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In terms of evaluating the water security situation of communities, it is necessary to use appropriate indicators. To do this, composite indicators are especially useful for policy-making on water resources, aiming to enhance water security, implementation, and monitoring of policy actions. The composite indicators of water security at the national level reflect the country's status in terms of water resource sustainability, human well-being, and water environment. In this study, the composite indicators of water security for D-8 countries were investigated in various dimensions using the data envelopment analysis model. Moreover, the status of selected countries was examined with regard to indicators related to the dimension of water security sustainability. The results provided by the proposed model showed that Malaysia, Bangladesh, Indonesia, Nigeria, and Turkey have better positions regarding the sustainability dimension compared to other countries. The water exploitation intensity in these countries was less than 40 %. Furthermore, the level of water availability in Malaysia, Bangladesh, and Indonesia was higher than 7000 cubic meters per person. It is worth noting that Low exploitation intensity and high availability of water in a country increased its water security in terms of sustainability dimension. The low water availability and very high water exploitation in Iran, Pakistan, and Egypt exacerbate their insecurity in the sustainability dimension. Due to the importance of the sustainability dimension in determining the water security status of countries, it is recommended to take this dimension into account.

The overuse of pesticides has harmful impacts on both the environment and human health. Implementing efficient techniques is crucial to manage pesticides and reduce negative impacts effectively. In order to achieve this objective, we evaluated the harm of pesticide application in vegetable fields in Shiraz and identified the factors that impact farmers' behavior in using pesticides. The Environmental Impact Quotient (EIQ) indicator was initially utilized to evaluate the effects of pesticide residues on both human health and the environment. Afterwards, the Logit model was employed to investigate the likelihood of excessive pesticide usage among farmers. Our findings suggest that farmers may not give high importance to environmental and human health considerations when deciding on pesticide usage. Market incentives, such as the quantity and price of vegetables produced without pesticide use, play a significant role in reducing pesticide use in Shiraz vegetable farms. The results of the study can help policy makers in implementing pesticide-free agricultural practices.

Water resources are under increasing pressure from population growth, socio-economic development, and climate change. The main user of freshwater is the agriculture sector, accounting for 70–80% of global water use. Consequently, increasing water productivity and reducing water use in this sector are vital for alleviating water scarcity. It has been alleged that domestic or international trade of water-consumed products from wet-provinces or countries to arid and semi-arid provinces or countries is one possible path to mitigate water shortage. In this regard, virtual water flows and their determinants in Iran are investigated in this paper. This study examines the main determinants of bilateral virtual water flows associated with international trade in agricultural goods among Iran and other countries using a gravity model of trade. The impacts of climate change and socio-economic change scenarios on the virtual water trade are simulated. The result of the gravity model indicated that bilateral virtual water trade flows are influenced by the classical determinants and all the mass-related variables (gross domestic product and population) are significant with expected signs. Finally, the result obtained from the simulation of climate and socio-economic change scenarios showed that under the pessimistic scenario of climate change and population growth rate of 0.98 and 0.44%, VW trade between Iran and other countries would increase by 41 and 66% in the periods of 2016–2045 and 2070–2099, respectively. As a consequence, identifying the appropriate countries for business interactions and adopting effective trade policies are very important and need attention soon. HIGHLIGHTS Bilateral virtual water trade flows are influenced by the classical determinants and all the mass-related variables (gross domestic product and population).; The size of the future virtual water flows was predicted under the climate and population change scenarios.; The average annual temperature and the population of Iran, as the determinants of virtual water flows, have a positive and significant effect on the net virtual water flows.;

The change in availability of water resources has a dynamic behavior and is influenced by many factors such as population growth and climate variability over time. Understanding the impacts of such factors on water resources vulnerability is essential for ensuring the sustainability of future water resources. In this study, a water resources sustainable index is built using a system dynamics model to assess the effects of different scenarios at the Kowsar dam basin in southwestern Iran where managing water resources is serious challenging due to periodic drought. Based on the baseline scenario, the total population, as well as total water demand, will increase and water supply will decrease throughout the simulated period. Therefore, the imbalanced supply-demand of water can cause the water system vulnerable. In this regard, water management policies should concentrate on the demand side of water to address the problem of water resource shortage in a good manner. Although pessimistic climatic conditions along with population growth put the water system in the worse situation of water availability, where the demand control policies likely help meet the increasing water demand. Compared to the pessimistic conditions, the water sustainability index improves in normal and optimistic conditions. The highest sustainability index was obtained after controlling water demand in optimistic weather condition. Consequently, the government should provide a context in which people learn to control their daily water consumption. Also, it suggests that we can conserve water resources in the agricultural sector with conservation policies.

To effectively tackle the issue of increasing irrigation water scarcity, farmers need to convert to modern irrigation systems with lower water use while achieving higher yields and profitability. Unlike the government support to cover a proportion of irrigation modernizing costs by public subsidies in Iran, the adoption rate is low. This is due to farmers' uncertainty about the trade-off between benefits from yield improvement and the added production costs. The historical gross margin of barley, wheat, forage corn, and tomato under surface, drip, permanent sprinkler, and semi-permanent sprinkler irrigation systems was generated using simulation and survey-based data for yield and published data for costs and prices over a 5-year period (2009–2015). The stochastic dominance (SD) and stochastic efficiency with respect to a function (SERF) approaches were used to evaluate the risk efficiency of various irrigation systems for main crops in the Bakhtegan Basin. Estimating certainty equivalent (CE), we ranked irrigation alternatives at different absolute risk-aversion coefficient (ra) levels. The findings show that drip irrigation systems for forage corn and tomato have higher CE values at all levels of absolute risk-aversion coefficient; however, the preferred system for barley and wheat varies with ra. Moreover, estimated risk premiums revealed that risk-neutral farmers would pay to move from surface systems to more efficient systems, whereas risk-averse farmers need to be paid to have the tendency to change their irrigation system. The important policy implication of these results is that risk premiums can consider justifying subsidy allocation in a manner that induces farmers to more risk-efficient irrigation systems.

Abstract Background and Objective: Water and soil resources protecting in agriculture has particular importance. This study attempts to determine optimal crop patterns in Firozabad plain taking to account agriculture sustainability with three objectives. For this purpose, utilizing Fuzzy mathematical programming, profit-maximizing as the economic goal and reduction in water, fertilizer and pesticides uses as environmental goals were considered. Materials and Methods: Deficit irrigation and water stress conditions, as well as the adoption of an appropriate irrigation system, was modeled with different decided variables to show the actual conditions of the plain in normal and drought years, by considering the upper and lower targets in the fuzzy model. Results: Results showed that all the three objectives contribute approximately the same levels of satisfaction and there are no clear differences between crop patterns with and without dry farming. In the case of drought years, wheat 25, wheat 49, barley 44, corn 3, sugar beet 48 and rice, and the same products with different levels of deficit irrigations were recommended in the normal year. Optimal crop pattern was determined and comparing it with the average crop pattern in the past 10-year in the region. Conclusion: To align with sustainable agriculture and protecting water and soil resources in Firozabad plain, it is not necessary to change the crop pattern of the area. The main difference is due to choose of an irrigation system, irrigation time, and changing the share of plains cultivation levels to products suitable.

In this study, an integrated system dynamics model was developed for scenario analysis in sub-sectors of the Kheirabad River Basin in southwestern Iran where managing water resources is seriously challenging due to population growth and periodic drought. Afterward, the variability of water demand and supply under baseline scenario and different water demand management policies, including water conservation and water pricing, was evaluated. Findings illustrated that with increasing population and cropland area if no further demand management policies were implemented, the total water demand and withdrawal of water resources increase by more than 0.75% annually. The annual surface water availability during 2018-2030 is expected to decrease by around -1.23%. Under these circumstances, the sustainability index of the water resources system is equal to 0.703, indicating that the water system would not be able to meet the total water demand in the near future. However, the water resource sustainability index increases significantly by improving irrigation efficiency and changing crop patterns at the basin. Also, the reduction in per capita water demand and domestic water pricing under the competition structure would help to improve the sustainability index to 0.963 and 0.749, respectively.

In recent years, due to excessive consumption and unbalance between water consumption and water resources, Iran has led to a severe shortage of renewable water sources. Therefore, in this situation, analyzing the status and presenting appropriate strategies is the main priority for policymakers. For this purpose, by designing a dynamic stochastic general equilibrium model, status of consumption of water resources has been studied in the household, agriculture and industry sectors. The existence and definite status of the stable situation, both parametric and numerically, has been investigated according to estimated values for Iran's economic parameters. According to the results of the research, it should be noted that at present, per capita water consumption is 1000 cubic meters per year. In other words, with current domestic consumption per capita, water per capita is less than that on the optimal Path. It is expected to achieve sustainable equilibrium in a long-term horizons by reforming consumption and providing policy solutions. Also, based on the simulation, from different policies, Establishing a 8-year limit on agricultural products with high water consumption is the most important policy for achieving the above equilibrium.

Intervening government and performing environmental policies are among solutions for reducing production externalities and achieving sustainable development. Indeed, institutional quality is an effective factor in selecting optimal environment policies. This paper tries to identify optimal environmental policy among common public tools for intervening (pollution taxes and permits) in the presence of environmental and economic uncertainties with various institutional quality degrees. In this paper, institutional quality is included in a dynamic stochastic general equilibrium model and its effect on choosing environmental policy is considered. The results showed that pollution permit is preferred to taxation on pollution with various institutional quality degrees. In addition, with improvement in institutional quality, if only shock is an environmental shocks, then taxation on pollution will be an optimal policy.

The growing demand for water and the declining trend in renewable water resources in most regions has led to serious limitations on water availability calling for the sustainable management of the harvestable resources. This has, in turn, encouraged most planners in the water sector to focus on demand management. A number of tools are already available for realizing water demand management goals; one such tool is establishing a water market. The present study is designed and implemented in two stages to investigate the role of a water market in water resources management. In the first stage, the creation of a water market at the farm and basin levels is simulated using a mathematical planning model. The second stage involves the investigation of the combined effects of the water market and water extraction rationing policies. It is found that rationing policies lead to reduced extractions from groundwater resources. The two-stage random cluster sampling method is used to collect the required data. Pilot villages are selected based on the data obtained from the first sampling stage. Pilot farms are then selected in the second stage based on water availability in each place. The input-output data, quantities of available water, and any other data required are finally collected through interviews with local farmers. Results reveal that the volume of exchanged water accounts for 9.5% of the total water consumed and the average improvement gained in farmers’ income ranges from 15 to as high as 42%. This clearly provides enough incentives for the farmers to enter the water market. Like all other water saving policies and measures, establishing a water market might increase consumption, contrary to the national objectives, in the absence of proper supplementary preventive measures. Thus, a second scenario is designed to investigate the combined effects of both water extraction rationing and water marketing. According to this scenario, the total annual irrigation water allocations to the representative farms in groups 1 and 2 are reduced by 20 and 30%, respectively, to observe reductions in farmers’ income levels of only 8 to 11%. This indicates that the simultaneous implementation of both water extraction rationing and water marketing is able to guarantee reductions in water consumption without any considerable decline in farm income levels. The water thus saved can then be used for groundwater protective measures and environmental water allocations. Water meters and volumetric water delivery systems as components of a sound water bookkeeping system considerable at both farm and basin levels will form the prerequisite measures to any water saving policies such as water marketing.

The main purpose of this paper is to determine the amount of subsidy required to promote the share of renewable energy in total electricity production. To do so, different scenarios have been studied by a hybrid approach of Computable General Equilibrium model. The results have been created by entering the details of technology-specific information for electricity generation into this model. The result of codification and calibration of the model shows that in the case of applying same subsidy to achieve 10 present shares of renewable energies in total electricity production, there is a need for 851 percent subsidy rate. Although in this case the wind energy is the only activated resource and the solar and biogas sections have not succeeded in achieving any rise in production rate. The other scenario was based on the unequal subsidy, proportional to disadvantage of different renewable energy. The result shows that, to achieve a balance growth of 4 percent energy productions from renewable sources, the rate of subsidy for wind energy should be 887 present. This rate for solar is 1776 present and for biogas is 1585 present. So, in the first scenario, the proper tariff for purchase of electricity from renewable energy is 4100 Rials per kWh. This tariff in the second scenario is 4260, 8520 and 7600 Rials per kWh respectively.

Iran's simple and environmentally extended commodity by commodity input-output (IO) model was used to determine the impacts of dietary changes on the Iranian economy and on the environmental load. The original model is based on the status-quo diet and was modified to include the World Health Organization (WHO), the World Cancer Research Fund (WCRF) and Mediterranean alternative dietary scenarios. A range of impacts occurred depending upon the relative changes in food items. The direction of changes was similar in the three alternative scenarios. The greatest and smallest impact occurred in the WHO and the Mediterranean scenarios respectively. Total changes in output in WHO, WCRF and Mediterranean dietary scenarios were calculated to be 7010.1, 4802.8 and 3330.8 billion Rials respectively. The outputs of rice, vegetables, fruit, bread and macaroni decreased, but those of live and other animal products increased. The output of non-food commodities and services increased as well. The environmental load increased for three dietary scenarios in comparison with the status-quo diet. The greatest and smallest environmental load occurred in WHO and Mediterranean dietary scenarios respectively. Thus, although dietary changes can have positive effects on economic output, in order to avoid negative environmental effects, it is necessary to consider strategies such as applying capabilities, particularly natural resources in an optimal healthy and environmentally diet, planning for improving forest covering and green space simultaneously with increasing economic activities and using indirect incentives, such as taxes and insurance, for promoting sustainable and healthy foods and reducing greenhouse gas emissions.

Computable general equilibrium (CGE) models have become a standard tool of empirical economic analysis and were extensively used to assess the impact of trade liberalization by policy analysts. In this study, the effects of imports tariff reduction as a trade liberalization index are investigated on key economic variables using computable general equilibrium approach. The data used in this study are obtained from the social accounting matrix of year 2001 in which parameters of model are calibrated accordingly. Results of simulations show that if the imports tariff rate is cut by 50% and 100% across all sectors, total supply and investment will reduce while total exports, total imports, household income and consumption will increase.

Since Iran is one of the most important countries in producing as well as exporting pistachio and dates Therefore, in this study after calculating exchange rate volatility using the criterion of standard deviation of exchange rate moving average, the effects of this volatility on the export supply of mentioned crops was investigated. Autoregressive distributed lag model, one of the co-integration analysis methods, was used to reach the aim. Export supply function of pistachio to German, Unit Kingdom and Italy and export supply of dates to German, Unit Kingdom and Turkey were estimated. The results indicated that exchange rate volatility has different effects on export of the crops to understudy countries. Therefore in relation to trade policies, the effect of exchange rate volatility on trade should be considered with respect to destined country.