IRAN-WATER RESOURCES RESEARCH
Year:2020 | Volume:15 | Issue:4 |Papers Count:33

In this study, a method has been developed that, through optimized selective withdrawal and release of contaminated water from lower level of the dam, helps reservoir water quality improvement and downstream water quality preservation. In the present study, the two-dimensional model CE-QUAL-W2 was used to simulate the reservoir water quality processes. The model was then combined with particle swarm optimization algorithm. This common simulationoptimization approach was able to find optimal operation policies to improve water quality inside and downstream of the reservoir. In order to increase the efficiency and reduce the computational time of the model, the reservoir quality simulation model was replaced with an artificial neural network model. The performance of the developed methodology was evaluated for a real case for a 2-year simulation period. Different scenarios for the reservoir operation were considered and using the simulation model (meta model), the concentration of the index pollutant was calculated and ultimately optimal operation policy of the reservoir was determined. The results showed that for the optimal operation policy the average amount of dissolved oxygen in reservoir outflow was about 25% higher than the current operating conditions. Also the status of the reservoir was improved to low eutrophication state in most of the months in comparison to the existing condition in which the reservoir eutriphication state is high in some months like June. The comparison between dissolved oxygen concentrations of the reservoir outflow in optimum operation policy with the existing operational conditions showed high efficiency of the proposed method and its significant effect on improvement of the reservoir water quality.

This paper studies the performance of Model Predictive Control (MPC) algorithm in improving the management of reservoirs in water transfer line. MPC is an optimal modern control which due to its proper function against sudden disturbances has been developed for engineering control problems. One of the main capabilities of the predictive control algorithm is the prediction modeling of the system in optimization function. This feature makes the designed controller for the system, with aware of the condition of system, in the future intervals, set the appropriate inputs to get the system’ s goals. In this research with using a predictive control algorithm while applying the constraints regarding reservoir and pump stations capacity, an optimal controller is designed for the Zarinehrood water transfer line to Tabriz. This network contains a total pipe length of 180 kms with 24 branches which is known as the largest transfer line in the Middle East. In this research the designed controller has been solved for the two objective functions, maintaining the safety water in the reservoirs and reducing the fluctuations in the pump stations. To evaluate the predictive control algorithm performance, the results of the MPC were compared with operator data (observed) and another control method called linear quadratic integral control algorithm (LQI). The obtained results show that the predictive control has been able to perform better than operator data and linear quadratic integral control. While yields high capability to satisfy all constraints while fluctuations in pumping stations have been decreased about 22% and the water in the reservoir tanks maintain the lowest error in the vicinity of the desired volume. Furthermore, the total amount of pumped water over the length of the transmission line has been decreased by 8% which indicates the better performance of the proposed controller.

One of the main responsibilities of water and wastewater companies in the field of operating of water distribution networks (WDNs) is the management and control of leakage from these networks. In this regard, active leakage control is one of the main strategies in reducing leakage and achieving economic level of leakage (ELL). In this paper, a practical methodology was developed to determine the economic level of leakage which is included the steps determining the points of pressure and flow rate measurements, collecting of required field data and cost data, the estimation of leakage level in the network and the determination of the economic level of leakage of the network based on the active leakage control strategy. Economic performance indicators such as the economic leakage index (ELI) and the economic network efficiency (ENE) are also obtained using the determined ELL. The developed methodology was applied for a district of the WDN of Mashhad. The results showed that the economic level of leakage in the study area is 27. 5 m3/connection/year. While the current level of leakage was estimated to be around 49. 2 m3/connection/year, based on the minimum night flow (MNF) analysis. Moreover, the ELI and ENE were calculated 1. 79 and 56% respectively. The developed methodology in this paper can assist practitioners and managers of water and wastewater companies for target-setting of the level of leakage and determining of the ELL based on it.

River discharge modeling is one the fundamental challenges of researchers and engineers over the past decades. Although using hydrological models is one of the best ways, but the lack of observed flow datasets for calibration of these models restricts the applicability of them in most catchments, especially in ungauged river basins. On the other hand, due to increasing satellite-based technologies over the past years, several remotely sensed datasets such as precipitation, temperature and surface soil moisture have been developed and because of having different spatiotemporal resolutions are interested by most researchers. This study addresses the efficiency of ASCAT surface soil moisture (SSM) for calibration of VIC-3L hydrologic model over the Sefidrood river basin (SRB). Findings on daily time scale indicate that the correlation coefficient (CC) between observed and simulated streamflow, using ASCAT dataset, is equal to 0. 75, while in the case of calibration of the VIC-3L model using only with hydrometric station datasets the CC value is equal to 0. 80. Moreover, at monthly time scale the performance of model in simulating streamflow is better than daily time scale. The relative error (RE) in simulating runoff volume at daily and monthly time scale is 17. 2% and 38. 5%, respectively and this shows that using ASCAT dataset at monthly time scale leads to reliable results. In addition, one the advantages of model calibration using satellite-based SSm is the extraction of the spatial pattern of model parameters over the catchment, while in the case of using observed discharge dataset for calibration of the model only leads to the constant values of model’ s parameter through the catchment. Based on the results of this research it highly recommended to use satellite-based SSMs for calibration of hydrological model, especially in data limited areas or regions in which ground observations are sparselydistributed or insufficient.

In recent decades, the unprecedented lack of water resources, contamination and ecosystem degradation in many parts of the world have forced researchers and policy makers to devote more efforts to maintain and restore the health of water associated systems to achieve a balance between human and nature. Human efforts to maintain full natural flows have had implications on the functions and biodiversity of river systems. Lake Bakhtegan and Kor River have been degrading in recent years due to the lack of environmental protection efforts. The purpose of this paper is to provide a comprehensive top-down methodology for assessing the environmental flow of Kor River. Adopting the methodology based on the system dynamics approach, the paper will estimate the environmental flow requirement of the river under different scenarios and explores its consequences on the socio-economic part of the basin. It was observed that by supplying the water needed by the natural system, the resources available for economic development would decrease, impacting particularly the level of agricultural development. The current trends which are dominating the basin will result in deterioration of water resources and complete destruction of ecosystems.

Recent advances in numerical weather and seasonal forecasts, make the water resources manager and operators very interested to involve the forecasts in real operation. Generally in the studies, the skill assessment of the forecasts would be done by comparing the forecasts with station gauge or gridded data which maight not reflect the real skill of the forecasts in basin scale. In this paper, the forecasts generated by the Noaa climate forecast system version 2 (CFSv2) were evaluated in the Dez dam basin. A combination of rain gauge data with satelite base precipitation estimates( Persiann-CDR) were used as the basis of evaluation. Result showed monthly precipitation forecasts with lead 1 has the best performance based on R and ROCauc although the underestimation is higher than other leads. Evaluation of the forecasts in 3 different percentile including below normal, normal and above normal, showed well performance in percentiles above 0. 6 and below 0. 4, also best monthly forecast performance with lead1 was 0. 88 for Nov, 0. 66 for Dec and 0. 8 for Mar respectively for percentile of category 1 to 3 based on ROCauc. Winter precipitation evaluation based on the SPI with 5 category, suggested that 50 to 60 percent of the times, the exact category was truly predicted while with on category difference the accuracy imrove up to 80 percent of the times.

In this research, with the aim of maximizing the income of Lake Urmia basin, a linear optimization model was developed to apply three kinds of constraints, including cropping pattern, available water and constant prices and price elasticityof agricultural products to optimize crop production and net imports of crop’ s virtual waterunder 18 scenarios. The considered constrains in optimizationwere consumed virtual water in the basin, available water and boundaries of increasing or decreasing in the crop production. Regarding the number of studied crops, results have a wide variation but in general, for farm crops and horticulture products, the largest changes in production and net imports of virtual water (comparing to the present condition) were observed for onion, mushroom, apple and grape. In examining the changes in basin income due to the implementation of developed scenarios, it was found that the scenario in which the available water is 60% of the present condition and price elasticity is applied has the highest profitability and is considered to be the most favorable scenario. Altogether, with the application of the proposed scenario, the optimum level of areas under cultivation is less than present for more than a third of the products, and the imports of these products should be increased for the basin. According to the results of this research, the pressure on the water resources of the basin will be reduces by importing virtual water.

Urban water demand prediction has been one of the contemporary concerns of modern urban societies. In this vein, many studies have been carried out comparing the performance of different models. By the introduction of artificial neural networks (ANNs), the discussion about the accuracy improvement of ANNs using wavelet transforms (WTs) was heated up. In many research, the effect of using WTs on the performance and the accuracy of ANNs drew many attentions. However, the effect of using WTs on the uncertainties associated with ANNs has not been investigated. In this study, the performance and the uncertainty of two ANN-based models, i. e., nonlinear autoregressive network with exogenous inputs (NARX) and extreme learning machines (ELM) were studied and the wavelet version of those, i. e., W_NARX and W_ELM were used for the prediction of urban water demand of Mahdie Residential Complex. The results indicated that NARX (regression coefficient (R) of 0. 955) is more accurate than ELM (R of 0. 787). On the other, the WT version of these models had the R of 0. 960 and 0. 847, respectively, indicating the outperformance of W_NARX model. The reason for the lower accuracy of ELM could be found in the complexity of the water consumer behavior and the simpler structure of ELM than NARX. Besides, the implementation of WTs had a positive effect on both models, but ELM more. The results of the uncertainty analysis of both models indicated a decrease in uncertainty. However, this was more considerable in W_NARX with the confidence interval of 98. 75%.

Predicting discharge prediction through modeling is inherently associated with important uncertainties. Then uncertainty in hydrological modeling is mostly reduced by increasing the quality of inputs, improving structure of models, and data assimilation. Even if we assume that the physical structure of the model is perfect, uncertainties in parameters, forcing variables and initial conditions will be reflected in the simulation results through complex error propagations. One of the actions that can be taken toward reducing uncertainty in hydrologic predictions is data assimilation. It provide a superior hydrologic state estimate by considering input and observation uncertainties. In the current study, the efficiency of assimilating stream-flow into a hydrologic model using the Ensemble Kalman Filter (EnKF) in the Roudak catchment is investigated. Four evaluation criteria including NSE, KG, LNSE, DCpeak are applied to estimate the predictive performance of results. Results show that EnKF improved estimated stream-flow compared to an offline calibration with SCE-UA as NSE, KG, LNSE, DCpeak are increased by 13%, 5%, 17% and %94 respectively. Also one-day ahead prediction of stream-flow could be estimated by acceptable accuracy.

Understanding complex relation between natural and human systems and dynamic co-evolution of human and water, is of great importance in planning for sustainable development. In the last decade, comprehensive recognition of such systems has been achieved through the historical study in sociohydrology science. This paper aims to apply sociohydrological aspects and investigate co-evolutionary history through the historical study, as the first step to understand coupled human-water system. To this aim, Mashhad basin was selected as one of the most important and complex basins in Iran, especially in the east of country. In this paper, when the stages of the historical socio-hydrology study had been classified, historical sequence of natural events/ human activities and changes of socio-hydrological components in Mashhad basin were investigated. Based on results, during the contemporary period, we recognized two periods of 1921 up to now, and 1966 up to now as expansion and contraction phases, respectively. Indeed, despite the contraction conditions, development has continued; obviously, the basin has not yet entered recession and recovery and new equilibrium phase. Finally, a perceptual model was developed to understand socio-hydrological system of basin where water resources quality and quantity and water demand are the most important internal forces, and hydro-climatic components are the most important external forces which effect on the coupled humanwater system co-evolution.

Heteroscedasticity as determining concept challenges the calculation and efficiency of mean precipitation at the extent of Iran territory. This inefficiency leads to emergence of error during calculation of annual water budget and of problem in water resources of country. Accordingly, in this study, building on the Masoodian climatic classification and investigating the precipitation data from146 synoptic stations at four temporal scales-heavy rain, semi-heavy rain, pre-precipitation, and low rain-the effect of Heteroscedasticity on mean precipitation were investigated by Levene Test. The results showed that besides the precipitation data have a normal distribution across all climatic regions, but the existence of limiting precipitations as outliers data, very high-variances and the variation of precipitation regimes from some station of a climatic region, resulted in rejection of null hypothesis of Levene Test and most of climatic regions are encountered Heteroscedasticity. Consequently, use of mean index could not provide complete recognition of precipitation status and precipitation distribution. Hence, to achieve an efficient mean of annual precipitation in country, it is necessary to do practice to enhance the calculated mean precipitation in climatic extent, with avoiding calculating mean at territory extent, and by accomplishment of improved climatic classification at watershed basin scale, gains better recognition of precipitation behavior at any climatic extent, and at whole territory extent in Iran.

In this paper, point prediction and prediction intervals (PIs) of artificial neural network (ANN) based downscaling for mean monthly precipitation and temperature of two stations (Tabriz and Ardabil in North West of Iran) were evaluated using general circulation models (GCMs). PIs were constructed by novel Upper Lower Bound Estimation (LUBE) method in which an ANN with two outputs was constructed for estimating the prediction bounds. Also, Bootstrap method as a classic technique for assessing uncertainty of ANN was used to further examine the proposed LUBE method. In this way, the accuracy of PIs was quantified by coverage and width criteria. Three GCMs, Can-ESM2, BNU-ESM, INM-CM4 and ensemble-GCM (ensemble of mentioned models) were used in four grid points around each of station for evaluating ANNbased downscaling of precipitation and temperature parameters. Comparison between the results of two methods indicated that LUBE method could lead to more reliable results than the Bootstrap method. PIs width and coverage probability were 10% to 40% lower and 2% to 10% higher than the Bootstrap method for different GCMs, respectively. Ensemble-GCM led to more accurate results so that computed PIs width and coverage probability were 10% to 60% lower and 2% to 20% higher than those for the single GCMs.

Water resource planning models traditionally incorporate hydrologic, water allocation and economic modules whose parameters should be properly estimated. This paper focuses on calibration of a water resource planning model. Our methodology includes three main parts: 1) development of a water resource planning model using WEAP software for Zarineh and Simineh River Basins located in Urmia Lake Basin in Iran, 2) application of VARS algorithm for sensitivity analysis of parameters of the developed model, and 3) usage of Many Objective Particle Swarm Optimization (MaOPSO) algorithm for model calibration and parameter estimation. It is worth mentioning that many objective optimization algorithms are utilized for problems with more than 3 objectives and here in this study we intend calibration of 7 objective functions defined based on Nash-Sutcliffe efficiency indices calculated in terms of residuals of time series of simulated and observed values of river discharge at stream gauges’ locations, dam reservoir’ s storage volume, and aquifers’ storage volume. Furthermore the model’ s parameters includes allocation priority, consumption rate, maximum withdrawal, and parameters of elevation-volume curves of aquifers. Sensitivity analysis using VARS algorithm shows that there are 17 influential parameters from total 27 parameters which are considered in calibration phase. To evaluate performance of MaOPSO, its results are compared to results derived using multi-objective PSO, which shows that MaOPSO has better performance dealing with such a complex problem.

Several relations have been presented to estimate the flow discharge passing the straight compound channels, most of which result in acceptable results in the experimental conditions, but are not accurate enough to be sued in the case of the field studies. In the present study, the Particle Swarm Optimization Algorithm was used to analyze the experimental and field data of the compound cross sections and a new relation was presented to estimate the total discharge passing the compound cross section. In the new suggested relation, in order to estimate the equivalent roughness coefficient of the compound cross sections, in addition to the relative depth, relative width, relative hydraulic radius and relative roughness (the ratio of the mentioned parameters in the floodplains to the main cross section), a new definition of the Reynolds number was used. The results showed that the proposed relation, with an average absolute relative error of 10. 4, could properly estimate the discharge in the compound cross sections so that the average absolute relative error decreased by about 38 percent in comparison to the previous studies performed by other researchers.

Rasht is one of the richest cities in rainfall in Iran, and because of collecting rain from the roof of the buildings a considerable amount of water can be stored, then designing and implementing of rainwater collection systems in Rasht can collect and save a significant amount of rainwater for usages like: green-space irrigation or Non-drinkable usages as whole. The catchment bank (rainwater storage bank) is the most important and expensive component of Rainwater Harvesting System (RWH) implementation on the roof of residential buildings. The reliability of these storage banks was estimated between 100% and 82% in three years of wetness, drought and normal index. The demand amount of this research is considered equal to the water needed for the irrigation of the cultivated grass in the green space of each building in the hot seasons. Then, we have estimated the optimum volume of storage bank using mixed integer linear programming method in LINGO. 17 software for each of the buildings considering the expected reliability coefficient of the storage banks (70, 80 and 90%). These volumes are between 1. 18 and 13. 49 cubic meters in three years of wetness, drought and normal index with different reliabilities. Finally, we have estimated the storage bank volume of each demand for one of the roofs in different demands and the results were calculated between 0. 55 and 5. 26 cubic meters.

Due to the relative constraints of water resources and excessive over-discharge of groundwater resources in the plains of the country, integrated water resources management is essential. Present study carried out to assess artificial recharge and flood spreading scenarios for integrated water resources management using WEAP model in Varamin plain. The required data, including the discharge of stream flow gauge of Shoor and Jajrood rivers, the volume of the Latian and Mamlu dams, rainfall, evaporation, population, population growth rate, water demand of drinking, agricultural and industrial sectors of the area in the base year of model (2016-2017) were gathered and entered in the software. Then, the artificial recharge scenario was developed and compared with the reference scenario in a 20-year period. The results showed that if the current status of water resources management continues, in the next 20 years, we will not be able to cover 16. 2 and 27. 4 percent of the water demand of agricultural and industrial sectors in Varamin plain, respectively. Whereas, if 33 million cubic meters of surface water streems of the region are injected to the aquifer by flood spreading method, annually, not only, 9. 2 and 17. 9 percent decrease in unmet water demand of agricultural and industrial sectors in comparison with the reference scenario, respectively, but also, based on current harvest volumes; the average of the aquifer storage increase from 351 to 388 million cubic meters, which will decrease the loss of groundwater resources of the region 1. 21 centimeters daily by the average 20-year period.

The unsustainable development and imbalance between supply and demand of water and its intensification in climate change are the most important issues in water resource management in Iran. This reveals the need to consider climate change on renewable water sources and water use. Therefore the current status and climate change of the basin have been assessed by integrating a comprehensive basin simulation approach using the SWAT model and the water footprint assessment framework. This framework used for assessing the stability of the basin and its potential impacts on water resources, agriculture and the environment. Therefore, assessment of basin status and climate change was carried out by calculating green water, blue water, groundwater and environmental sustainability indices. Simulation and analysis of the water resources system and agricultural sector under the climate change condition were done during the period (2017-2046) coupled results of three general circulation models under the three emission scenarios of RCP2. 6, RCP4. 5 and RCP8. 5. Evaluation of the sustainability indicators in the current situation indicates the instability of groundwater and the environmental requirement of Lake Tashk-Bakhtegan. The results also showed that under climate change conditions, the hydrological basin status will be more critical. This is mainly due to the increasing burden on the water resources of the basin due to the increase in water footprint (6 to 16%) caused by changes in the water requirement of agricultural crops in the basin. This, coupled with the 8 to 18 percent reduction in available water in the basin under climate change, indicates a worsening of the water stresses in the basin. In these conditions, the most important measures are to reduce the water footprint by reducing the consumption considering the potential of water resources.

Urbanization growth, increasing population and water demand, especially the increasing demand for drinking water in Iranian cities, particularly metropolises, have created a great challenge for water resources management in the country. Optimal use of effluent in urban water management prevents the inter-basin water transfer plans from being tolerated and consequently reduces heavy costs and reduces negative social consequences. In this paper, an extended model for planning, management and optimal allocation of municipal effluent by mapping the network flow and applying optimization methods is introduced. The objectives of this model are to minimize the total cost of the system by considering the technical, economic and environmental constraints as well as minimizing the use of existing raw water. By solving an application problem, the model's performance is verified and its validation is achieved by using MATLAB optimization software. This model can facilitate the policy making and decision making of managers in the licensing of municipal effluent allocation.

The Iranian civil code under the influence of Fiqh-e-Imamiyyah, accepts the possibility of private ownership of water. Nevertheless, in order to control of overexploitation of water resources The Law of Water and Its Nationalization in 18 July 1968. In this law, while abandoning the private ownership of water, the public ownership of this vital fluid was accepted. In the same way, the concerns of maintaining public and national interests after the Islamic Revolution caused the enactment of article 45 of Constitution. In this article the water was recognized as a public wealth that shall be being at the disposal of the Islamic government to utilize in accordance with the public interest. Afterwards, in order to enforcing of this article, the law of the law of Fair Water Allocation was passed in 7 March 1983 and has stabilized the public ownership of water. The plurality and sometimes the conflicts of the legal texts of this domain has been led to ambiguity of the legal system of ownership of water resources and to disagreements. This article is aimed to examination of legal system of water resources ownership with a comparative study in Fiqh-e-Imamiyyah and French law. The results of this research shows that such as France, the water is a sort of public goods in Iranian law system. Consequently, instead of regarding the law of water as a matter of private law that is able to be a subject of private ownership, it should be considered as a subject of public law.

Population growth and the development of industrial and agricultural activities have led to the increasing demand for more water resources. One of the ways to compensate for water scarcity is Inter-Basin Water Transfer (IBWT). Over time and with the progress of implementation of these projects, numerous challenges such as environmental, economic, social and technical issues have arisen in a variety of areas that make difficult to decide on their implementation and selection. For this purpose, it is necessary to identify and prioritize effective criteria and indicators more precisely of these projects. In this paper, the criteria and indices were first classified by Delphi method into 8 main criteria and then they were prioritized by ANP and AHP. The results showed that the priority of the main criteria that in both methods were the same and the normal weight of political-security, health and environmental criteria is 0. 36, 0. 16 and 0. 15, respectively. In AHP, transmission options aimed at supplying urban, agricultural, industrial and environmental water are 56%, 17%, 16% and 11%, respectively. But in the ANP, drinking water is the first priority with 56 percent, followed by industrial water with 18 percent, agricultural water with 14 percent and environmental water with 12 percent, respectively. The results show the accuracy and precision of the use of the ANP model in ranking among different alternatives in any inter-basin water transfer projects.

Nowadays, balancing the water allocation to environmental and other demand nodes is one of the most important issues in Iran. For instance, an important reason for the critical situation of the Lake Urmia is lack of proper allocation of water for different demand nodes (i. e. the required water allocation for Lake Urmia). It is also important to consider the implications of lake water allocation to agricultural, environmental, municipal, and industrial demand nodes. This paper intends to quantitatively evaluate these effects in the Lake Urmia basin on different demand nodes such as Lake Urmia over 60 years under different water allocation scenarios in the context of sustainability. For this purpose, three well-known performance criteria such as reliability, resiliency, and vulnerability were evaluated for East Azarbaijan, West Azarbaijan, and Kurdistan provinces and also Lake Urmia. In the next step, using the intelligent decision system (IDS), the grade-based sustainability of water resource management scenarios in the Urmia Lake basin was investigated. The results showed that full allocation of the Lake Urmia water requirement resulted in reduced water allocation to the agricultural sectors which may have different socio-cultural-political consequences. In spite of decline of water allocation for the agricultural sectors in the first scenario (full allocation of Lake Urmia water requirement), this scenario was chosen as the top scenario with sustainability (utility) of 0. 94. This index for the second scenario is 0. 83. Finally, it is suggested to further evaluate the sustainability of the agricultural sectors by implementing corresponded different management options.

Domestic wastewater produced in bathing, washing clothes and other similar water use is called greywater. Greywater is far less contaminated than wastewater produced in toilets and can be reused on site with little or no treatment in non-potable applications like toilet flushing and landscaping. The On-site Greywater Reuse system has various strengths and weaknesses and, in addition, there are opportunities and threats for this system in Iran. The present research systematically identified and prioritized the strengths, weaknesses, opportunities, and threats (SWOT) of On-site Greywater Reuse in Iran by combining the SWOT analysis with the Fuzzy Analytic Hierarchy Process (FAHP) and referring to the experts' opinions. Results suggested that the negative external factors (threats) enjoyed higher relative importance and, consequently, would have greater influence on the development of this system in Iran. However, since the strengths and opportunities ranked second and third in importance, it seems that this system will have a clear future if the appropriate ST strategies. Strategies that use the system's strengths to try to neutralize the impact of external threats.

In this study, flood control projects in the Karun River were evaluated using bifuzzy and fuzzy multi-criteria group decision making model. For this purpose, four main criteria of economic, environmental, social and technical and fifteen subcriteria were used. Then, optimistic and pessimistic scores were used to rank the projects according to different subcriteria. The results showed that the economic criteria with fuzzy weight of (0. 202, 0. 310, 0. 452) had the most impact on the evaluation process, and the technical, environmental and social criteria were ranked next. The results also showed that the overall ranking of flood control projects based on bifuzzy and fuzzy method is different. So that the ranking based on bifuzzy method as follows: Detention dam, diversion channel, dredging, dike, beach construction, and groyne. But based on the fuzzy method, diversion channel and detention dam have first and second priorities, respectively. So, based on the results of both methods, it is suggested that Khuzestan Water and Power Authority, as the proctor of Karun River, put the construction of detention dam and diversion channel in higher priority than other flood control projects and provide the funding needed to carry out these projects.

Droughts affected by climate change are among the most devastating weather events, causing significant damage both in natural resources and in human life. In this study, in order to investigate the effect of climate change on drought, both precipitation and temperature future period (2030-2050) were calculated with CanESM2 model under RCP8. 5 scenario in the Douganbodan station in Gachsaran city. Then, drought was evaluated with Standardized Precipitation-Evapotranspiration Index (SPEI) during the base (1985-2005) and future periods in different time series. Finally, severity and duration variables of drought were analyzed for the calculation of joint probability and return period with the multivariate copula function. The results show that monthly temperature under RCP8. 5 scenario has increased by 2. 2° C and precipitation has been reduced by 5. 5%. Drought evaluation results show that the number of dry and wet periods is reduced by increasing the length of the scale, but the longest period increases. Also, the number of drought periods relative to the base period have increased under the RCP8. 5 scenario. The Frank function was selected as the best fitted function with the mean values of the three fitting indicators, RMSE (0. 38), NSE (0. 9) and AIC (-101. 9). The results of analysis of joint return period of a drought event with a severity of 10 and duration of 10 months for the base period and RCP8. 5, respectively, were 5 and 4 years, that indicate a decrease in the return period of severe drought and their increase in future under RCP8. 5 scenario relative to the base period.

There are a number of aquifers in the northern half of Hamadan province that, deepening of water wells into the bedrock resulted in CO2 leakage into the aquifers. Groundwater level data near gas charged water wells indicating abnormal behavior in groundwater level fluctuation. Comparison of observation well hydrographs, variance inflation factor and field evidence in the gas charged and background areas shows that the observed abnormal behavior in water level fluctuation is not influenced by rainfall and groundwater pumpage variables. Due to high pH buffering capacity in the aquifers and decrease of PCO2 correlation with pH and TDS in the gas charged waters compared to the background ones, the main factor for increasing salinity in the gas charged waters is the intrusion of deep saline water with gas into the aquifers. In fact, the deepening of the wells into the bedrock, by lowering hydrostatic pressure, causes gas-rich saline water to enter the aquifer. As wells begin pumping during the irrigation season, the aquifer recharge rate by saline water exceeds the discharge rate of the wells, resulting in elevation of groundwater levels around the gas charged wells.

The agricultural sector is the largest consumer of water resources. Therefore, Sustainable water allocation to this sector is more essential. Surface and groundwater are both important sources for agriculture water supply. Previous studies have emphasized that the conjunctive water use of surface and groundwater can reduce the risks associated with uncertain surface water supplies and their fluctuations. The cyclic and noncyclic(traditional) storage systems are two main kinds of conjunctive water use systems. The main difference between these storage systems is their method of artificial recharge which in the noncyclic storage system, the artificial recharge only occurs during the spill, but in the cyclic storage system, the artificial recharge can occur any time. In other words, the regulated water is not allocated to artificial recharge area in noncyclic method. In the current study it was tried to quantize and compare Sustainability of water allocation in the agriculture sector with cyclic and noncyclic approaches. The results indicated that in the noncyclic operation of the system, the aquifer is recharged in wet season and its storage used in dry season. Therefore, by management and regulation of surface water in cyclic operation compared with noncyclic operation, the sustainability index increases from 0. 69 to 0. 86, respectively.

Runoff coefficient (RC) is included in the rational method for computation of runoff, and is used in water balance to measure infiltration and the excess rainfall. The RC is the percentage of rainfall which is made runoff, and depends on topography, slope, soil texture, plant coverage, and rainfall. These features alter temporally and spatially along the watershed. A semidistributive model, TOPMODEL is such that the topography of the hillslope and the contributing levels play the main role in runoff generation. It is also capable of computing soil moisture deficit at each point along the hillslope. In the current research, the effects of the hillslope topography on infiltration, temporally and spatially, and its spatial changes are examined using TOPMODEL and according to the topography. To this end, first, the parameters of TOPMODEL and its equations for complex hillslopes were developed. By combining with SCSCN model, the impact of geometry of complex hillslopes on RC was investigated. The runoff hydrograph of the hillslopes was scutinized using the rational method combined with the complex time-area model. According to the results, the divergent hillslopes have a smaller RC, as well as flood, than the parallel and convergent ones. Also, the convex hillslopes have smaller RC, as well as flood, with respect to the straight and concave ones. As for the convergent-concave hillslopes, the runoff is 80% more than that for the divergent-convex.

Climate change and global warming are the biggest challenges in the present era, which have affected the global and regional hydrologic cycles. Precipitation is one of the climate elements that has been directly affected by the rising global average temperatures. One of the most important negative effects of climate change is increasing the intense precipitation and henceforth occurring flash floods. The present study firstly analyzed the trend and jump of the short duration observed rainfalls (10 minutes to 3-hour duration) in the Mehrabad station located in the west of Tehran by using Mann-Kendal and CUSUM approaches, respectively. The trend test indicated an increasing trend in the short duration rainfalls amount at the 99% confidence level while 1978 was distinguished as the jumping year. For using dynamic downscaling to meet the fine spatial resolution required in the present study, the PRECIS regional model was employed to evaluate the changes in the intensity, duration, and frequency of the short duration rainfalls, derived from the daily rainfalls by applying a special time downscaling factor, after the year of the jump for historical data and also under the A2 and B2 emission scenarios for future. The results of the IDF analysis showed that in the far the future (2070-2100) the amount and intensity of precipitation would increase significantly over a given return period. There is also a significant increase in the frequency and probability of occurrence of extreme precipitation.

Iran's water management has been involved in the "command and control" chain. What is clear is that this approach has failed to produce social and ecological reliability in the country's water bodies with different functions. The sign of these instabilities is the occurrence and intensification of socioeconomic conflicts over water usage and access. In line with global efforts to overcome and overcome imperative imperial governance issues, validating the presence of social institutions in decision-making at governance levels is a serious challenge. This paper, while questioning the implications of the nature of the rule of command for multilevel governance, using the theory of "practice", will explain the social management of water-management-practice and articulates this tool in pursuit of sustainable water security. Then, with an example of successful and gives credit to Water Banking as a social practice as well. It is considered as a tool to show the meaning of social water banking and water management as a social practice at the same time.

In arid and semi-arid regions with limited surface water resources, the growth of different economic and social sectors requires sustainable management of existing water resources, especially groundwater resources. The Groundwater Footprint Indicator is a useful tool for assessing the sustainable use of groundwater resources and its associated ecosystem services. In this study, the sustainable use of 27 alluvial aquifers in the east of Urmia Lake at northwest of Iran has been investigated by groundwater footprint indicator. In order to integrate quantitative assessment along with the sustainability of water quality for agricultural use, an integrated groundwater footprint indicator based on GIS spatial analysis has been used for assessment. This assessment will assist water sector managers in adopting appropriate policies and measures for the sustainable management of the aquifer system, especially for the Urmia Lake basin, which has faced salting water problems in the adjacent aquifers. The results show that 20 alluvial aquifers have a GF/A greater than 1 and 7 alluvial aquifers have a GF/A equal 1 and no alluvial aquifers have sustainable use of groundwater resources. Also, 24 alluvial aquifers have iGF/A greater than one and only three alluvial aquifers have iGF/A equal one, indicating that most aquifers are contaminated by saline water intrusion and excessive aquifer withdrawal. As a result of the scenario of a 10% reduction in agricultural consumption, the 14 aquifers shift to a quantity sustainable use state. This scenario also contributes to the improvement of the iGF indicator and shifts the 10 aquifers to a quality sustainable state.