mohammad hossein niksokhan

Optimizing water use in agriculture is crucial for sustainable resource management and increased productivity. Water footprint analysis, which measures the total water used directly and indirectly throughout a product's life cycle, offers valuable insights for improving water management practices. This study investigated the gray and white water footprints of a greenhouses cultivation, bell pepper, under different conditions including misting and pot cover. Evapotranspiration rates were used to calculate water demand under various scenarios. Nitrate (NO3), potassium (K), and total phosphorus (TP) were monitored as key chemical parameters to calculate the gray water. Three scenarios including stringent (S1), normal (S2), and lenient (S3) are established based on water quality standards. The findings revealed that misting and covering pots significantly reduced the gray water footprint compared to non-misting or uncovered scenarios. The total gray water footprint for bell peppers under misting and covered conditions was 2976 m3/ton, while it reached 3968m3/ton under non-misting and uncovered conditions, this represents a reduction of nearly 33% due to the combined effect of misting and pot cover. Importantly, water quality standards also played a significant role, with stricter standards leading to a higher gray water footprint (e.g., a difference of 2655m3/ton between scenarios S1 and S3 under misting and covered conditions).The white water footprint, representing freshwater directly used for cultivation, also varied across different scenarios.

The approach of water, energy and food correlation can be defined as an approach to evaluate the development and implementation of policies that emphasize the security of these things at the same time. The purpose of this research is to provide a method to analyze the relationship between water, food and energy in the crop production chain. Based on the proposed method and according to the amount of water and energy consumption, four indicators of water and energy consumption and water and energy productivity, and also based on these indicators, a combined index of water, food and energy nexus is proposed. This research has conducted on the Borkhor plain of Isfahan province and the MODFLOW model has used to simulate the watershed quantitatively and since the objective functions in this study are linear, multi-objective linear programming was chosen to solve the optimization problem. The goal of solving the optimization problem is 4 scenarios of water consumption minimization, energy consumption minimization, profit maximization, as well as water, food and energy maximization scenario. The results show that although each of the scenarios alone reflect the positive effects of reducing water and electricity consumption, but by using the scenario of combining water, food and energy, in addition to reducing water and electricity consumption, farmers' profits have also increased significantly, so that the amount of water consumption before optimization was 50 million cubic meters per year, but after optimization and applying the scenario of maximizing the correlation of water, food and energy, it decreased by 8% and reached 46 million cubic meters per year, and the amount of consumption Energy decreased by 9.7% from 13150330 kilowatt hours per year to 11867563 kilowatt hours per year and in addition, the profitability of the products before optimization was 6301966 million Rials, which after applying the scenario of correlation of water, food and energy with 21 The percentage of increase reached 8015264 million rials and on the other hand, with the continuation of the optimal scenario, the level of underground water in the state of maximizing the correlation of water, food and energy will decrease by 0.478 meters less than the existing conditions and and on the other hand, by continuing this trend in the long term, we will see a significant impact on the level of underground water.

In recent years, the changes in the intensity and frequency of precipitation and the occurrence of severe floods and droughts have prompted decision-makers to consider the effects of climate change in their plans. Due to the existence of impervious areas in urban environments, a more significant part of precipitation is convertedto runoff, and the changes in precipitation patterns resulting from climate change can affect the performance of drainage systems. On the other hand, with the change in precipitation pattern, the amount of pollutants washed from the surface is changed, and in this way, the quality of runoff is also affected. Nowadays, coupled atmosphere-ocean general circulation models (AOGCMs) are considered the most advanced and reliable tools for simulating climate change. Recently, a coupled model intercomparison project Phase 6 (CMIP6) hasbeen introduced as the latest version of AOGCMs, which can simulate future periods with high accuracy. The sixth assessment report evaluates the changes in climate variables by combining Representative Concentration Pathway (RCP) and Shared Socioeconomic Pathway (SSP) scenarios. According to this report, in addition to covering different climates, future scenarios should also consider the socio-economic aspects of development. The CMIP6 models have higher spatial resolution than the models of previous reports. A review of the research background in the assessment of climate change effects on precipitation and runoff shows that most of the studies have been conducted using the models and scenarios of the fifth and earlier reports, and only a few of them have included the scenarios of the sixth report in their evaluations. In this regard, our research evaluated climate change effects on urban runoff based on the CMIP6 models’ predictions.

District 10 of Tehran municipality is selected as the case study. This region is located in the south of Tehran and has an area of about 800 ha. Due to its high population density, lack of enough green space, and a high percentage of impervious areas, runoff management is a priority for this region. Moreover, the presence of agricultural land highlights the need for runoff quality management in the study area. The MehrAbad synoptic station is the nearest to the case study, and its observation data during the base period is gathered for evaluating the changes in hydrological variables under climate change. For implementing the methodology, different CMIP6 models were first assessed, and those with high performance in precipitation prediction in the historical period were selected. Their projections under SSP1-2.6 and SSP5-8.5 for the future (2021-2050) were downscaled using the LARS-WG model. Then, the statistical method was employed for disaggregating the LARS-WG’s daily output into 6-hour design precipitation. In the following, maximum and minimum values of precipitation were determined as optimistic and pessimistic scenarios, respectively, and the stormwater management model (SWMM) was implemented for simulating the runoff under these scenarios. The SWMM subdivides the watershed into sub-watersheds and utilizes three primary processes for runoff quality and quantity simulation. First, generated runoff is calculated by determining the hydrological characteristics of the sub-watersheds in the hydrologic process. Then, the canals route runoff to the outlet using a hydraulic process. In the quality process, the runoff quality is simulated using build-up and wash-off equations. In our research, the study area was subdivided into 84 sub-watersheds. Changes in runoff volume, peak flow, and total suspended solid (TSS) concentration at the watershed outlet were evaluated under climate change. Correspondingly, for assessing the performance of the drainage system, the changes in the flooded volume of the system were quantified.

According to the results, in all models under SSP5-8.5, monthly precipitation will increase in January, February, and March and decrease in August and September. Also, under SSP1-2.6, the precipitation trend is predicted to fall in September. The highest increase in precipitation compared to the base period is related to August under SSP1-2.6. In addition, with a decrease of 37.4 %, the highest reduction in precipitation is associated with February. The most evaluated prediction uncertainty is related to August under SSP1-2.6. This month, precipitation changes range from +226.31 to -18.34 % compared to the base period. Also, predictions on an annual scale do not show a specific trend. The changes in annual precipitation vary from a -9.8 % decrease to a 5.4 % increase compared to the base period. Then, by analyzing the 6-hour rain, the predicted values of HADGEM3-GC31-LL and CMCC-ESM2 were identified as the highest and lowest values, respectively. The 6 h rain with 5 and 10-year return periods under the pessimist scenario will increase by 31.4 and 26.8 % and decrease by 2.5 and 11.3 % under the optimistic scenario, respectively. The results of performing SWMM under a pessimistic scenario showed that in the return periods of 5 and 10 years, runoff volume would increase by 25.2 and 20.7 %, and TSS concentration will decrease by 21.4 and 18.2 %, respectively. Besides, in this scenario, the flooded volume of the basin increases to 42.12 %. Performing SWMM under an optimistic scenario revealed that with the reduction of precipitation compared to the base period, in the return period of 5 and 10-years, the runoff volume will decrease by 2.2 and 8.3 %, and the TSS concentration will increase by 2.5 and 10 %, respectively.

Performing SWMM under an optimistic scenario shows that with the decrease of 6-hour design precipitation, the quantitative parameters (runoff volume and peak flow) decrease, and TSS concentration increases at the watershed outlet. Furthermore, under the pessimistic scenario, quantitative parameters increase, and TSS concentration decreases with the increase in precipitation. More examination revealed that despite the decline in precipitation, the number of flooded nodes remained constant under optimistic scenarios indicating the drainage system’s vulnerability even under base-case rain and a little less. Moreover, the increase in flooded volume and the number of flooded nodes under the pessimistic scenario make it necessary to utilize management strategies to improve the runoff collection systems’ performance under climate change. In this regard, low-impact development (LID) practices can be used as a climate change adaptive approach in future works.

Naphthenic acids are a group of polar organic carboxylic acids that are present in crude oil naturally. They are cycloaliphatic carboxylic acids which have 10 to 16 carbons, which gained importance since the early twentieth century because of corrosion in oil refineries. Moreover, they are the most important environmental pollutants caused by oil extraction from oil sand reserves. Heavy crude oils which have high concentration of naphthenic acids are usually considered as poor-quality oil and sold at a lower price. Often, the high concentration of naphthenic acids in crude oil reduces the life of the equipment which are used in the exploration and refining process because of corrosion. Hence, researchers are increasingly interested in the chemical properties of naphthenic acids and the acidic components of the crude oils. The most popular methods for the identification and analysis of naphthenic acids are liquid and gas chromatography (GC), liquid-liquid extraction, Fourier transform infrared spectroscopy (FTIR), and solid-phase extraction (SPE). Naphthenic acids are the most important environmental pollutants caused by oil extraction from oil sand reserves. Previous studies have revealed that naphthenic acids can be absorbed by fish, but their distribution in different tissues of fish has not been specified. Experimental samples showed the highest toxicity to fish, while there was less toxicity to invertebrates and algae. Moreover, naphthenates have various industrial utilizations; they are used in synthetic detergents, corrosion inhibitors, lubricants, fuel and oil additives, wood preservatives, insecticides, fungicides, pesticides, wetting agents, napalm thickening agents, and oil desiccants that are utilized in painting and treating wood surfaces.

Fair, just, and equitable water allocation is one of the key subjects in water resource management and decision-making. Governments state that water allocation policies are just. However, a precise definition of these subjects and their unique applications in water sector are not still clear for researchers or policy-makers. This study reviews literatures and uses a descriptive and deep analysis of distributive justice in the water resource policies. Therefore, finding the answer to how to distribute justice to environmental resources like water is one of the key steps in water resources studies and policymaking. Its main objective is to introduce a methodology for just environmental resource allocation. Based on the principles of justice, a flowchart is recommended to define the steps and scopes of a just water policy. In addition, the applications of different distributive justice theories and their modern concepts are compared and discussed for water reallocation. Accordingly, the differences would be cleared between equality, difference, equality of opportunity, welfare, deserve, and entitlement for water justice research.

A new approach was presented to manage simultaneously reservoir outflow quantity and quality. Two strategies were used to control reservoir outflow quality: (1) reservoir inflow control with Best Management Practices (BMPs) in the watershed and (2) outflow management by reservoir operational strategy. Soil and Water Assessment Tool (SWAT) model was linked to a reservoir water quality simulation model (CE-QUAL-W2), the linked watershed-reservoir model was coupled with Multi-Objective Particle Swarm Optimization algorithm (MOPSO) to find the best set of decisions to optimize the reservoir outflow quality and quantity objectives. The approach was applied to Alavian reservoir and its watershed, in Iran, for a 6-year time horizon. The results show the proposed approach could reduce reservoir outflow phosphorus concentration while increasing downstream water supply. The implemented BMPs outperformed the reservoir operational strategy in terms of reservoir outflow quality reducing outflow phosphorus concentration up to 45% comparing with current conditions. Among the four applied BMPs, filter strips had more effect on reducing nutrient loads.

Water, food and energy are the main resources needed for the development of communities. The nexus view emphasizes the interconnected management of these resources and has been applied with a focus on three sources at the macro level. In this research, evaluation and prioritization of effective factors and methods of optimal resource allocation based on the nexus approach of water, energy and food production with the Analytic Hierarchy Process (AHP) in Alborz province has been considered. For this purpose, the criteria were compared in pairs in a hierarchical analysis with the opinions of experts and their importance was determined. Criteria including water, food and energy were considered. Factors affecting the optimal allocation of resources in Alborz province were determined and presented as multiple choice and compared in pairs based on questionnaires completed by experts. The results showed that the water criterion with the relative weight of 61.4% has the greatest impact on the evaluation process compared to other criteria and the energy and food criteria with the relative weight of 26.2% and 12.4% have the most impact, respectively. Among the developed strategies, education and awareness raising with a score of 35.9% was ranked first, and environmental policy with a score of 26.6% was ranked second. Therefore, it is suggested that strategies for education and promotion of awareness and environmental policy be given priority.

Wetlands and gulfs are peculiar ecosystems comprising of both land and water habitats. This, gives rise to a rich biological diversity which seldom occur elsewhere on the planet. Unhappily, must of our wetlands countrywide have undergone massive negative changes during the recent years losing much of their surface and depth. These changes have been the result of multiple causes such as climate changes, decreased rainfall in line with increased evaporation, human activities such as dam construction. Our coastal wetlands have been affected by sea water level changes. Gorgan Gulf is the sole gulf in Iran that has been located in southern part of the Caspean Sea. It has been registered as biosphere reserve in Ramsar convention. The only permanent way that connects Gorgan Gulf to Caspian water is Ashoursdeh-Bandar Torkaman; a way with approximate width of 2500 meters and depth of at most 3.3 meters when the Caspian water level rises in northeast parts of the Gulf. Caspian water level may vary as a result of one or a combination of multiple factors such as: climate change, tectonic processes and human activities. The effect of each one is not the same as the other factors. Needless to say, that any alteration in Caspian level shall exert direct effect on Anzali wetland and river systems resulting in manipulation of morphology and animal life and even economy of the coastal areas. Furthermore, since wetlands are usually affected by seas and rivers, any change in sea and river dynamics shall definitely affect . In this study, different layers of Gorgan Gulf current pattern for one year with inclusion of Caspian level changes using Mike 21 has been simulated and analyzed.

Mike 21 hydrodynamic module was used for the purpose of studying Caspian current pattern. This module is the most basic model of Mike 21, and other modules of this model are dependent on the outcome of this module. This module is able to simulate water level changes and currents in two dimensions; therefore, it has the capability to study full details of a current in different spots. This model is helpful in studying the water level and current patterns of seas, rivers, gulfs and coastal areas which are affected by wind and tides. This module is also used to simulate combinational effects of such phenomena. It can model inconstant currents with inclusion of bed changes, mass changes and tide changes.

This model is able to solve the three-dimensional incompressible Navier-Stokes equations with the inclusion of Boussinesq approximation and hydrostatic pressure, using unstructured mesh. Unstructured meshes are better than rectangular structured meshes for the purpose of covering complicated borders such as coastal lines and islands borders. Horizontal unstructured mesh is a collection of 20 layers, perpendicular in direction, for sigma and z level system which uses 10 sigma layers for the distance between surface level up to -40 m, and 10 sigma layers from -40 to sea bed and 10 layers with fixed thickness (z level) 4-150. We use finite volume as our numerical methodology to solve equations. This study covers the whole Caspian Sea. We use unstructured mesh to simulate currents. Mesh dimensions vary from 0.25 degrees in northern part to 0.01 degree in some spots of southern part. To layer the model vertically, sigma and z level system was applied. In the implemented current model, time step was fixed between 0.01 to 60 seconds. Results demonstrate that Caspian currents are often counter-clockwise, which had previously been reported by some researchers as well. Western current is north-south and southern current (parallel to coast) is east-west, and eastern current is south-north. Current rate starts to fade in bottom layers, and current direction tends towards right due to Ekman transport. It can be seen in all seasons of the year. Furthermore, a current when is parallel to coast may be affected much more from topography. Sometimes currents may be deviated towards deep water as a result of being affected by bed. This can be observed in bottom layer more than elsewhere. Results indicated that overall Caspian current in western border more intensified in autumns, while weaker in eastern border. However, in winters, big storms take place and overall current becomes intensified in southern part of the Caspian Sea. In summers, which weather is often calm, currents are weak in central part of Caspian Sea, yet intensified in eastern border. It is evident that in Gorgan Gulf and surrounding area, where coast has low slop, wind pattern and topography of currents is weak and current rate begins to slow down in central and western parts. In southeast part of Caspian Sea, current rate and current direction reach to the least levels possible in various layers as a result of low depth and weak rate of currents. In this part, current layering cannot be observed. Effect of Water Level on Surface Area of Gorgan Gulf To study the effect of water level changes to Gorgan Gulf morphology, we study the effect of past year decrease of water level on Gorgan Gulf. We calculated Gorgan Gulf surface area for various years along with water levels. We found that water level has a nearly 15 cm of decrease; therefore we assumed a trend of 5 cm decrease in water level for Gorgan Gulf for the future. We extracted Caspian water level from the Anzali station records available. Given the low depth of Gorgan Gulf as well as rather low slope in most parts of the Gulf, it can be anticipated that if water level continues to decrease, most part of gulf area and particularly gulf inlet (Chapgholi channel and Ashouradeh channel which connect Gorgan Gulf to Caspian Sea) shall undergo remarkable morphological alterations.

Generally, it can be suggested that the current has had a similar pattern during the first three months (Gregorian calendar) which occurs when current rate has the utmost rate in western spots of middle Caspian, yet the current has less intensity in western part. In these three seasons, current rate is very low and near to zero in various layers surrounding Gorgan Gulf. In June, July and August, it is observed that current starts to dominate in a direction parallel to the coast of Gorgan Gulf. This domination is evident in cold months as well. However, its intensity starts to fade when warm months approach. It is noteworthy this occurs in July as a result of both the coastal-parallel current and the effect of north-east current in eastern border. Results indicate that the current in eastern border as well as the current risen parallel to southern coast have immense effect on current pattern of Gorgan Gulf. When the direction of the eastern border current is towards south-north, the intensity of the current inside the gulf starts to decrease, but when this direction is towards north-south, the current starts to dominate the gulf evidently. Also, when the current that is risen parallel to southern coast has noticeable intensity, part of this current penetrates to the gulf causing the gulf water to circulate. The coincidence of the eastern border current in north-south direction and the current risen parallel to southern cost exerts the highest effect on water circulation in Gorgan Gulf giving rise to the highest current rate in the gulf.

Transmission of pollutants to high vulnerability groundwaters is significant due to the uncontrolled growth of water harvesting from wells in recent years. One of the significant parameters for the pollutants transfer to groundwater is the presence of colloidal particles. These particles often facilitate the transfer of pollutants to lower soil depths in saturated conditions. However, in particular circumstances, they also delay the transmission of pollutants. Therefore, it is necessary to study the effect of various parameters on the transfer of pollutants in the presence of colloids. In this research, in order to investigate the effect of various parameters and the effect of colloid presence on pollutant transfer, first, a hexavalent chromium transmission experiment was performed in the presence of bentonite colloidal particles in a saturated porous medium column. Then a one-dimensional numerical model has been developed based on three-phase equations and interactions of soil, colloid particles, and pollutants in a saturated porous medium. The equations in this research include six differential equations that have six unknown parameters. These equations are solved with finite difference method, which uses two points reverse differential approximation for derivatives of time and central difference approximation for spatial derivatives. The numerical model was calibrated with experimental results with a determination coefficient of 0.98 and constant coefficients of the equations were optimized. Investigation of the important parameters showed that by increasing the deposition rate of colloidal particles on the solid matrix, less pollutant content was transferred, which is a fact for the effect of colloidal particles on pollutant transport. Also, increasing the rate of pollutants absorption by colloidal particles and increasing the flow velocity, increases the pollutant transport. The results indicated that doubling the hydrodynamic diffusion coefficient of the contaminant and colloidal particles increased transmission by more than 100 times at the beginning of the experiment and by approximately 15% at the end of the experiment. Finally, the increase in porosity increases the gap between the particles and the chromium transmission. The results of this study indicate the significant effect of bentonite colloidal particles in facilitating and enhancing chromium transport in saturated porous media. Also, the diffusion coefficient has the most influence on chromium transport in the presence of colloidal particles in the saturated porous media. As a result, the presence of colloidal particles in groundwater-contaminated environments should be monitored and the effects of parameters in that environment should be determined by modeling to take the necessary measures to control it.

Since allocating water to satisfy environmental water share can cause a conflict among governmental organizations supplying water, withdrawing water, and protecting the ecosystem, recognizing and analyzing such situations is paramount significance and can avoid encountering serious conflicts. In this research, we analyzed the actions of involved organizations which are either using or supplying water from Ilam’s dam to find the equilibria and the possible outcomes of the conflict.

We used Graph Model for Conflict Resolution to study the actions and strategies of rival organizations managing water allocation and involving in water conflict. The involved organizations are determined based on uses of Ilam’s dam. To define the strategies, all the measures and decisions of these organizations have been studied since 2005. In addition, the effect of drought years on the players’ actions is taken into account. Finally, we compared the status-quo with the results of the base line strategy of the model.

Equilibria results suggest that in states 27 and 32 the Jihad Agriculture Organization and the Water and Wastewater Companyare interested in withdrawing more water to achieve their goals. As a result, the Department of Environment will complain against them to protect ecosystem and provide the required environmental water share. In this case, the Regional Water Authority and the Governorship can play a dominant role in accomplishing to the stable outcomes. Furthermore, it is shown that the status-quo is not stable.

Analyzing this conflict indicates that all players have enough power to change the game's output. Therefore, their goals and measures can effectively change the equilibria and the future of the conflict

The aim is first to express the differences and identify three models, namely, Gene Expression Programming (GEP), Neural-Fuzzy Network (ANFIS), and Bayesian Network (BN), and compare them with each other. Furthermore, the research's central question is whether the superior simulation meta-modal in this study can be a suitable alternative to conceptual models in the conditions of lack of data and information.

The data used for this study are the daily rainfall and flow data of the Gamasiab Nahavand River in 10 years from 2002 to 2012. For the prediction or simulation stage, the data of the blue year 2012-2011 have been used.

In the training phase and according to the coefficient of explanation and the square root of the mean squares error and the AIC criterion, it is observed that in all three models, both in the training phase and in the test phase, we see a minimal difference in the amount of these parameters. Moreover, all three models' results are close to each other with almost a minimal difference, and almost the relative superiority of the GEP model can be seen.

The results indicate that the simulator meta-model of gene expression has an excellent ability to simulate and predict the river's daily flow, this simulation meta-model can be a suitable alternative to models in the absence of data and information. Be conceptual. Also, the speed of implementation of the gene expression programming model was faster than other models and was able to provide results in a short time.

Taleghan River is one of the most important rivers in the country because of its flow to Taleghan Dam, which supplies drinking water to this area as well as part of the city of Tehran. Long-term river discharge data are needed to design hydroelectric power stations and manage water resources. Regarding the existing monitoring stations are scattered and cannot provide sufficient hydrological data for the basin we employ rainfall-runoff models which are popular tools for expanding hydrological data over time and space. In this paper, the feasibility of applying a conceptual rainfall-runoff model called HYMOD to a part of Taleghan River Basin is investigated. The generalized probability estimation method was used for model calibration and uncertainty analysis. The results show that the observed discharges are satisfactorily consistent with the observations, indicating that the hydrological model is working well and applying HYMOD to estimate long time series of river discharge in the study area is turning reasonable results.

Reservoirs of hydropower plants have a significant impact on water shortages as large amounts of water evaporate from the surface of the reservoirs and become out of reach. This is a major issue in hydrology and water resources, which results in the availability of water resources. In this regard, the concept of water footprint was used to calculate the water consumed in the process of generating electricity from these plants. In this study, to calculate the water footprint in electricity produced in hydropower plants of the country, data on the annual evaporation volume (m3) and annual electricity generation (m3/TJe) from 17 hydropower plants in Iran for the period of 2010 to 2017. The results showed that on average, the largest water footprint in electricity produced by Droudzan power plant was 287649 (m3 / TJe) and the lowest was related to Masjed Soleyman power plant and equal to 405 m3 / TJe. The average water footprint in electricity production from Iranian hydropower plants was estimated at 6132 (m3 / TJe).

The present study aims to determine the annual water footprint trend of wheat production in Esfahan province during the period 1982-2016. In order to investigate the trend of water footprint time series of wheat production, Mann-Kendall Trend test and Sen's slope estimator were used. After ranking the cities from the point of view of the water footprint and water footprint trend, using the Social Choice Rules (SCR), the best city for wheat cultivation was identified in Esfahan province. The results showed that the average total water footprint of wheat production in Esfahan province was 4122.73 m3/ton and according to Mann-Kendall statistics, there is a decreasing and increasing trend and this trend was significant for the Fereidan, Fereydun Shahr and Isfahan cities at a level of 90%. The results also indicate that the low amount of water footprint indicator or the decreasing trend of this indicator in producing a product in a region is not an acceptable criterion for choosing that area for cultivating that product and by using bargaining simulations such as social choice rules, it is possible to identify the best region for cultivating each product and to change the pattern of cultivation in its policy of work to preserve water resources and increase productivity. In this study, from the point of view of the water footprint, Fereydun Shahr was selected as the best city for wheat cultivation in Esfahan province

Uncertainty analysis is an inseparable step in the process of hydrological modeling. Quantitative assessment of the uncertainty in the simulation model outputs and its parameters, thereby increasing confidence in the results of modeling and understanding of the sources of uncertainty. Due to the increasing use of groundwater management model and predict the behavior of the aquifer, this research is seeking to analyze the uncertainty in quantitate-qualitative aquifer simulation and its effect on optimization results. Using SWAT hydrologic model, the amount of recharge is specified and entered into MODFLOW groundwater flow model and MT3DMS transmission model. In this research, the DREAM(zs) algorithm (based on Monte Carlo Markov chain algorithms) was used to examine the uncertainty of MODFLOW model parameters. Then by linking the model with MOPSO, the optimum head and salinity are obtained in the aquifer. The results show that the accuracy of the inputs of the model leads to the desirability of the results in relation to the intended purpose of reducing the water table.

In order to apply a proper management, it is necessary to identify the groundwater level in the plains for a long-term planning and use the potentials in the water plains more efficiently. In this study, the monthly statistical information for the 5 water years (1388-1289 to 1392-1393) related to the water levels of 8 piezometer in the Lour-Andimeshk plain aquifer was used. At first using the tiessen method, the average weight of each piezometer was obtained and the time series of the major plain, which represented the hydrograph of the aquifer of the study area, was calculated. Then using, the conceptual  groundwater model of Modflow and the simulator Meta model of the gene expression, the hydrograph of the aquifer unit was modeled and the results were compared. The results showed that the conceptual model of Modflow with an explanation coefficient of 0.7836 in the testing phase compared to the transmutation of gene expression with an explanation coefficient of 0.739 with a very slight difference has a better performance.

Sustainable management of Urban Drainage Systems (UDSs) is challenging since the hydraulic characteristics and pollutants discharged into catchment areas are constantly changing. Quantifying the resilience of UDSs is a crucial step towards long-term and sustainable management of these chatments in urban areas. This study was performed to evaluate the resilience of UDSs against flooding through combining hydraulic performance of stormwater drainage network with the system performance function. To conduct this performance evaluation extreme rainfall intensity values for different return year periods ranging from 2 to 100 years were used for catchment drained into the West Flood-Diversion (WFD) system in Tehran. Both hydraulic and hydrodynamic simulations were performed for these stormwater drainage system under two scenarios: with and without BMPs. To further evaluate the systems performance and resilience, additional simulation analysis was performed using one specific flooded node under extreme rainfalls with different return periods. The results showed that adding a vegetative swale to the drainage system would decrease the nodal flooding duration and the flood volume up to 15% and 47%, respectively. The results also shown that the resilience against flooding will increase from about 0.4% up to 6% under the above-mentioned conditions. From the results of this study, we can conclude that employing some types of BMP along with the existence low-impact development measures within the traditional urban drainage areas may be sufficient to increase the system resilience and sustainable control of flooding.

One of the most effective techniques to reduce evaporation rate is to use suspended shade covers to create shadow on the water bodies. Black polyethylene is a material that can be used for covering as porous fabric like sheets. In this study, energy balance analysis was used to evaluate the effects of using this type of covers in dam reservoirs on evaporation rate. Minab dam was selected as case study and energy modeling was conducted with respect to different scenarios. Results show that the use of black porous polyethylene can reduce evaporation by an average of 77% and 83% in the case of using single-layer and double-layer, respectively. This amount of evaporation reduction could be lead to reduce 11, 22 and 33 million cubic meters for 30%, 60% and 90% covering scenarios, respectively, for Minab dam reservoir.

Increasing of population is caused that water demands in domestic, industry and agriculture sectors are raised. This situation is needed implementing effective decisions to achieve optimal water allocation considering inter basein water transfer, water value and economical issues. This research presents a methodology for optimal water allocation with considering transferred water and users utilities in Qom province. Qom is located in drought area of Iran. In the proposed methodology, Particles Swarm Optimization (PSO) optimization model has been used for optimizating sum of benefit ratio to water allocated amount as goal function. This methodology has been developed in two cases; with and without considering transferred water and users utilities. In the second case, utilities of stackeholdes are considered in two concept: Water value and Strategic management. According to experts’ estimations, for defferent demands some weights of priority have been estimated. The results show better allocation in strategic management and water value concepts.

The two factors of the trend of climate change and urban development pose a challenge to urban drainage infrastructures due to the adverse impacts on precipitation extremes and urban environment. Nowadays, Sustainable Urban Drainage Systems (SUDS) have become quite popular as a result of their positive effects on the water quality, quantity, amenity, and recreational affairs in urban landscapes. Today, the majority of the world agrees that a sustainable drainage approach has an influence in reducing global climate change and adapting to this phenomenon (which has already started). The current paper reviews recent progress in the development of sustainable drainage, based on interdisciplinary studies. First, the reasons behind moving towards a sustainable urban drainage system are mentioned and then, existing models and decision-aid tools to assess different types of SUDS are compared and discussed. This paper also explains some limitations and challenges related to applying SUDS in practice and finally, the results and conclusions are presented.

Nowadays, one of the most important concerns in many countries is water supply for sustainable development. So for efficient management of groundwater resources, on the one hand, we need an appropriate tools for modeling, on the other hand, we need measure sustainability to check the performance of scenarios. This paper analyzes the sustainability condition using an integrated modeling framework that consists in sequentially a watershed agriculturally based hydrological model (Soil and Water Assessment Tool, SWAT) with a groundwater flow model developed in MODFLOW, and with a TDS mass-transport model in MT3DMS in Esfahan-Borkhar in Iran. SWAT model outputs are used as MODFLOW inputs to simulate changes in groundwater flow and storage and impacts on stream–aquifer interaction. MODFLOW output (groundwater velocity field from MODFLOW) are used as MT3DMS inputs for assessing the fate and transport of TDS. Heads and concentrations of each cell of model (MODFLOW and MT3DMS) are used to calculate the developed Sustainability Index (whith 3 performance criteria, Reliability, Resilience and Vulnerability) under three scenarios. The results indicate that SI in simulation period is 0.052 and under first, second and third scenarios are respectively 0.040, 0.033 and 0.050.

In recent decades, using water resources is increased for the sake of industrial, domestic and agricultural water consumptions by increase in urbanization and industrial development in Karaj region that fraction of groundwater resources is too much according to the recent drought years and reduced precipitation in Middle-East. These outcomes has caused groundwater level drop, reduced in aquifer storage and many springs and qanats were deserted and dried up. Therefore, studying groundwater status accurately, groundwater level drop reasons, the consequences and presenting solutions to conservation and balancing groundwater are essential matter in this study area that all of them depends on determining reasonable policies for exploiting from the aquifer. Therefore, three scenarios entitled optimistic status, pessimistic status and continuing current exploitation status were defined to predict groundwater level of Karaj study area from water year 2014-15 until water year 2023-24 utilizing MATLAB interface. According to the results, 12.834 m, 17.019 m and 4.906 m water level drops were computed for continuing current exploitation status, pessimistic status and optimistic status, respectively.

Water quality trading (WQT) is an economically incentive-based strategy that focuses on finding the optimal discharge permit market for surface water quality management. The amounts of traded discharge permits determine the interactions of emission sources in the market. Pollutantsthat are able to provide extra permits can satisfy the demands of other participants for credits. Finding appropriate permit sellers and buyers depends on their marginal costs, enthusiasm for participating in the market and the impacts on the quality of checkpoint for waste load allocation (WLA). It was recommended that the feasibility and cost-effectiveness of WQT should be analyzed in advance for practice. This needsto estimate the projected loads, environmental standard limits, the incremental and total abatement costs, and finally to optimize WLA. In addition, the assignment of total maximum daily loads (TMDLs) is required. This can be carried out through the simulation methods. However, TMDLs and WLAs with focus on limiting total nitrogen (TN) may be different to the phosphorous or biochemical oxidation demand (BOD). Therefore, the outcomes of WQT may be dependent on different factors such as the spatial location of pollutants, discharge loads, river self remediation, and economical and environmental conditions. All emphasizes on this fact that WLA using WQT requires analytical studies in different cases. This research primarily aims atfinding the optimal WLA in the downstream of Sefidrud in which the trading discharge permits (TDP) based on TN may qualify the pollutantsfor market interactions. It intends to assess the feasibility of WQT policy and compares the analytical results to the case of Gharesoo River. Finally, the effectiveness of integrating wastewater reclamation with TDP is introduced as a solution and compared with the results of Gharesoo River.
The study area is limited to the downstream catchment of Sefidrud in which it starts at the spillway of Sangar Reservoir at headwater. This ends up to the Caspian Sea after 55 km length. Here, the main pollutantsare identified as domestic, agricultural and industrial sources. This area receives the effluents of 10 point sources and rice farm lands. The flow rates and the projected TN load (kg/day) discharged to the surface water are estimated using the export coefficients, typical concentrations of TN and the statistical reports of their discharges as for the Gharesoo River. These were simulated by Qual2kw and the terminus point is the checkpoint. TMDLs are calculated by limiting TN to 4.5 mg/L at checkpoint. The impacts of discharge load reduction incurred by emission sources are also determined through the sensitivity analysis and normalized as previous studies.
This research addressesthe feasibility of nitrogen discharge permit market in Sefidrud and compares its effectiveness to the Gharesoo River. For this purpose, in the first scenario, the outcomes of conventional TDP policy are calculated and in the second scenario, its integration of wastewater reclamation market is examined.
The simulation results reveal that the concentrations of total and organic nitrogen can be reduced from 10 and 6.6 mg/L at checkpoint to 4.5 and 1.4 mg/L, respectively. This is conducted using the TMDL policy. This improvement may totally cost 70 billion Rials in a year in the catchment. In this regard, if the wastewater treatment operators appropriately use the secondary units, it can be expected that the classification of river based on water quality index promotes one degree.
In order to study the feasibility of conventional TDP, the WLA is determined using the typical procedure outlined by previous studies. Allocation ofabatement duties to the pollutantswith lower marginal costs as permit sellers may decrease the annual TN abatement costs about 1340 million Rials. It only saves 2% in comparison with TMDL approach and may not receive significant outcomes. In contrary, the results of TDP in Gharesoo River approved its economical efficiency. Here, total savings may exceed 35%. This is discussed as a matter of difference in the total nitrogen discharged between the domestics and agricultural users. The ratios of nitrogen loads in domestic effluent to the agricultural drainage are, respectively, 0.58 and 0.71 for Sefidrud and Gharesoo Rivers. This ratio is introduced as an index to compare the feasibility of nitrogen discharge permit market. Since the point sources are typically assigned as permit sellers to supply credits for non-point sources, this index may imply that whether the trading has sufficient permits. Studying these two cases for nitrogen permit market indicatedthat in lower ratios, the market may find more limits to supply credits. In this regard, it is concluded that the success of market does not rely on the expansion of catchments. It mainly depends on the existence of centralized point-sources and the agricultural land uses. It is also confirmed that the balance between permit demand and supply is the key of a successful trade.
In the second scenario, this study introduces an integration of TDP and wastewater reclamation market. This intends to find an economical solution to increase the credits for trading. If the reclaimed water is used for irrigation of crop lands, about 15 credits may be added to the conventional trading. In addition, the necessity of nitrogen removal would be reduced. This is due to the fact that the agricultural users require the nutrient contents of reclaimed water and simultaneously domestic wastewater treatment plants prefer not to remove nitrogen to sell their effluents with higher values. Consequently, marginal nitrogen abatement costs are dramatically reduced. In this regard, total cost savings would be increased to 57% and 63% in Sefidrud and Gharesoo catchments, respectively. It shows that the integration of markets not only provides more flexibility to the system but also makes markets promising as an economical solution.
In the first scenario, the primary price of permits can only be determined on 150 thousands Rials. Some stakeholders and dischargers may lose their economical incentives for participation in TDP. As a result, they would leave the market and make the predicted interactions fail. In order to increase the robustness of conventional market, it is recommended that point-sources should use discount factor about 15 to 25% for credits. In this condition, the equity in benefits may increase and make market more stable. However, the shadows of unstable and breakable market turn this strategy into a challenging solution. Therefore, in the second scenario, the integration market is introduced. Regarding the analytical results, it is understood that market would be changed into a more flexible strategy that no longer is dependent on the permit price for stability. In contrary to the first scenario, the point sources are not obliged to use the discount factor. However, they would freely reduce the permit price to increase the economical incentives of the permit buyer (non-point source). It is claimed that in this scenario, the permits can be sold about 99% cheaper than the first scenario and simultaneously all sellers may use the maximum benefits obtained. These results have similarly been achieved in Gharesoo River as well.
Finally, it can be discussed that using the integrated reclaimed water and discharge permit market depends on the capabilities of wastewater treatment plants to supply permits enough in regard. In other words, a highly populated city is required in the study area to provide the secondary treated wastewater and its related permits for the integrated market. Therefore, some recent studies have introduced approaches in which they may find further flexibility and economical savings in the market. For example, using artificial aeration is recommended for small areas with permanent streams in which the dissolved oxygen and BOD concentration are the major quality problems of water. Here, the integrated market is able to fill the blanks for nitrogen control and reduce more abatement costs. The second approach is to identify the amounts of tradable permits through index like dissolved oxygen where multiple pollutants such as BOD and nitrogen have to be controlled simultaneously. For example, the dischargers who are not able to provide nitrogen limits should abate more BOD in their effluents to address DO limits instead. In TDP program, this approach can increase the flexibility for pollution abatement but has high uncertainty and complexity. This is recommended to be used only in small areas with limited non-point sources. Meanwhile, the integrated market can be associated with this approach and increase its outcomes. Third approach points to the fact that in trading between point-non point sources, the seasonal demands and supplies should be considered. Therefore, in large watersheds with high non point sources, using seasonal WLA may reduce the overall abatement costs and increase the equity. However, this depends on that wastewater treatment plants should be practically able to obey various WLA policies through different seasons. Consequently, designing operationally flexible tertiary treatment units is a key factor for successful seasonally integrated discharge permit and reclaimed water market. Therefore, it can be outlined that the integrated market can be combined with different technical or management based approaches but needsto be studied in advance. The selection of optimal alternative and also permit pricing mat require an analysis based on game theory approach.

This study concluded that water quality trading strategy is not necessarily an efficient and promising practice to manage all surface waters. It depends on how much stakeholders attain economical benefits to participate in this voluntary strategy;otherwise, it would be failed. In this case, for nitrogen discharge permit market, it is recommended that the reclaimed water is used for irrigation withhigh content of nutrients. Therefore, the obligations tohigh nitrogen abatement and its managementcosts would be decreased. This makes the conventional market change into a more flexible strategy that is almost independent onprimary permit price. As a consequence, the market shape turns into a free interaction with the lowest monitoring requirements. However, it requires further studies to analyze the details of interactions with respect to the variations of permit demands in time. In addition, the combination of different qualitative parameters such as BOD, TN and DO may change the economical outcomes.

The entrance of nutrients and sediments to the water resources has become a challenge in water quality management. Accordingly، identifying main polluting sources and estimating total loads discharged to the surface waters are indispensable for simulation and management. The purpose of this study is to use Soil and Water Assessment Tool (SWAT) to estimate nitrogen and phosphor loads discharging to the Zrebar Lake. In addition، it is intended to identify the effects of land uses and variations of time and spatial pattern of discharges. Currently، this lake contains fresh water and is used for recreational purposes while tackles with eutrophication problem because of agricultural activities. Regarding the results، the irrigated farmlands have the highest nitrogen discharge on June and August while it is on May for phosphorous. For dry crops، the highest value of nitrogen and phosphorous loads respectively belong to October and September. These are attributed to the way farms are irrigated and the amounts of fertilizers applied.