Water resources management faces with very important economical, social, financial and environmental objects and aims that can pointed below issues answering with new demand in conditions accession quantity and quality restrictions of water supply, decrease and removal locks of effective and optimal usage of water resources, presentation of better services in operation of water plans, make social equality between different income groups and to conserve water resources for attained to said aims, one of important actions of water resources management is water demand management and to purpose water as economic commodity. For this reason, converting of instrumental tendency of water supply to non-instrumental tendency is very precious. In this variation, aim of water resources management is use of economic tools that one of important tools is pricing. In this study, for all around acquaintance with this important matter, tariff and pricing surveys in visionary and application circuits.

Introduction: Optimal management and proper use of available water resources is an inevitable necessity. Therefore, this study was conducted to investigate the effect of irrigation water prices on its demand in the agricultural sub-sector of Iran. Materials and Methode: The typical methods of pricing include calculating shadow prices for various types of water resources using mathematical models, using the full cost of water resources, or using farmers’,willingness to pay for water as a reference for pricing. To determine the shadow price of water and its demand function, we use a different way from other studies by using stochastic nonparametric envelopment of data (stoNED model). This paper investigates the technical efficiency of Iran’, s agriculture sector, and estimates the shadow prices of agricultural water at provincial level. Then based on the estimates of the technical efficiency and shadow prices, we measure the price elasticity of demand for agricultural water. In order to estimate the shadow prices of agricultural water and the price elasticity of demand for agricultural water, we collected a provincial level input-output dataset of the agricultural sector. Our dataset spans from of 2005-2016. The cross-section units encompass 30 provincial administrative districts. Input variables include labor, Pesticides, fertilizer and water. Results and discussion: The results showed that the average efficiency of irrigation water in the agricultural sub-sector during the study period was equal to 83. 02%. Gilan and Qom provinces had the highest (87. 76%) and lowest (81. 85%) water efficiency during the study period, respectively. The average shadow price of irrigation water among the provinces of the country is 1108. 93 rials per cubic meter. The highest average shadow price of water during the years was related to Gilan province with 1161. 16 Rials per cubic meter and Mazandaran, East Azarbaijan, Markazi and Fars provinces with prices of 1153. 48, 1129. 54, 11126/47 and 11123/75 per cubic meter are in the next categories, respectively. Also, the results of estimating the irrigation water demand function showed that the irrigation water demand in the agricultural sub-sector is inelastic (0. 16) and the elasticity of water demand to technical efficiency is equal to 8. 37. Based on the obtained demand function, the variables of water price, price of other production inputs and water efficiency have a significant effect on irrigation water demand in Iran's agricultural sector. Among the studied variables, technical efficiency, with the largest coefficient, is considered as the most effective factor in irrigation water demand. Suggestion: This result shows the need to pay more attention to the issue of water efficiency and efforts to improve the efficiency of irrigation water in the agricultural sector. Also, according to the results, increasing the price of irrigation water in agriculture sub-sector will not have much effect on reducing demand and water consumption in this sub-sector and reducing irrigation water consumption in agriculture sub-sector will be possible by improving water technical efficiency. Therefore, based on the results obtained from this study, it is suggested that the policy makers providing facilities and incentives consider suitable conditions for farmers to accept and implement the change of cultivation pattern towards low-water crops and the application of low irrigation systems in lands.

Formulation of appropriate pricing policies should include consideration of the inelasticity and elasticity of agricultural demand for water, when economic instruments should be considered concurrently with social and environmental requirements. The data were collected using multi stage random sampling method in 2006. The result showed that there was a positive and significant relationship between the number of productive datepalm, the total labor used and the number of irrigation with amount of date production. Marginal productivity of water in gravity and drip irrigation method is 0.194 kg and value of marginal productivity of water was calculated 204.06 Rials in this irrigation method. Marginal Economic Research Institute, Tehran, Iran productivity of water in basin irrigation system method is 0.13 kg and value of marginal productivity of water was calculated 140.73 Rials in this irrigation method. The cost of each m3 of water was calculated 67.23 Rials on the base of 20 percent interest rate. Demand elasticity for water in gravity drip irrigation and basin irrigation system methods has been -3.035 and -2.093 respectively which show that demands for water are elastic in both irrigation methods.

Sustainability of water resources has the most important role in the sustainability of agricultural systems. In this study, positive mathematical programming applied in 2018 to evaluate the sustainability of water resources and to determine the cropping pattern in Golestan province based on water demand management policies, i. e. water price increase by 50% and 100%, and reducing water quota by 10% and 20%. First, according to water price increases and water quota policy scenarios, the cropping pattern was evaluated in this area. Then, by using the sustainability indicators such as gross margin (GM), water consumption, economic efficiency, and labor efficiency the sustainability of water resources was calculated. Based on water price increases by 50% and 100%, water consumption and GM decrease by, respectively, (2. 72% and 5. 44%) and (5. 06% and 9. 99%). Also, based on water quota policy of 10% and 20% reduction, water consumption and GM decrease by, respectively, (8. 9% and 11. 56%) and (0. 54% and 1. 75%). In addition, GM per unit of water in agricultural sector decreases by 2. 41% and 4. 81% in response to to water price increase by 50% and 100%, respectively, and in case of 10% and 20% reductiion in water quota policy, it increases by, respectively, 9. 17% and 11. 09%. Water price increase by 50% and 100% and water quota reduction by 10% and 20%, increase water labor efficiency by, respectively, (0. 78% and 1. 6%) and (2. 6% and 5. 8%). Based on the result, if the government is going to increase water sustainability by using demand management policies, the water quota policy is more efficient. Also, the government should support farmers by direct payments to compensate for their lost profits. It is also recommended that irrigation methods with high efficiency be employed.

Given the strategic remarkable rank of pistachio in non-oil exports, inputs’ management in its production is so important. As the scarcest input in agricultural sector, water is considered to be among the most important inputs of pistachio production. Water inadequate supply and climate conditions increase water demand in pistachio growing areas. It is necessary to determine the real value or price of water for establishing a balance between its demand and supply. Therefore, this study has aimed at estimation of water economic value. The method used in this research is the production function approach. Requested data sets were obtained from the questionnaires was filled out for crop years of 2013-2014. The results show that the average economic value of irrigation water is 50360 RLS but the average price paid by farmers is 1771 RLS per cubic meter of water. Thus, there is a wide gap between water value and the price paid by farmers with which appropriate pricing of water based on its economic value can be eliminated.

The serious obstacles to improve water supply, has caused world debates, seeking some solutions to tackle the problem of shortages in water supply. t. Therefore, programs and policies have focused mainly on appropriate pricing approach of. Since the water industry in Iran has been monopolized by the government, an effective pricing approach is assumed to maximize the social welfare with consideration to the cost.. To consider the mentioned aspects to price water, this study used the Ramsey approach. Thy study estimated the Ramsey price of water used for the agricultural sector in Hamadan province of Iran. To determine the price, the Agricultural water demand function was estimated using time series data for the years 1370-88. Using the estimated demand function the price elasticity of demand was calculated. The water production function was also estimated using time series data for the years 1370-88. In order to estimate supply and demand functions, the ARDL model and Microfit econometric software were used. Using production function and demand function, the marginal cost and price elasticity were calculated. Applying the calculated ratios through MATLAB software, the Ramsey price of water for agriculture was measured. According to the results of this study, in the year 1388 the Ramsey price of water for agriculture was more than the paid price for industry.

Background and objectives: Water as the most scare input in the production of agricultural products is not only a limiting factor for agricultural activities, but also is obstacle to other economic and social activities. The limited water resources of Iran, regardless of inter-year variations, are almost constant. Water supply of different sectors faces a lot of constraints with increasing population and development in different dimensions and rising standards of living. So, we need to look for suitable solutions for water demand management. Implementing policies that increase the incentive for consumers to save and prevent the loss of consumption of this valuable input is very effective and important. One of these policies is the pricing of water resources in different ways in the agricultural sector. Investigation of internal studies on water valuation shows that there is a great difference between the economic value of water and paying farmers for water. Water pricing policies based on the economic value of water can be effective in allocation and optimal use of water. Therefore, it is necessary to do various studies in order to apply appropriate policies to the climatic conditions of different regions. Pricing policies in different parts of the country in most cases are used only by area pricing. Due to the problem of water crisis, the growing demand, and the gap between water supply and demand, area-based pricing method does not provide sufficient incentives for optimal use of agricultural water. Therefore, this study examines the different methods of water pricing such as area pricing, volumetric pricing and combination of both. Therefore, this study examines the optimal consumption of water resources for the purpose of water and soil conservation in Gonbad-e-Kavous County, Golestan province. This syudy considered the volumetric pricing and composition of volumetric with area-based methods in addition to area-based pricing method that is the innovation of this study. Materials and methods: Since that different agricultural policies can not be investigated and analyzed in the laboratory environment, so the potential effects of these policies should be investigated by appropriate instruments of policy before, during and after the implementing of policy. Therefore, due to the importance of the subject, in this study, the Positive Mathematical Programming (PMP) model is used to simulate farmers' behavior in the downstream lands of Golestan Dam (1) in Gonbad-e-Kavous County, in the implementation of various water pricing methods such as Area-based, volumetric and mi combined of them. In this study, data were collected using random sampling method and 20 scenarios were investigated. The GAMS software package is also used to analyze the information in this study. Results: The results of this study show that water demand in all three methods (area-based, volumetric and combined) will decrease from 22. 6 to 48. 8% as water price rises in different scenarios. The highest water demand reduction is related to the combined, volumetric and area-based water pricing method, respectively. Conclusion: Applying appropriate water pricing methods makes water be distributed optimally between users based on the value of marginal product and provides incentives to save and prevent loss. Therefore, based on the results of this study, it is recommended to use a volumetric and area-based pricing method in combination.