Water Resources Management of Hirmand River Basin for Agricultural Productions Using Stochastic Dynamic Programming

In this study, the water content that is allocated for agricultural productions was analyzed using stochastic dynamic programming. The technical coefficients used in the study referred to the agricultural years, 2013-2014. They were obtained through the use of simple random sampling of 250 farmers in the region for crops like wheat, barley, melon, watermelon, and ruby grapes under the scenarios of drought and normal and water that is required in the most sensitive growth stages. Production function and profit function were obtained from the yield-water-product function of crops using Eviews software. Expected net profit of the system and optimal allocation of water were also calculated based on the GAMS economic analysis software. Results of the model indicates a reduction in wheat, barley, melon and watermelon production area under cultivation while at the same time an increase in ruby grapes cultivation areas under optimal conditions. The results showed that the cultivation of the ruby grape was the best product with the highest expected profit in normal and drought conditions. In general, when the expected value of net profit is positive, managers would act optimistically and they would promise the optimal level of water allocated to the farmers.