سید سعید اسلامیان

The relationship between intensity-duration-frequency of rainfall is a significant tool for estimating flood discharge. According to the sparsely available rain gauge stations and the development of technology, it is possible to use satellite rainfall data with different temporal and spatial resolutions. PERSIANN rainfall data with a time resolution of 1 and 6 hours were used in this research. Also, the spatial resolution of these data is 0.04 x 0.04 degrees. Rainfall data from synoptic stations around the Kan basin were also used. Three common continuous probability distributions of Gamble, Pearson type 3, and Log Pearson type 3 with return periods of 2, 5, 10, 25, 50, and 100 years were investigated to calculate and check the IDF curve. In general, the precipitation intensity obtained from Gumble's method was more than Pearson Type 3's method. Log Pearson type 3 distribution did not provide acceptable results in this research. The two interpolation methods of inverse distance weighting and empirical Bayesian kriging were used to generalize the frequency intensity curves to the entire Kan basin. The results showed little difference between these two methods, except for Pearson type 3 probability distribution.

This research was conducted using pozzolans produced from date palm leaves at the nanoscale and some mechanical properties of concrete were investigated. The studied properties are compressive strength, tensile strength, elasticity, and durability of concrete containing date palm leaf pozzolans in a sulfated environment. The results of this study showed that in concrete made with pozzolan at low ages, the amount of compressive strength of concrete is less than control concrete, and at older ages over time, the amount of compressive and tensile strength increased; to the point that at 128 days these parameters were approximately 12.35 and 5.8 times higher than that of seven days. The modulus of elasticity values in the treatments containing pozzolan were significantly reduced by nearly 18 percent compared to the control concrete. The performance of treatments containing palm leaf nanoparticles in a sulfated environment was better than control concrete. Finally, according to the cases studied, it can be concluded that the use of 20 percent pozzolanic palm nanoparticles with a strain ratio of 318 compared to control concrete, has significant deformation values. Hence, the use of this makes the material as a filler possible for expansion and contraction joints.

Due to pollution in nature by lead (Pb), the canola stalk (CS) and water vapor-activated biochar (BC) adsorbents were utilized to remove lead from polluted solutions in the lab. The water vapor-activated biochar adsorbent was prepared in 500-degree Celsius carbonization temperature and 700-degree Celsius activation temperature. Lead adsorption isotherm experiments were carried out in 25 degrees Celsius. Experiments were performed to determine the best adsorbent pH level and the best adsorbent dosage level. Both CS and BC adsorbents were amended with magnetic iron oxide nanoparticles (Fe3O4) at 5% (w/w), and the lead adsorption isotherm experiments were carried out using the new adsorbents. The results indicated that the water vapor-activated biochar adsorbent modified with Fe3O4 (BC-5%) is the best adsorbent for the lead pollutants removal. In this adsorbent, the maximum of adsorbed quantity was found equal to 63.62 mg g-1, the Langmuir constant was obtained equal to 0.06790 L mg-1, coefficient of determination was computed equal to 0.9798 and standard error of the estimate acquired equal to 3.219.

Density current is one of the factors influencing the transfer of sediments to reservoirs of dams. One of the practical methods to control sediments is to build an obstacle in the path of these currents.

In this laboratory research, the behavior of the Density current under the effect of cylindrical obstacles made of wood with a diameter of 1.5 cm and a height of 30 cm (more than the height of the body of the Density current) was evaluated. Therefore, by considering variables such as floor slope, concentration and discharge, the values of the density current head were determined. Machine learning algorithms such as adaptive neural fuzzy inference system and artificial neural network were used to model the results.

Based on the results, the density salt flow head was modeled using machine learning algorithms such as adaptive fuzzy neural inference system and artificial neural network and the performance of these two methods were compared. The results showed that machine learning algorithms are useful in modeling the density salt flow head. And the regression of the adaptive neural fuzzy inference system for the training and test data was 0.99 and the regression of the artificial neural network was 0.94 and 0.91, respectively.

By comparing the two methods, it was found that the adaptive neural-fuzzy inference system is more effective in modeling the percent reduction of the head of Density current than the feed-forward artificial neural network method.

Density current is one of the most important factors in the sedimentation process of dams. Increased sediment will reduce dam storage capacity and makes significant challenges for relevant engineers. Therefore, understanding the dynamics of density fluids and related sediment patterns is very efficient for dam reservoir management.

The purpose of this study was to create an intelligent model with appropriate adaptation to laboratory data so that, it can be used in future designs with different variables. Therefore, in this study, the percentage of reduction of density salt current head under the influence of trapezoidal permeable obstacles (aggregates with a diameter of 1 cm), taking into account variables such as discharge, slope, concentration and height of obstacles in laboratory.

Based on the results, the density salt current head was modeled using the artificial neural network feed-forward method and the classical multivariate regression method, and the performance of these two methods was compared. The results showed that the intelligent feed neural network intelligent method in modeling the percentage reduction of density salt current head is significantly superior to the multivariate regression method so that the training, calibration and test regression values ​​ are 0.99, 0.98 and 0.98 were obtained for neural network and 0.92, 0.91 and 0.91 for multivariate regression, respectively.

The performance of the artificial neural network is much better than the multivariate regression method.

Changing the date of the first fall frost and the last spring frost is an important phenomenon in agriculture that can be one of the consequences of global warming. Using general circulation models (GCMs) is a way to study future climate. In this study, observations of temperature and precipitation were weighted by using Mean Observed Temperature-Precipitation (MOTP) method. This method considers the ability of each model in simulating the difference between the mean simulated temperature and mean precipitation in each month in the baseline period and the corresponding observed values. The model that had more weight, selected as the optimum model because it is expected that the model will be valid for the future. But, these models are not indicative of stationary climate change due to their low spatial resolution. Therefore, in this research, the outputs of GCM models are based on the three emission scenarios A2 and B1 and A1B, downscaled by LARS-WG for Isfahan station. The data were analyzed by SPSS software at a 95% confidence level (P<0.05). The results indicated that in the Isfahan in the future period 2020-2049 based on the three scenarios, as compared with baseline period 1971-2000, the first fall frost will occur later and the last spring frost will occur earlier. The first fall frost will occur later for 2 days (based on the A1B emission scenario) to 5 days (based on the A2 emission scenario) and the last spring frost will occur earlier for 2 days (based on the and B1 emission scenario) to 4 days (based on the A2 emission scenario). Finally, the best distribution functions for the first fall frost and the last spring frost for the baseline period and under climate change were selected and compared using the EasyFit software.

Density currents are often the main cause of sediment transport in deep water and reservoirs. To prevent sedimentation in critical locations of dams, various methods have been proposed, including placing obstacles in the path of these currents. in this study, the effect of discharge, inlet concentration, slope and height of trapezoidal permeable obstacle on the behavior of density current has been investigated . 72 experiments were performed with variable discharge of 1, 1.5, and 2 liters per second and variable concentrations of 10 and 15 g/l, slope of 0.5%, 1% and 1.5% and obstacle height of 1,1.5 and 2 times the body of density current. The percentage of flux reduction was determined and the effect of other parameters was evaluated. The results showed that slope, concentration and inlet discharge are the factors affecting the momentum and by increasing each of these parameters, the efficiency of obstacle with heights of 1 and 1.5 times body density current decreases. In case of obstacle with a height of 2 times the body, when the current collides with the obstacle, there is a lot of turbulence, which decreases the momentum of the current, and complete control is performed. Thus, the average percentage of flux reduction for the dimensionless ratio of height 1 is about 38%, for the dimensionless ratio of height 1.5 is about 52% and for the dimensionless ratio of height 2 is about 86%. Finally, linear and nonlinear regression of the average percentage of flux reduction data was obtained.

The upcoming climate change has become a serious concern for the human society. These changes, caused and aggravated by the industrial activities of the international community and the increase in the concentration of greenhouse gases in the atmosphere, are seen as a threat to the food security and environment. Temperature change and precipitation are studied in the form of different probabilistic scenarios in order to have an outlook for the future. The present study was conducted to address the effects of climate changes on temperature and precipitation in Qazvin plain in the form of five AOGCMs including Hadcm3, CSIRO-MK3, GFDL, CGCM3 and MICROC3.2, and 3 greenhouse gas emission scenarios of A1B, A2 and B1, based on different possible scenario combinations in the next 30 years, 2021-2050 and 2051-2080 (near and far future). On basis of the study results, all 4 target stations, on average, will have experienced a change between two ratios of 0.5 and 1.4 of  the observed precipitation period  by the end of 2050, and the mean temperature will have had a change  between -0.1 to 1.6 °C, relative to the observed period.  By the end of 2080,  the  precipitation will also have fluctuated between the two proportions of 0.5 and 1.7 times of the observed precipitation period and the mean temperature will touch an increase between 0.6 and 2.6 °C. Both SPI and SPEI indices suggest the increment in the number of dry periods in the near and far future. However, the total number of negative sequences differed considering the 3, 12 and 24-month intervals at the stations level. Given the SPEI index, as compared to the base period, the total negative sequences of drought and number of dry periods will increase at 3 stations of Avaj, Bagh-Kowsar and Shahid-rajaei-powerhouse and decrease at Qazvin station in the future; however, SPI gives different results, such that  for Bagh-Kowsar, there will be an increase in both total negative sequences of drought and number of dry periods, as  compared to the baseline period; three other stations will have more dry periods, specifically, but less total negative sequences. The results reported that the drought events would become severe, and the wet events would become extreme in the future.

Determination of the breach parameters and resulting hydrograph of the embankment dam failure due to overtopping and piping erosion has great importance because of the significant injuries and environmental impacts. In this research, by investigations on the erosion mechanisms, the affecting processes on the embankment dam failure are examined, and empirical relationships are presented to determine the peak outflow discharge (Qp), time, and breach characteristics in the overtopping and piping failure cases. Physical models with different heights and technical specifications were constructed and failed in the experimental flume to study the breach expansion rates. In the other part of the research, new empirical relations have been developed to predict the eroded volume (Ver) based on the breach characteristics and the contribution of various resources including historical, experimental, and hypothetical failures of the real embankments. The BREACH mathematical model has been used to obtain the failure parameters related to the hypothetical breach of the recent dams. According to observations, the failure time (tf) is highly dependent on hydraulic and breach characteristics. Therefore, the tf is considered as a function of these characteristics in the proposed formulas. Based on the performance indices, the values of the determination coefficient (R^2) for the newly proposed Qp relations are equal to 0.94 and 0.91, respectively, in the overtopping and piping failures. This coefficient for the development of the Ver relationship is equal to 0.98, and for the development of tf equations are equal to 0.85 and 0.87, respectively. Since the outflow hydrograph of a breached embankment dam is largely depended on the geometry and evolution time of the breach, the failure hydrographs of real embankments are simulated using a combination of regression analysis and evolutionary algorithms as a case study.

Density current is one of the most important factors in the sedimentation process of dams. Because this current is one of the important factors affecting the reduction of life efficiency of large dams, so understanding sedimentation patterns to manage the reservoir of dams is very effective. Accordingly, in this study, the reduction percentage of the density current head flux under the influence of trapezoidal permeable barriers (filled with sand grains with a diameter of 0.5 cm) is investigated also variable parameters effect such as discharge, slope, concentration and height of obstacles on density current control is examined experimentally, based on the results, the reduction percentage of the density current head flux was modeled using the artificial neural network feed-forward method and the classical multivariable regression method, and the performance of these two methods was compared. The results showed that the intelligent method of feed-forward artificial neural network has a significant advantage over the multivariable regression method in modeling the reduction percentage of the density current head flux.

Due to the high cost of construction of the dams, increasing the lifespan of this construction structure has been considered by water engineers. Sediments near the dam wall reduce the useful life of this structure. Constructing obstacles in the path of density currents be is one of the most widely used methods in controlling these sediments. In this study, the effect of permeable obstacles on density current head flux has been studied experimentally. The obstacles were made in the shape of trapezoid and were filled with sand particles with a diameter of one centimeter also salt were used to prepare the density current. In these experiments, the effect of inlet flow, flume slope and obstacle height on density current was investigated. Examining the variables of this study, it has been found that the reduction percentage of the density current head flux for the dimensionless ratio of height 1 is between 33.1 to 61%, for the dimensionless ratio of height 1.5 is between 43.2 to 63.3% and for the dimensionless ratio of height 2 is between 68.2 to It is 100%, also increasing the inlet flow ratio and flume slope increases the momentum of the current and thus reduces the efficiency of the obstacles. In addition, at the end, the density current head was modeled as linear and nonlinear regression.

Embankment dam is always the most suitable and most available (considering the type of materials) of the structure in the water-related structures and is also suitable for feeding the groundwater table. In contrast to the advantages of embankment dams, the main problem in the use of these types of dams is the water seepage in the dam body. One of the ways to control the seepage at the foundation of the embankment dams is the use of a cut-off-wall. In the current study, the calculation of seepage current through finite element method using GeoStudio software was performed without the use of common computational methods such as grid flow or design using dam width and water heights behind the dam. A sample of embankment dam with a specific surface of the reservoir has been studied. Different parameters of the dam such as the permeability coefficient of different components and the height of the cut-off-wall and the location of the cut-off-wall are compared to the core of the dam as a variable, and an outline for the seepage rate from the dam various states are obtained. Also, using Genexprotolls.5 software based on the obtained data and regression analysis, a genetic programming interface has been developed to calculate the seepage rate from the dam foundation according to the variables introduced. The level of leakage from the dam is reduced by displacing the cut-of-wall toward downstream as well as increasing the coefficient of permeability of the dam shell. The results show that the variations of coefficient of permeability of the core dam have a small effect on the leakage rate of the dam foundation. On the other hand, increasing the permeability coefficient of the dam foundation increases significantly the leakage from the dam foundation.

Wastewater/runoff reuse is one of the strategies for sustainable water resource management which, based on the consumption type, requires supplementary treatment and standardization due to a wide range of environmental contaminations. Wastewater recycling not only reduces the pressure on fresh water resources but also is so frugal in comparison to the huge costs and the environmental and socioeconomic impacts of water transfer projects, especially between the basins. Nowadays, the application of bio-methods such as constructed wetlands has increased significantly due to the high cost of conventional wastewater treatment approaches. Constructed wetland systems have different design methods depending on the desired outlook (wastewater or runoff treatment). With regards to the flow patern, the system classifies into free water surface flow, and horizontal and vertical subsurface flow. Design configurations of the constructed wetlands depend on the kinematic description of biological reaction as well as the designer’s knowledge of the flow pattern. In this paper, the related literature is reviewed and the required supplementary treatment of secondary effluent of the treatment plant is presented. Then the performance of different types of constructed wetlands in removal of pollutants is investigated. Finally the principles of constructed wetlands design with the aim of harvesting and treating runoff and wastewater have been thoroughly described. The design criteria are presented based on the observed obstacles for such evolution in the field of water recycling. The feasibility of constructed wetlands is then investigated, especially in arid and semi-arid regions. By presenting the justified plan for the system application, the required measures for site selection of such constructed wetland systems are expressed.

Creation and conservation of urban parks is challenging in arid environments where daily thermal extremes, water scarcity, air pollution and shortage of natural green spaces are more conspicuous. Water scarcity in the arid regions of Iran is major challenge for water managers. Accurate estimation of urban landscape evapotranspiration is therefore critically important for cities located in naturally dry environments, to appropriately manage irrigation practices. This study investigated two factor-based approaches, Water Use Classifications of Landscape Species (WUCOLS) and Landscape Irrigation Management Program (LIMP), to measure the water demand in a botanic garden. The irrigation water volume applied was compared with the gross water demand for the period from 2011 to 2013. On average, WUCOLS estimated an average annual irrigation need of 1164 mm which is 15% less than the applied value of 1366 mm while the LIMP estimate of 1239 mm was 9% less than the applied value. Comparison of estimated and applied irrigation showed that a water saving of 9% can be made by the LIMP method. The outcomes of this research stressed the need to modify the irrigation requirements based on effective rainfall throughout the year, rather relying on long-term average data.

Flood discharge estimation with different return periods is one of important factors for water structures design and installation. On the other hand, a lot of rivers existing in Iran watersheds have no complete and accurate hydrometric data. In these cases, one of the suitable solutions to estimate peak discharges with different return periods is the regional flood analysis. In this research, 55 hydrometric stations were used. For this purpose, at first, peak discharges in different return periods were estimated using the EasyFit software. Then, the effective variables on the peak discharges were collected and the input variables of the models were selected by using gamma test with the help of the WinGamma software. Finally, data modeling was performed using the support vector machine, artificial neural networks and nonlinear multivariate regression techniques. Quantitative and qualitative assessment of the results using various indices including Nash-Sutcliffe Efficiency Coefficient (NSC) showed that SVM modeling method had the most accuracy in comparison to the other two modeling methods to predict the peak discharges in the Namak Lake Watershed.

In the present study, we used 27 precipitation average monthly data from synoptic, climatologic, rain-guage and evaporative stations located in Zayandeh-Rud river basin for the period of 1970-2014. Before interpolating, the missing data in the time series of each station was reconstructed by the normal ratio method. Also, for the data quality control, the Dickey-Fuller and Shapiro-Wilk tests were used to check the data stationarity and normality. Then, these data were interpolated by six interpolation methods including   Inverse Distance Weighting, Natural Neighbor, Tension Spline, Regularized Spline, Ordinary Kriging and Universal Kriging; then each method was evaluated using the cross-validation technique with MAE, MBE and RMSE indices. The results showed that among the spatial interpolation methods, Natural Neighbor method with MAE of 0.24 had the best performance for interpolating precipitation among all of the methods. Also, among Ordinary Kriging, Universal Kriging, Spline and Inverse Distance Weighting methods, respectively, Exponential Kriging with MAE 0.54, Quadratic Drift Kriging with MAE of 0.5, Tension Spline with the MAE of 0.54 and Inverse Distance Weighting with the power of 4 with MAE of 0.57 had the least error compared to other IDW methods.

Horizontal subsurface flow constructed wetlands have long been applied to improve water or wastewater quality. Previous studies on wetland systems have focused on trying to comprehend the processes leading to the removal of pollutants. Comparatively, there have been fewer studies dedicated to the assessment of flow distribution on hydraulic behavior through the wetland. Researchers declared the aspect ratio (length to width ratio), inlet-outlet configuration, the size of the porous media and the loading rate of constructed wetland could influence hydraulic retention time (HRT). Su et al. (2009) have stated that in free water surface constructed wetlands, when the aspect ratio is greater than 5, the hydraulic efficiency will reach 0.9, or even higher. If the project site or field area cannot meet the theoretical standard, the recommended aspect ratio is higher than 1.88 to ensure some hydraulic efficiency greater than 0.7. The present study was an attempt to analyse, with the aid of 3D numerical simulation and tracer study, how flow distribution affected hydraulic behavior by using 3 different input flow layouts. The treatment system consisted of a horizontal subsurface flow in a constructed wetland having an aspect ratio of 6.5 and the bed slope of one percent. The geometry of this system, which was 4 m wide × 26 m long × 1 m deep, was planted with Phragmites australis. Inlet configurations were selected as a variable parameter. Three different inlet flow configurations including midpoint-midpoint (A), corner- midpoint (B) and uniform-midpoint (C), with the same fixed outlet configurations, were studied. The average flow discharge in each configuration was 6.58, 6.52 and 6.4 m3/day, respectively. Dye tracer was used to draw retention time distribution curves in each configuration for assessing the internal dispersion, short-circuiting and hydraulic parameters such as effective volume rate which is derived by division of mean retention time per nominal retention time. The 3D model presented, which was built on the Comsol Multiphysics platform, was implemented for fluid flow to show internal hydraulic patterns in the system. Hence, the hydraulic model used the Darcy equation to simulate a stationary water flow through the bed. The simulations were verified by using real data obtained from the existing constructed wetland. It was mostly used to show pressure throughout the system for each configuration of the inlet and the outlet. The mean retention time for each configuration was found to be 4.53, 3.24 and 4.65 days, respectively. A marked reduction of the mean hydraulic retention time signified leaving tracer concentration from the outlet rapidly, high short-circuiting and dead volume and finally defective treatment process influenced by changing the inlet to the corner. According to tracer breakthrough curve, the effective volumes for configurations A and C were 87.5%, as compared to 62.1% for the configuration B. The two-day difference of tpeak between configurations 2 and 1, and 3 was probably due to the establishment of preferential streamlines resulting in short-circuiting and areas of dead volume in the system. The value of tpeakis related to dispersion, in the sense that a retention time distribution curve with a small peak time generally contains low dispersion. Simulation results showed the pressure difference from the inlet to the outlet ranged from 12-14, 14-15 and 10-13 cm H2O for A, B and C layouts, respectively. It was shown that the maximum pressure gradient occurred at the outset of the influent wastewater at the inlet, and it was gradually reduced to the lowest values at the outlet ports. Consequence of surface pressure demonstrated uniform pressure from inlet toward outlet at configuration C. Simulated streamlines approved this result, while range of high and low pressure area at configuration B was the most. There was a strong association between tracer experiments and simulation works. One of the major findings of this study was the significant shorter hydraulic mean retention time of the corner inlet setup. There are many that may cause these effects, although short-circuiting may be the primary one. A large low-pressure zone appeared at the opposite corner that was neither inlet nor outlet in this configuration. This paper investigated the hydraulic performance and short-circuiting effects on water flow due to three different inlet patterns (i.e. midpoint, corner, and uniform) in horizontal subsurface flow wetlands based on dye tracer measurements and numerical modeling. The results showed that the uniform inlet could provide the highest hydraulic efficiency (i.e. longest hydraulic retention time, HRT), in comparison to other two setups. The performance of the three different layouts was also investigated in terms of hydraulic parameters. Short-circuiting was influenced by lower hydraulic retention time, leading to inadequate treatment. Uniform-midpoint and midpoint-midpoint yielded the best effective volume as compared to the corner-midpoint. It was demonstrated that these two cases increased dispersion and used the whole capacity of the constructed wetland for the treatment process. The most important result of this paper was the evaluation of internal hydraulic pattern thorough the wetland, something not investigated in previous research works. Based on the simulation results, the spatial pressure distribution in wetland cells was depicted. Finally, it can be concluded that the best configuration of inlet-outlet layout based on both numerical simulations and physical experiments is uniform-midpoint. Meanwhile, midpoint-midpoint is preferable to corner-corner by all performance criteria.

Regionalization is one of the useful tools for carrying out effective analyses in regions lacking data or with having only incomplete data. One of the regionalization methods widely used in the hydrological studies is the clustering approach. Moreover, another effective factor on clustering is the degree of importance and participation level for each of these attributes. In this study, it was tried to use a broad range of attributes to compare their performance in regionalization. Then, according to the importance and role of each attribute in regionalization, the appropriate weight for each of the attributes in each category was determined using the principal component analysis (PCA) method, and the effect of this weighting in forming the homogenous regions was investigated by the Ward's clustering method. In this regard, the maximum 24-hour rainfall data of 63 meteorological stations located in Urmia Lake Basin (ULB) was used in this study during a time period of 30 years (1979-2008). Furthermore, seven categories of attributes were defined in order to regionalize the rainfall. The results showed that by considering different attributes and combining them with each other, a different clustering is obtained in each category in terms of the number of clusters and stations. Among seven categories of attributes, it was found that the geographical and climatic-geographical categories of attributes showed a more appropriate clustering over the ULB. Additionally, the weighting of attributes could have more effect on improving homogeneity and forming the independent clusters in most cases in terms of the scattering of station and how to locate over the basin.

Understanding the concept of water balance is one of the most important prerequisites for sustainable management of water resources in the watersheds. Therefore, the components of water resources in a catchment system should be compared at different time periods, and also the effect of each of them should be identified on varied hydraulic components of the hydrological systems. The SWAT model is an example of a physically based hydrologic model which can be used for large-scale simulating and monitoring of water cycle processes based on the characteristics of the catchment area and its climatic conditions. The main object of this study is the hydrologic simulation and water balance estimation for the period 2000-2009 in the Zayandeh-Rud River Basin. The Zayandeh-Rud River Basin is located in the arid and semi-arid central region of Iran. This area is very variable in terms of rainfall. As well as the state of water resources and water consumption is very complicated in this catchment. In the present study, the soil and water assessment tool (SWAT) used to simulate water balance in the Zayandeh-Rud River Basin. The input required data included digital elevation model, land use map, soil texture map and meteorological information including daily rainfall data and minimum and maximum temperature data were introduced to the model and the model was implemented with these data. The sensitivity of the flow-effective parameters was determined using the p-value and t-state criteria by the SUFI2 algorithm in the SWAT-CUP program. The model was calibrated monthly and validated with the selected parameters in the sensitivity analysis using the Nash-Sutcliff criteria and the coefficient of determination by the application of the data of six stations including. Calibration of the model was conducted for 2000-2006 and validation of the model for the years 2007-2009. The results of sensitivity analysis showed that considering the characteristics of the study area, the SWAT model is more sensitive to the 17 effective parameters on runoff. The selected parameters also confirm the results of previous research carried out in the region. The sensitive parameters selected in the sensitivity analysis step were used to calibrate the model. In the next step, the parameters of SWAT-CUP software were entered. After that, these parameters were repeated 1000 times with the SUFI2 algorithm, and the optimal value for each parameter was determined. The Nash-Sutcliff coefficient and the coefficient of determination in the six hydrometric stations are greater than 0.56 and 0.69 in calibration and verification periods respectively, which indicates that the model has a satisfactory ability to run in runoff simulation. The contribution of the components of the water balance including evapotranspiration, surface runoff, lateral flow, groundwater flow, and deep aquifer recharge was calculated from annual basin precipitation. The amount of extracted water from the hydrological components indicated that the largest share of the water balance was related to actual evapotranspiration, the range of variations in the type of precipitation in the study area ranged from 60.1% (2000) to 92.7 % (2007). After evapotranspiration, surface runoff with a change of 22.2% (2005) to 8.6% (2009) and groundwater flow with a change of 14.2% (2000) to 20.5% (the year 2007) had relatively high fluctuations and a large share in the basin balance. These results indicate that the lateral flow with a range of 3.1 to 1.9% had no significant change in these years. Also, the deep aquifer recharge with the range of 1.2 to1.5% was the lowest in 2003 and 2009, respectively. The results showed that the calibrated model for the Zayandeh-Rud River Basin had a desirable performance for both calibration and validation periods. Therefore, the SWAT model has acceptable performance for simulating the water balance of the area. In addition, the results of this study showed that 65.98% of the total annual precipitation in the basin is in form of evapotranspiration, which compares to the other water balance components has the highest part. As well as surface runoff with 15%, groundwater flow with 13.7%, lateral flow with 1.5%, and deep aquifer recharge with 0.8% have other parts of the water balance components in Zayandeh-Rud River Basin. The results also indicate that the highest water losses in the soil and groundwater resources of the basin are due to evapotranspiration. Therefore, serious measures to prevent the loss of water through evapotranspiration in the region to be necessary. The results of this research can be used to predict the effects of climate change and the applicable management practices in the region, which are presented in scenarios to the model.

Treatment capability of a constructed wetland is heavily dependent on the uniformity of flow moving inside the wetland. This modeling study was performed to evaluate the effect of flow distribution on internal hydraulic behavior of horizontal subsurface flow constructed wetland. To accomplish this objective of the study, three different inlet flow configurations including (1) midpoint, (2) corner and (3) uniform while keeping a fixed midpoint outlet flow for all configurations. The model used in this study was based on COMSOL Multiphysics platform for subsurface flow differential equation in porous mediums (Darcy law). Hydraulic head zoning indicated uniform flow distribution in form of parallel streamlines from inlet to outlet in configuration 3 while substantial number of shortcuts and a noticiable difference between high and low pressure areas were observed in configuration 1 and 2. Results obtained from the simulated streamlines and pressure contours throughout the wetland confirmed the field observation results. Hydraulic head range at each configuration is 14.35, 15.25 and 13.05 cm, respectively. Results indicated an appropriate hydraulic performance of the uniform inflow configuration to use the whole capacity of constructed wetland for treatment process. Meanwhile, midpoint inlet configuration had a proper performance by considering some criteria to reduce dead volume and shortcuts.

North Mahyar plain in Isfahan, is one of the plains which has confront water crisis. In these circumstances, attention to the capacity of the resources and proper management is an important issue to pass this condition. Chitsazan et al. (2013) noted that artificial neural network is able to figure out the relation of hydrologic parameter. Also, this tool can be used in water resources management (Coppola et al., 2005). Therefore, by applying artificial neural network, water-table data and cropping pattern in plain, three land-use scenarios were designed. Water table was simulated for water year of 2008 with one-layer network, Levenberg–Marquardt algorithm, and three functions in MATLAB­­_R2012a. Water table map was prepared by using simulated water table in ArcGIS 10.2, and zoning was performed according to the costs of water pumping. Results showed that 61-86 percent of the plain in all three scenarios had medium limitation. Also, using different management in field like fallowing and planting low-water use crops caused 3 and 5 percent increase in acreage of "without limitation" lands, respectively.

Evapotranspiration is one of the most important components of the hydrological cycle and hydrological models for planning irrigation system water. In this study, the amount of evapotranspiration using the FAO Penman-Monteith for synoptic weather stations of Isfahan and Rasht that located in parts of central and northern Iran in the period 1970-2011. Some of the most important meteorological variables affecting it in the scales of seasonal and annual was calculated. In addition, changes were also analyzed and compared. For this purpose, non-parametric test of Mann-kendall and parametric test of regression was used. The results showed that the annual scale evapotranspiration changes in Rasht, and Isfahan stations had the significant increasing trend (5% level). At these station, the temperature increased and the minimum relative humidity decreased but of course was greater than other variables. In the seasonal scale both positive and negative trends have been observed. Isfahan Station evapotranspiration trends in other seasons except in winter is negative (5% level). Rasht Station evapotranspiration trends in other seasons except in spring was positive (5% level). Among the studied variables, seasonal and annual of number of sunshine hours was increased (level 5%). Maximum and minimum air temperature trend at both stations in the annual scale was increased (5% level). Comparing the results of the review process, potential evapotranspiration and temperature changes by both tests showed contradictory phenomena in the process of evaporation variables in Isfahan Station.

Water scarcity forced farmers to use wastewater as water source, without considering its effects on environment and resultant contamination of soils and plants especially with heavy metals. The objectives of this study are to evaluate the application effects of zeolite as soil amendments on the uptake of Cd by spinach (Spinach Oleares L.) irrigated with wastewater (containing 10 ppm Cd). Different levels amounts of zeoilte (0, 1% and 5% w/w) were added to the soil and the experiment was conducted as a completely randomized design in a green house with 3 replications. The results indicated that, the addition of zeolite 1% (w/w) in soil treated with wastewater reduced cadmium concentration in plant, and consequently the percentage of extractable Cd using DTPA was decreased. However, application of zeolite 5% (w/w) increased the soil salinity, and as a result increased Cd concentration in the plant but this increase was not statistically significant, comparing with control. Spinach biomass did not differ significantly under irrigation with wastewater, but the Cd available in wastewater caused a decrease in Spinach biomass yield.

This study investigated the effects of climate change on the evapotranspiration amount and water balance in the Zayandeh-Rud river basin. Two important weather stations; Isfahan and Chelgerd stations, located in the East and West of the basin respectively, were selected for investigation in this study. The combination of 15 GCM models were created based on the weighting method and three patterns of climate change including the ideal, medium and critical were defined. Using the proposed patterns, the effects of climate change on temperature and evapotranspiration in Isfahan station and precipitation in Chelgerd station were estimated under the A2 and B1 emissions scenarios. Two indices were considered to determine the sustainability of agricultural water consumption in the study area. Ratio of evapotranspiration in the East part of the basin to precipitation in the West part was defined as EPR index (Evapotranspiration-Precipitation Ratio), and the ratio of maximum agricultural water deficit to the amount of agriculture water need, was considered as maximum deficit index (MD). Results showed that the annual temperature would increase between 0.63-1.13°C in the eastern part of the basin. The west precipitation in the basin would reduce between 6.5-30% in the ideal to critical patterns. Summer season, showed the most amount of increase in the temperature, and winter season, showed the most amount of decrease in precipitation. The A2 emission scenario showed more temperature increase and more precipitation decrease in comparison with the B1 emission scenario and also indicated that the potential evapotranspiration would increase by 3.1 to 4.8% in the basin. The EPR index will increase between 13-52% and MD index will increase between 9-35% in Zayandeh-Rud river basin under different climate change patterns. The results revealed the imbalance between agricultural water use in eastern part and the precipitation in the western part of the basin. In other words, in these conditions, appropriate management strategies and planning should be implemented to ensure the sustainability of water resources in Zayandeh-Rud River Basin.