Mohammad Hassanli; Peyman Afrasiab; Mahmoud Sabuhi; Hamed Ebrahimian
Abstract
The economic value of water is one of the most important factors for allocating water among various consumptions and encouraging users to take necessary actions to increase investments related to improving water productivity. There are several methods for economic valuation of water. In this study, due ...
Read More
The economic value of water is one of the most important factors for allocating water among various consumptions and encouraging users to take necessary actions to increase investments related to improving water productivity. There are several methods for economic valuation of water. In this study, due to the key role of water in irrigation of agricultural products, residual valuation method was used for agricultural wells in Varamin County, with a wide range of water salinity. The average economic values of water for cucurbits, wheat, barley, and alfalfa were 2513.1, 5334.5, 1933.0 and 5647.6 Iranian Rials per cubic meters (IRR.m-3), respectively. The exchange price of water among the farmers in the study area was calculated as 5231.8 IRR.m-3, which was close to the calculated residual value for wheat and alfalfa crops. The coefficient of determination (R2) for the relationship of economic value and salinity of irrigation water for the above crops was 0.806, 0.878, 0.865 and 0.702, respectively, which indicates that the main changes of economic value of water is related to salinity of water. According to the relationship between salinity and irrigation water value in the study area, the residual value of water was zero in the electrical conductivity of 3.61, 7.30, 6.05, and 8.24 dS.m-1 for cucurbits, wheat, barley, and alfalfa, respectively. As a result, the water pricing policy in the study area should be such that for water salinities higher than the mentioned values, the selling price of water is set lower than the current value, so that the farmers do not suffer losses. Another option is that choice of crop should be based on greater resistance to salinity and its economic value.
Akbar Alipoor; Kamran Davari; Mohammad Mousavi Baygi; Mahmoud Sabuhi; Aziz Izady
Abstract
Groundwater is the largest source of freshwater available on Earth, which has been threatened with extinction in many countries due to overdraft. Determining the optimal cropping pattern along with a reduction in water resources allocation that does not lead to a reduction in farmers' income can be an ...
Read More
Groundwater is the largest source of freshwater available on Earth, which has been threatened with extinction in many countries due to overdraft. Determining the optimal cropping pattern along with a reduction in water resources allocation that does not lead to a reduction in farmers' income can be an appropriate strategy for groundwater sustainability. In the present study, a method has been proposed that, in addition to the sustainability of groundwater, minimizes farmers' loss of income. For this purpose, four groundwater use scenarios were first defined and groundwater level changes were calculated for each scenario using Neyshabur Decision Support System model. Also, economic productivity of water was estimated using a questionnaire for 242 agricultural wells and 9 dominant plants in Neyshabur plain, in 2016. To minimize farmers' income reduction, water was reallocated to different crops and the areas of cultivation were determined based on the ratio of economic productivity percentages of each crop. Due to changes in groundwater level and existing conditions, the scenario in which groundwater use was set equal to renewable water (414.9 M.m3) was selected as the best scenario. Implementation of this scenario would reduce the allocation of 227.5 M.m3 for groundwater sustainability. The results showed that the reduction of water allocation would result in a decrease of 27061 hectares of cultivated land area and a decrease of about 83.5 billion Tooman (local currency) in revenue. In order to compensate for the decrease in income, alternative crops of pistachio and saffron were suggested due to their higher economic efficiency and lower water consumption. In the proposed pattern, 18,000 hectares of saffron or 4473 hectares of pistachio replace the current crops that have the highest percentage of cultivated land in summer vegetables and sugar beet.