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Droughts have a significant impact on surface water resources, especially in arid and semi-arid regions. Computational and data handling limitations have constrained previous time-series analyses. However, advances in cloud computing services and remote sensing technology allow for a more detailed examination. This study integrates multi-source satellite-derived data with a cloud computing platform to assess the impact of long-term drought on surface water and water balance in Iran from 2000 to 2021. Given the varying effects of drought on highlands and lowlands, the analysis was conducted at three levels: the entire country, the highlands, and the lowlands. The results of this study reveal imbalances between water balance from 2000 to 2021, with notable disparities observed during 2000–2007, 2009–2014, and 2016–2019. The results also show varying drought trends (e.g., −1.22 in 2000 and −0.73 in 2021), with severe conditions captured in 2008 (SPI: −1.92). Additionally, our analysis illustrated that lowlands were more impacted by droughts compared to highlands. Long-term drought and permanent surface water had correlation values of 0.33 across the country, 0.33 in the highlands, and 0.31 in the lowlands. For seasonal surface water, coefficients were 0.18 for the entire country, 0.16 for the highlands, and 0.18 for the lowlands. Overall, long-term drought had minimal effect on reducing surface water. These findings show that drought is only part of the explanation for the decrease in surface water resources. [ABSTRACT FROM AUTHOR]

In Iran, water scarcity is increasing due to the rapid growth in economy and population, but also due to waste and overuse. Marginal water resources (unutilized water of lower quality) can provide important options to augment water supply or replace freshwater use. In this way, they can reconcile the seemingly opposing views of water development and water management. Encouraging reuse and circulation of marginal water can enhance water availability and conserve freshwater. This paper analyses water reuse options and policies in Iran. It explains policy constraints based on the type of water for reuse and compares the water reuse policies in Iran to regional experiences. Such a contextualization of Iran's policies from a regional perspective provides opportunities for mutual learning and lessons for policy reforms. For Iran, there is a need for investments and comprehensive reuse policies. New water sources need to be appropriately identified, treated, delivered and accepted by endusers and society. [ABSTRACT FROM AUTHOR]

Although all of the existing water resources and lakes in the world are not suitable for agriculture, their preservation plays a very decisive role in preventing environmental disasters. Unfortunately, water sources in many countries are not strictly protected and are in danger of drying up as a result of artificial factors. Lake Urmia located between East and West Azerbaijani provinces in Iran is one of these lakes. Since the 1990s of the last century, the water level in Lake Urmia, which is considered one of the largest lakes in the world in terms of salinity, has decreased and is currently facing the threat of drying up. The complete drying of the lake will not only damage the ecosystem in the region, its side effects may also manifest in neighboring countries and the whole Middle East region. This process will also accelerate the migration flow from the region to other provinces and neighboring countries. Thus, the lake crisis in Urmia is hazardous for the entire region. The purpose of this study is to reveal the main causes of drying lake, predict threats emerging in the region and look for solutions to eliminate this crisis. [ABSTRACT FROM AUTHOR]

Inter-basin water transfer projects are among the highly controversial issues in water supply policies. These projects have economic effects on the sources and destination areas. The costs and benefits of these projects should be investigated for their justification. This study examines the economic and welfare impacts of the Taleghan Water Transfer Project (TWTP) in Iran using a water-embedded multi-regional computable general equilibrium (WMRCGE) model. The results indicate that the increase in the equivalent variation (EV) of the water-receiving area is 6.9 times greater than the EV loss in the water supply area. Thus, the welfare improvement in the water-receiving area is much higher than the welfare loss in the water-supplying area. The results also indicated that the increase in total output in the water-receiving region is three times the total output reduction in the water supply region. [ABSTRACT FROM AUTHOR]

The pressing issue of the impact of changing agricultural policies on the water, food, and energy nexus is of utmost importance in today's world. This issue is particularly critical in countries currently grappling with a severe water crisis. This work develops a national-level water, food, and energy (WFE) nexus model using a combination of system dynamics modeling (SDM) and agent-based modeling (ABM). The WFE model focuses on water resources, with agriculture being the primary user. A model agent was designed for agriculture which includes a variety of agricultural products with varying yields, blue water and greywater consumption, energy consumption, and land area under cultivation for each crop. This paper's systems dynamics model is intended for application to meet the nutritional needs of a country's population by balancing water and energy resources and consumption while maintaining food security. The model's application covers two scenarios in Iran, a country under severe water stress. The first scenario involves nutrient supply based on the current diet, while the second scenario suggests a lacto-ovo diet. The outcomes of this study reveal that both scenarios can would lead to water and energy savings. For example, the implementation of Scenario 1 and 2 can reduce the groundwater storage deficit that occurred during the five-year study period by approximately 65% and 85%, respectively. Furthermore, based on the high volume of water saved in both scenarios, the increase in the volume of greywater is deemed neither significant nor hazardous. Considering new policies of agricultural production can lead to a new balanced diet in terms of nutrients and energy, which can impact the achievement of sustainable WFE resources. The findings of this research could prove beneficial for national policymakers who seek to promote sustainable WFE resource management. [ABSTRACT FROM AUTHOR]

Early human habitation of the arid to semiarid Central Iranian Plateau was strongly connected to the availability of water and associated natural hazards, such as flooding and drought events. In this geoarchaeological study, we focus on the occupation at the prehistoric site of Ajor Pazi within the formerly active fluvial environment of the Varamin Plain. Through radiocarbon and luminescence‐dated sediment cross‐sections, we apply multivariate statistics to sedimentological characteristics of bulk samples collected during a rescue excavation in 2018. Based on facies interpretations, we differentiate depositional processes and present their implications for the environs of Ajor Pazi. Our results show evidence of settlement activities between 6.4 and 5.6 ka cal B.P. (4.4–3.6 ka cal. B.C.E.). Phases of reduced geomorphodynamics can be distinguished when soil‐forming processes take place. Our findings provide insights into the hitherto scarcely explored Transitional Chalcolithic II period during which the site of Ajor Pazi emerged and began to shape its environs. [ABSTRACT FROM AUTHOR]

Groundwater resources play an important role in meeting the water needs of agriculture and industry. Therefore, identifying the factors affecting the potential challenges of groundwater resources can be key to proper implementation and management, considered the main goal of the current research. In this study, agricultural groundwater poverty index (AGPI) and industrial groundwater poverty index (IGPI) were developed based on General, Effective, and Data mining methods for the study period 2012–2020 in the West Azerbaijan Province, Iran. Both agricultural and industrial sectors were classified into five categories with 17 and 15 associated variables, respectively. The total scores of AGPI and IGPI were obtained (48.63, 47.80, 49.67) and (33.35, 33.60, 33.37), respectively, for General, Effective, and Data mining methods in the West Azerbaijan Province. In 2012–2020, the qualitative classification of the sustainability status of groundwater resources for the agriculture and industry sectors was at a good and very good level. The crop cultivation patterns of Pea, Beans, and Lentils products require management reforms to avoid the relative unsustainability in groundwater resources. Also, Production of Food and Beverages, Tobacco products, Production of Coke fuel, Oil refineries, and Nuclear fuels, Chemical Products, Rubber and Plastic products, and Non-Metallic Mineral Products could face management challenges in the West Azerbaijan Province. As the agricultural sector puts more pressure on groundwater resources than the industrial sector, it is expected that the southern part of the province will be more affected by water crises in the future. Also, the countries' internal management plans and international relations, such as the Joint Comprehensive Plan of Action (JCPOA), could have a significant impact on the status of their water resources. Due to saving time and money, it is highly recommended to use the Data mining method to develop the AGPI and IGPI in practical projects. The results of current study will have a critical impact on improving and optimizing the performance of implemented groundwater resource management projects in various temporal–spatial levels. [ABSTRACT FROM AUTHOR]

In recent decades, the depletion of surface water resources within the Lake Urmia Basin (LUB), Iran, has emerged as a significant environmental concern. Both anthropogenic activities and climate change have influenced the availability and distribution of surface water resources in this area. This research endeavors to provide a comprehensive evaluation of the impacts of climate change and anthropogenic activities on surface water resources across the LUB. Various critical climatic and anthropogenic factors affecting surface water bodies, such as air temperature (AT), cropland (CL), potential evapotranspiration (PET), snow cover, precipitation, built-up areas, and groundwater salinity, were analyzed from 2000 to 2021 using the Google Earth Engine (GEE) cloud platform. The JRC-Global surface water mapping layers V1.4, with a spatial resolution of 30 m, were employed to monitor surface water patterns. Additionally, the Mann–Kendall (MK) non-parametric trend test was utilized to identify statistically significant trends in the time series data. The results reveal negative correlations of −0.56, −0.89, −0.09, −0.99, and −0.79 between AT, CL, snow cover, built-up areas, and groundwater salinity with surface water resources, respectively. Conversely, positive correlations of 0.07 and 0.12 were observed between precipitation and PET and surface water resources, respectively. Notably, the findings indicate that approximately 40% of the surface water bodies in the LUB have remained permanent over the past four decades. However, there has been a loss of around 30% of permanent water resources, transitioning into seasonal water bodies, which now account for nearly 13% of the total. The results of our research also indicate that December and January are the months with the most water presence over the LUB from 1984 to 2021. This is because these months align with winter in the LUB, during which there is no water consumption for the agriculture sector. The driest months in the study area are August, September, and October, with the presence of water almost at zero percent. These months coincide with the summer and autumn seasons in the study area. In summary, the results underscore the significant impact of human activities on surface water resources compared to climatic variables. [ABSTRACT FROM AUTHOR]

Selecting appropriate climate change scenarios is crucial, as it influences the outcomes of climate change impact studies. Several storylines could be used to investigate the sensitivity of water resource schemes to weather variability and improve policymakers' adaptation strategies. This study proposes a comprehensive and generic methodology for assessing the future climate change impact on semi-arid and arid zones at the basin scale by comparing delta perturbation scenarios to the outcomes of seven collections of GCMs (general circulation models). The findings indicate that the two scenarios predicted nearly identical declines in average reservoir discharges over a monthly timescale. Consequently, their maximum values are almost similar. The projected decrease in the streamflow for the period 2080–2099 is approximately 48%—the same as the ratio from the delta perturbation scenario of Future16 (a 30% precipitation decrease and a 30% potential evapotranspiration increase). Furthermore, delta perturbation scenarios allow the impacts of model sensitivity to climate change to be clearly identified in relation to GCM scenarios. Delta perturbation scenarios allow for an extensive collection of possible climate changes at the regional scale. In addition, delta perturbation scenarios are simpler to create and use; therefore, they might complement GCM scenarios. [ABSTRACT FROM AUTHOR]

The growing increase in demand for water and the lack of balance between water supply and demand have led to conflicts among the downstream stakeholders of the international Hirmand River. This river is shared between Iran and Afghanistan and is located in the southeast of Iran, in the Sistan region. The Vardkhaneh is divided into two branches, Parian and Sistan, and it is the only main source of water in the Sistan region of Iran. The inner part of Hirmand catchment is considered bankrupt concerning its water resources, so there is a need to take the current status and resulting issues into account in order to resolve conflicts. In Hirmand catchment, four different games of bankruptcy theory, namely proportional (Pr), adjusted proportional (AP), constrained equal award (CEA), and constrained equal losses (CEL), were developed as optimization models based on genetic algorithms. For this purpose, the catchment was simulated with 26 scenarios using the WEAP 2022 version software for an average time period. The results of the bankruptcy game modeling showed that water could be effectively allocated to resolve conflicts among stakeholders. It is therefore recommended to use such a model to resolve fights and optimally allocate resources, even in bankrupt catchments. [ABSTRACT FROM AUTHOR]

The allocation of water in areas which face shortage of water especially during hot dry seasons is of utmost importance. This is normally affected by various factors, the management of which takes a lot of time and energy with efforts falling infertile in many cases. In recent years, scholars have been trying to investigate the applicability of fuzzy interval optimization models in attempts to address the problem. However, a review of literature indicates that in applicating such models, the dynamic nature of the problem has mostly been overlooked. Therefore, the aim of the present study is to provide a fuzzy interval dynamic optimization model for the allocation of surface and groundwater resources under water shortage conditions in West Azerbaijan Province, Iran. In so doing, an optimization model for the allocation of water resources was designed and then was validated by removing surface and groundwater resources and analyzing its performance once these resources were removed. The model was then applied in the case study of ten regions in West Azerbaijan Province and the optimal allocation values and water supply percentages were determined for each region over 12 periods. The results showed that the increase in total demand has the greatest effect while the increase in groundwater industrial demand has the least effect on the supply reduction rate. The increase of uncertainty up to 50% in the fuzzy interval programming would lead to subsequent increases in groundwater extraction by up to 19% and decreases in water supply by up to 10%. The increase of uncertainty in the fuzzy interval dynamic model would cause an increase in groundwater extraction to slightly more than 10% and a decrease in water supply to 0.05%. Therefore, implementing the fuzzy interval dynamic programming model would result in better gains and would reduce uncertainty effects. This would imply that using a mathematical model can result in better gains and can provide better footings for more informed decisions by authorities for managing water resources. [ABSTRACT FROM AUTHOR]

The severe shortage of water resources is the most important cause of the uncontrolled abstraction of groundwater resources in semi-arid regions. In this regard, modeling and forecasting groundwater levels can help in the accurate estimation of watershed water consumption and sustainable agricultural development. In the present study, the interaction effect of surface and groundwater using SWAT, WEAP, and MODFLOW models on agricultural water consumption of Kavar plain in Fars province has been evaluated. Also, the simultaneous impact of climate change, increasing the efficiency of irrigation systems, and changing the cultivation pattern to predict the groundwater level in the future were analyzed. For these purposes, first, the changes in crop pattern and type of irrigation systems during the decade 2008 to 2018 were investigated; then different management scenarios were defined to balance the groundwater level. The results of predicting climatic parameters indicate that in all three scenarios of emissions in the next period (2021–2040), the temperature will increase (0.54–1.01 °C) and precipitation will decrease (3–10%). The combination of SWAT and WEAP models with the MODFLOW model showed that by using these models, the interaction behavior of surface water and groundwater, the amount of recharges, and groundwater level can be quantitatively simulated. Also, applying different irrigation scenarios in the models showed that by adjusting the cultivation pattern and improving surface and pressurized irrigation efficiencies, the amount of groundwater abstraction in dry and normal conditions can be reduced by 23 to 42 percent. Therefore, the groundwater level will increase in the next period. [ABSTRACT FROM AUTHOR]

The knowledge of surface and groundwater interactions within the region, as well as the computation of surface and subsurface elements impacting them, are necessary for principled planning for the sustainable and optimal functioning of water resource systems. Investigating the effects of the surface–groundwater interaction by establishing a dynamic link between surface and groundwater models in the Lur plain, which is situated in Western Iran downstream of the Balarood River dam, is one of the main goals of this study. Every element of the surface and groundwater systems in the research area is connected to every other element of the model, allowing data to flow back and forth between the two systems at every time step. To calculate groundwater level values, the flow between aquifers, etc., and send the results back to the WEAP model so that this process continues until the simulation's conclusion, the withdrawal amount, infiltration, river level, runoff, etc. are imported to the WEAP model from the MODFLOW model in each time step. Optimizing the monthly volume of extraction from surface and groundwater resources to meet current consumptions during a 30-year planning horizon is another objective. The Multi-Objective Grey Wolf Optimizer (MOGWO) algorithm is connected to the integrated model body in order to carry out the system optimization. The primary and secondary goals of the optimization process are, respectively, to minimize the amount of groundwater withdrawal at the conclusion of the operating period and to maximize the percentage of meeting water needs. The proportion of monthly removal from surface and groundwater resources is one of the decision factors. Two managerial scenarios—the integrated operation based on the present condition (reference) and the integrated operation by carrying out the optimization process (optimal)—are established to examine the effects of the dam and aquifer operating together. The outcomes demonstrate that, in comparison to the reference scenario, the proportion of meeting farms' water demands during low water months is enhanced by 10% to 30% following the execution of the optimizer algorithm and the use of the integrated model body's optimal allocation parameters. The average drawdown in the Lur plain after the period, following system optimization, is equal to 7.6 m, which is 2.5 m better than the reference scenario. The outcomes of planners' decisions are quickly transformed into the whole system, and the subsequences are observable in both surface and groundwater sections. The results show that the MOGWO algorithm combined with the integrated operation model in the dynamic link mode is an effective solution for better management of the dam and aquifer. [ABSTRACT FROM AUTHOR]

Precipitation is the most important climate element in supplying Iran's water resources. Its regular temporal distribution will guarantee the sustainability of water resources. Estimating precipitation behavior in near future will improve managing water resources. Therefore, the current study aimed to examine precipitation regulation in near future (2021–2040). To this end, five models–namely GFDL-ESM4, MPI-ESM1-2-HR, IPSL-CM6A-LR, MRI-ESM2, and UKESM1-0-LL–along with the data of 95 synoptic stations were used. Upon estimating precipitation by the use of these models, the estimated data were ensemble using a multi-model ensemble model, which was based on the correlation-weighted average. Assessing the estimation error indicated the reduction of error rate in the ensemble data. Precipitation concentration index (PCI), precipitation concentration period (PCP), and precipitation concentration degree (PCD) were used to study precipitation regulation in near future. The results suggested more precipitation regulation in the north, northwest, and northeast of Iran, while more precipitation concentration was observed in southern parts of Iran. The precipitation concentration in southern parts of Iran indicates lower precipitation regulation in this area. [ABSTRACT FROM AUTHOR]

This study examines the influence of human activities and climate variability on 86 dams and hydropower across Iran. The term 'mirage water' is introduced to estimate the impact of these factors on inflow. Data analysis shows that out of 1729 m3s−1 of mirage water, 705 m3s−1 are contributed by anthropogenic activities and 1024 m3s−1 by precipitation deficits. This indicates that some parts of Iran's strategic investments in water resources management over the past 60 years have failed. The study underscores the necessity for enhanced management practices and infrastructure investments to ensure sustainable water resources in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Historically, there has been a dispute over water allocation between users and policymakers in Iran's Zayandeh‐Roud Basin (ZRB). In this study, we used the "System of Environmental‐Economic Accounting for Water" (SEEAW) framework in combination with the hydrologic model "Soil and Water Assessment Tool" (SWAT) to achieve the water balance in ZRB. We used SEEAW to combine a wide range of water‐related statistics across stakeholders and SWAT to evaluate the unknown agricultural water use. The SWAT model is calibrated based on the stream flows and crop yields in the basin. The model assess the renewable water of the basin into two components, about 363 and 70 mm as green and blue water, respectively. Also results from the physical water supply and water use tables demonstrates that the agricultural sector uses 78% of the total renewable freshwater, followed by the residential, 16%, and the industrial sector, 6%. The flows of water from source to services in ZRB are traced based on the water supply and water use tables. The flow diagram shows that 8 MCM of industrial reused water was transferred to the agricultural sector, and 137 MCM and 18 MCM of water from the wastewater treatment plants to the agricultural and industrial sectors, respectively. Furthermore, the results show that the index of the basin dependence on groundwater resources is high (61%), the value of water stress is high (0.88) and the dependence of the basin on transboundary water resources is 30%. Therefore, this method is highly beneficial for achieving a conceptual water balance in disputed basins without enough agricultural water uses data. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the concentration of nitrate in drinking water resources and its carcinogenic risk in the southern provinces of Iran in 2020. Raw data of nitrate concentrations were obtained from wastewater and water Company of each province, and Mont Carlo Simulation (MCS) was considered 10‐5 for estimating human carcinogenic risk. Our results demonstrated that in the drinking water resources of Khuzestan and Fars provinces, the nitrate level was 59 and 72 mg/L, respectively, higher than the World Health Organization (WHO) recommendation. The calculated carcinogenic risk of nitrate for Khuzestan and Fars provinces were higher than the range set by WHO and Health Canada, 8.8 × 10−5 and 1.3 × 10−5, respectively. Exposure to an unacceptable nitrate level through drinking water can affect blood carrying oxygen and cause methemoglobinemia and a significant relationship with gastrointestinal cancer spread. [ABSTRACT FROM AUTHOR]

This research has mapped the Quaternary equilibrium line altitude (ELA) using White's and Porter's methods to reconstruct past and present temperatures using a regression model in the Gharaghom basin located in northeastern Iran. The potential impact of climate change on glaciers was detected by using an artificial neural network. A regression model between temperature and altitude based on available observation data and reconstructed data indicated that the present temperature lapse rate of − 0.41 °C would occur for every hundred meters of increasing altitude in stations. The reconstruction of the past temperature of the Pleistocene revealed an increase of about 10.36–10.5 °C for the mean annual temperature of the current temperature in the basin. The recent ELA rises from the Pleistocene 2236 m and 2200 m a.s.l. according to White and Porter's methods, respectively. So, considering the present temperature lapse rate and the highest altitude of 3271 m, the maximum Pleistocene ELA depression would be about 800 m due to modern temperature increase of 10.36–10.5 °C compared to the past Pleistocene temperature. Based on the neural network projection model, linear growth in temperature would occur for the next three decades (2021–2051) in the Gharaghom basin. The minimum temperature has been much more affected than the maximum temperature, so global warming has caused an increase in the monthly minimum and maximum temperature in most seasons in different parts of the basin based on trend analysis. The average temperature rise of 0.19 °C for future decades would consequently affect the water resources. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFASs) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are environmental contaminants with unfavorable impacts on human health and nature. This study aimed to determine the PFOA and PFOS concentration in water and fish samples from Karun, the largest river in Iran. According to the results, the PFOA and PFOS in water samples were 5.81–69.26 ng/L and not detected (n.d.)–35.12 ng/L, respectively. The dry season displayed higher concentrations in water samples than in the wet season. The maximum PFOS concentration measured was related to Barbus barbules sp. (27.89 ng/g). The human health risk assessment indicated minor risks (hazard ratio, HR < 1) from PFOA and PFOS through consuming contaminated drinking water and fish. Only HR value of PFOS in downstream area exceeded slightly 1.0, indicating potential health risk due to consumption of the river fish. Considering the average PFASs concentration, the risk quotients (RQs) showed low ecological risk. [ABSTRACT FROM AUTHOR]

In this study, variations of macroinvertebrates are considered as a criterion for assessing biological diversity and ecosystem health in the downstream reach of a river-reservoir system. Unlike most of the previous studies, this biological diversity index is then used in a multi-objective reservoir operation optimization model as an objective function instead of a constraint. Two objectives of supplying water demand and ecological diversity were maximized for the case of the Aboulabbas Dam in Khuzestan Province in southwest of Iran. Based on the historical records of water quality and macroinvertebrate samples, a relationship between these two parameters was used in the optimization model formulation. Evaluation of the results in a 10-year period and comparison with single-objective optimization shows that using the proposed methodology, the biodiversity and ecosystem health has been improved while achieving an acceptable level of water supply reliability. [ABSTRACT FROM AUTHOR]

Today, one of the most important issues in the field of common water resources management is the allocation of water resources to different stakeholders with different interests. Game theory and conflict resolution methods, taking into account the interests and strategies of the players, provide efficient methods for allocating reservoirs water resources to stakeholders. In this research, for the first time, a wide range of different methods of game theory are used in order to allocate the water resources of Idoghmosh Dam reservoir (East Azarbaijan—Iran) to the agricultural and environmental stakeholders in the downstream. For this purpose, the NASH and four methods of bankruptcy theory, including PRO, AP, CEA, and CEL are used in this research. Also, in this research, the dam component is considered as a player. In the presented model for the optimal allocation of water to consumers, for the first time, the combination of game theory and the MPA as main innovation of this study is used, and the results obtained from it are compared with the GA. The proposed model is used in the base period (1987–2000) and the 14-year climate change period (2026–2039). In the following, for the first time, a wide range of different efficiency indexes of reliability, resiliency, vulnerability, flexibility, availability, supply to demand, volume reliability and SSD are used to analyze the reservoir operation policies. The results show that for each agricultural and environmental player in different base and future periods, the performance of different game theory methods on different indexes has been different. For example, the results for the agricultural player in the future period show that MPA with PRO method and then AP provided the best results for the indexes of vulnerability, resiliency, reliability, SSD, and supply to demand, that the similar values provided using GA and other bankruptcy methods have assigned lower values than MPA. [ABSTRACT FROM AUTHOR]

Performance indicators are rapidly becoming popular in performance assessment of water supply systems (WSSs) for finding the weaknesses and solving them. The selection and use of the key performance indicators (KPIs) for WSSs need the consideration of the regional and local conditions. Moreover, analyzing the results of the assessment requires a clear understanding of the relationship and intensity of the interaction of the KPIs with each other and the overall performance index. In this study, fuzzy Delphi method was used for selecting the KPIs in four dimensions for urban WSSs of Iran. Then, influential network relationship map of dimensions and selected indicators were determined and constructed by using fuzzy DEMATEL method. To facilitate the draw of the maps and more clarity, K-means clustering was used. Then, influential weights of the KPIs were calculated by using fuzzy DANP method. Among the KPIs, Aging of Mains related to the organizational dimension is the most independent and causal one. Further, Complaints related to the social dimension are the most dependent and affected indicator. The organizational dimension is the most causal dimension with high influence on the environmental, economic, and social dimensions. Therefore, the organizational dimension should be prioritized for improving the other dimensions and should be well-promoted to have a positive impact on overall performance. The outcomes provide a good guide for WSSs management, and researchers can use the data and methods of this study in other similar fields. [ABSTRACT FROM AUTHOR]

Choosing the best policy to reduce water consumption concerning social, economic, and environmental dimensions is a major challenge for policymakers. The purpose of this study is to evaluate agricultural sustainability and cropping pattern changes due to Water Resources Consumption Reduction Policies based on different scenarios. For this purpose, a study area in northern Iran with three different climates was selected. The required information including documentary and field data obtained from the farmers' questionnaire and face-to-face interviews with 492 farmers in 2019–2020. To achieve the objectives, Positive Mathematical Programming (PMP) and Analytic Hierarchy Process (AHP) were applied. The results showed that quota policies can be considered as the best policy, and pricing policies only increase the farmers' costs. Also, WRCRP will lead to changes in cropping patterns and the amount of water consumed in all climates. Most discrepancies among the effects of WRCRP on sustainability are related to the importance of each economic, social and environmental aspect. In fact, selecting each scenario by government is dependent on the status of the region on that specific time. It is necessary for the policymakers to evaluate their considered policies before implementation to reduce the negative economic, social and environmental impacts. [ABSTRACT FROM AUTHOR]

Climate change has increased the vulnerability of arid and semi-arid regions to recurrent and prolonged meteorological droughts. In light of this, our study has sought to assess the nature of future meteorological drought in Lake Urmia basin, Iran, within the context of future climate projections. To achieve this, data from 54 general circulation models (GCMs) was calibrated against both in situ and Global Precipitation Climatology Centre datasets. These GCMs were then employed to project drought conditions expected over 2016–2046 under RCP2.6 and RCP8.5 as the most optimistic and pessimistic scenarios, respectively. To provide a comprehensive analysis, these RCPs were combined with two different time scale Standardized Precipitation Index (SPI), leading to eight different scenarios. The SPI was calculated over two temporal scales for the past (1985–2015) and future (2016–2046), including the medium-term (SPI-6) and long-term (SPI-18) index. Results showed that while precipitation is expected to increase by up to 34%, parts of the basin are projected to face severe and prolonged droughts under both RCPs. The most severe drought event is expected to occur around 2045–2046 under the most pessimistic RCP8.5 scenario. Severe droughts with low frequency are also anticipated to increase under other scenarios. By characterizing meteorological drought conditions for Lake Urmia basin under future climate conditions, our findings call for urgent action for adaptation strategies to mitigate the future adverse effects of drought in this region and other regions facing similar challenges. Overall, this study provides valuable insight into the impacts of climate change on future droughts that can adversely influence water resources in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

In Iran, the mountain snow cover generally feeds major rivers and thereby largely provides water resources required for improving human lives and protecting nature. Hence, understanding historical variability and trends in mountainous snowpack water resources in Iran in response to global warming and climate change can play a critical role in the sustainable development of this country. Accordingly, this study investigated long‐term (1982–2018) snowpack climatology at 13 hydrometeorological measurement stations scattered throughout the Iranian mountain ranges, with a focus on Elburz, Azerbaijan, Zagros, and Khorasan mountainous regions. The non‐parametric Mann‐Kendall test was used to detect statistically significant (p < 0.05) trends, the Pettitt test to identify possible abrupt shift years, the Pearson's correlation coefficient to measure relationships among different time series, and the partial correlation to determine the most important climate factor influencing snowpack dynamics The annual snow depth (maximum snow depth) significantly declined throughout Iranian mountain ranges during 1982–2018, with an average rate of 1.0 (3.4) cm decade−1. The annual snow cover days (SCDs) also showed significant decreasing trends, ranging from 3 to 15 days decade−1 during 1982–2018, in 69% of the stations studied. Such considerable reductions in snow depth and cover days were mainly related to the compound effects of substantial increases in temperature, sunshine, and wind speed as well as decreases in precipitation and cloudiness during the SCDs across the Iranian mountain ranges. However, precipitation was the most influential climate factor controlling snow resources throughout both the Elburz and Zagros mountains in Iran. [ABSTRACT FROM AUTHOR]

The use of technology in drinking water treatment plants can be employed to reduce the uncertainty between urban water supply and demand. This study introduces the application of effluent treatment in drinking water treatment plants to reduce the generated effluent and balance groundwater resources. To achieve this, poly-electrolyte compounds were employed to treat the generated effluent in drinking water treatment plants, resulting in significant sedimentation of the Effluent volume and increased availability of water to meet the demands. In the drinking water treatment plants of Tehran city, to compensate for aquifer deficits, 50 million cubic meters of water per year were discharged as effluent from the cycle. However, by modifying the recycling process and utilizing poly-electrolyte, it is possible to reintegrate this water into the cycle. This water volume can be utilized as a substitute for exploiting groundwater resources. To assess the effectiveness and prioritize water allocation, three technical, economic, and social criteria were defined and calculated for each water treatment plant. To evaluate the impact of this process change on the groundwater level, a hybrid model called ANN–WOA was utilized. Based on this, four variables, including groundwater level, recharge, precipitation, and groundwater discharge, were defined as input variables to the model. 10 years was used for training, and 2 years was used for testing the model. Ultimately, the quantitative improvement of the groundwater was assessed the downstream of each water treatment plant using an appropriate index of desirability. The economic index value for allocation and the level of social satisfaction based on stakeholders' perspectives were completed. Ultimately, in the SWARA–COPRAS multi-criteria decision-making model, the prioritization of allocation for each water treatment plant was determined. The results demonstrated that by substituting this water volume, the desirability index increased by an average of 23%, which can be effective in balancing groundwater resources. Furthermore, the results indicated that the priority for allocation was given to the industrial sector, followed by the nearest green spaces available. The findings of this study illustrate that the use of new technologies in effluent treatment plants can be effective in reducing the exploitation of groundwater resources and achieving groundwater balance. [ABSTRACT FROM AUTHOR]

Presence of fluoride in drinking water resources is one of the most important challenges related to water management and health issues. This study aimed to monitor the fluoride concentration in rural areas of North Khorasan province, Iran. During a seven-year sampling period, the water quality of over 500 points was assessed annually, based on SPADNS colorimetric method. The geostatistical analyses and spatial distribution of fluoride were performed through global Moran's I index (spatial autocorrelation), and inverse distance weighting (IDW). In addition, the health impact probabilities of fluoride were evaluated via comparing concentrations with Iran national standard and the health risk assessment method recommended by EPA. According to the results, the measured concentrations of fluoride were in the range of 0–8.73 mg/L (average ± SD = 0.855 ± 0.458 mg/L). The lowest fluoride concentrations were determined in Esfarayen and Farouj counties (0.63 mg/L) and highest ones in Maneh Samalghan (0.9 mg/L). Moreover, Global Moran's I was calculated to be close to zero, indicating a random distribution of fluoride throughout the province. The average THQs for adult and children age groups were 4.94 and 3.61, respectively, which showed a high non-carcinogenic risk for both adult and children age groups. However, the concentration of fluoride in all studied water resources has not exceeded the standard and was in a good condition. Therefore, it is necessary to control the excessive concentrations, especially in areas with higher amounts. [ABSTRACT FROM AUTHOR]

The water shortage crisis is one of the main concerns that is threatening the biological security in Iran. According to available data and information, providing a framework for the assessment of water poverty in Iran seems crucial. The land-dividing unit in Iran is the province, and most of the governmental information is gathered based on this unit. In this sense, Isfahan province, which is one of the central provinces in Iran that is suffering from water crises, has been selected. The water poverty index (WPI), which is adopted in accordance with Iran's situation, including five components of resources, access, capacity, use, and environment, has been used for each of Isfahan's cities. "Capacity" and "use" has the greatest correlation, and it seems any advancement in water utilization for economic purposes might result in increased capacity, and vice versa. Also, there is a positive correlation between WPI and components of access, capacity, use, and environment. It can be interpreted that the lack of access to water services may be due to a lack of income or education. Finally, access, capacity, and use showed the strongest relationships between WPI and its subcategories. Therefore, these three elements should be the main focus of any initiative to manage the water poverty in Isfahan province. [ABSTRACT FROM AUTHOR]

The incorporation of a reliability analysis in the design of hydraulic structures can provide insights into management strategies that may consider potential failure modes, uncertainties, and corresponding risks. This study evaluates the reliability of water supply channels (applicable to channels in design or existing) using the reliability theory based upon field observations, specifically two failure modes observed in channels in the Maragheh-Bonab plain of Iran. Failure Mode 1 occurs when the main channel cannot pass the design flow. Failure Mode 2 occurs when the intake from the main channel is not responsive to the design flow. The formulation established the performance function based on the safety margin and load/resistance, where the mean-value first-order second-moment method approximated the mean and variance of the performance functions. The formulation was implemented in the water supply channels of the Maragheh-Bonab plain, northwest of Iran. The results of Mode 1 confirmed high reliability values in most channels, which compliments economic optimization efforts. A conclusion from this study highlights a safety issue is that although the channels are conservatively designed, the Failure mode 2 can still occur where water overflows the main channel. This study also provides a practical guide for the design or analysis of canals by providing reliability curves as a function of the distance between the regulator gate and the intake channel. These curves can assist with locating or relocating intake channels and show an inverse relation between reliability and the distance. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to develop strategies for risk management and accurately model the potential outcomes in hazardous zones. Methods: The initial step of this study involved conducting HAZOP studies to identify all process nodes and deviations in an urban watertreatment plant located in Markazi province. Subsequently, all risks associated with the identified deviations were evaluated using a qualitative risk matrix. To enhance the scientific accuracy of the risk assessment results, the fuzzy HAZOP methodology was employed. Finally, the assessed risks were prioritized with precision, and PHAST software was utilized to visualize critical scenarios and determine the zones of catastrophic consequences. Results: The initial findings from the HAZOP investigations conducted in the chlorination unit of the treatment facility reveal a total of 41 deviations out of 55 identified risks. Out of these risks, 47 (85%) were classified as high risk (HR), while 8 (15%) were categorized as medium risk (MR). The results of the risk assessment clearly demonstrate that the risks are of significant concern, despite the presence of existing controls. Ultimately, eight scenarios were identified and extracted from the analysis. Conclusion: Based on the research results, it is imperative that all chlorination facilities undergo redesigning to prevent corrosion, erosion, leakage, and rupture and to conduct risk-based inspections (RBI). Furthermore, regular chlorine leakage drills should be included to enhance emergency response and preparedness. [ABSTRACT FROM AUTHOR]

The current research aims to assess the feasibility of groundwater resources in two soft and hard formations of the Shamil-Takht basin using logic and operators Fuzzy and Boolean in the GIS environment. For this purpose, eight and seven thematic layers in the soft and the hard formations were investigated and analyzed separately. The layers were prepared in a raster format in the GIS environment and then each of the layers was classified according to the values of usefulness obtained with Fuzzy membership degree and 0 and 1 Boolean values. In the next step, AND and Gamma operators for Fuzzy layers and Algebraic Multiplication operators for Boolean logic were used in combining layers. The groundwater potential map of the studied area was obtained from the desired pixels resulting from performing the operations at the output. Based on this, in Fuzzy logic, 77.1% of the area of soft formation and 11% of the area of hard formation, and in Boolean logic, 24.1% of the area of soft formation and 1.74% of the area of hard formation had the possibility of water sources. Areas with high potential of groundwater resources were in areas with low slope and cultivated and areas with weak potential of water resources were in areas with alluvial and sedimentary formations. Also, the field investigations confirm that the emerging springs and existing wells in the Shamil-Takht basin are located in the areas with the lowest slope and high density of the waterway. [ABSTRACT FROM AUTHOR]

Water has been a hot topic in international disputes and negotiations in recent decades, and its management has been prioritized by governments. The system dynamics (SD) method is a management tool that allows users to interfere with model development in addition to explaining complicated systems of water resources by facts. The Sistan region is suffering from a water crisis due to its high dependence on the transboundary river of Hirmand, frequent droughts in recent two decades, and severe competition of different sectors for water consumption, so it needs modeling in which the present conditions of the region can be included and it can eventually help the management of the available water resources. This research aims to investigate the water resources in the Sistan region for their management and allocation under different managerial scenarios. The results show that scenarios like increasing irrigation efficiency, reducing evaporation loss, reducing cultivation area, adopting an optimal cropping pattern, and Afghanistan's adherence to Iran's water rights increase water resources and reduce water shortage. Among the 12 studied scenarios, the scenarios of adopting an optimal cropping pattern and Afghanistan's adherence to Iran's water rights are most effective in reducing water shortage so that they reduce water shortage by 440.61 and 643.94 million m3 versus the base year, respectively, ultimately resulting in the alleviation of the agricultural water shortage. On the other hand, the scenarios of stabilizing dust and ensuring sustainable fauna and flora ecosystem can reduce water supply to the agricultural sector versus the base year. So, it is recommended to develop economic, social, and cultural ties with Afghanistan to ensure the release of water to Iran by this country. In addition, to cope with the issues and reduce water non-supply, it is recommended to adopt the scenarios of dust stabilization, sustainable fauna and flora ecosystem, and the development of cultivation area, as well as the scenarios of increasing irrigation efficiency, reducing evaporation, and adopting an optimal cropping pattern. [ABSTRACT FROM AUTHOR]

Background: Several contaminants such as trace elements can pollute drinking water sources with subsequent toxic effects on humans. These compounds may also accumulate in target organs and result in carcinogenic reactions. Objectives: The concentrations of heavy metals, including arsenic (As), nickel (Ni), zinc (Zn), aluminum (Al), copper (1), cobalt (Co), lead(Pb), cadmium (Cd), iron (Cd), tin (2), antimony (Sb), chromium (3), and mercury (Hg) were aimed to determine in the drinking water of Tehran, Iran and to assess the carcinogenic and non-carcinogenic risk for consumers. Methods: A total of 66 tap water samples were collected from 22 regions of Tehran and their heavy metal contents were measured by inductively coupled plasma mass spectrometry (ICP-MS). The non-carcinogenic and carcinogenic health risks were calculated, using hazard quotient (HQ) and incremental lifetime cancer risk (ILCR), respectively. Results: The findings revealed that the mean concentrations of measured elements were lower than the maximum permissible limits established by Iranian National Standards, United States Environmental Protection Agency (USEPA), and the World Health Organization (WHO). HQ was less than 1 for all metals except Cr and ILCR was higher than 1X 10-4 for Cr and Cd, which may cause human health risk. Conclusions: No carcinogenic effects were posed by heavy metals contamination in the drinking water of Tehran; however, the content of Cr and Cd may cause human health risks because of the high daily intake of tap water throughout the lifetime and the tendency of these metals to accumulate in the human body organs. Therefore, implementing ongoing programs to monitor heavy metals in municipal drinking water and applying appropriate corrective actions to prevent the transfer of these pollutants to drinking water is crucial. [ABSTRACT FROM AUTHOR]

Large salt lakes are long-term witnesses to climatic conditions and land use in their basins. The majority are experiencing a drastic drop in water levels due to climate change and human impact. Endoreic Lake Urmia (NW Iran), the sixth largest salt lake worldwide, is a striking example of this decline. Quantification of the relative contributions of natural variability and human impact on the lake's water supply is therefore essential. Here we present isotopic and radiocarbon analyses of surface and groundwater from the Shahr Chay River catchment, entering Lake Urmia on its western shore, and radiocarbon dating of a sedimentary core. Lake Urmia behaves like a large saltwater wedge almost entirely fed by the river and shallow groundwater. This leads to trapping of residual brines and formation of CH4 and secondary CO2 greenhouse gases, impacting sediment geochemical records and corresponding time scales for paleoenvironmental reconstructions. We conclude that (1) salt lakes functioning like a saline wedge, allowing organic matter oxidation, could contribute to increasing methane sources or reducing carbon sinks globally, and (2) endoreic basins worldwide need to be monitored before aridification-related salinization leads to the establishment of a saline wedge precluding any possibility of return to an equilibrium state. [ABSTRACT FROM AUTHOR]

In general, the sustainability of the water supply system is indicative of an adaptive operational approach, wherein the decision-maker adjusts the system's performance based on the availability of water resources in a given time frame. In light of this, a novel framework is proposed in this study to evaluate sustainability, including three key indicators: resilience, reliability, and vulnerability. To address stressors that may lead to system failure, a multisectoral water allocation optimization is undertaken. In order to account for the future implications of climate change on the hydrological cycle, a simulation step, is incorporated, utilizing the Soil and Water Assessment Tool (SWAT) under various emission scenarios (RCP4.5 and RCP8.5), prior to integrating the streamflow data into our proposed optimal framework. To calibrate and validate historical data (2014–2019) and simulate future streamflow patterns (2025–2085), the Sistan Basin, located in an arid region of Iran, is analyzed as a case study. In light of the anticipated adverse impacts on the water supply system, certain adaptation measures, such as demand shrinkage scenarios, are considered to further appraise the proposed framework. Based on the final output, it is evident that the agricultural and industrial sectors, being the primary water consumers, are more susceptible to negative impacts resulting from the reduction in system sustainability. This susceptibility is primarily attributed to their highest vulnerability and comparatively lower reliability. [ABSTRACT FROM AUTHOR]

The quality of water resources used for drinking and their health effects is vitally important. The present study investigated the concentrations of F−, NO3−, and metal elements like Hg, Mn, As, and Pb in the groundwater resources and their health risk assessment on the west margin of Urmia Lake, Iran. Sampling points were selected and taken from 121 groundwater resources in the summer of 2014. Heavy metals (Pb, As, Mn, and Hg) were measured by ICP-OES (inductively coupled plasma optical emission spectrometer, model: Arcos, Germany), and some ions (Na+, NO3−, F−, and Cl−) by flame photometer and spectrophotometer according to the standard methods, respectively. The nitrate concentration range in groundwater samples measured from 1.7 to 137 mg/L and fluoride from 0.4 to 4.5 mg/L. The probabilistic method and Monte Carlo simulation were used to estimate carcinogenic and noncarcinogenic risks. The concentration of study elements in most samples was obtained in the WHO (World Health Organization) recommended range. The order of HM (heavy metal) concentration is based on the overall mean: Mn > As > Hg > Pb. The HI (hazard index) level was found to be more than 1 for noncarcinogenic risk for As and NO3− and permissible risks for the other elements and fluoride. ELCR (excess lifetime cancer risk) levels of As were acceptable, except for some sampling points, the central region in the study area, near the seashore of Urmia Lake. Finally, it can be stated that the groundwater resources in the studied area are acceptable for drinking in most places. Still, due to the effects of As and NO3− contaminated water, the quality is unacceptable for drinking in some places. So, monitoring water quality is recommended by finding contamination sources to decrease the health risks of drinking consumption. [ABSTRACT FROM AUTHOR]

Precipitation prediction is one of the most effective management aspects for rehabilitating dried water resources such as Urmia Lake, Iran. This study was conducted to investigate the efficiency of the first-order multi-site autoregressive [MSAR (1)] model in the spatiotemporal simulation of annual precipitation in the Urmia Lake basin. To determine the model parameters, data from the period of 47 years (1961–2007) were used. These parameters were obtained by computing the lag-zero (lag 0) and lag-one (lag1) correlation among the annual precipitation time series of stations. A 12-year period (2008–2019) was used to evaluate the model. The region's precipitation in a year (t) was estimated based on its precipitation in the previous year (t − 1). The mean absolute error percentage (MAPE) for the test data was 16.7%. Also, the statistical characteristics of the generated and historical data were similar and their differences were not significant. Therefore, considering the appropriate efficiency of the MSAR (1) model in forecasting and generating annual precipitation, its application is recommended to help better manage water resources in this area. [ABSTRACT FROM AUTHOR]

In the last few decades, the mismanagement of water resources in Iran has caused major problems. Returning to and updating earlier indigenous technologies and knowledge, accompanied by incorporating new technologies adapted to local conditions, offer distinct advantages for meeting current and future needs and achieving sustainable development. This research utilizes an extensive study of literature from internal and external sources, and the opinions of specialists and experts, gathered via a questionnaire, plus Exploratory Factor Analysis to identify and assess the most important criteria or applicable factors of indigenous knowledge relevant to the water resources planning and management in the study area—Yazd Province, Iran. Six criteria—protection and stability, integrated management, holistic (comprehensive) approach, cost-effectiveness, compatibility, and dynamism—are found to be more important than others for the area. Variables, including biodiversity conservation, principled structure in the system of construction, operation and maintenance, economic compatibility, and wildlife conservation, are ranked higher than other variables. In the next step, the six criteria/factors are weighted using the Best Worst Method, and also, a linear programming model is created in Lingo software. The integrated management and holistic approach are found to have the highest and the lowest weights, respectively. Protection and stability, along with cost-effectiveness, jointly rank second. Finally, compatibility and dynamism rank third and fourth, respectively. To promote more appropriate strategies for planning and managing water resources in Yazd Province, this research offers regional and local planners and policy-makers a means of employing the strengths of the updated indigenous knowledge by applying the selected criteria. The approaches described are also applicable to similar areas worldwide. [ABSTRACT FROM AUTHOR]

Nitrate (NO3ˉ) and fluoride (Fˉ) are two major potential contaminants found in the groundwater of Iran. These contaminants are highly dangerous to humans if consumed more than the safe limit prescribed by the WHO. Therefore, in this study, the urban and rural drinking water resources of Isfahan province (central Iran) were investigated to evaluate the quality of groundwater from the perspective of NO3ˉ and Fˉ. The calculated saturation index (SI) shows that the majority of samples are mainly undersaturated or in equilibrium with respect to potential minerals. The most likely interpretation for undersaturation with respect to most minerals is either that the minerals are not present if they are reactive or if they are present, then they are not reactive. This study reveals that the majority of the groundwater samples belong to the Ca-Mg-HCO3 water type. Further, in this study, potential physicochemical variables have been used to calculate entropy weighted water quality index (EWQI). The EWQI reveals that the majority of the groundwater in the area is of good quality. Results show that the water chemistry in the area is largely governed by the water-rock interaction. This study based on large data sets reveals that the majority of drinking water resources are uncontaminated by Fˉ. However, the groundwater is found to be largely contaminated by NO3ˉ. The bivariate plot suggests that the unscientific farming practices and overuse of manures and fertilizers are largely responsible for high content of NO3ˉ. Therefore, emphasis should be given on the cost-effective environmentally friendly fertilizers. The findings from this study will aid the governing authorities and concerned stakeholders to understand the hydrogeochemical evolution of groundwater in this region. The results will help formulate policies in the area for sustainable water supply. [ABSTRACT FROM AUTHOR]

One of the innovative approaches to supplying water demands for irrigation and recreational purposes is the treatment and reuse of greywater. However, during the coronavirus pandemic, greywater has the potential to be polluted by SARS-CoV-2. Therefore, it is unsafe to reuse it during the peak of the COVID-19 outbreak. In this research, a membrane bioreactor combined with an ultraviolet disinfection system is applied to treat the greywater and remove the SARS-CoV-2 virus up to the required quality for irrigation or flush tank purposes. The results showed membrane bioreactor could remove 94.3 ± 1.2% of initial chemical oxygen demand and be partially successful in virus removal. Fifty percent of secondary treated effluent samples were still positive for SARS-CoV-2 RNA. The results also illustrated that ultraviolet disinfection could reduce faecal and total coliform by more than 99% and eliminate the SARS-CoV-2 virus. The tertiary treated effluent biochemical oxygen demand, chemical oxygen demand, and total coliform were 1.7 ± 0.2 mg/l, 18 ± 1.2 mg/l, and below 3 MPN/100 mL, respectively. Moreover, all of the samples of the tertiary treated effluent were negative for coronavirus RNA. Therefore, the tertiary treated effluent characteristic satisfied Iran's standards for wastewater reuse in irrigation. [ABSTRACT FROM AUTHOR]

Access to sufficient and safe water particularly in vulnerable countries is one of the most important goals targeted by the United Nations for 2030. The agricultural water supply is crucial in arid areas such as Iran. In water supply projects, employers usually seek less duration and cost, and higher quality, however, contractors seek a reduction of fluctuations in project resources, especially human resources, and these goals may be in conflict with each other. Therefore, finding an optimal project schedule considering different project objectives is vital for managers to achieve stakeholders' satisfaction. In this study, the four main project objectives including time, cost, quality, and resource leveling as well as the activity dependencies and resource constraints are addressed through fuzzy optimization. The proposed model was first implemented on a small-sized project instance for validation; then, the model was solved by the Nondominated Sorting Genetic (NSGA-II) and Multi-objective Particle Swarm Optimization algorithms using the information of a real-world agricultural water supply project. The results of the first Pareto set for different alpha-cuts in relation to the fuzzy quality factor show a set of solutions and different alternatives for project implementation which leads to a number of execution modes each of which may result in achieving the project objectives. Finally, the most ideal solution with a duration of 178 days was selected using the fuzzy TOPSIS method. The findings demonstrate the validity of the proposed model concerning the needs of agricultural water supply organizations. [ABSTRACT FROM AUTHOR]

The extensive exploitation of water resources in Chaharmahal va Bakhtiari province has led to a destructive impact on the water balance and quality of the region. In order to evaluate water quality of the study area, water quality parameters from 132 wells were analyzed to prepare spatial distribution maps of the IRWQI index. To analyze spatial and temporal rainfall anomalies, the SPI index was spatially interpolated using the ordinary Kriging method. Principal component analysis was used to investigate the relationship between water quality parameters. The suitability of data for PCA was evaluated by the Kaiser–Meyer–Olkin and Bartlett tests. Additionally, water balance components of the study area, including surface runoff and ground water, were simulated using the WetSpass-M model. According to the results of the IRWQI index, 54 wells, mostly located in built-up and agricultural lands, had poor quality․ Investigation of the average groundwater quality during the years 2007 to 2017 shows that the trend of groundwater quality decreased. Comparison of drought and water quality maps showed similar patterns so that in areas with extreme drought, water quality was bad. The highest and lowest recorded concentrations for nitrates were related to built-up and rangeland lands with concentrations of 35 and 21 mg/l, respectively. Comparison among land use classes showed that in the rangelands, groundwater quality was better and nitrate level was lower compared to agricultural and built-up areas. Overall, the results of this study show that water quality can be affected by land use types and water balance components. [ABSTRACT FROM AUTHOR]

Given the increasing population growth and rapid global economic development, the conflict between reduced available water resources and increased water demand in many countries has become a challenging issue; confirming the necessity of allocating optimal water resources to equate water conservation and environmental sustainability. Uncertainties and climate change together deteriorate the complexity of optimal allocation related to water resources used for the agricultural sector. The present study sought to design an uncertainty-based random boundary interval multi-stage stochastic programming (URBIMSP) model by integrating the Kataoka's criterion method and chance-constrained programming within a general optimization framework to control the uncertain information which exists in both constraints and goal functions. The developed model was applied to a case study of water resources allocation in the Marand basin, Iran. Then, a conjunctive water allocation system was arranged to identify the introduced model in two planning periods which were 2023 to 2025 and 2026 to 2028. The results indicated that different water allocation schemes and water shortages with varying net system benefits would be achieved under different stream flow levels and different risk scenarios. The result was significant for carrying out a comprehensive analysis of the tradeoffs between total net benefits and related risks. Finally, the findings demonstrated that improving irrigation efficiency and upgrading irrigation systems are the key strategies for farmers to achieve economic benefits while also help to mitigate environmental impacts. [ABSTRACT FROM AUTHOR]

Objectives: In recent years, due to the inappropriate quality of distributed water by the public water network in many parts of Iran, especially in the central areas, the use of desalinated water has been widely developed. Therefore, for any planning and intervention, it is very important to have information about the current situation and social, cultural and economic factors affecting this development. As a result, this study was conducted with the aim of Investigating the rate and factors of approach to desalinated water in Kashan and Aran-Bidgol cities in 2018. Methods: This study is an ecological study on the samples of Kashan and Aran-Bidgol people. The tool is a questionnaire completed over the phone. The collected data were analyzed using descriptive statistics and SPSS16 software. Results: About 83.2% of the samples in Kashan and Aran-Bidgol cities use desalinated water for drinking, cooking and tea making, 44.2% of the samples use a small household water purifier and 39% buy purified water from sales centers. The filtration technology in both categories is reverse osmosis. Conclusion: In the studied cities, the salty taste of water taken from the public network and samovar sediments are the most important reasons for consumers to switch to purified water, and demographic characteristics such as age, gender, educational and economic level, etc. did not play a significant role in this approach. [ABSTRACT FROM AUTHOR]

Objectives: Considering the importance of underground water sources, continuous evaluation of their quality should be considered to prevent chemical pollution. Therefore, the purpose of this research is to investigate the changes in the chemical quality of water in the Qanats (aqueducts) and wells of Ardestan Plain during the years 1995 to 2019. Methods: This research was conducted retrospectively in 2021 based on the data collected by Ardestan Department of Natural Resources during the period of 1995-2019. Data were analyzed by SPSS software, version 2016 and compared to Iranian drinking water quality standards. Results: Data showed that Total Dissolved Solids (TDS) and the Total Hardness of well water were increased 367.3, 168.8 respectively. These parameters were increased by 188.1 and 90 mg L-1 for Qanat water, respectively. And other water quality parameters were increased including magnesium, calcium, sulfate, bicarbonate, chloride and Electrical Conductivity (EC). The trend of TDS and TH showed that in the all of the well water exceeded from the drinking water standard especially in 2019. Conclusion: Paying attention to the process of chemical changes of water in the Ardestan plain reminds us that in the future, water sources will be at risk of damage, especially in the low-altitude parts of the plain. [ABSTRACT FROM AUTHOR]

Considering the limited water resources and the increasing need for fodder in arid and semi-arid regions of Iran, it is necessary to introduce new sorghum cultivars with high performance and stability. This study aimed to evaluate the yield stability of forage sorghum genotypes via AMMI and GGE biplot analysis to identify the high-yielding and most adapted genotype for release in Iran's arid and semi-arid regions. Nine promising forage sorghum lines (KFS2, KFS9, KFS10, KFS11, KFS12, KFS15, KFS16, KFS17, and KFS18), along with one commercial cultivar (Pegah), were studied at seven regions of Iran (Karaj, Gorgan, Borujerd, Sanandaj, Shiraz, Yazd, and Zabol) during the 2018 and 2019 growing seasons. The results of AMMI analysis showed that line KFS2 had the lowest AMMI stability value (ASV) and was identified as a stable genotype. The AMMI1 and AMMI2 biplots indicated that KFS2, KFS9, and KFS17 had the least interaction with the environment. The GGE biplot analysis showed that line KFS18 had the highest dry matter yield (DMY) in most environments. According to the average-environment coordination (AEC) biplot, line KFS18 followed by KFS17 were identified as the most desirable genotypes. Furthermore, among the studied environments, Gorgan and Karaj regions were the most discriminating environment for the genotypes evaluated as well as the ideal environments for sorghum cultivation. Overall, line KFS18 with the maximum DMY (32.05 Mg ha−1) and general adaptability across various environments can be introduced as the superior genotype for cultivation in Iran's arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Regarding the development of the northern provinces of Iran, which are considered the most populated part of the Caspian coast, the provision of water resources is one of the main priorities, especially in the tourism industry and the development of coastal settlements. As a result, seawater desalination is an appropriate solution to meet rising water demand in most coastal areas. This research has the aim of investigating the possibility of using desalination technology and detecting suitable places for the construction of desalination plants on the southern coasts of the Caspian region. In this study, the construction of desalination plant units was prioritized and ordered based on multi-criteria decision-making methods using capacity and environmental strength, considering coastal and marine environmental, technical, and operational criteria such as water quality, distance from the estuary, land use restrictions, and socio-economic criteria including water consumption and population. The results obtained using techniques for ordering preference by similarity to an ideal solution (TOPSIS) and simple additive weighting (SAW) methods showed that Mahmoudabad, based on decision models, is the most appropriate and sustainable place to participate in desalination. The coastal area of Nowshahr is determined to be the most inappropriate. In addition, desalination discharge limitations are a determining factor in the location and design of these units on the southern coasts of the Caspian Sea. Due to distributed environmental restrictions in the Caspian coastal areas, the construction of small desalination units and the use of modern saline wastewater management approaches are highly recommended to control environmental issues. [ABSTRACT FROM AUTHOR]

Growing agricultural and domestic demand exacerbates water shortages globally, creating substantial environmental challenges, especially in lakes and wetlands ecosystems. This paper presents a stationary policy to restore and sustain the water level in natural lakes using a new version of hedging rule that accounts for time-dependent environmental demand and the water allocation to the agricultural and municipal sectors under different climate change projections. The proposed framework is demonstrated via operational policy derived to rehabilitate Lake Urmia in Iran. To simplify the modeling process, all reservoirs in the basin are replaced with an equivalent reservoir (ER) to allocate the available water between potential users. The ER is then operated using the set of hedging rules derived for staged restoration and sustainability of the lake level while meeting other stakeholder objectives. A system dynamics-based model is used to simulate the multi-sectoral system of the basin while using a built-in optimization algorithm to develop the most desirable multi-period operational policy. The lake-level condition is investigated by producing lake-level duration curves, while the reservoir performance indices (reliability, resiliency, and vulnerability) are used for assessing water supply in the basin. The results indicate that the proposed framework is highly effective in restoring lake level while meeting agricultural and municipal water demand in the basin. The proposed model provides a stationary policy for the lake restoration accounting for the dynamic variation of the lake level and fluctuations of the reservoirs inflow due to climate variability and change. [ABSTRACT FROM AUTHOR]

The accurate estimation of evapotranspiration is crucial for enhancing crop water productivity and effectively managing water resources. This research offers a novel method that integrates satellite data and crop coefficients to calculate ETc and ETa on a daily basis and overcome the limitation of low temporal frequency of non-commercial satellite data. The study was carried out in the southern part of Khuzestan Province, Iran, on sugarcane crops in the Amirkabir Agro-industries area. The method involves obtaining Landsat-8 data with an 8-day temporal resolution, which was used to estimate Land Surface Temperature (LST) using a Single-Channel Algorithm. The estimated LST was then validated with in-situ canopy temperature measurements and used to predict the crop stress coefficient (Ks) based on its relationship with the crop water stress index (CWSI). The crop coefficient (Kc) was obtained using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm, and both Ks and Kc were utilized to calculate daily ETa by multiplying by the daily reference evapotranspiration (ET0) obtained from local meteorological data. The results indicated that the crop coefficients of sugarcane in the initial and mid-stages were 12% and 18% higher, respectively, compared to the FAO56 guideline. The aggregated decadal and monthly ETa showed good agreement with the WaPOR datasets, with an RMSE of 8.7 and 1.93 mm, respectively. This approach offers a potential solution to the challenge of obtaining remote sensing data with a higher temporal frequency. [ABSTRACT FROM AUTHOR]