Irrigation water demand management in Ardalan plain with emphasis on pricing policy

Agricultural sector is the largest consumer of water in the country. Therefore, offering comprehensive methods of water resources management and planning the right policies in order to increase water productivity in this sector seems to be necessary. For this purpose, in the present study an economic modeling inclusive of Positive Mathematical Programming (PMP) and the approach of Maximum Entropy (ME) to assess the impacts of irrigation water pricing policy on the management of water demand in Ardalan plain was used. The required data are related to the agronomical year 2013. The results showed that absolute value of demand price elasticity for alfalfa and tomatoes that have a higher water requirement is more than other selected products and farmer's demand for water in the production of these products is more elasticity. In addition, the results showed that increasing the price of irrigation water (under scenarios of 200 to 1000 rials compared to the condition of base year) leads to the reduction of the area of irrigated wheat, alfalfa, tomato and sunflower and increase in the area of irrigated barley and watermelon in the cropping pattern of the region. Also, applying this policy leads to the reduction of consumption water in the cropping pattern from 2.04 to 7.83 percent and the reduction of farmer's gross profit from 1.96 to 7.65 percent in Ardalan plain. Finally, applying the irrigation water pricing policy and using the cropping pattern change strategy along with it was recommended to reduce the demand of irrigation water and sustainability of water resources in Ardalan plain.