optimal multi-crop irrigation areas associated with reservoir operation policies in a reservoir-irrigation system. Optimal area allocations are considered by addressing an appropriate mathematical model. The reservoir operations are related to releases policy, monthly water allocations, and occasional reservoir spills in a monthly operating time. The objective is to maximize the annual benefit of the system by supplying irrigation water for a proposed multi-crop pattern over the planning period. Herein, three sets of constraints are applied to the system: achieving monthly balance in the reservoir, covering water demand for crop production, considering evaporation loss from the reservoir, and governing equations for reservoir release and operations. The provided model is formulated with these constraints linked together by appropriate additional constraints as a linear programming model. Sensitivity analysis of inflow and alternative irrigation policies is conducted to investigate their effect on the final results. The methodology is applied to a real case study of a reservoir-irrigation system in Iran to show the applicability of the model.