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 wasanalyzed using stochastic dynamic programming. The technical coefficients used in thestudy referred to the agricultural years, 2013-2014. They were obtained through the useof 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 andwater that is required in the most sensitive growth stages. Production function and profitfunction were obtained from the yield-water-product function of crops using Eviewssoftware. Expected net profit of the system and optimal allocation of water were alsocalculated based on the GAMS economic analysis software. Results of the modelindicates a reduction in wheat, barley, melon and watermelon production area undercultivation while at the same time an increase in ruby grapes cultivation areas underoptimal conditions. The results showed that the cultivation of the ruby grape was thebest product with the highest expected profit in normal and drought conditions. Ingeneral, when the expected value of net profit is positive, managers would actoptimistically and they would promise the optimal level of water allocated to thefarmers.