فهرست مطالب hajar fazlolahi

Optimal water consumption and the supply & demand management would require a better focus on the economy of water resources. This study evaluates the effects of virtual water on the economic value of water resources using a mathematical model. The model has been applied to the Arak Plain, central Iran, for four strategic crops of wheat, barley, alfalfa and corn with three weighting methods of “cultivated area”, “water consumption volume”, and “income”. Meteorological and agricultural data, water consumption data as well as incomes and expenses of the water section in 2015-2016 were used in this research. Results show that the economic value of agricultural water resources in the Arak Plain increased for all the three weighting methods by considering the virtual water that led to substituting the products. Replacing alfalfa with sorghum would increase the economic value of water resources by 36.0%, 28.0%, and 40.5%, using the three weighting methods of “cultivated area”, “water consumption volume”, and “income”, respectively. Increasing the economic value of water resources is one of the main ways towards sustainable development and food security.

In this paper, the effect of inter-basin water transfer on the economic value of water resources has been investigated through a case-study of the Kamal Saleh dam from the Sarband Basin to the central Arak Basin. For this purpose, by using the mathematical model developed in this research, the economic value of agricultural water was investigated without regard to transferred water resources and considering its impact for wheat, barley, alfalfa and corn. The input data for this study was included meteorological and agricultural information, volume of consumed water, wastewater volume, volume of water transfer from Kamal Saleh Dam, as well as information about costs and incomes of the crop year 2015-2016. The results showed that water transfer to Arak city would increase the economic value of agricultural water resources in this city. So, the economic value of water estimated from three methods including weighing the area under cultivation, the volume of water consumption and product income for increasing crop area of corn were increased 10, 7.5 and 9 percentage, respectively . In addition, by increasing crop area of alfalfa the economic value of water estimated from all three methods was increased 2%. Increasing the economic value of water resources can be one of the solutions to sustainable development and food security. However, inter-basin water transfer projects should be implemented with all technical and economic and environmental factors, with emphasis on social and political considerations.

Considering the quantitative and qualitative limitations of water resources, determining economic value of waters can have a significant impact on water demand and consumption management. For determine the economic value of water, a mathematical model has been developed in this research. The AWPM has been applied for Soghan in Kerman Province, Iran and water prices for each product were obtained. The highest price obtained for water from pricing method based on the type of product in the region of Sughan is 47577 (Rls / m3) for pistachios and the lowest price is 683 (Rls / m3) for potato. Also, the results of model implementation showed that the price obtained for water from methods that estimate the price of water based on the type of product and considering the factors such as the area and volume of water are more than methods that do not include product types. The features of this model are the exact calculation of agricultural water prices, the flexibility of the model and the user friendly of the model. This model can be used as a rapid and accurate tool for of agricultural water prices calculation.

Economic development and efficient use of water resources is largely dependent on water as an economic good, and it is to be considered using the economic approach in order to manage it. The main objective of this paper is to determine the economic value of agricultural water based on crop-types and financial efficiency of farmers in seven areasof Markazi province, Iran in the 2012-2013 crop year. For this purpose, a localized developed mathematical model was used to calculate the economic value of water for 4 crops including wheat, barley, alfalfa and corn by three different weighting methods including the volume of water, the area under cultivation and the income from each one of the products. Among the above mentioned methods, the weighting method - which is based on the volume of water - is selected as the most appropriate method. The economic value of water based on this weighting method and for the studied areas including Mahallat, Komijan, Shazand, Saveh, Delijan, Khomein and Ashtian were obtained equal to 5700, 5550, 5000, 6700, 3800, 4800, and 6050 rials per cubic meter of water, respectively. The financial efficiency for all the three alternatives; free water, 10% of the calculated price and the actual price of water from the farmer were calculated. Results revealed that financial efficiency is sensitive to changes in income and it is more sensitive than changes in costs. Irrigation efficiency and financial efficiency are not aligning in all cases. This means that in the first place, in order to increase farmers' financial efficiency, the farmers' incomes should be increased, and secondly, by subsidizing in other conditions, the farmer’s costs should be reduced.