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A Fully Fuzzy Linear Programming (FFLP) formulation for the reservoir operation of a multipurpose reservoir in presented in the ongoing paper. In the real world, water resources systems usually have complexities among social, economic, natural resources and environmental aspects, which lead to multi-objective problems of significant uncertainties in system parameters, objectives and in their interactions. These uncertainties in FFLP reservoir operation model are considered by being treated as fuzzy sets. In the present study, an FFLP reservoir operation model is developed where all parameters and decision variables are fuzzy numbers. The developed model is demonstrated through a case study of Jayakwadi reservoir stage–II, Maharashtra, India with the objectives of maximization of annual releases for irrigation and hydropower generation. The FFLP reservoir operation model is solved to obtain a compromised solution by simultaneously optimizing the fuzzified objectives and the corresponding degree of truthfulness, using linear membership function. The degree of correspondence (Correspondence) obtained is equal to 0.78 and the corresponding annual releases for irrigation amount of 367 Mm3 and while annual releases for hydropower generation being 216 Mm3. the present study clearly demonstrates that, use of FFLP in multipurpose reservoir system optimization presents a potential alternative to attain an optimal operating policy.

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Decisions relating to most irrigation-planning problems need to be made in the face of hydrologic uncertainties, which make the irrigation-planning problem more complex. The uncertainties can be tackled by formulating the problem as Fuzzy Linear Programming (FLP). In the present study, Single Objective Fuzzy Linear Programming (SOFLP) irrigation planning model was formulated for deriving the optimal cropping pattern plan with the objective of minimization of cost of cultivation and maximization of net benefits for the case study of Jayakwadi Project Stage-I in Godavari River sub-basin in Maharashtra State, India. The objective function coefficients, technological coefficients, and stipulations/resources under consideration were taken as triangular fuzzy numbers. The interactive approach was used to solve SOFLP model by involving the Decision Maker (DM) in all phases of decision-making process. The SOFLP model gave better results at highest degree of the membership value by keeping balance between feasibility degree of constraints and satisfaction degree of objectives. The minimized cost of cultivation and maximized net benefits for irrigation planning for the SOFLP model proposed, was found at greatest membership degree of 0.406 and 0.331, respectively, with the consideration of balance between the feasibility degree of constraints and satisfaction degree of goal. The DM can be involved in all phases of decision process, which is very essential in real world problems of irrigation planning where the data/information is vague or uncertain.