عنوان مقاله [English]
In this study, a model for optimal allocation of water from a single purpose reservoir to an irrigation project with pre-determined multiple cropping patterns were developed. The model is consisted of two modules: (I) the intra-seasonal allocation model (non-linear programming) which is intended to maximize the total farm income. It is used for allocation of water among different crops for a definite combination of state variables (inflow class, rainfall class, reservoir storage classes at the beginning and at the end of the season) for growth season and (II) seasonal allocation model (stochastic-dynamic programming) which is used for the convergent operating policy over seasons for optimal expected farm income over a year. The model was applied to Ardak reservoir dam (North east of Iran) in an arid region and ensuing results were discussed. This methodology is proposed for using in similar reservoirs of Iran to ensure optimal usage of our limited national water resources.