Optimum allocation of Hirmand river water in Sistan area

摘要

One of the biggest planning problems in less developed countries is insufficient recognition of potentials and nonoptimal application of the production factors. This research is a case study of Shibab district located in Sistan region of Iran.The necessary data were collected from a random sampling of 105 farmers during 1998-1999 through questionnaires. Three different cropping patterns suitable to temporal allocation of water i.e. 247, 336, and 185 mm~3 per year were selected. Linear Programming model was used for finding the optimal patterns. Technical coefficients were calculated by means of farmers sampling. Results indicated that the most important restriction in agricultural activities of this area was water scarcity in summer season. Shadow prices of water in June & July with 247mm~3 annual water capacity was 228 and 54.6 Rials respectively ($=1750Rials). On the other hand in drought which water volume was between 136-202 mm~3, shadow price was about 174,5 Rials. Estimation of normative demand function for water implied that quantity of water demanded had negative relationship with its price and demand curve would be stepwise. Shadow price for >= 274 mm~3 water volume was zero and point elasticity for 127 mm~3water capacity was equal to one(0.9999). There was land constraint only in situation of 335 mm~3 available water capacity and shadow price of one hectare was estimated around 940110 Rials. Furthermore, with increasing in water quantity, limitation of fertilizer was observed. Ignoring the effect of self-sufficiency constraint from model were considered and the results showed that by remove of these restrictions, total net revenue can be increased. In this paper outcomes about water allocation for different activities in agricultural sector of study area were analyzed and some suggestions are given for optimum allocation & utilization of water resources.