IRAN-WATER RESOURCES RESEARCH
Year:2019 | Volume:15 | Issue:3 |Papers Count:33

Modeling socio-hydrological interactions are one of the essential requirements for water resources management in water-stressed areas. The Ardabil aquifer (Northwestern Iran) is one of the restricted aquifers under intense development activities. The water table is dramatically declining leading the area to an upcoming environmental disaster. To address this problem, a simulation-optimization model has been developed in this study, which simulates groundwater level changes and determines the optimal water exploitation values. The simulation and optimization models have been linked by a new method in MATLAB which provides access to various MODFLOW packages and takes up less memory for iterative runs. The simulation-optimization model has been then linked to an agent-based model, which simulates agents’ behavior and their interactions. For the purpose of this modeling, firstly the key agents and their desirability have been determined. Then, the particle swarm optimization algorithm was used to estimate the agents’ desired groundwater exploitation values. In the next step, the best solution was selected according to the experts' point of view using the compromised programming method. Finally, the agent-based model provided the final exploitation values, taking into account social pressure and management rules (incentives and penalties). The results showed that groundwater demand can be reduced up to 22% in comparison to the initial value. This demand reduction resulted in 90 cm increase in the groundwater level for the entire plain.

Harirud River is one of the main sources of water in the northeastern regions of Iran and the south of Turkmenistan. Harirud is a provider of drinking and agricultural demand for a large number of people and regarded as one of the concerns of the two countries in terms of water sustainability. The planning and management of water resources in the transboundary basin because of missing or lack of access to weather information and hydrology in the riparian countries is stressful. In this paper, by coupling the SWAT hydrologic model and WEAP water resource planning and management model, we have tried to study the effect of upstream development as well as climate change on water inputs from the Harirud Transboundary River to Iran and Turkmenistan. The years 1955 to 1996 considered for calibration and the period from 1997 to 2016 to validate the SWAT model. The R2 and NS numbers were 0. 66 and 0. 65 for the calibration period, 0. 7, and 0. 72 for the calibration period, respectively. Most areas of the Doosti basin will face a rise in temperature (about 1. 5 to 3. 8 degrees) and precipitation decline, especially in upstream mountainous regions. Based on the results of the operation of the Salma Dam and RCP 8. 5 climate change scenario, the reliability and sustainability of agricultural water supply in Iran and Turkmenistan will reduce to less than 3%. Changing the climate pattern will face the challenge of meeting the environmental needs of downstream of Doosti and Salma dams. This trouble reveals the necessity of hydro policy between the riparian countries. If the current condition continues in this way, water shortage in Sarakhs becomes the primary social challenge in the northeast of Iran.

Groundwater is one of the main sources of freshwater in coastal areas and it is accordingly essential to prevent excessive seawater intrusion. In case of seawater intrusion into coastal aquifers, remediation of aquifer requires long-term and expensive efforts. Therefore and for the purpose of determining the optimal management strategies, a simulation-optimization model can be used as a decision model. In this study, a simulation-optimization decision model has been developed for Ajabshir plain aquifer via the SUTRA numerical model and the evolutionary optimization algorithm of ant colony optimization. In order to reduce the runtime of simulation-optimization decision model, parallel processing in the population computations of optimization algorithm was used. Two management problems have been examined in this study with objective functions and constraints under opposite behavior; minimizing the net recharge rate (meaning the maximizing extraction from the aquifer) and controlling the seawater intrusion (preventing the deterioration of groundwater due to salinity at the control points). Results from simulation-optimization decision model exhibited that by changing the extraction pattern in different aquifer zones, the net recharge of the aquifer in the second half of year decreases by-1. 87 million cubic meters compared to the current situation (Increase extraction) in the first management problem. In the second management problem, the average salinity concentration at the control points decreases 30%.

The purpose of this study was to investigate water consumption behavior and its determinants among wheat farmers in the Orzuiyeh county, Kerman province. This study is a descriptive-analytical research (Correlation type) that was carried out with the aid of a survey. The statistical population of the study was wheat farmers in the Central District of the County (N=1350), from which 132 farmers were determined as sample study population by using Bartlett and colleague sample size table. The study instrument was a questionnaire validity of which was confirmed by a panel of experts. In order to measure the reliability of the questionnaire, a pilot study was conducted and its reliability was calculated using the Cronbach's alpha coefficient (0. 58-0. 86). Based on the results, the water management behavior with an average of 4. 68 revealed that farmers' behavior in terms of water management was fairly favorable and suggested that farmers have actually taken measures to reduce water consumption. The findings also showed that there is no significant relationship between age, education and household size with water management behavior. The results of discriminant analysis indicated that the characteristics of wheat field structure (land area, total cultivation area, wheat area, irrigation method and water supply source) were the most important variables of farmers' water consumption behavior.

Detection of noise (anomaly or outlier) from flow data in water distribution networks (WDNs) is implemented in data preparation and prepossessing to achieve reliable historical data. This improves the assessment and management of leakage and helps the efficient operation of the network. The main objective of this paper is to develop a new methodology based on unsupervised learning methods for noise detection in a flow data set in water distribution networks. The developed methodology includes three steps 1-required data acquisition, 2-data validation and normalization, and 3-anomaly or outlier detection using the density-based spatial clustering of application with noise (DBSCAN) algorithm. The proposed methodology is applied for inflow data into a zone in Tehran's urban water distribution network which has 15-min reading intervals for the year 1394 (April 2015-March 2016)). The results showed that the developed methodology is capable in detection of anomalies caused by different types of pipe breaks and unusual legitimate consumption such as water usage due to changes in water consumption pattern or unauthorized consumption. Therefore, this methodology can be used as an applied and flexible tool for flow data monitoring and detecting and eliminating different types of outliers.

The countrywide imbalance between supply and water demand is one of the most important issues of water resources management in Iran, especially in the agricultural sector. In this regard, international exchange of agricultural products and virtual water trade, which is defined as the water embedded in goods, can be regarded as a means to manage water resources. Sugar beet is amongst the low productivity products in the country with high water demands. In this research, the amount of pure water demand and the virtual water associated to production of sugar beet, sugarcane, and the corresponding produced sugar is calculated using the Cropwat software. We also investigated the virtual water exchange and its dependency on other countries. During 2005-2014, the major origins of importing sugar were from UAE, Brazil, Switzerland, England and India. It is shown that in the case of importing sugar from such countries instead of national production of sugar during that period, about 13 billion cubic meters of water could have be saved. However due to different risks of security and climate change, increasing of country’ s water dependency on other countries should take into consideration the long-term effects of virtual water import. The concept of a reliable level of virtual water trade is expected to be embedded in export/import policy making as an important issue in terms of water and food security.

Wetlands are one of the important natural habitats across the world and have a lot of environmental benefits especially for energy circulation in the environment. In such aqua habitat, animals and plants are dependent on each other and the ecological role of each sustains the ecosystem. To conserve environmental and socio-economic values of wetlands, it is of vital importance to determin their ecological water requirement. In this research the wetland environmental water requirement was determined by using a combined hydrologicecological method. The international Anzali wetland, which has been enrolled at the Ramsar convention, was selected as the case study. In this method, the historical hydrologic condition of rivers entering the wetland and the Caspian Sea water level as the prominent and influential factors on the hydrologic condition of the wetland were analyzed. The key index was then selected considering the most important ecological functions for the wetland. The relationship between the depth and water surface level of the wetlands and the ecological condition of the selected index were investigated across the different parts of the wetland for different years. Based on the results, the ecological level and the pertinent volume of the wetland were determined at minimum and optimum conditions.

Accurate estimation of transported sediment by rivers plays an important role in water resources management. So the selection of proper methods for estimation of suspended sediment is an important objective to that goal. In this regard, application of intelligence models (e. g., ANN, SVR) has substantially improved the prediction of suspended sediment. Using these models, an important step in suspended sediment modeling is the proper input selection since input vectors determine the structure of the model and, hence, influence model results. In the most studies, only climatic and hydrological variables have been used as suspended sediment estimators using data-driven models. Therefore, this study was designed to determine the effective and accessible geomorpholigical variables in suspended sediment estimation for the Tamar catchment. To accomplish this goal, the effect of the Index of Connectivity (IC) as a hydrogeomorphic input, in addition to the hydrologic inputs, was investigated. Comparison of the results for different input patterns indicated that using IC along with hydrological inputs improved the model efficiency reported by decrease in the root mean squared error (9. 63% and 26. 36%) and increase in the Nash– Sutcliffe efficiency (25. 80% and 21. 85%) and in the coefficient of determination (13. 20% and 45. 94%) respectively for ANN and SVR models.

The aim of this study was to apply COPRAS and Grey COPRAS multi-criteria decision making methods to selection of the best agricultural sector water supply alternative for adaptation to the effects of climate change in Gharranghu basin in East Azerbaijan province. According to the existing hydroclimate conditions, adaptation scenarios in agricultural sectors were selected and based on the results of water resources evaluation and planning model (WEAP), risk indexes in each scenario were calculated based on mathematical equations. In order to prioritize and select the best alternative, adaptation scenarios were considered as alternatives, and risk indexes are regarded as criteria in COPRAS and COPRAS-G multi-criteria decision making methods. Results showed risk indexes will be improved by implementing adaptation policies, so that drought risk index would decrease through reduction of water consumption from 5% to 25%. Also, the best alternative for adapting the impacts of climate change phenomenon by using COPRAS method was the fifth alternative, namely 25% reduction in water demand in agricultural sector, while COPRAS-G method introduced second alternative namely 10% reduction in water demand as preferred alternative. It should always be assumed that any prediction of results for the coming years is associated with uncertainty due to complex climatic conditions and its resulting effects.

In this research, water balance components in Mehrgerd watershed was simulated using the SWAT hydrological model to investigate the model efficiency and its ability to use as a water balance simulator in the Mehrgerd watershed. For this purpose, the necessary data such as precipitation, minimum and maximum temperatures, relative humidity, sunshine hours, daily wind speed, and monthly discharge as well as required maps including digital elevation model (DEM), land use, and soil were provided. A sensitivity analysis was done using the OAT method to determine the sensitive parameters. The calibration and validation of the model were conducted by Sufi-2 algorithm respectively for the periods of 2004 to 2012 and 2013 to 2016. Monthly runoff simulation accuracy was calculated using the determination coefficient (R² ) and Nash Sutcliffe (NSE) index which were 0. 73 and 0. 69 for calibration and 0. 71, 0. 58 for validation, respectively. The results showed that 64% of precipitation enters the atmosphere through evapotranspiration and approximately 31% of it goes to the waterway as the surface runoff and lateral flow. Finally, from 6 % of water entered into the soil layers, about 1% joins the underground water. The results of this research showed the acceptable performance of the SWAT model to simulate the water balance in Mehrgerd watershed and the model can be used for water resources planning in this study area.

Lake Urmia, located at northwestern of Iran, is the biggest territorial lake in Iran and one of the most hyper saline lakes of the world with a basin of 51876 km2. In recent years, as a consequence of excessive water extraction in upstream, ambitious water projects and decrease in precipitation, the lake water level has been dramatically lowered. One of the important factors to analyze the drop in Lake’ s water level is the Water Balance of the Basin In this research, in order to evaluate basin’ s water balance, different tools like GLEAM, lake water balance and the updates by the Iran Water Resources Management Company have been used. Based on the results from GLEAM, the basin’ s Natural Renewable Water (NRW) for water year 1394-1395 have been 5780. 59 MCM more than 83% of which has been used in agricultural sector. The estimated Available Water based on the updates by the Iran Water Resources Management Company was 3% less and the calculated Available Water based on historical data was 45% more than GLEAM’ s result. Another important note is that in the study water year, 1541. 02 MCM of the Potential Water have been used in the basin, from which, 421. 4 MCM of it was regarded to the reduction in lake’ s water level and the remaining 1119. 62 MCM, have been provided by the groundwater supplies which caused reduction in ground water level in the basin. The official data released by the Iran Water Resources Management Company (IWRMC) have reported the basin’ s groundwater exploitation as 2210. 99 MCM for the water year 1389-1390.

Although, many studies have been reported on meteorological drought monitoring and analysis, similar studies on groundwater drought in regions with high abstractions are lacking. In this paper, the effects of groundwater extraction from aquifer were investigated and groundwater drought analysis was performed using the naturalized groundwater level time series in Qazvin plain. For this purpose, MODFLOW-ANN coupled model were used to obtain the time series of naturalized groundwater level over a 50-and a 3-year period. Then, the groundwater drought was monitored by means of the SGI and was compared with the SPI and SHDI indices. Also, drought characteristics were calculated during the 50 year period and the regions with higher drought hazard were determined. Results showed that abstraction caused severe negative trend in the groundwater level. Also the aquifer was in long duration dry condition in about 47% of the time. Groundwater level changes have a 9 months delay to changes in precipitation and surface flow rivers. Groundwater drought is more strongly correlated with hydrological drought than with meteorological drought. Also, Boeinzahra county has a higher and Qazvin and Alborz have a lower hazard than other regions.

One of the most effective tools for water demand management is the recognition of price and income elasticity for water demand. In this study, using systematic review and metaanalysis, the factors affecting the price and income elasticity for household water demand in Iran have been investigated. Accordingly, first, using Rosenthal and Robin's approach in systematic review, the effects of price and income elasticities for household water demand have been calculated. Then, based on the heterogeneity between the calculated effects of the effect sizes, random and fixed effects models were used to combine the results. Finally and according to the results, the variables related to the water demand profile, the survey data, the water price, the water pricing structure, the model, the estimation method, the study area, and other characteristics of the study, the estimated values of Prices and income elasticity have been affected on household water demand. So water demand management policies should be based on these characteristics.

Excessive exploration of groundwater causes seawater intrusion (SWI) in coastal aquifers. The purpose of this study is to investigate the effect of aquifer bed slope on SWI characteristics including salt wedge toe position, thickness of mixing zone and seawater volume in the aquifer. Different scenarios under various bed slopes and directions were defined and numerical dispersive SEAWAT code was used for modeling. Two different boundary conditions (i. e. constant head and constant flux) were also applied to freshwater inflow at landside. The simulation results demonstrated that in the confined aquifers with landside constant flux, the SWI extent and thickness of mixing zone have increased when the slope changes from a positive value (i. e. longitudinal slope toward the sea) to negative amount (i. e. longitudinal slope toward the land). The results of this study showed that when the aquifer bed is considered flat, the SWI specifications including salt wedge toe position, mixing zone thickness at bed and saline water volume were lower than in cases with negative slope and higher than in cases with positive slope. Type of freshwater inflow at land boundary also influenced the results. In confined aquifers, when land boundary condition was changed from constant flux to constant head, salt wedge characteristics were not significantly changed. Finally, variation in the aquifer bed slope affect the gravity factor (potential head) in the related equations accompanied with pressure head. This plays a key role on SWI specifications in confined coastal aquifers.

Improvement of water productivity (WP) in the agricultural sector is one of the necessities of sustainable use of water resources, crop production sustainability, water demand reduction, and fulfillment of food security for the increasing population of Iran. In this research, through facilitated brain storming meetings and harvest of the ideas of the experts and resource persons participated from the water and agricultural sectors of the country, the software and managerial issues and challenges (socio-economic and policy– institution) associated with the improvement of WP in Iran were systematically identified and developed in the form of problem trees. Based on the results, the main source of the above issues could be identified in the five following categories namely as: 1) Insufficient accordance of the country’ s policies with the WP, 2) lack of proper implemented plans for the integrated management of water supply and demand, 3) lack of proper measures, incentives, and or motivation for investing on the development and of the water resources and O&M of the water infrastructures, 4) low levels of efficiencies in the planning, study, design, and implementation of the country’ s water resources and associated infrastructures, and 5) insufficient activities on training and capacity building programs require for the improving of WP. The suggested strategies are: 1) More accordance of the country’ s policies with the WP concept, 2) more stability and consistency in the developed policies and the plans, 3) making more incentives, motivations, and measures for real water savings, 4) A shift from centralized provincial management of water to the basin-wide management, 5) establishment and or completion of data bank, 6) demand management through inverse solutions, i. e., virtual water management, 7) revisions in and or more accordance of the higher education system with the water management and WP subjects, 8) empowerment of stakeholders and participatory management, 9) Upgrade of education and making required capacities in the Stakeholders, 10) making revisions and re-orientation of water resources researches in the line of water saving, and 11) mainstreaming of improvement in WP in other disciplines of agricultural sector (livestock, fisheries, and etc. ).

The purpose of this study was to analyze the cycles and mutations of average temperature in south east of Iran based on neural networks and general atmospheric circulation models under climate change scenarios. The data used in this study consisted of the average daily temperature recorded in synoptic stations in Ahwaz, Abadan, Dezful, Khoramabad, Sharekurd and Hamadan, NCEP Reanalysis data and output data of the third edition of the HadCM3 global climate model under the A2 and B2 scenarios for the base period (1991-1961 AD). Except for the prediction of other steps including data calibration, the assessment and validation was done in MATLAB and the maps were produced through Surfer. The temperature estimated based on the output of general circulation models in scenarios A2a and B2a of HadCM3 showes an increase of up to 1. 5 ° C in most areas by the year 2099. The results of the analysis of the temperature cycles showed that based on the output of neural networks and models of general circulation in the scenarios A2a and B2a the temperature has short cycles of 2 to 4 years. The results of the Alexandersson test showed that the average temperature on the South West of Iran indicated a meaningful mutation from 2050 onwards.

Environmental problems are among the major problems facing humankind in the recent century, and so far, various indices have been proposed and examined to assess them. Accordingly, in this study, to evaluate the ecological environmental quality (EQ) of 500 pixels (pixel area=1km2) around the city of Tabriz (center of East Azerbaijan Province) and 500 pixels around the city of Rasht (center of Gilan Province), Iran, with different climates, the EQ index has been investigated using Artificial Neural Networks (ANN) and remote sensing techniques. Eco-environment Background Value (EBV) based on a scoring and ranking system, was used to evaluate EQ. The higher the EBV, the better the ecological environmental quality. For the modeling, indicators including vegetation index, wetness index, Land Surface Temperature (LST), and Digital Elevation Model (DEM) data as well as precipitation and temperature were exploited as input of the three-layer back propagation artificial neural network (BPANN) model. The average of the data for the past 8 years for these indicators for the study regions were entered the network; once seasonally and once annually. The analysis showed that the ANN model has acceptable performance for estimating complex environmental functions, which are affected by various environmental parameters. The best performance of the network was obtained for Tabriz region in the spring with a root mean square error (RMSE) of 0. 02 and coefficient of determination (R2) of 0. 95. The better network performance for Tabriz compared to Rasht may be due to the weakness of the remote sensing tool in examining areas like Gilan with high vegetation density (VD) and high relative humidity (HRH). It seems that the high VD and HRH impede proper reflection without deviation from the land surface and disrupts the reception of the required data. Analyzing the spatial correlation between EQ and the land uses, it was found that forest lands were the best eco-environmental area, whereas the urban area had the relatively worst EQ. Human activities are a major impact on the EQ in this area.

Water footprint index shows actual consumption of water in three components: blue, green and gray. Nowadays, the modern management of water resources with integrated approach takes into account the concept of water footprint. In this research, wheat water footprint was evaluated at strategic zones with regards to water resources (blue water, green water and gray water) and an optimal cropping pattern in different climates of Iran was presented. For this purpose, 33 provinces of the country were first classified according to the UNESCO cluster. All stations were classified in 6 climates; Plentiful Humidity Cool Warm (PH-C-W), Semi-Arid Cold Warm (SAK-W), Semi-Arid Cool Very Warm (SA-C-VW), Arid Cool Warm (A-C-W), Arid Mild Warm (A-M-W), Arid Cool Very Warm (A-C-VW). Then the water footprint was calculated and evaluated in each climate for all three components as blue, green and gray water. The results showed that the highest amounts of blue water footprint are seen in the central and southern parts of Iran. The highest amounts of green water footprint was seen in the northern and western parts and the maximum gray water footprint was for the southern parts of the country. The average of green, blue and gray water footprints was obtained respectively as 503. 3, 1392. 8 and 286. 2 m3/ton over the country. The results showed that wheat crop cultivation was not recommended in A-C-W and A-CVW climate zones of Iran.

For an efficient management of the water resources the evaluation of the interactions between surface water and groundwater is essential. Dezful-Andimeshk plain, as the largest and the most important agricultural plain in Khuzestan province, are experiencing increasing demand on surface water and groundwater resources for the agricultural use. Accordingly the assessment of the relationship between aquifers and rivers for the proper management of water resources in this plain is of great importance. To this aim, this study applied cluster analysis to determine the interactions between groundwater resources and surface waters in the designated plain. In this study, the qualitative parameters of 37 groundwater wells and 3 hydrometric stations associated to Shavour, Dez and Karkheh rivers were investigated in normal, dry and wet periods. EC (Electrical conductivity), main cations (Ca2 +, Mg2 +, Na+, K+) and major anions (Cl-, HCO3-, SO4 2-) were assessed in water samples. Then, using cluster analysis, the similarity between stations was determined and the dendrogram indicated three distinct groups. The first group demonstrated the similarity between the Shavour river, Dez river and the right-hand seafront aquifer. The second group denoted the qualitative repository wells in the southern plain and the third group reflected the similarity of the Karkheh River with the wells neighboring the river. Results have shown that Dez River recharge directly affects the quality of the aquifer in the plain. Also it seems that Karkheh River has the least similarity to the surface water and groundwater resources in the plain.

This study was carried out to evaluate the economic and technical effects of climate change on the agricultural sector of Gharehso basin in Golestan province. In the first part, using the IHACRES rainfall-runoff model and rainfall, temperature, and monthly runoff data during the base period (1994-2010), the Ghareso river flow was simulated during the period of 2011-2040. Then, the probabilistic status of water resources allocation and provision of agricultural sector was evaluated by WEAP model. In the second part, in order to reduce the negative effects of climate change on the agricultural sector, using the goal programming economic model, optimal cultivation with the goals of minimum water consumption and maximum future profits was determined. The results of the first part showed that runoff decreases in the upcoming periods by 31. 34% compared to the base period. In addition, the results of the WEAP model indicate an increase in the unmet need of the agricultural sector in the region under study. This result suggests that with the continuation of climate change in the future to reduce the negative effects in agriculture, the region's cultivation pattern should be changed to remove cotton and increase the area of barley and rice. These changes were identified in the results of the second part of the model through the Goal Programming Model. In the optimal cultivation pattern, the gross profit of farmers in the studied area in the period of 2011-2040 increased from 1386 billion Rials to 1991 billion Rials compared to the base year. It is suggested, since the results of the Goal Programming Model have included conflicting objectives (minimizing water consumption and maximizing profit and cultivation area), its results (changed cultivation pattern) should be used as a guide for decision makers.

The Karun basin is one of the most important water supply sources in the country. However, no comprehensive study has been done on rainfall and river flow in this basin. According to importance of subject, in this study the trend changing of rain and river flow of the Karun basin in 74 meteorological stations and 46 hydrometric stations in three monthly, seasonal and annual periods using non-parametric mann-kendall test (TFPW-MK). The results showed that the trend of more than 82 percent of the stations on annual basis are descending and. On monthly scale, the most precipitous months of the year (Day, Bahman and Esfand) have decreasing trend, and the trend of more than 99% of stations in the month of Esfand (73 stations) having a decreasing trend. On seasonal scale, 50. 5% of annual rainfall in the basin occurs in the winter. In this season trend of more than 45 percent of the stations (32 stations) in the winter season are descending trend rates in significant. Due to the decreasing trend of rainfall variation in the catchment area, the river flow should be reduced, and the results of this research confirm this point. The results showed that the trend of more than 82 percent of the stations on monthly basis are descending trend and 63 percent of the stations are descending trend rates in significant.

In recent years, due to frequent droughts and water scarcity, artificial recharge projects are recognized as an operational solution to overcome the water scarcity. Despite the effectiveness of such projects to develop region, there is no information about their impact on the environmental sustainability. In this research, the artificial recharge project of Katuyeh (Larestan-Fars) has been ecologically evaluated by the forest, rangeland and watershed management method over two different periods (i. e. before and after implementation of the project, 2009-2016). For this purpose, 4 criteria and 18 indicators (six water indicators, five vegetation cover indicators, three land use indicators and, four soil indicators) were selected based on experts’ opinions, data availability and consistency of the indicators with the ecological condition of the region. In order to weighing the criteria, expert's opinions were used in Delphi method and Snowball framework. The results showed that the sustainability of the development of the region from environmental view after the implementation of the project has changed significantly before its implementation, the region with a moderate degree of sustainability before implementation of the project has achieved a good degree of sustainability at the time after the implementation of the project. The sustainability upgrade has been made with a slight slope. Therefore, it can be concluded that the construction of the artificial recharge project has been able to improve the environmental sustainability of the area.

Leading towards sustainable water use and optimal allocation of water resources, water banks are efficient institutions. Water banks facilitate the trade of surface water and groundwater and engender water security. This study develops a couple agentbased groundwater model in NetLogo platform to assess economic and hydrologic impacts of water bank's water buyback programs in the case study of Rafsanjan Plain. Results show that buyback programs can temporarily ameliorate the condition of the Rafsanjan Aquifer, so there is a need for taking other measures, like the cap-and-trade policy, in conjunction with buyback program. The drawdown of aquifer's unit hydrograph reduces from 80 to 58 cm per year owing to the buyback program. Moreover, the water bank improves the economic situation of the area as it increases the farmers' net benefit by 6 percent.

After construction of dams according to different needs, the most important issue addressed by the exploiters and researchers is the issue of optimum operation management of reservoirs. In recent years, various meta-heuristic optimization techniques have been used for the reservoir operation optimization. In this study, an improved version of Charged System Search algorithm is presented to enhance the exploration ability and escape from local optima. For this purpose, a special mutation operator is used and a Mutant Charged System Search algorithm is introduced. Then, the validation and evaluation of the efficiency of this new improved algorithm are compared with other well-known meta-heuristic algorithms in solving the mathematical benchmark optimization problems. The new method achieves optimal results for 17 functions out of 18 functions. The proposed algorithm is used to solve two benchmark problems of operations of multireservoir sestem, namely four-and tenreservoir sestems. Accordingly, the best values are obtained 308. 29 and 1194. 23, respectively. Finally, the efficiency of the algorithm for optimizing the operation of the two-reservoir system (Gorgan-Rood basin dams) is evaluated using various performance evaluation criteria. The results show the proper performance of the CSS algorithm and its mutated version in solving the multi-reservoir operation optimization problems. According to the results, the best solution achieved by the proposed algorithm is 0. 22. Also, this algorithm showed the best performance by providing 94. 63% and 95. 30% of total demands of Golestan-Voshmgir multi-reservoir system.

Generation of electrical energy requires water as well as water conveyance and treatment to energy. For encounter to challenges and uncertainty about the water and energy nexus, requires to understand the nature of this linkage to identify, approve and execute the appropriate policies. The aim of this study is the evaluation of water and energy nexus at freshwater production by SWRO desalination. For this purpose, assuming that the electric power supplier for the desalination plant is a thermal power plant with a cooling tower or once-through-cooled, the specific water withdrawal in a thermal wet tower-and once-through-cooled plants using S-GEM model and specific energy consumption in RO plants using solution– diffusion model was calculated. The results indicate in the production energy sector, the practical power effect on fuel consumption and consequently water withdrawal. Also, in the desalination plant, the physio-chemical parameter, and temperature of feed water, and ERD type effect on specific energy consumption. Finally, the indirect volume of water withdrawal, fuel and thermal energy consumption to produce a cubic meter of desalting water was obtained which could be used by effective institutions to better manage the supply and demand of water and energy.

There are several approaches for flood hazard mapping and prioritization, but the distributed and GIS-based methods are amongst the best and widely used. On this basis, in this study a new distributed method is applied which considers the interaction between the effective factors. By using a linear combination the flood hazard map is created for the study area and divided into five classes including very high, high, moderate, low and very low flooding hazard potential. Verification of this approach by using recorded destructive floods at different hydrometric stations indicated that the performance of this method, especially on identifying areas with very high and high hazard levels, is very remarkable. For example, the results of distributed approach in Shirgah-Talar, Razan-Noor, SoleimanTange, Ghoran-Talar and Doab-Challos hydrometric stations are fully matched with recorded historical floods most of them have over 50-year and 100-year return periods.

To estimate the potential damage by a flood event it is essential to calculate the depth of water. Hydraulic methods for flood routing and calculation of water depth is time-consuming, complex and costly due to the need for river sections at appropriate distances. The use of hydrological methods such as the linear Muskingum method for flood routing, in addition to its simplicity and low cost, offers an appropriate accuracy. So far, the linear Muskingum method has been used to calculate the outflow hydrograph while in economic analysis and flood damage estimation and flood management and engineering, calculation of depth changes over time is of great importance. Therefore, in the present study, using the linear Muskingum method and the PSO algorithm the variation in the downstream depth of water (instead of outflow discharge) have been calculated over time for the river reach between the hydrometric stations of Mollasani and Ahwaz on Karun River. The new method presented in this study presented a good accuracy with more simplicity and less cost compared to the hydraulic methods.

In this study, the Meymeh River was selected with regard to the construction of a reservoir dam in its direction, with the aim of determining the effective factors in decreasing water quality and providing curative solutions. For this purpose, with field investigations, sampling stations (35 stations) were determined along the path of the river and for one year (96-95) the monthly discharge, EC and Temperature were measured at the selected stations. In the following, after the samples were transferred to the laboratory, also their physical and chemical properties were measured. The results showed that the water quality of the river decreases gradually from the upstream to downstream of the river, due to the arrival of the water of the Sulfur Springs and the Syvol River with an average annual electrical conductivity of 21600 and 77750 μ s/cm respectively, the electric conductivity of the river arrives to more than 23, 000 μ s/cm. Therefore, after the confluence of the Sarkadeh to the Meymeh river, the electrical conductivity of the Meymeh river arrives to more than 11, 000 μ s/cm. To solve this problem, establishment of channels in the salt zones, suitable infrastructure, construction of tunnels and pipelines to transfer water of the salinity factors to the downstream of Meymeh dam were suggested.

In this paper, the paper entitled “ Evaluation and Comparison of Different Methods of Reference Evapotranspiration Based on Mass Transmission Methods in Iran and Its Zoning by Using GIS” by H. Ghamarnia and Z. Niazi, Iran-Water Resources Research (Fall 2018, Vol. 14, No. 3, Pages 318 to 338), is discussed. After a brief introduction about the importance of the topic, the advantages and disadvantages of the issue are discussed.