The Effects of Restriction Policy of Agricultural Water Supply on Cropping Pattern: A Case Study of Dehgolan Plain in Kurdistan Province of Iran

Over recent years, unconventional extraction of irrigation water for producing agricultural products has decreased the level of groundwater in Dehgolan Plain of Kurdistan province in Iran, putting this vital resource at serious risk. This study aimed at investigating the effects of restrictive water supply policy on cropping patterns, farmers' incomes and the amount of water extraction from groundwater aquifer of Dehgolan Plain. For this purpose, a positive mathematical programming (PMP) model along with a maximum entropy (ME) model was developed and estimated. The required data was obtained in a two-stage cluster sampling method through completing 96 questionnaires from farmers in the villages of the region for the 2015-2016 farming year. The results showed that the irrigation water reduction policies had a great impact on the cultivation pattern and led farmers to products with more economic efficiency in water use. Furthermore, as a result of this policy, the gross margins in the first to third scenarios will decrease by 4.94, 9.96 and 14.94 percent, respectively, and the economic return on irrigation water will increase by 5.65, 12.64 and 21.63 percent, respectively. In conclusion, according to the results of this study, the strategy of restricting water supply along with the changes in cultivation pattern might effectively reduce water extraction and contribute to maintain and sustain the groundwater resources of the Dehgolan Plain.