نشریه علوم محیطی
سال شانزدهم شماره 1 (پیاپی 59، بهار 1397)

Over recent decades, climate change and the lack of adequate and timely rainfall, leading to a lack of adequate water for irrigated plants and limited renewable land and water resources, has resulted in the heterogeneous spatial and temporal distribution of fresh water as well as rapid population growth, including in Iran, There are increasing problems in providing water resources for various uses. One of the main requirements for meeting global food needs is access to sustainable agriculture and its development. In order to achieve this, appropriate measures should be adopted to prevent damage to the system of limited resources in each region. Groundwater is always an important source of fresh water and groundwater management, at the first stage, requires the identification and operation of aquifers under natural conditions. In most hydrological questions and groundwater resource studies, the availability of groundwater resource data and statistics is of great importance. In order to assess the effects of development in existing conditions and to provide management methods for groundwater resources, both quantitatively and qualitatively, mathematical and computer simulation of these resources is a powerful tool for the optimal utilization of these resources. Numerical modeling of groundwater in aquifers is an important tool for the management of water resources. This model can be used to estimate the hydraulic parameters as well as water resource management. The aim of this study was to simulate fluctuations in groundwater levels in the aquifer Zanjan located at a latitude of 47 degrees 50 minutes 49 ° East and latitude 36 degrees 20 minutes north and 37 degrees using GMS software. This model is a combination of code Modflow and GIS using the finite difference method, the ground water level simulation. For this research the information needed to run the model that were introduced to the model, included: positions of border aquifers, at different heights above ground level bedrock aquifer; the amount of withdrawals from well tapping positions; the position of and water level in observation wells; the hydraulic conductivity layer; and nutrition. After the preparation of the conceptual model and the determination of initial and boundary conditions, the simulation will be discussed. The flow simulation model was calibrated in a steady flow. The results of the calibration results in a steady state showed a reasonable balance between the observed and calculated results in October 2002. After calibrating the nutritional value 0/000321 meters per day, it was found that this amount is 1/98 times the amount of power input to the model. The amount of horizontal hydraulic conductivity layers of sand,/silt and sand,/gravel were measured at 28.57 and 40.4 km per day, respectively, and then the unsteady flow model calibration mode for distances between 2002 and 2007, using trial and error to achieve the best balance between the level observed daily. Projected drops in groundwater levels were calculated, based on the implementation of the model for 2007 and 2015 and 2022. The root mean square error, mean absolute error and mean error, respectively, were 17/41, 15/22 and -0.6. The root mean square error and average error with respect to the amount equal to 26/29 and -8/43 showed the good accuracy of the model. The water level calculated for the converter, groundwater flow is from the southeast to the northwest of the current slope correspond area. The model was implemented with the assumption of the rate of groundwater abatement and constant nutrition for a 15-year interval from 2007 to 2022. Maps obtained for the groundwater level in the years reflect a sharp drop in the water level as the result of continued indiscriminate harvesting of the Zanjan underground water aquifer.

Nowadays, dues to limitations in raw material supplies, the pulp and paper industries face problems in achieving an efficient system for producing multiple and valuable products. Moreover, the loss of a large portion of raw material during processing and restrictions on the use of fossil fuels with regard to sustainable development, need to be addressed through the development and reform of efficient methods such as bio-refinery. By using various pre-treatment methods, bio-refinery breaks down raw material to their parts to obtain intermediate products such as sugars (glucose and xylose) that can be transformed into bio-based products with high value-added at the next step. By using a bio-refinery approach to evaluate the potential of the most important papermaking industrial waste, this study was carried out by focusing on xylan hemicellulose extraction for the production of high value-added products. After the first preparation of bagasse pith, its chemical compounds were determined using the standard methods. For ease in obtaining a better quality and quantity of xylan, bagasse pith was treated with two process of alkali pre-treatment (soda cooking with 2, 4, 6 and 8% alkali concentration for 5 and 15 minutes and at a temperature of 110 and 140 ˚C) and bleaching with sodium chlorite. This was then evaluated in terms of yield and lignin content. For the xylan extraction, the bleached pulps were treated with NaOH in different dosages (8, 10 and 14 %). Extracted samples were characterized by weight loss, recovery rate, percentage of xylan extraction as well as FT-IR spectroscopy. Results showed that 26% of xylan and 20% of lignin in chemical compounds are present in the untreated bagasse pith. During the first processing of bagasse pith, the conditions of an 8% concentration for NaOH, an extraction time of 5 minutes and a temperature of 110 ˚C were selected due to the greater yield and less lignin of the pulps, as well as a 6-step bleaching process in part due to greater holocellulose and less lignin. This showed that delignification (alkali cooking) led to lignin removlg as well as facilitating of the hemicellulose extraction. Hence, it can be expected improve of the xylan extraction with alkali extraction. In xylan extraction, increasing of NaOH consumption from 8 to 14 percent increased the recovery rate of xylan to 22% so that, under these conditions, the extracted xylan content was 4.53 g. FT-IR spectra also confirmed that lignin decreased with alkali pre-treatment and bleaching and, by increasing NaOH consumption, xylan extraction was increased which is, of course, the major hemicellulose in bagasse pith. Bagasse pith is rich in the carbohydrate specific xylan so that its alkali pre-treatment and bleaching led to lignin loss and more accessibility to this carbohydrate. Finally, xylan extraction using 14% NaOH was suggested as the optimized extraction method due to greatest yield and percentage of extracted xylan. Hence, it can used to produce bio-based products in a bio-refinery concept.

Over the past few decades, several models such as the LP model have been used for watershed management and planning as well as determining optimal cultivation patterns for agricultural planning. Management and planning methods are the most important applied management tools for optimal allocating of environmental resources, in order to gain the most profits in the different fields including natural resources, water resources and etc. The purpose of this study was to develop an optimal land use model with an environmental approach using a combined linear programming mathematical optimization method to determine the optimal land use area through spatial optimization of multi-objective land allocation to determine the best location of land uses. In this study, by using optimization methods, we tried to produce an environmental model which is compatible with the social and economic conditions of the watershed for determining the better use, conservation and rehabilitation of existent natural resources. For this purpose, a single objective linear programming model with an environmental approach was used for land use optimization and a multi-objective optimization model for optimal allocation of resources. After collecting and analyzing the data and entering them into the single-objective optimization model of linear programming, a mathematical model was first developed that determines the optimal area of land uses in the basin and then, using the spatial optimization model for multi-objective land allocation, the optimal land uses location was determined. The proposed combined model is an efficient one because it can simultaneously determine the optimized area and location of land uses. The results showed that the proposed combined model can be the base for correct management of resources and decrease the degree of soil erosion to nine percent and increase the amount of profit to 96 percent.

The air temperature parameter is one of the most important measures for identifying the climatic and environmental conditions of each region. Today, LST maps can be prepared without physical contact with objects or surfaces by using thermal infrared data. Awareness of the spatial and temporal distribution of LST is essential to determine the land energy balance, and evapotranspiration and meteorology studies are essential. LST is a function of pure energy on the land’s surface which depends on the amount of energy reaching it, surface emissivity, humidity, and air flow. The present study intends to investigate the state of daytime LST in Iran in different months of the year based on the output of MODIS Terra images. In this study, the fifth MODIS Terra product called (Mod11C3 v005) was used with a spatial resolution of 5×5 kilometres and a daytime time period which became monthly data after the necessary processing. In this study, considering the significant precision of the day-night-based physics algorithm of Wan et al. (2002), this method was used to study Daytimte LST in Iran. After the data were decoded, an array was obtained with the dimensions of 4855×62258. Land surface temperature zoning was conducted by using the kriging geo-statistical method with the lowest error rate and the highest precision in mountainous areas. The statistical characteristics of LST in Iran during different months showed that the highest average of LST in Iran with 46.1 °C was in July. In the warmest period of the year, and in particular in the hot zones of Iran (the southern coasts), there is less variation in the temperature which consequently leads to less variation in LST in the country. Hence, less spatial autocorrelation should be observed in the warm half of the year, which indicates a more stable temperature during the warm period. The study of LST during the 15-year period from 2001 to 2015 and based on the output of the MODIS sensor for different months of the year showed that the distribution of LST in Iran was severely affected by geographical conditions, especially its latitude and topographic condition. From West to East and from North to South, there was an increase in LST in all months of the year. The Lut Desert is the warmest area in the country with temperatures rising to 59° C on hot days. The spatial processing of daytime LST in Iran showed that LST was strongly affected by latitude and altitude, and topographic conditions played an important role in the spatiotemporal distribution of LST, which is completely consistent with the studies conducted by those who asserted that each temperature range has a high degree of consistency with its environmental and geographical properties, in particular with its elevation, latitude and slope characteristics. Although the temperature zones provided for the various months of the year have the considerable spatial continuity, some parts of a temperature cluster have appeared in the form of islands in other zones, indicating the effect of complex topographic and local conditions on the occurrence of these temperature islands compared to its surroundings, which causes a spatial variation in temperature and an increase in the desire to LST clustering in Iran, or in other words, to climatic implantation.

Stated preference methods are a set of methods for economic valuation of environmental goods and services which elicit individual preferences for goods and services using hypothetical market behaviour situations. They include the contingent valuation (CVM) and choice experiment (CE) methods which share a common theoretical basis in explaining the behaviour of choice. Based on neoclassical economic theory, WTP/ WTA estimates derived by the CVM and CE should be the same. However, several recent studies have shown that they differ. The goal of this article is to compare the ability of the CVM and the CE to elicit WTA for the conservation and environmental status improvement of the Hara forests. To achieve this goal, the WTA of local communities living in the areas adjacent to these forests was evaluated based on data derived from questionnaire surveys. The CE and CVM questionnaires with a dichotomous choice format were carefully designed with WTA measurement and local people were asked about their preferences for reduced access to the Hara forests under hypothetical scenarios in which they would receive monetary compensation for reducing or forgoing forest utilization. The collected data were analyzed using conditional logit and binary logit models. The results showed that, when people are faced with different format hypothetical questions they present different behaviours. The results of the conditional logit model showed that more than half (57.75%) of local respondents tend to receive compensation for increases in environmental risk associated with conservation programmes. They prefer recreational opportunities to other two attributes (Hara cutting and fishing) with a compensation of 233940 IRR day-1. The results of the binary logit model for CVM survey data showed that 99 percent of respondents were willing to accept a reduction in their forest utilization and participate in the protection programmes. The mean WTA was estimated at 331,411 IRR/household/day (9,942,330 IRR/month). Then the welfare values estimated by the two methods were compared. The findings from this comparison showed that the welfare value estimated through the CVM (331,411 IRR/household/day) is much smaller and approximately one-sixth that obtained by corresponding CE (1,959,000 IRR/Day). The results also suggest that the CE method has a greater capacity to explain the choices made by consumers. This is because, in the CVM, only a single attribute – price - is used to describe the interested good and the choice of individuals is affected only by the amounts bid and socioeconomic variables; while in CE, the multiple attributes are used for describing the good and environmental change alternatives which results in the choices of people affected by interaction with the socioeconomic characteristics of respondents. Meanwhile, the CE method is effective for estimating welfare changes at different levels of environmental change; the CVM method, in contrast, estimates the value of a change in a single level, which is also a high level of protection. Due to the divergence of the results, it is impossible to say which method is more credible. It can only be acknowledged that the CE method can help decision makers and policymakers to prioritize different aspects of decision-making by gaining useful information about the final WTA of community members for the various attributes that improve on the project or the proposed design.

Feeding habits studies are one of the most important subjects in fisheries science. The investigation on feeding habits of true crabs is one of the most significant factors in the study of the growth and survival of crabs. The distribution, growth, and reproduction of crabs are all largely dependent on the availability of prey. The feeding habits of the Indo-pacific swimming crab, Charybdis hellerii (A. Milne-Edwards, 1867) were studied in the northern Persian Gulf during the period from June 2015 to May 2016. Sampling was conducted along coastal waters by monitoring bottom shrimp trawlers. A total of 371 stomachs were measured of which 197 were full and 174 were empty. Crabs stomach contents included: 60.75% crustaceans, 11.5% fish, 8.6% molluscs, 6.1% seagrass, 5.3% mixed, and 7.7% undetectable and non-food as sand and gravel. The gut vacuity index was 46.9% during the research which showed medium nutriment in this animal. Crustaceans, fish and molluscs were the dominant main food in gut. The results indicated that gut vacuity index was not statistically different between crab with barnacles and crabs without barnacles (P> 0.05). The recorded results showed that this species is omnivorous and its diet is medium. There were no significant differences in the preference for food items between the different sexes of crabs. The Indo-pacific swimming crab, as are other portunid crabs, are carnivores with a preference for animal food and the behavior of active predators of sessile and slow-moving macro-invertebrates.

Due to its location in a semi-arid and dry region and proximity to major wind erosion centres, especially Meighan desert and wetland, the mega-city of Arak is facing the problem of air pollution. The main objective of this study is the identification of sources of and tracking dust storm routes entering Arak metropolitan area from domestic sources using the HYSPLIT Model. The present study was carried out using HYSPLIT model, NAAPS model, MODIS satellite imageries and GADS weather data from the NECEP weather prediction centre for 22 June 2016 (2 Tir 1395). The modelling was performed using a retroviral tracking method for identifying the motion direction of dust particles in three stations with a height of 10, 200, and 500 metres, respectively. The research results demonstrated that most frequent motion directions not only cross the Kashan and Qom desert lands and are, thus, a source of dust storms but also cross Meighan dessert wetland and its surrounding desert lands which are the main source of dust particles of the mega-city of Arak. The forward direction of dust particles transported from Meighan desert wetland and Kashan Qom desert lands over a distance more than 400 km towards the Northwest of Iran influences the air quality index (AQI) of cities such as Arak, Shazand, Hamedan and even Sanandaj. These findings are in agreement with the optical depth of dust particles and the amount of surface dust in terms of the NAAPS model and the suspended particle concentrations in the cities located on the direction of particle dissipation. Also, these results are in accordance with the previous studies in terms of erosion assessment, indicating that the numerical models have the ability for tracking and identifying sources of dust storms satisfactorily.

With an increase in population and greater demand for agricultural and aquaculture activities, the importance of water resource quality and quantity have increased and, consequently, surface water resources are faced with more pollution than other water resources. Generalizing point measurements of water quality characteristics to maps is of special significance in most water resource-related studies. Interpolation techniques may be used to estimate unknown parameter values. The aim of this study is to use the best interpolation method for water quality assessment of Zarin Gol River and the effect of different human activities. For this purpose, samples were collected from 12 study stations in winter and spring 2016. Then, the spatial variations of physical and chemical parameters of surface water were determined including DO, NO3, PO4, Turbidity, pH and TSS and Hilsenhoff index (water quality index) using interpolation functions based on cross validation technique (lowest value of RMSE, highest value of R2 and lowest close to zero values of spatial data MBE and MAE) of deterministic and geo-statistical methods in a GIS environment. The results showed that, for all the studied parameters, the kriging method was more suitable than the IDW method and was selected for mapping. The results of the modelling showed that the maximum value of the Helsenhoff index was observed in stations 2 and 10 (5.31 and 5.2, respectively) during the winter season with a relatively weak class in terms of water quality. The results of indices showed that stations located downstream of fish farms were more polluted than those located upstream of or away from farms and enjoyed the self-purification process. Investigation of special variations in the environmental characteristics of water showed that increasing the physical and chemical parameters of surface water along the river, including wastewater discharge from villages, fish farms and agricultural activities, has a direct impact on water quality and the pollution level increases and the river water quality decreases from upstream to downstream.

One of the challenges facing water and wastewater companies around the world is water loss from water distribution networks following burst pipes and leakage, which imposes high economic, social and environmental costs on these companies. So, every year a large part of the budget of water and wastewater companies is allocated for the repair and rehabilitation of the pipe network. Therefore, knowing the frequency of burst pipes will help in estimating network leakages and selecting appropriate management strategies for dealing with these. Various factors affect the failure of water distribution pipes, one of the most important being water pressure. Therefore, the development of models to predict failure based on effective factors precisely is necessary to achieve optimal leakage management in water distribution networks. In the present study, using a developed model and analysis of pressure and burst field data in the urban water distribution network, the relationship between pressure and burst rate has been determined for a district of Tehran. The study area has 516 km of mains pipelines that include many types of material such as polyethylene, ductile iron, steel, PVC and asbestos cement. Both polyethylene and ductile iron pipes were selected for the investigation because they comprise 93 percent of the network length. After collecting and revising the statistics and information about the bursts and pressures recorded during the years 1386 to 1395, we have calculated the average zone point and the pressure index at this point and assigned it to the whole area. Finally, the pressure-burst relationship was presented individually for each material in the pipes. The prediction model of the failure consists of two parts, namely independent and dependent parts, through which the pressure parameter is linked through a power component to the failure rates. In this study, the maximum daily pressure at the average zone point was used as a pressure index in the pressure-burst relationship. The pressure-burst relationship for polyethylene and ductile iron based on maximum the daily pressure index is presented separately. In the relationships obtained for comparison, both the average of maximum daily pressure and the maximum of maximum daily pressure values were used. The results of this study showed that, in the dependent pressure part, the average of the maximum daily pressure index presents a more accurate result compared with the maximum value of the maximum daily pressure index and has a higher correlation coefficient. The reason for the inappropriateness of the maximum value of the maximum daily pressure can be temporary and non-permanent overload in one or more days of the year. As it may not really have caused a failure but has been involved in the calculation, this index does not have an accurate prediction of burst. Also, the relations are obtained for two conditions with a power pressure of 3 and an unknown situation, which indicates that, in the case of unknown power, higher correlation coefficients are obtained. Thus, for polyethylene the power is equal to 3 and the correlation coefficient = 0.97, while for ductile iron, the power was equal to 2.7 and the correlation coefficient = 0.99. According to the relationships obtained, it can be concluded that the pressure-burst model could predict the number of failure of main pipes in the water distribution networks well. The results also showed that pressure variations more often affect burst frequency in the polyethylene than the ductile iron pipes. The exponent of pressure in the failure prediction model also depends on the pipe material and is larger for polyethylene in comparison with ductile iron material, and the average for the maximum daily pressure index was a more accurate indicator in the failure prediction model. According to the results of this paper, we can improve pressure management and rehabilitation strategies for the reduction in burst frequency. By applying accurate pressure management and awareness of material susceptibility to burst, it is possible to reduce failure rate and, consequently, water loss.

One of the phenomena related to air pollution that has been witnessed in western and south-western regions of Iran in recent times is that related to dust, an atmospheric phenomenon that has adverse environmental effects and impacts. Dust storms have had many negative effects on health, economics, society and the environment, resulting in huge damage to human resources, health, industry, and especially agriculture. The purpose of this study is to quantify the tangible (market) and intangible (non-market) damages caused by dust-related phenomena in the city of Ardakan. The data required in this study were obtained from the statistics and data recorded in Ardakan offices, as well as the completion of 244 double bounded dichotomous choice questionnaires in the agricultural sector and 509 questionnaires in the air pollution and urban green areas during 2016 using 30 pre-tests and Michels and Carson. In this study, the tangible and intangible damages of dust are valued using the conditional valuation method and market price. Using the logit model, the factors that affect the willingness to pay are estimated for each section using Shazam 9 and mathematical calculations using Maple Version 18 software. The results of this study showed that income and education variables have a positive and significant effect on people's willingness to pay for air pollution and urban green space. The variables of age, number of households and gender all had a negative and significant effect on people's willingness to pay for air pollution and urban green space in the face of the dust phenomenon. In the agricultural sector, variables such as age, number of employed people, education and income have a positive and significant effect on farmers' willingness to pay for agricultural products in the face of the dust phenomenon. The total value of the damages against this phenomenon to respond to air pollution is estimated at 33,185,478,480 Rials, the maintenance of agricultural products at 50,431,570,000 Rials and the maintenance of green space against dust- related phenomena at 30,736,160,140 Rials per year for the city of Ardakan. Also, the tangible losses from dust-related phenomena in terms of increased water consumption due to washing during dusty days is 2,762,736,640 Rials, the negative impact of dust on physical health and treatment costs and mortality due to asthma and bronchitis diseases at 15,548,414,040 Rials and the negative impact on the livestock sector and treatment costs and cattle losses were calculated 131,451,400,000 Rials using a market approach The results indicate that the total value of intangible and tangible damages for the city of Ardakan in 2016 were 114,353,208,620 Rls is 149,762,550,680 Rials, respectively. The value of the willingness to pay people in agriculture was higher than for other sectors. The livestock and poultry sector also has the highest figure among other tangible costs. Therefore, this estimate provides policy makers and authorities with the guidance needed for controlling the effects of dust on human environments.

Given the role of the environment and free trade in achieving sustainable development in recent years, in this study, we survey the effect of trade liberalization on the quality of the environment. In simple words, the removal or reduction of trade barriers in international trade is trade liberalization. At the same time, oil is a factor that has a direct impact on the prices of goods and services and the trade flow, and is one of the factors affecting on air pollution the oil exporting and importing countries. Because oil is important in environment-related issues, this paper studied the effect of oil price shocks on the quality of the environment. To achieve this goal, we used panel data methods and collected data for 1980-2013. The results show that both trade liberalization and oil shocks have a significant and negative effect on environmental pollution and carbon dioxide levels in the air. Countries can achieve a high quality of the environment and sustainable development through trade liberalization measures. Given that most shocks led to increase oil prices, so countries with low consumption and alternative clean energy can reduce environmental pollution.

Environmental problems are one of the most important issues in major cities and metropolises as the result of conflict with the natural environment since urban development is necessarily associated with the domination of buildings, industries, transportation, and economic activities on natural spaces. Strategic Environmental Assessment is a comprehensive, formulated and systematic environmental impact assessment of policies, plans, and plans the options of which include reporting through their findings and their application in the decision-making process. A descriptive and analytical method was used to study and evaluate the strategic environmental impacts of urban development, Based on the concepts of the Strategic Environmental Assessment (SEA), using MADM statistical techniques and operational research such as the Analytic Hierarchy Process Analyzer (AHP), questionnaires were distributed and completed for determining the proper emphasis on and valuation of among experts (whose content was calculated using the Cochran formula) . The questions related to urban management and the environment and topics such as the municipality, environment, governorate, natural resources, etc.. Finally, the results were analyzed using Expert Choice software. The aim of the SEA process is to recognize the advantages and disadvantages of the environmental effects of a comprehensive plan and minimize the negative impacts of the implementation of the plan. For strategic evaluation, two criteria and 10 sub-criteria were selected which, after assessing and evaluating the environmental criteria, the sanitary exclusion of wastewater and residues, weighing 0.417, and reducing air pollution, with a weight of 0.245, were the most important and among the top priorities; the sub-criteria of emphasis on improving the quantity and quality of water resources, with a relative weight of 0.208, restoration of green space or missed pastures, with a relative weight of 0.077, and emphasis on increased soil quality and fertility, with a relative weight of.053, were placed in the third to fifth levels of priority, respectively. Among the non-criteria related to the physical components, the realization of a healthy city plan, increase in access to open and green spaces, and paying attention to the urban architecture of the native, with respective weights of 0.34, 0.264 and 0.159, were in the first, second and third places. Quality improvement measurements for informal settlements, with a relative weight of 0.094, realization of optimum density, with relative weight of 0.085, and the optimal distribution of applications in the city, with a relative weight of 0.058, were the third to sixth priorities. Zahedan contains suburban neighborhoods such as Shir Abad, Karim Abad, Babaeyan, etc. Most of these neighborhoods are deprived of welfare infrastructures such as water, sanitation, etc. The structure and texture of soil geology are such that there is no possibility of constructing wells, According to the results of the strategic assessment, urban environmental pollution such as sanitary wastewater-residues, air pollution, water pollution, restoration and access to open and green urban areas, access to a healthy and habitable city, attention to architecture, local urbanism were identified which are all are the consequence of accelerated development of modern cities. Therefore, greater attention by officials, planners and urban managers is required to prevent more urban environmental degradation, and it is necessary to provide citizens with fair access to welfare indicators.

Life cycle assessment (LCA) is a methodology for measuring the environmental impacts associated with a product, process or activity, by identifying, quantifying and evaluating the resources consumed, along with all emissions and wastes released into the environment. This study examined the environmental impacts for Maize production under Moghan climatic conditions by using LCA methodology. This analysis considered the entire system which was required to produce one ton of maize grain. For this purpose, a functional unit was assumed based on ISO14040 methods which included the extraction of raw materials (e. g. fossil fuels and minerals), the production and transportation of farming inputs (e. g. fertilizers) and all agricultural operations in the field (e. g. tillage and harvest). As a first step, all emissions and the consumption of resources connected to the different processes were listed in a Life Cycle Inventory (LCI) and related to a common unit, namely one ton of grain. Next a Life Cycle Impact Assessment (LCIA) was carried out, in which the inventory data were aggregated into indicators for environmental effects, which included climate change (global warming), acidification and eutrophication (terrestrial and aquatic ecosystems), land use, phosphate resource depletion, potassium resource depletion and water resource depletion. After normalization and weighting of the indicator values it was possible to calculate summarizing indicators for resource depletion and environmental impacts. The values for climate change (global warming), acidification and eutrophication (terrestrial and aquatic ecosystems), land use, phosphate resource depletion, potassium resource depletion and water resource depletion were estimated at 0.04, 0.29, 0.50, 0.11, 0.03, 2.27, 0.75, 0.03 and 0.56, respectively. As a result, among environmental effect categories (EcoX) the highest environmental impacts were observed in the eutrophication (terrestrial) and acidification categories; among the resource depletion categories (RDI), the depletion of fossil resources had the greatest negative environmental impact for maize production in the Moghan region. It seems that management systems based on a low input system, including organic fertilizers and minimum tillage, could be regarded as an alternative management strategy for reducing problematic environmental impacts.

Recently, land use change is one of the main potential causes in losing biodiversity and ecosystem services. Dams as main human-made structures play an important role in saving surface water. Due to the rapid increase in dam construction over the last 40 years in Iran, the contradiction between dam productivity and the loss of ecosystem services has become an issue of increasing concern. The aim of this study was to investigate the impact of Sahand Dam construction on land use, land use changes and ecosystem services. In this study three Landsat satellite images were used to track land use changes over a period of 28 years (1989, 2006 and 2017). First, these images were used for geometric, atmospheric and topographic correction. The maximum possibility of different land uses and cover were determined using a supervised classification method and their accuracy was checked again by field inspection. The user authenticity and Kappa coefficient calculated and resulted in value of 63 and 79 percent respectively. The value of ecosystem services and changes in land uses carried out using aerial photographs and satellite imagery between 1989 and 2017 throughout 49400 ha of areas around Sahand Dam in East Azarbaijan Province. The results showed that the total area for rangeland decreased significantly between years 1989 and 2017 while there has been a noticeable increase in cropping land. In general, the share of area under rangeland decreased by 56% over period 1989-2017. The total area for rainfed and irrigated cropping areas increased by 38 and 32 percent, respectively, indicating significant changes in this area. As regards to the services of ecosystem value, land use changes from rangeland to crop land led to a 35900000 dollars annually loss in ecosystem services value ($10.6 per hectare per year). To conclude, although dam construction and shifting from natural land toward crop land may be profitable but due to the depletion of the ecosystem capacities to deliver ecosystem services, long-term losses may exceed short-term gains. Land use and policy-making should aim at balancing society needs and preferences, while considering the long-term negative effects of dams and ecosystem service losses. Therefore, providing a land management roadmap for future economic development programs is now receiving a great priority. It will be beneficial if natural ecosystems are preserved and used adequately.