Iranian Water Research Journal

Abstract Municipal wastewater is the mixture of domestic wastewater, small amounts of industrial and storm water, drain water, surface infiltration, and ground water. It usually consists of a number of contaminants, such as suspended solids, biodegradable organics, pathogens, nutrients, refractory organics, heavy metals and dissolved inorganics. Direct discharge of untreated wastewater into the natural water bodies is not desirable, as the decomposition of the organic waste would seriously deteriorate the water quality. In addition, communicable diseases can be transmitted by the pathogenic microorganisms. Nutrients such as nitrogen and phosphorous, along with organic material can lead to excessive growth of undesirable aquatic life, when discharged into the aquatic environment, and can also lead to the pollution of groundwater, when discharged in excessive amounts on the lands. For these reasons, treatment of wastewater has become necessary for the protection of the environment, keeping in view public health, economic, social and political concerns. In recent years, various methods for eliminating pollutants have been investigated, in which the electrocoagulation process with proper removal efficiency and low sludge production is considered as one of the newest and most desirable methods. The purpose of this study was to evaluate the efficiency of removal of COD, BOD₅ and Coliform bacteria from wastewater of Urmia refinery using electrocoagulation method and optimization of the process. To do so, the effect of different parameters such as time of electrolysis, current density, pH, flow rate and conductivity of the solution was investigated. This experimental study was carried out in an electrochemical recirculating tubular reactor with an iron pipe as the cathode and some iron rods inside it as the anode. For sampling, the inlet of the Urmia wastewater refinery was considered. In order to increase the electrical conductivity of the aqueous solution, sodium chloride was applied as the electrolyte. After performing the electrochemical reactions, the treated wastewater was evaluated for clotting and COD and BOD₅ analysis. To determine the characteristics of the sludge the SEM and BET analysis was done. Results showed that, increasing the time of electrolysis increases the amount of metal and hydroxide ions produced in the anode and cathode of an electrochemical cell. Therefore, with the large amount of hydroxide flocs, the removal efficiency increases. With an increase in current density, the rate of removal increased, and then it did not change significantly, so it can be probably said that there is a limit to the rate of adsorption of pollutants to the flocs. It has been established that the effluent pH is one of the important factors influencing the performance of electrocoagulation process. The maximum removal was observed at a pH around of 7; considering the nature of the reaction between ferrous and hydroxide ions, this was not unexpected. When pH is lower than 4, Fe(OH)₃ is in its soluble form (Fe⁺³), and when it is higher than 6, Fe(OH)₃ is in its soluble form of Fe(OH)₄^-. Since Fe(OH)₃ has a major role in removing dye, when pH is 7, the rate of dye removal is the highest. With an increase in electrolyte concentration, electrical conductivity of the solution increases, and the voltage needed for accessing a certain value of electric current density decreases; less electric energy is also consumed. With an increase in the rate of the flow passing through the reactor, the removal efficiency decreases because the high flow rate of circulation of the solution in the reactor causes decrease in retention time of the solution in the reactor; therefore, the solution is not treated completely. The released cations from the electrocoagulation process lead to infertility of the negative electrical charge produced by the cell wall of the bacterium. The final optimum conditions during the electrolysis time 40 min, the current density 7.036 A/m², pH 7.8, conductivity of solution 1477 ms/cm and flow rate 1.97 L/min was obtained. In these conditions the removal efficiency 93% of COD, 94% of BOD₅ and 100% of Coliform bacteria was determined, which is completely agreeable with the environmental standards. As it is evident, the size of the constituent particles of the sludge as a cluster is about 0.1 mm. Based on the results of BET analyses, the specific surface area, total pore volume, and mean pore diameter of the sludge are 56.4 m²/g, 0.27 cm³/g, and 19 nm, respectively. 

Abstract Approximately, 94% of the total water renewable sources is allocated to agricultural. The total irrigation efficiency in this section is estimated to be less than 43%. The water consume efficiency can be increased using new irrigation methods. Correct selection of irrigation system is an important section in optimal operation of water resources. The necessity of paying attention to the characteristics and limits of irrigation systems, the physical and chemical properties of water and soil, and the environmental, economical and social consequences, cause the irrigation system selection to become a relatively complex problem. The semi-portable sprinkler irrigation systems that are categorized as pressurized irrigation systems have not been evaluated in some areas of Markazi province. Although, these systems are previously evaluated in some areas such as Arak Plain, but due to the long time span and increased cultivation area, re-examination is needed. Therefore, the performance of 10 semi-portable sprinkler irrigation systems was investigated in Arak, Shazand, Khondab and Kamijan areas. This research includes collecting fundemental information, field measurements and software calculations. An anemometer was used in order to determine the wind speed. The samples were taken and sent to the laboratory before the experiment, in order to determine the both physical and chemical peroperies of the soil such as soil moisture. All testing fields were carried out during the irrigation andwindless or low wind speed days. In each test, system’s hydraulic variables, such as sprinklers pressure, were measured at the time of performance. A pressure gauge was installed on the next raiser and pressure was measured immediately to increase the accuracy. The sprinklers’s flow rate was also measured by volumetric method using a 20-Liter gallon, a chronometer and two hoses. The each sprinkler’s flow rate was determined from its catalog, in order to improve accuracy. We attempted to select the sprinklers’ locations in the points where pressure is moderate. The water collecting cans (each 15 cm height and width) were placed in a 3 * 3 m mesh. Then after an hour of operation, system was shut down and the water inside the cans was measured using a calibrated measuring cylinder. After the field operations and data collection, the computational operations were performed to determine the system’s technical evaluation parameters. The evaluation parameters in this study include Coefficient of Uniformity (CU), Distribution Uniformity (DU), Application Efficiency of Low Quarter (AELQ) and Potential Efficiency of Low Quarter (PELQ), that are calculated for both testing block and Total system. The evaluation results of 10 systems indicate that due to inappropriate design and implementation, all of the evaluation parameters are less than allowed range (81% ≥ 81% CU and 81% ≥ 67%), but also, mismanagement is effective. In all of these systems, due to the lack of precipitation and depletion of groundwater’s surface, farmers use deficit- irrigation, which equality of application and potential efficiency prove this. On the other hand, except the KF system, in all systems, the number of simultaneous sprinklers in operation is increasing compared to those in the approved design, which is one of mismanagements leading to decrease of pressure. The spray’s radius can not be estimated resulting in lack of distribution uniformity and inadequate irrigation in some areas and deep penetration losses in other areas. Increasing the number of simultaneous water sprayers in operation is a significant objection. The calculated actual efficiency varied from 37.9% in the KHH2 to 63.8% in the KHN system. The calculated pressure changes varied from 13% in the KHH2 to 43% in the KM system. The average discharge varied from 1.7 L/s in the KHF to 2.88 L/s in the KF system and spray losses were estimated from 5.5% in the KHN to 32% in the KHF system. The test block’s DU in the varied from 47% in the KF to 71% in the KHN system and the CU varied from 58% in the KHH1 to 83% in the AG system. The DU in all system varied from 44/3% in the KF to 68/5% in the SHJ system. The test block’s PELQ varied from 39.5% in the KHH2 to 67.3% in the KHN system and in the whole system varied from 37.9% in the KHH2 to 63.8% in the KHN system. The test block’s AELQ varied from 39.5% in the KHH2 to 67.3% in the KHN system and in the whole system varied from 37.9% to 63.8%. In conclusion, according to the results, the semi-portable sprinkler irrigation systems in the plains of Markazi Province are not in proper conditions and have various design and implementation problems.

Abstract In Iran, the use of pressurized irrigation systems is increasing. Supplying energy to pump the water is one of the pressurized irrigation system’s requirements. Because of non-renewal, extraction costs and environmental hazards of fossil fuels, the solar energy utilization has become inevitable. The solar energy is one of the most important and cleanest forms of new energies, which can return the initial cost of solar system to the customer in long term. One of the reasons for Iran's failure to use the large part of its cultivated land is the long distance from the national electricity network and high electricity costs. In this study, the solar and electric pumps were compared economically to pump water in nine gardens under cultivation of three crops of pistachio, almond, and walnut, using drip irrigation networks. The gardens are located in Tehran and Hamedan Province. The drip irrigation system is applied to these gardens. The gardens were classified into three groups: small (less than 5 hectares), medium (5 to 60 hectares) and large (more than 60 hectares). First, pumping station was designed and then, investment costs were estimated for all the studied gardens. The Lorentz solar pump special design software was used in order to design and simulate the photovoltaic system. It is assumed that electricity would supply for these areas in two ways including: 1) installation of photovoltaic systems in remote areas without national electricity grid consumption 2) electricity transmission through the construction of transmission lines and trans-installation. These two conditions were compared by the present value method at two interest rates of 5 and 10%. In order to convert the future costs to present value, real interest rate index is required. Considering the difference between the service life of equipment for electric pumps and solar pumps, as well as solar panels, the lifetime of the projects was considered unequal in calculating the current value. The results showed that the utilization of photovoltaic pumping near the electricity distribution network is economic only for 60-hectare pistachio garden with an interest rate of 10%. In the medium-size walnut garden , with the same interest rate, despite the slight difference in investment cost, it does not differ from electric pumping. In the case of distance from the power distribution network, photovoltaic pumping will be more economical by decreasing the size of the farm (less capacity and pressure) and increasing the distance from the power distribution network. However, other factors such as temperature, sunshine, radiation intensity and solar angles may also affect the photovoltaic pumping during different seasons. The results also showed that the photovoltaic pumping of irrigation system is economic for small and medium pistachio and walnut gardens, 0.5 km far from the electric distribution network, by the interest rate of 5 and 10%. By increasing the distance from the electricity distribution network, only the costs of power lines transferring to electric pumping increase and the use of photovoltaic pumping is more justifiable. Changes in the current value of costs for both pumping methods at a rate of 10% relative to 5% interest rate will lead to cost reductions. In remote areas, which it is difficult to access the electricity distribution and transmission networks, the use of photovoltaic pumping is reasonable and economic. Therefore, in this study, there is a specific distance from the electric distribution network for each area.

Abstract Construction of dams on limestone formations, however morphologically, has an appropriate form; but usually causes seepage from the reservoir to the downstream. Also, the construction of a dam on calcareous-karst formations has the risk of over seepage from the reservoir, and the existence of the karst leads to complicating this issue. Therefore, various methods of hydrogeological analysis are needed to determine the condition of reservoir karstification and dam axis in the karstic areas. The Beheshtabad dam is in investigation studies stage and approximately situated at the far end of the anticline axis named Sangwill, which composed of dolomitic limestone with roughly 700 m thickness. The right side of the reservoir is mainly in direct contact with this karstic formation. Hydrogeological analysis for determining the reservoir’s seepage in right side includes measurement of water level and boreholes hydrochemical analysis, measuring springs discharge and hydrochemical condition of springs and environmental isotopic studies. The results showed that karstic aquifer’s water level on the right side of the reservoir has very similar fluctuations with a difference between the minimum and maximum of 2.5 to 3 m. The water level from the northern limb with a level of about 1625 decreases toward the spring in the southern limb with a level of about 1595 and a gradient of about 0.007. Also, spring discharge in the sought limb has the same fluctuation with three recession curve coefficients. The recession curve coefficient α₁ in the order of 10^-2 indicates the intermediate flow (diffuse-conduit) make up 15% of the flow and the coefficients α₂ and α₃ in order 10^-3 indicate the diffuse flow accounts about 85% of the aquifer flow. The hydrochemical and isotopic parameters of springs and boreholes also have low fluctuations. These anion and cation variations are less than 20% and for Ec and acidity are less than 5%. The amount of environmental isotopes in springs and boreholes does not show any significant variations so that the standard deviation obtained from the monthly acquired data is less than 1.2 per mil for δD and less than 0.2 per mil for δ¹⁸O. The amount of environmental isotopes shows that the springs source is about 2300 m and composed of heavy rainfall and snow in two limbs. Also, the isotopic composition of downstream springs is the average amount of isotopic value boreholes in the north and sought limbs showing that springs catchment area in left side (SP_L) and right side (SP₅) is recharged from both limbs of the anticline. Finally, the results of the studies show that the Jahrom-Asmari karstic aquifer on the reservoir’s right side is an aquifer with diffuse to diffuse-conduit flow. The aquifer is recharged through two anticline’s limbs and mainly through the joints and fractures system. The groundwater flows from the northern limb to the southern limb and is discharged into the downstream springs. In such a condition, a hydraulic connection between the anticline’s northern and southern limb exists. This connection is formed at the time of reservoir formation, between the reservoir and the lower springs of the dam axis with a higher gradient (around 0.037). Therefore, by the dam impoundment, the major seepage current in the right abutment of the reservoir in the north limb of anticline flows toward the south limb and finally is discharged in downstream springs of the dam axis.

Abstract Water scarcity is one of the problems to the utilization of water resources in the agriculture sector. Therefore, a principled management of water resources is needed to optimally meet the water requirements of this sector. The Irrigation water allocation management could play an important role in confronting the water scarcity of the agriculture sector. The use of optimization technique to optimally allocate water and land has recently been proposed and used in many studies and it was proved to be very effective in the optimal water allocation problems. Rabie et al. (2015) allocated water to the lands irrigated by the Ordibehesht canal of Doroodzan irrigation network in Fars Province, using genetic algorithm. Results indicated that total cultivated area could be reduced by up to 12% under optimal water allocation situation. The results of the study conducted by Mizaei et al. (2017) on optimizing the cropping pattern of Golestan irrigation network using genetic algorithm, demonstrated that 38% of the available water left as the surplus water after the optimization. This amount of water could increase the cropping area by 1388 hectares. In this study, an optimization model was created to optimally allocate the available water to the Maroon irrigation network, which is located in Khuzestan Province, Iran, using the genetic algorithms optimization method with the purpose of maximizing the total net benefit. First, the water requirement of all crops in the Maroon irrigation network was calculated according to Allen et al. (1998) using Cropwat 8.0 software. Then, an optimization model was created in order to optimally allocate the irrigation water to the cropping pattern of the Maroon irrigation network using Matlab software. In this model, the water year was divided into 36 periods consisting of 10 days. The amount of irrigation water depth of the crops and their cropping area were considered as the crucial variables of the model. As genetic algorithm has been proved to be effective in the recent optimal irrigation water allocation and cropping pattern studies, the genetic algorithm optimization method was used to allocate the irrigation water to the Maroon irrigation network with the in order to maximize the total net benefit (Faghihi et al., 2015; Rabie et al., 2015; Mirzaei et al., 2017). Furthermore, the particle swarm optimization method was used in order to verify the results obtained from genetic algorithm optimization method. Comparison of the results obtained using the mentioned optimization methods can demonstrate whether the genetic algorithm results are verified or not. In order to achieve the optimal solution, both optimization methods had some parameters to be set. The parameters were set using the Vikor index according to Akbaripour and Masehian (2013).  The total net benefit maximization results obtained from particle swarm optimization method verified the maximization results of total net benefit obtained from the study model using genetic algorithm optimization method. The model’s results indicated that the cropping patterns of all crops are increased except alfalfa and wheat. The total network’s cultivated area is increased by 1271 hectares, which means that 14% of the network’s abandoned area could be cultivated. There are so many lands that were cultivated in the past and is not currently under cultivation because the available water resources cannot meet all of the water requirements of the agriculture sector in the study area. So, some lands were abandoned and are not under cultivation anymore, but the optimal allocation of irrigation water is an efficient strategy to handle the water scarcity challenge in the agricultural sector; and some of these lands could be cultivated again, which leads to a more efficient agriculture sector. Furthermore, the irrigation depth was reduced in all of the crops, but the model compensated the reduction using the available soil moisture. So, the crops were exposed to insignificant amount of water stress and the crops yield is not significantly reduced, however, the amount of total water use is not significantly reduced in comparison with the current irrigation water allocation situation because the network’s total cropping area is increased. The water resources’ allocation optimization lead to increase in total net benefit by 74.9 billion Rials. The results also proved the efficiency of genetic algorithm in this water allocation optimization model by increasing the total cropping area and the network’s total net benefit. 

Abstract In recent years, rising water table has been reported in many cities around the world. Therefore, water table fluctuations in these areas can affect structures. Mashhad city is one of the major metropolises in Iran and due to indigenous population and tourists, it needs various resources to supply water. The city's water needs are supplied from the Mashhad aquifer, Dousti dam and other catchment areas. The water table uplift in Mashhad city caused problems for commercial and residential complexes with a depth of more than 20 m of excavation, leading to penetration of groundwater to buildings basement. In addition, the existence of groundwater during the excavation in the second subway tunnel has been created serious problems. The lack of full development of drainage systems and municipal sewage networks have led to an increase in rising groundwater levels in some parts of the city. Also, the urbanization development and the ever-increasing depth of soil excavation in urban areas may have affected the ground water situation. Therefore, the aim of this research is to assess the major factors affecting the groundwater uplift in Mashhad city. In order to determine the relationship between these factors and water table fluctuations, time series analysis was used in both time and frequency domains. According to the groundwater hydrograph, a decreasing trend is observed during the years 2005-2009. While, from 2009 to 2014, these fluctuations followed the uptrend. The time series analysis indicates that rainfall and evaporation did not have significant impacts on the fluctuations of groundwater level in these areas, due to the existence of impermeable surface in the city, low infiltration of rainfall in the soil, and water table depth more than 5 m. The annual expansion of the sewage network and transfer of collected wastewater to wastewater treatment plants with a lag time of 1 to 2 months have a significant effect on reduction of water table in areas with sewage network; while in areas without sewage network, due to the water penetration from septic wells into groundwater, the water table has been increased. The arrival of more than 800 million m³ of water from Dousti dam and reduction of more than 40% of discharged groundwater in the Mashahd aquifer with lag time of 1 to 2 months, are the most influential factors in groundwater uplift. The lack of sewage networks development in the southern regions and some central parts of Mashhad city has led to an increase in groundwater levels in these areas. Due to the soil extraction from saturated and unsaturated zones during the second subway  line drilling and the development of excavation and construction of civil engineering projects in the city's central area, especially around the Imam Reza's holy shrine, the soil porosity has been decreased. This porosity was previously filled with water, while they are now occupied by impenetrable materials. Therefore, the water has been forced to migrate to other places. The aim of this research is to assess the major factors affecting  groundwater uplift in Mashhad city, Iran. In order to determine the relationship between these factors and water table fluctuations, time series analysis was used in both time and frequency domains. The obtained results show lag times between water table and rainfall/evaporation, transferred water from Dousti dam to the town, discharged water from aquifer, and expansion of sewage network in regions with and without network were 9, 2-3, 3-4, 1-2, 3-4, 2-3 and 3-4 months, respectively. In this study an expected drawdown by exploitation from aquifer, an expected rise due to water transfer from Dousti dam, an the expected rise in groundwater surface level in regions without sewage network, and an expected drawdown (if no water was transferred from Dousti dam) equal to 0.5, 0.44, 2.7, and 1 m, respectively, have been occurred. Also, the effects of soil excavation in line 2 of subway and urban foundation digging on the groundwater and soil properties were studied. The results indicate that the water storage capacity in saturated/unsaturated zones have been reduced and water table raised about 1.25 m in the town aquifer.

Abstract Dam reservoirs are among the most important sources of fresh water. In the event of a loss in the useful volume of the reservoirs, their capacity for water containment and storage decreases. The most important factor in reducing the useful volume of the reservoirs is sedimentation, and the most important factor of sediment transfer in reservoirs is dense current. The dense current is a stream created by density difference between two fluids under the gravitational acceleration. Experiments were carried out at the Hydraulic Research Laboratory of Faculty of Water Science Engineering, Shahid Chamran University of Ahvaz, in a flume with 780 mm long and 70 cm height with a slope of minus 1 to 3.86%. The flume was divided into two sections using a sluice gate. The right side of this gate was filled with the clear water. The gate at the flume’s end maintained the clean water level. On the left side, the water and salt solution is entered. This gate was able to be rapidly opened and discharge the water and salt solution with a specific flow rate into the clear water. In the present study, four different modes of application of three successive obstacles were investigated for dense current controlling. The height of the obstacles was considered by three ratios of dense current body height as h_r =0.5, 0.75, 1(h_r = h_m/h, where h_m is the obstacle height and h is the average height of the dense current body). In three obstacle configuration modes, the heights of the obstacles were equivalent and in the fourth state, three obstacles with similar dimensions were placed ascendingly. Experiments were performed at 3 slopes of 0, 1.5 and 2.5%, with two concentrations of 10 and 20 gr/L and a constant flow rate of 1 L/s. The results showed that the frontal dense flow at all slopes and both concentrations of 10 and 20 gr/L, had almost the same velocity before reaching the obstacles. As the frontal dense current encounters the first obstacle, its speed significantly decreases and continues to decrease until the last obstacle. The highest percentage of frontal discharge control at two concentrations of 10 and 20 gr/L was for  and was calculated to be 84 and 87%, and the lowest percentage of the frontal discharge control at same concentrations was for , and was calculated to be 25 and 31%, respectively. For the ascending configuration obstacles, the percentages of frontal dense current discharge control at the slopes of 0, 1.5 and 2.5% for the concentration of 10 gr/L were 74, 52 and 44%, and for the concentration of 20 gr/L was 78, 58 and 48%, respectively.

Abstract Nowadays, the construction of dams is one of the most important solutions for the storage of surface water. Due to fresh water limitations, the construction of reservoir dams to control the surface water resources in Iran is inevitable and necessary. In dam reservoirs, the turbidity current is usually the cause of sediment transfer and deposition. If the current is completely stopped in the middle areas of the reservoir, the amount of sedimentation will be reduced at the bottom of the dam wall and, as a result, the main functions of the dam will not be disturbed. Therefore, it is necessary to study this phenomenon. One of the methods for hydraulically changing the turbidity current is to roughen it or to use a barrier in the bed. Several studies have been carried out on the turbidity current velocity so far, and controlling it by roughening and barriers. However, it seems that no studies have been made on the effects of the angle and location of submerged impermeable plates on the turbidity currents. In this study, 42 experiments were carried out on the effects of the submerged impermeable plates on the head velocity and the height of the turbidity current head. For this purpose, an experimental flume with 30 cm width, 10 m length and 46 cm height was used. The turbidity current entered the flume with concentrations of 20 and 40 g/l, and bed slopes of 1 and 2%. In order to investigate the effects of the angle of the submerged impermeable plates, impermeable plates which came into seven different mounting angles of the plates with respect to the current axis (0, 15, 30, 45, 60, 75, 90 degrees) and also, impermeable plates with eight locations were located across the current. Measurements of velocity and height of the head turbidity current were made on six sections with 50 cm distances. Then, based on the data obtained, and by dimensional analysis of Edgar Buckingham’s method (Buckingham π methodology), the non-dimensional graphs of velocity, height and Densimetric Froude Number of the head of turbidity current were plotted. According to the performed experiments, the results of this study are presented in two sections. In the first section, the results are related to the effect of the plate angles; in the second, the results are related to the effect of the plate positioning. Generally, due to the collision of the turbidity current with the plates, the non-dimensional velocity was reduced along the mounting route. Also, the Densimetric Froude Number was decreasing along the current route. The results showed that by increasing the plates’ angle, the decreasing gradient of the dimensionless velocity increases along the dimensionless route. Therefore, the plates with angles of 75° and 90° which are in the vertical and near-vertical position relative to the current axis, are affecting the current velocity more than plates at other angles. In general, the turbidity current velocity decreased by 8.6 to 27.1% with respect to the control state, in case of different angle of mounting of the plates with respect to the current axis. With a concentration of 20 g/l and the slope of 1%, the plates with the mounting angles of 75 and 90° relative to the horizontal axis of the turbidity current provide the most significant decrease in the velocity in comparison with the control, with 26.4 and 27.1%. The analysis of the plates’ position showed that when the plates are mounted across the canal’s total width, they provide the most significant reduction in the velocity in comparison with the control. In general, in different conditions, the turbidity current velocity increases to 6.3% in the worst location and decreases to 45.1% in the best location relative to the control state (in bed without submerged impermeable plates). With a concentration of 20 g/l, the plates at the position of 2, with 45.1% at the slope of 1%, and 29.5% at the slope of 2%, made the biggest decrease in the current’s head velocity in comparison with the control. Also, with the concentration of 20 g/l at the slopes of 1 and 2%, the position 5 made the biggest decrease in the velocity with 33.9 and 38.3%. Slope investigations showed that with the concentration of 20 and 40 g/l, the slope increase will reduce the effect of the plates on the velocity.

Abstract The melted ices, reduced snow covers, increased air temperature, change in frequency and duration of droughts and change in precipitation patterns are evidences of the climate change (Ehsani et al., 2017; Huber and Knutti, 2011; IPCC, 2014). Different alternatives of driven factors (population and economic growth, technology efficiency and type of used energy) are considered in the 21st century to project the greenhouse gasses in the Representative Concentration Pathways (RCPs). These assumptions lead to the three RCPs, including a stringent mitigation scenario of RCP2.6, an intermediate scenario of RCP4.5 and, a very high greenhouse gasses emission scenario of RCP8.5 whose radiative forcing is +2.6, +4.5, +6 and +8.5 W/m2, respectively in the year 2100 relative to pre-industrial values. The global warming is +1, +1.8, +2.2 and +3.7 ℃, respectively at the end of the 21st century (2081-2100) relative to 1986-2005 (IPCC, 2014). The study of the temporal variability of the observed precipitation and temperature in southern Iran showed that the precipitation and temperature trends are negative and positive, respectively (Tabari and Talaee 2011a, 2011b; Kousari and Asadi Zarch 2011; Tabari et al. 2011; Kousari et al. 2011). There are large dams such as Dorudzan and Molasadra, and natural lakes of kaftar, Arzhan and Parishan over the study area, which may adversely be affected due to climate change in future. Therefore, the objective of this study is to find how the climate variables of precipitation and temperature, drought duration and intensity of extreme storms will change under the climate change. Six climatic stations are selected based on the longest common daily records of precipitation and temperature data (1978-2005) in order to investigate the climate change in the study area. In this study, the daily outputs of the 22 CMIP5 models are applied for the climate change study. The LARS-WG is used to downscale each GCM-predicted data in the six stations. The observed daily data during the 28-year period of 1978-2005 are inputted to the LARS-WG to calibrate it for each station. Then, to verify the LARS-WG at each station, the 28-year daily precipitation, minimum and maximum temperature are generated and statistical characteristics of the generated data (statistical distributions and mean values) are compared with observed ones at significance level of 0.01 using Kolmogorov–Smirnov (K-S) and Student’s t-test (Semenov and Barrow, 2002). The verification results imply that the LARS-WG reproduces the daily data well in the six stations. The change factors are calculated using the given GCM data and relevant grid box to downscale that GCM output for each climatic station. The change factors are calculated using a transient approach in which 5-year future time windows shifted forward by 1-year.  The downscaling results in Abadeh station indicate that the mean annual temperature will increase from 14.3 ℃ during the period 1978-2005 to 16.1, 16.7 and 17.7 ℃ under the RCP2.6, RCP4.5 and RCP8.5, respectively, leading to the warming by +1.8, +2.4 and +3.4 ℃, respectively. The downscaling results show that the mean annual precipitation will decrease from 452 mm during the observation period (1978-2005) to 386, 353 and 357 mm under the RCP2.6, RCP4.5 and RCP8.5, respectively, leading to precipitation reduction by 14.6%, 22% and 21%, respectively. The intensity of extreme storms with different return periods are estimated using the maximum annual series during the observation period and three RCPs. The goodness of fit on statistical distributions of Exponential (1P and 2P), Gamma (2P and 3P), General Gamma (3P and 4P), Log-Gamma (2P), General Extreme Value, Normal, Log-Normal (2P and 3P), Pearson (2P and 3P) and Log-Pearson (3) shows that the General Extreme Value is the best-fitted statistical distribution on maximum annual series. Then, the intensity of 2, 5, 10 and 20-year return period storms are determined using the fitted statistical distribution. The results indicate that the 2-year return period storms will be intensified, the 5-year storms will not change, but the intensity of the 10-year and 20-year storms will decrease in future due to the climate change. The 12-month SPI analysis indicates that the wet and normal periods will slightly increase, while droughts will decrease in the period 2040s under the three RCPs. The SPI analysis in the second period (2070s) show that the wet periods will not change, the normal periods slightly increase, but drought conditions may be intensified, especially in RCP2.6 and RCP8.5.

Abstract In water scarcity conditions, water resources management and accurate use of available water for sustainable production of required products are the essential approches in arid and semi-arid areas. To achieve this management, the evapotranspiration plays a very important role that is one of the main components of the hydrological cycle and successes of water projects. In the other words, sustainable production depends on the correct estimation of the evapotranspiration. Determination of the water requirement of crops and gardens will increase the irrigation efficiency and improve water management in the field. In order to estimate the evapotranspiration, it is necessary to accurately calculate reference evapotranspiration. So far, many experimental methods have been proposed to estimate the reference evapotranspiration. The FAO Penman Montieth method is one of the most precise methods to determine of this parameter. But, the limitation in using this method is calibrating for areas that determined to be studied. Over the last few years, new tools and innovative methods have been widely used to estimate the reference evapotranspiration. Therefore, it is necessary to check the correctness of these models and methods for different regions. Sistan is one of the fertile regions of Iran, which, unfortunately, over the years, the phenomenon of drought has been swept away the active farming in the area and destroyed a boom in agricultural production in this region. Nevertheless, the main occupation of rural people in this region is still agriculture. Any neglect on the water category in this area, can be a serious damage to it. Winds for more than 120 days are the main climate features of this region that has extremely been increase the evaporation. Therefore, it is necessary to extract the highest efficiency from the limited water in the area. So, in this research, the effective climatic parameters to calculate of daily reference evapotranspiration in Sistan plain were identified and analyzed, using different scenarios of the combination of meteorological parameters. These scenarios were used as inputs models of decision trees, random forest and deep learning. The best scenario was extracted by results of models. Then, the accuracy of the results was compared with the experimental method of FAO Penman Montieth as the basis method. Scenarios were M1 - M25. The data used in these scenarios were: max, min and average of two temperature and humidity parameters, rainfall, sunshine, wind speed, and pan evaporation. The data were provided from the Zabul meteorological stations for 2009-2018. For validation, 80% of the data have been use for training and the remaining 20% for testing the models. Results of these models were compared with the estimated results by the FAO Penman Montieth model and shown, in decision tree model, M10 scenario with the lowest error rate (RMSE=1.003) and the highest correlation coefficient ( R=0.983 ) was the best scenario. In random forest model, M10 scenario with the lowest error rate (RMSE=1.003), MAE=0.8 and the highest correlation coefficient (R=0.983) was the best scenario. In deep learning model, M5 scenario with the lowest error rate (RMSE=0.517), MAE=0.399 and the highest correlation coefficient (R=0.996) was the best scenario. In results of the supporting machine model and selecting the best model, by evaluating the comparison of decision tree and deep learning models, it was shown that a specific pattern can be introduced for Sistan region with proper accuracy for estimating daily reference evapotranspiration and should introduce a superior scenario for each model. In order to deliberation the importance of various meteorological parameters in the results of the mention models, among all the parameters which have used in decision tree model, average temperature, wind speed, maximum temperature and minimum temperature, respectively, had the most importance. In random forest model, maximum temperature, wind speed, average temperature and pan evaporation had the most importance, respectively. Finally in deep learning model, average temperature, maximum temperature, wind speed and minimum humidity, respectively, had the most effect on calculation of daily reference evapotranspiration in case study region. As a general conclusion it can be expressed that deep learning model is the best model among selected models and M5 scenario in deep learning with the highest correlation coefficient (R=0.996) and the lowest error (RMSE=0.517), had a good accuracy to modeling of daily reference evapotranspiration.

Abstract The use of models in snowy basins, due to the effect of snow’s properties, requires quantitative and qualitative knowledge of the factors influencing the melting and runoff resulting from it. Temperature is one of the factors. The impact of its variation on the performance of model based on the degree-day approach should be explained. For this purpose, in the Samsami catchment, at longitude of 50°10ʹ2.2ʺ to 50°26ʹ14.6ʺ East and latitude of 32°5ʹ16.5ʺ to 32°15ʹ1ʺ North, by the area of 266km², the performance of the SRM model in different melting season in years 1393 to 1394, was evaluated using a product of maximum eight-day snow cover (MOD10A2) and criteria in order to assess EI efficiency and Volume Ratio. The assessment was performed with the help of ENVI and ArcGIS softwares. Determination of snow melting season was carried out using snow cover curves. In order to determine the beginning of the melting season, changes in snow cover levels between 2008 and 2016 were investigated in the Doab Samsami’ basin. This basin is one of the northern Karun sub-basins in Chahar Mahal and Bakhtiari Province with an average rainfall of 1.175 millimeters per year. The precipitation consists 61% snow and 39% rain. Due to the significant drop of snow in the basin, there are large permanent and seasonal springs. The  Dezdaran and Koufi springs can be named as the important ones. These springs have a relatively large reservoir and are the origin of two rivers, which are named after them. The rivers join together in the geographical position of 50°17ʹ15ʺ East and 31°10ʹ14.1ʺ North, near the Samsami village at 1993 m altitude above sea level, and form the Doab Samsami river. The study basin has the Doab Samsami meteorological station and Safa Abad hydrometric station at the basin’s outlet point. The basin lacked a snowstorm station, which is why the synoptic Kouhrang station, the nearest Synoptic station to the Doab Samsami basin, was assisted. The use and interpretation of model simulation results are subject to the study of temperature’s variations in different altitudes. The model performance in different melting months is different due to the variable state of the structure of snow accumulated, due to temperature. The temperature difference in the melting months, due to the stacking on the snowpack, causes the snow to ripe. On the other hand, the ripening of snow causes delays in runoff due to melting and, as a result, the difference between observational and simulated discharge. Because the ripening phenomenon is directly related to the temperature, it can be claimed that the RMS model performance decreases with temperature increase, in proportion to the melting season. In addition, the accuracy of SRM model decreases by increasing the temperature. In February to May, the Volume Ratio rises from 10 to 40% due to a  16° C increase in temperature. The observed difference between simulated and observational values in May, the end of the melting season, was seemed that the value of the volume difference increased to 40% and reduced the efficiency by -0.55. These results were obtained in March, the second month of melting, with a mean temperature of 4° C, which indicate that the volume difference decreased by 3.5% and the efficiency index increased to 0.81. Hence, due to the very good results of the SRM model in March, its simulation results can be used with acceptable capability to estimate the snow flood from the studied basin. However, the use of the model in months with a high mean temperature and the end of the melting season, due to snow structure transformation, has a significant error in the simulation results. In order to estimate the snowflake outflow, more attention should be paid to the role of the springs. The necessary modifications are made in simulation results. Statistical simulations include the Volumetric Difference (%) and Efficiency Index (Dimensionless) in each months of February, March, April, May, that are 17.1, 3.5, 14, 40% and 0.83, 0.81, 0.66, -0.55, respectively. Therefore, it is seen that gradually, with the melting months, the accuracy of model estimation decreases. So, the use of model outcomes in the end months of melting requires temperature correction. The best fit and lowest compliance are observed in March and <ay, respectively.

Abstract Water shortage in the Iranian plateau has always been the main concern, and one of the most important achievements of people in this region is to devise methods of irrigation and water management. Following the selection of the city of Isfahan as the capital of the Safavid Empire, size of the city expanded, and its population continued to increase. These two factors created the need for a systematic structural design for water management. This research has tried to look at the water management system in the Isfahan in Safavid era, by researching the historical documents. This study is a historical research, and is conducted with an analytic approach, based on a documentary and library study.
Shah Abbas I and his designers succeeded to organize the city water supply system in response to the significant increase of population of the city. In the first step of the decision to increase the volume of water from the originate which is taking place in different periods. But due to various technical, climatic, and instrument flaws, this project wasn’t successful in Safavid period. After the failure of this project, in the second step, decision for a better target management of this volume of water access was taken. Water volume and time management was planned based on Sheikh-Bahai scroll. This document is now the most important historical source in this regard.
The most important Safavid achievements in the field of management practices is designing a developing city based on access to water resources. the expansion of the Safavid city generally occurs to the west and south, i.e. in the direction of the river entry and its splits into the city fabric. Accordingly, the loss of water due to its leakage and evaporation decreases during the water supply route in rivers along the way. In the region of Isfahan, when moving from the west to the east near to the central desert, the climate, evaporation, and type of soil changes.
During this period, the urban needs of water was provided from underground resources; We read in all travelogues and historical sources of this period that there were several factors behind this choice: water wells, Qanats, and springs were lighter and softer than river water. The high level of underground water in the region of Safavid Isfahan made these resources in every part of the residential area accessible. Water for irrigation of gardens and fields was provided from branches of the Zayandehrood River called Maadi. Many of these splits were created before Safavid with the aim of irrigating gardens and farms. In the Safavid period, changes in these structures occur. Firstly, in addition to irrigating farms and gardens of outskirts, the urban structures and the architecture made for water supply also improves. Secondly, new splits were defined in order to supply the water of emerging parts in the developing process of the city. Niasarm watercourse that before Safavid irrigated only the farms, in Safavid period, due to the changes in the fabric of the northern shore of the river, firstly irrigated the gardens near to Alah-Verdi-Khan and Khaju bridges and then the residential quarters of this area. Farshadi watercourse also plays a similar role in his way to the east by crossing the Safavid structures such as Madar-Shah school and caravanserai. However, the most important watercourses for this research are Shah-Kabir or Jouishah and some ways are advised and the share of each space from the watercourse is identified. According to the Sheikh-Bahai scroll, the Fadan watercourse is the most effective water supply in the urban fabric, the ancient part particularly; and mentioning its share, a section titled "urbanization" is clearly identified. Following some of the shares named in the scroll, the water supply of this watercourse to the northern and the eastern fabric of the city are shown.
In the heyday of the Safavid, management of water resources was very efficient and accurate. At the end of the Safavid period, the government fell, corruption and bribery were common, and simultaneously, the water management system became very shaky. Increasing pressure on farmers shook the foundations of the economy, and accelerated the fall of the government. On the other hand, the discontent of farmers, lead to the decline of government.

Abstract Increasing population growth leads to more food production, which requires more activities in the agricultural and industrial sectors. Therefore, regarding to lack of available water, development of effective strategies for water resources management is necessary. One of the strategies that have been considered in water resources management in recent years, especially in the agricultural sector, is increasing the accuracy of the measurement or estimation of evapotranspiration. Monitor and evaluation of changes in certain periods of time is important in determining the amount of the water consumed by plant and planning irrigation, and thus determining the irrigation systems capacity. But since direct and indirect methods of calculating this parameter have limitations, remote sensing methods for calculating evapotranspiration have been taken into consideration, recently. Also, remote sensing data combined with some meteorological data providing a tool to estimate regional ET, has given advances in remote sensing technology. One of the models based on remote sensing data is the Surface Energy Balance Algorithm for Land (SEBAL), in which these parameters have significance in estimating regional ET: land surface temperature, albedo, emissivity, and normalized difference vegetation index (NDVI). In the present study, Lenjan region in Isfahan province, Iran, which was under rice cultivation, was selected.  The model of Surface Energy Balance Algorithm for Land (SEBAL) was implemented on 8 satellite images of Landsat 8, from June to September 2017 (growing season). For this purpose, the main components of the energy balance equation (including net radiation flux, soil heat flux and sensible heat flux to the air) were calculated for each image. Also, the instantaneous evapotranspiration flux for each pixel was estimated according to the residual energy balance equation. The Net Radiation is the electromagnetic balance of all incoming and outgoing fluxes reaching and leaving a flat surface. Soil heat flux was empirically calculated using vegetation indices, surface temperature, and surface albedo. Sensible heat flux was computed applying wind speed observations, estimated surface roughness, and surface to air temperature differences. Besides, empirical methods of evapotranspiration were also evaluated in the study area, including: Blaney- Criddle, Hargraves- Samani, FAO- Pennman- Monteith and Kimberly- Pennman. Calculating ET regarding to these methods, weather data was collected from Zarrin-shahr weather station and Zefreh evaporation station. Cropwat software was applied for calculating ET by FAO-Pennman-Monteith method. To compare and evaluate the efficiency of SEBAL model with the others methods, three indices have been used included: root mean square error, mean absolute error and coefficient of determination. According to the results of this research, the SEBAL model in the studied area has the maximum and minimum daily evapotranspiration in the images of June 25 and September 11, equal to 7.95 and 5.88 mm/day, respectively. Among the various parameters affecting the SEBAL algorithm, the net radiation flux parameter had the most effect on the results of this algorithm, comparing with the other parameters such as vegetation indices, surface albedo, and incoming and outgoing of radiation. Among the different empirical methods, FAO-Pennman-Monteith, calculated with Cropwat, estimated ET more than other methods because this method considers the water depth in soil surface. Hargraves- Samani and Blaney- Criddle were in the further ranks after FAO-Pennman-Monteith. At last, NETWAT had the lowest estimation, in comparison with the other methods. Also, Hargraves- Samani and Blaney- Ciddle had the less percent error, due to its suitable correlation with SEBAL results. SEBAL algorithm has been able to estimate the temporal and spatial variation of evapotranspiration in the studied area with an acceptable accuracy. Alternatively, this algorithm can be used to replace time-consuming and costly methods of calculating evapotranspiration at different surfaces. Regarding to outcome of this study, the volume of rice's evapotranspiration in cultivating season were estimated as in the range of 6100 – 8600 cubic meter per hectare, by different methods. Some other researchers calculated the water demand of rice as 9500 to 15000.This deference could be originated from two factors. Cultivating period is the first factor which is considered as 140 days in water need calculations and its relevant tables. Cultivating period in the studied region was 110 days, in practice. It should be noted that the earth warming and increasing in the average temperatures during cultivating period can influence the reduction of cultivating time. The second factor which can be the reason of deference in estimated water demand of rice, is neglecting that the irrigating was stopped at the end of cultivating time.

Abstract The atmospheric conditions and rainfall shortage have increased the utilization of groundwater resources in the northern regions of the country. Therefore, the evaluation of groundwater resources in the aquifer of the Nekarod plain is of a great importance due to the high use of groundwater resources and subsequent use of chemical agents such as fertilizers and pesticides in agricultural lands. In recent years, lack of appropriate management of groundwater in the East of Mazandran province, Iran, causes a critical situation in groundwater resources. Therefore, the purpose of this study is assessing the vulnerability of aquifer Nekarod area in with DRASTIC model. In the current study the potential of groundwater contamination was evaluated with the DRASTIC model. This model evaluates the groundwater potential vulnerability in aquifers with seven different parameters, including: Depth, Net nutrition, Aquifer media, Soil media, Topography, Non-saturated media, and Hydraulic conductivity. All data were provided by Mazandran Reginal Water Authority (2016-2017). According to the data, the most vulnerable situation was determined in September and October, due to the minimum level of groundwater. In order to gain the purposes, the weights for each of the parameters were first determined using the layer overlay method in GIS software, for each of the seven parameters and the desired range. Weight ranges in the DRASTIC method are from one to five, in ascending order of importance. Then, the columns of each of the ranges in the GIS were converted to the Raster layer. Thereafter,  the total number of layers with the obtained weight was summed up, using the Raster calculator. In the next step, the risk maps were finalized in the region according to the model of the DRASTIC. Kriging statistical method was used to illustrate the variation of water quality elements. To determine the correlation coefficient of the results from the DRASTIC model and the aquifer data, Spearman method was applied. Also, SPSS 22 software was employed to determine the final stroke index with nitrate, pH and EC parameters. The results of the evaluation with the DRASTIC model in the area of Nekarod showed that the area with a high vulnerability only has 17.33 percent of the total area of the region and the area with low vulnerability potential covered 52.97 percent. Also, the most vulnerable depth was determined in range of 3 to 9 meters with 62.71%. The most extended area (87.28) with the highest contamination risk had the precipitation less than 500 mm and slope of 0-2%. Pearson statistical test was used to show the relationship between the results of the DRASTIC model and the values of nitrate, pH and EC, which was 0.610, 0.254 and 0.277, respectively. The Nekarod plain is one of the major contaminated areas due to the use of pesticides and chemical fertilizers with the aim of increasing the yield of agricultural products. Therefore this plain is vulnerable and suffers from lack of groundwater management. According to the results of the DRASTIC model for assessing vulnerability, the southeastern part of the region has the highest vulnerability due to the different texture and physical conditions of the soil, and the north-east to a part of the center of the plain has a low vulnerability. Downstream areas (northern part) have the more coarse texture than the southeastern part, and this is due to the movement of materials to the Caspian Sea, so there is less pollution there. By verifying the model of the DRASTIC and determining the coefficient of correlation between the data (2016-2017) and observed values of the model, it was determined that the DRASTIC model had significant results in the level of 0.05. The correlation in nitrate results has the highest amount in compare with pH and EC, which could be due to the contamination in groundwater. The amounts of pH and EC had inverse correlation with the results of the model. So that with increasing pH, the value of contamination index decreased in the model; while for the parameter of nitrate, the effect is direct and positive. Consequently, applying DRASTIC model is an appropriate scientific strategy for studying and determining the sensitivity of the aquifer in the region of Nekarod. The results of this study corroborated two relevant researches which applied DRASTIC Model for other aquifers in Iran (Ghaen and Ansimeshk).

Abstract Because evaluating and measuring efficiency in different irrigation managements is time-consuming with high cost, models can be applied for different irrigation scenarios and could overcome these problems. Variation Crop models are appropriate tools for investigating irrigation management and their effect on plant production. The purpose of this study was to evaluate the efficiency of two models, including AquaCrop and Saltmed, for simulation of yield and soil salinity variation. The accuracy of the results of the simulation models depends on the accuracy of the required data of the model. When the measurement and determination of the input data are valid, then the applicability of model will be evaluated in different conditions after calibration and validation. There are necessary parameters for applying Aquacrop and Saltmed models: details of crop growth stages, root effective depth, sowing and harvest date, harvest index, crop coefficients in different growth stages, duration of wheat phonological growth stages, initial soil salinity in different layers and some irrigation data including depth and time of water application. In this regard, the two models of AquaCrop and Saltmed have been investigated, which are among the functional models with high ability and efficiency to simulate crop yield and soil salinity performance. This research was conducted in Ramseh region of Hamidieh, Khuzestan, Iran. The latitude and longitude are 33º4'N and 47º41'E, respectively. In this regard, three pilots of 10 hectares were selected and in each of these parts, three pilot trials with an area of 2000 square meters were considered for evaluation and measurement. In the first year, using traditional irrigation management of farmers and using the initial salinity levels, soil physical and chemical characteristics compared to the simulation of two models, Aquacrop and Saltmed. These models can simulate crop yield, Biomass and soil moisture variation in saline and non-saline condition. In this investigation, Aquacrop version No. 4(2012) and Saltmed No. 3-04-02(2015) have been used for crop production and soil salinity simulation. During irrigation season, reference evapotranspiration has been determined using climatic data of Ahvaz synoptic station. Gathered data included: minimum and maximum temperature, minimum and maximum relative humidity, precipitation, sunshine hours and wind speed. Also during the growing season, the volume of irrigation water, irrigation hours, water use efficiency and root depth were determined. At the end of the growing season, direct measurement of selected farms in three replications was carried out to determine the wheat grain yield and biomass along with soil moisture changes in the soil profile. According to the measured data, two models of Saltmed and Aquacrop were calibrated for the first year of cultivation. Results of calibration of the first year were evaluated for verifying the results of the two models in the second year. The standard error (SE), Root mean square error (RMSE), Normalized root mean square error (NRMSE), correlation coefficient (R²), mean bias error (MBE), and model efficiency (EF) were used to determine the accuracy of the models. The results of the first year showed that the normalized error of root mean square index for grain yield and biomass values in the AquaCrop model were 4 and 5%, respectively, and these values for the Saltmed model, were 8 and 9%, respectively. This statistical index for simulation of soil salinity with Saltmed model was about 18% and in AquaCrop model was 53%. Therefore, the Saltmed model is more consistent with the measured data of soil salinity. Also, the results of the second year that were used for validation showed that the normalized error of root mean square index for yield and biomass in the AquaCrop model was 4% and 4% respectively, and these corresponding values for Saltmed model were 22 and 14% respectively. Also, simulated of soil salinity results in the second year with Saltmed model showed that this model with normalized error of mean square error(26%) was more accurate for soil salinity simulation than AquaCrop model with normalized error of mean square error equal to 47%; therefore, the AquaCrop model has a better performance than Saltmed model for yield simulation. Also, the performance of Saltmed model has high efficiency and accuracy in simulating soil salinity than AquaCrop model. So based on the goal of projects and precision of simulation data, these individual models can be applied.

Abstract Introduction: Since long ago, controlling the floods and artificial groundwater table`s recharge have been one of the most important aims of performing floodwater spreading systems in arid and semi-arid regions. On the other hand, determining appropriate locations to perform the floodwater spreading systems based on various indices is of utmost importance. However, determining appropriate locations for performing floodwater spreading plans using traditional methods was very difficult that caused complex problems in this regard. Therefore, geographic information system as well as its techniques is able to integrate various information layers into different models and they can be used in floodwater spreading due to their short-time consumption and high accuracy in locating appropriate areas. One of the mentioned problems can be related to the southern plains of Ilam Province; since it is not only encountered with the shortage of surface and groundwater resources, but also the occurrence of destructive floods. Considering the fact that it is not possible to use watershed management methods in upper flood plains of the studied areas, the best method for controlling floods and using surface currents is performing floodwater spreading projects. Thus, the current study investigated the effective factors in locating areas susceptible to floodwater spreading in southern plains of Ilam Province using Multi Class Map model through a geographic information system.  Methods: This study has utilized 1:50000 and 1:250000 topographic maps of National Geography Organization of Iran, geological land use and capability maps, the province`s political subdivisions, satellite images from Landsat 8 sensing OLI of 2013 as well as ILWIS, version 3.3, software. In this study, five parameters of quaternary units, slope percentage, alluvium thickness, land capability and land use were investigated as the affective factors in locating areas susceptible to floodwater spreading as well as artificial recharge in southern plains of Ilam Province using Multi Class Map as stated below. Preparation of geological mass layers (alluvium units, Bakhtiari, Aghajari and other structures), slope layer (with 0-2, 2-5 and more than 8 classes), alluvium thickness layer (a thickness of less than 20, 20-40, 40-70 and more than 70 m), land capability layer (alluvial flood plains, hill-sided plains, plateau, mountain and hill). Integration of prepared mass layers and creating primary layers for areas susceptible to floodwater spreading: Prepared information layers were integrated using Raster Calculator function and the studied area was zoned regarding areas susceptible to floodwater spreading. Preparing land use map: In this research, utilizing land use was actually considered as the limiting layer for floodwater spreading areas. By limiting layer, those areas are intended that despite having best susceptible circumstances for establishing floodwater spreading systems, they can be used for administrating the system, for example, agricultural lands, forest areas and urban regions. Extracting the map of areas susceptible to floodwater spreading: The final map of areas susceptible to floodwater spreading were produced with two classes of appropriate and inappropriate floodwater spreading with the area of 436821 (34%) and 843941 (66%) hectares, respectively. Results: The obtained results of this study indicated that considering the prioritization of effective factors in locating areas susceptible to floodwater spreading, the slope index, quaternary units, alluvium thickness and land capability had the weighted means of 52.5, 42.5, 38.5 and 27, respectively. Regarding the slope map, the area of the mostly appropriate, somehow appropriate and inappropriate lands were approximately 489393, 15393 and 535271 hectares, respectively. According to the quaternary units` map, the area of the mostly appropriate, somehow appropriate, appropriate and inappropriate lands were approximately 324680, 322418, 84825 and 548839 hectares, respectively.  Based on the alluvium thickness layer, the area of the mostly appropriate, somehow appropriate, appropriate and inappropriate (other areas lacking alluvium, which were located in the structure confining area) lands were approximately 324680, 322418, 84825 and 548839 hectares, respectively.  According to the land capability and resource map, the area of mostly appropriate, somehow appropriate, appropriate and inappropriate lands were approximately 122735, 70375, 123432 and 964220 hectares, respectively.  Therefore, the effective factors in locating areas for establishing floodwater spreading network as well as weighing and integrating prepared layers were investigated and the map of final zoned areas susceptible to floodwater spreading was provided, which showed that the administration of such plans in geographic information systems was possible and the obtained results enjoyed high accuracy.