مجله پژوهش آب ایران
پیاپی 46 (پاییز 1401)

Water scarcity is the most important problem affecting the growth and yield of crops in arid and semi-arid regions such as Iran. Therefore, due to limited water resources, it is necessary to optimize water consumption and use deficit irrigation techniques. In recent decades, agricultural development and declining rainfall have put severe pressure on groundwater resources. In Fars province, which is one of the most important provinces in terms of agricultural production, more than 70% of agricultural water is supplied from groundwater resources. This has caused a sharp drop in the level of groundwater aquifers. The development of new irrigation systems due to the high potential efficiency can contribute to the balanced use of water resources. Of course, according to the FAO, the new irrigation system alone is not enough, and in addition, attention must be paid to controlling water allocation. Previous research has shown that irrigation scheduling, which determines the start and end of irrigation, can be effective in reducing water consumption in farms and orchards. Safflower can be mentioned among the oilseeds compatible with the climatic conditions of Iran. The object of the study was to investigate the effect of different irrigation managements on some agronomic and yield traits of safflower cultivars.

The experiment was conducted in the form of split plots in a randomized complete block design with three replications at Zarghan Agricultural Research Station in 2020. Irrigation levels (cut off irrigation in buttoning stage (I1), supply of 25, 50, 75 and 100% of water requirement until the end of growing season I2, I3, I4 and I5, respectively) as main plots and cultivars of Local Isfahan, Goldasht, Sefeh and Faraman as subplots. Each subplot consisted of four planting rows with a length of 6 m and row spacing and plant spacing per row of 60 and 5 cm, respectively. Some traits such as day to maturity, plant height at harvest time, yield measured. Crop water stress index (CWSI) and economic and physical water productivity were calculated. Economic analyzes were also performed. In order to estimate the economic productivity of water (in Rials per cubic meter), it is necessary to obtain the net profit per hectare. For this purpose, the total planting, maintenance, harvesting and irrigation costs of safflower farm in the year of the research were estimated. The amount of gross income was also obtained by multiplying the selling price of the product by the amount of performance. Benefits to cost ratios and the difference between benefits and costs were also calculated and examined in different cultivars and irrigation treatments, and the best treatment and cultivar were introduced economically. The amount of water required for each treatment was calculated by Penman-Montieth method and measured and delivered using volume meters. Data were analyzed by SAS software and the means were compared using LSD test.

The results of correlation study of different traits showed a significant positive relationship between day to end of flowering, day to physiological maturity, number of bolls per plant, number of seeds per boll, 1000-seed weight and biological yield. The highest grain yield in the treatment of 100% water requirement (I5) was in Faraman cultivar (2688 kg/ ha). The lowest grain yield in water cut treatment in buttoning stage (I1) was related to Sefeh and local cultivars of Isfahan with yields of 758 and 779 kg/ha, respectively, which were in one statistical class and did not differ significantly from each other. The highest irrigation water productivity and total water productivity were related to irrigation cut-off treatment and 75% irrigation treatment with values of 0.383 and 0.274 kg/m3, respectively. Economic water productivity was also higher in (I4). In all cultivars studied, the amount of net profit was higher in (I5) where irrigation was done completely. The difference between the net profit of (I4) and (I5) was about 20 million rials per hectare. The benefit-to-cost ratio also increased with increasing irrigation water, but the difference between (I4) and (I5) was not significant in all cultivars. The highest economic water productivity in all cultivars was obtained in (I4). Among the studied cultivars, the highest and lowest values of the studied economic indicators belonged to Faraman and local cultivars of Isfahan, respectively. Using water stress baselines obtained in this study, by measuring leaf temperature, air temperature and air humidity, the time of occurrence of different water stresses can be obtained and based on that, the start time of irrigation can be determined.

Water resources scarcity is the biggest challenge for food production. In addition to the problem of water shortage, salinity stress is also an important limiting factor in agricultural systems that disrupts the growth and development of most plants. So, drought and salinity stresses are among the main environmental and biological stresses that reduce agricultural and horticultural productions all over the world, especially in arid and semi-arid regions. High evaporation, low rainfall, water scarcity, soil salinity and low quality of available water resources are the serious concerns in arid and semi-arid regions that threaten the sustainability of agriculture in these areas. It can be said with certainty that proper management of irrigation and drainage is the main key to protecting water and soil resources, maintaining their quality and continuing irrigated cultivation to meet the growing nutritional needs of the world. Due to the fact that native cultivars of plants in each region show better adaptation reactions in critical conditions, this experiment was performed to evaluate the tolerance of pistachio Badami rootstock as a native cultivar of Ardakan region to salinity and drought stresses.

In this research, in order to investigate the interaction effect of salinity and drought stresses on pistachio seedlings, a factorial experiment was conducted as a completely randomized design with three replications in greenhouse of Pistachio Research Station of Ardakan city located in Yazd province. The irrigation treatments were applied as 5 (I1), 10 (I2) and 15 (I3) days of irrigation interval. Four salinity levels of irrigation water included 0.5 (S1), 4 (S2), 7 (S3) and 10 (S4) dS/m. The amount of irrigation water was determined by weighing the pots before each irrigation and raising the pots soil water content to field capacity. Furthermore, 30% more water was applied as leaching fraction. Electrical conductivity of the drainage water was determined throughout the applying of stress treatment by taking the samples of the drainage water. At the end of the treatments period, in addition to the actual evapotranspiration of each treatment, morphological traits of seedlings including leaf area, shoot dry weight, plant height, stem diameter, root dry weight and main root length were measured. The main and interaction effects between water and salinity stress levels were separately evaluated, using SPSS software. The analysis of variance (ANOVA) was performed using Duncan’s method to determine statistically significant differences between the means (p ≤ 0.05).

Results showed that the main effect of the irrigation intervals and salinity levels of irrigation water were significant on all of the traits except seedlings height at one percent level. However, the interaction effects of irrigation interval and salinity were only significant on evapotranspiration, leaf area and root dry weight. The increasing irrigation water salinity from 0.5 to 10 dS/m, the average evapotranspiration decreased by 17% and increasing the irrigation interval from 5 to 15 days, the average evapotranspiration decreased by 49%. Increasing the irrigation interval caused a greater decrease in evapotranspiration than increasing the irrigation water salinity. Comparison of shoot and root dry weights at the lowest salinity level compared to the highest salinity level showed a decrease of 60 and 58%, respectively. Increasing the irrigation interval from 5 to 15 days also reduced the average dry shoot and root weights by 27 and 29%, respectively. By increasing irrigation interval from 5 to 15 days and increasing salinity from 0.5 to 10 dS/m, leaf area decreased by 46 and 79%, respectively. In general, based on the results, the effect of salinity on reducing the shoot and root morphological traits of pistachio was more than the effect of drought, the most important reason can be the toxicity of salinity ions, especially sodium and chlorine in disrupting the internal metabolism of pistachio especially photosynthesis process. The results of comparing the mean of traits such as dry weights of shoot and root and leaf area, showed that the best irrigation interval for pistachio in greenhouse condition was 10 days. The readily available water for 2-year-old pistachio seedlings for shoot dry matter production was also determined 41 percent. The salinity threshold of soil solution for reducing shoot and root dry weights for 2-year-old pistachio seedlings of Badami cultivar were obtained 8.8 and 7.0 dS/m, respectively. These threshold values indicate that the pistachio root growth begins to decrease at lower salinity. In other words, by increasing salinity, while continuing the process of water uptake by root, dry matter increases in the shoot section, it means, the pistachio shoot growth begins to decrease at higher salinity. The slope for decreasing shoot and root dry matter was 4 percent per unit increase in soil solution salinity. The results of this research can be used for water management in greenhouses and by farmers for growing pistachio seedlings of Badami cultivar.

About 34% of the lemon produced in the country is obtained from Fars province. This province, like many parts of the country, is one of the arid and semi-arid regions, and water management is of particular importance in it. In order to better plan and manage water resources and increase the amount of crops and water productivity of farms and gardens, sufficient information should be available on the amount of water used in different crops. Considering the importance of lemon fruit in Fars province and conducting little research on the amount of irrigation water for this product in the country, it can be useful to investigate this index and the water productivity of this product in the Fars province.

In this project, the water productivity and the amount of irrigation water given by gardeners for lemon production during one year (2021) were measured without providing technical or expert advice to the gardeners. The location of the research was the seven most important cities in Fars province in terms of lemon cultivation area, including Qhir-Karzin, Jahorm, Darab, Lar, Kazerun, Farashband and Mohr. In each city, 10 gardens and a total of 70 gardens were selected for data collection and monitoring. The desired gardens in the cities were identified and selected with the help of experts from the agricultural jihad organizations of the provinces. The studied lemon orchards were selected in such a way as to cover various factors such as irrigation method, soil texture, variety and quality of irrigation water. The yield was obtained in three consecutive years and their average was used in the analysis. The selected gardens were all equipped with drip irrigation system. The amount of discharge from the water source was measured by calibrated meter in each of the selected gardens three times a year. After determining the flow rate of water entering the orchard, by carefully monitoring the irrigation program of the orchard and also measuring the area under cultivation, the volume of irrigation water for lemon trees in each of the selected orchards was measured. The amount of evapotranspiration of lemon trees in each region was calculated using the meteorological data of the nearest station to the project implementation area in the last 10 years and the year of conducting the research using the Penman-Montieth method. The values of net required water of lemon were also obtained from the National Water Document. The gross required water of gardens was obtained and compared with the irrigation water volume of gardens by t-test. Variance analysis was used to investigate yield changes, irrigation water volume and water productivity in lemon production in the target cities.

Among the selected orchards, due to differences in irrigation management, soil salinity and other factors, the amount of irrigation water volume varied from about 6000 to 21000 m3/ha/yr. The average total volume of irrigation water was 13376 m3/ha. In terms of regional average, the lowest and highest amount of irrigation water volume was related to Jahrom and Darab with 10030 and 16433 m3/ha, respectively. The average total volume of applied water, in which the amount of effective rainfall is added to the volume of irrigation water, was estimated to be 14407 m3/ha/yr. The range of changes in the volume of applied water in gardens varied from about 7000 to 22000 m3/ha. Therefore, it can be said that the contribution of rainfall in the year of conducting the research was on average about 100 mm or 1000 m3/ha. In terms of volume of applied water, the highest and lowest amount belonged to Kazerun and Jahorm cities with 18799 and 10768 m3/ha, respectively. Irrigation water productivity in selected orchards ranged from 0.69 to 3.21 kg/m3 and averaged 1.52 kg/m3. Comparing the volume of irrigation water with the gross water requirement in different areas showed that in some regions over-irrigation and in some deficit irrigation was done. But in general, the average difference between the volume of irrigation water and the annual gross water requirement was 255 m3/ha, which was not statistically significant. However, the volume of irrigation water at the rate of 1735 m3/ha was more than 11640 m3/ha of long-term gross water requirement, which was statistically significant at the level of 1%. Therefore, it is necessary to apply irrigation scheduling and determine the exact water requirement to increase the productivity of the lemon orchards in Fars province.

Knowledge of the turbulence characteristics in open-channel flow is of importance in hydraulic engineering. Phenomena such as the flow resistance are linked to the velocity distribution and the characteristics of the turbulence structure. Kironoto and Graf (1995) studied turbulence structure of rough, non-uniform open channel flow and measured velocity, turbulence intensity and Reynolds stress profiles. They reported that the turbulence intensities and Reynolds stress decrease in accelerating and increase in decelerating flows (compared with the ones in uniform flow). Liu et al. (2004) presented a detailed study of the turbulence characteristics of hydraulic jumps at low Froude numbers (<3.3) using ADV. They noted that the ADV underestimates the mean velocity in bubbly two-phase flows. Yang et al. (2006) investigated the interaction of the vertical velocity v and the streamwise velocity u in a gradually accelerating flow. The analytical result shows that the non-zero vertical velocity causes the Reynolds shear stress profile to deviate from the conventional linear distribution in a 2-D flow. Islam et al. (2007) studied Turbulence characteristics downstream of a forced hydraulic jump using ADV. They founded that with the longitudinal distance Reynolds’ stresses decrease linearly and turbulence kinetic energy at each section decreases gradually. the results of Dey and Sarkar (2008) study showed that the rate of decay of jet velocity in a submerged jump increases with increase in bed roughness. Jesudhas et al. (2018) revealed that the expanding shear layer interacts with the free surface resulting in intense undulations and breaking up of the free surface. Most of the aforementioned investigations focused on the turbulent structures of the free or submerged jumps on smooth or rough bed in a rectangular channel. There is a considerable dearth of understanding of the effect of bed roughness and side walls divergence on the turbulent structures in submerged jumps. The present study aims to investigate turbulent characteristics of flow in submerged hydraulic jump over rough bed of stilling basin with divergent side walls.

The experiments were conducted in a hydraulic laboratory of the University of Tabriz in a metal-glass horizontal rectangular flume. The facility had been relatively large-size channel 0.5 m wide, 0.5 m high and 10 m long. The sidewalls had been made of glass for observational purpose with 0.5 m high and 2.1 m long. The inlet flow conditions were controlled by a vertical sluice gate. In order to create a desirable submergence factor in the flume, the tailwater depth was controlled by an adjustable tailgate located at the downstream end of the flume. The upstream gate opening was fixed (2.1 cm) in all of the conducted experiments. To investigate the effect of roughness, discontinuous dissipative elements of lozenge shape with two heights (1.4 and 2.8 cm) were installed on the horizontal bed. Three glass physical models were built with divergence ratio (B = b1/b2) of 0.4, 0.6 and 1 (where b1 and b2 are the widths of the stilling basin in upstream and downstream of the hydraulic jump, respectively). During the jump, flow depths were measured using ultrasonic sensors Data Logic US30 with operation range of 10–100 cm and accuracy of ±0.1 mm that were mounted above the channel. Submergence ratio (S) which is defined as (〖(h〗_t-h_j)⁄(h_j)), whereas h_t= tailwater depth and h_j= conjugate depth of free jump. It was important that h_t was measured at the location where the free surface profile became parallel to the bed, and h_j was estimated from the well-known formula of the conjugate depth of free jump which is 0.5b(√(1+8〖Fr〗^2 )-1). The instantaneous velocity components were extracted by a SonTek acoustic Doppler velocimeter (ADV). The ADV measurements were taken in the central vertical axis, which is along the centerline of the flume in vertical lines at different streamwise distances from the sluice gate. By computing the values of signal correlation coefficient (COR) and signal-to-noise ratio (SNR) for each of the three ADV receivers, the accuracy and the quality of the collected data were controlled.

The flow field in submerged jump on horizontal channel with gradually divergent side walls and rough bed was measured by an acoustic Doppler velocimeter. The vertical distributions of time-averaged velocity components, turbulence intensity components, and Reynolds stresses at different streamwise distances from the sluice opening and the horizontal distribution of bed-shear stress have been presented. Presented charts provide a good understanding of the process of decay of jet velocity in submerged jumps on rough beds. The bed-shear stress decreases with increase in streamwise distance and increases with increase in bed roughness. The important observations of the turbulent structures of submerged jumps on channel with gradually divergent side walls and rough bed are summarized below:With increase in bed roughness and decrease in side walls divergence, maximum values of u ̂ occurrence depth (compared to channel bed) would be increased.Increasing bed roughness would results increase in the growth rate of boundary layer which produces more shear stress and more energy dissipation.Variations of u^+ is more than v^+ which is causing more jet distribution ratio in horizontal axes vs vertical axes.Increasing bed roughness and decreasing side walls divergence would increase 〖uv〗^+Reynolds’ stress and turbulence.The length of fully developed zone reduces with increase in bed roughness and reduce in divergence ratio.The bed-shear stress decreases with increase in streamwise distance and increases with increase in bed roughness and decrease in side walls divergence.

Hydraulic jump is a phenomenon that occurs due to the change of current from supercritical to subcritical. In water-depleting buildings, or relaxation ponds, methods are usually used to control the jump in the ponds, which can be used to stabilize, control, and reduce the length and depth of the secondary hydraulic jump. In a stilling basin, different main variables such as floor geometry (including initial and final steps, etc.), plan geometry (including gradual or sudden divergence), bed roughness (to increase shear force) and change in flow rate (by adding It is localized or extracted from water) causes a change in the dimensions of the hydraulic jump or a reduction in the destructive energy of the initial flow.

The experiments were conducted in a flume with Plexiglas bed and walls, which was 8.0 m in length, 0.40 m in width, and 0.60 m in depth. It was connected to a hydraulic circuit allowing for recirculation of discharge. The discharge in the flume was obtained from an overhead tank. The discharge was measured by a calibrated magnetic flow meter located in the supply line with ±5% accuracy. Water entered the flume under a vertical sluice gate, 1.2 m deep. The supercritical depth was controlled by the upstream sluice gate, while the tailwater depth was controlled by the downstream sluice gate. The point gauge with an accuracy of 1 mm was used for the measurement of the depth of water at various locations in the flume. In each experiment, the flow velocity was measured by using a pitot tube in several sections of the jump length. In this study, the expansion ratio is considered in the range of 0≤B≤2, and the height of steps are 0≤B≤6. In total, 108 experiments have been conducted in the range of Froude numbers of 4.9 to 9.5 and discharge 30 to 50 (L⁄s).

In this study, the velocity profiles were measured in the jumps on abrupt expanding channel with a negative step. The velocity profile variations are similar to that of a wall jet, so the boundary layer growth and the maximum velocity, um, decrease with increasing longitudinal distance (x) from the beginning of the jump. To investigate the similarity of these velocity profiles, the length scale (b); the value of y at which (u=0.5u_m ) and ∂u⁄(∂y<0) was determined. Results shows the dimensionless velocity profiles for all expanding data and the negative step in experiments in which velocity profiles are measured. The maximum velocities in the sudden divergent channel and the eternal negative bed step occur at higher points than in the classical wall nozzle.In addition, the results shows the shear force coefficient ε increasing with the Froude number. The shear force coefficient for hydraulic jump in a abrupt expanding channel is 14 times that of hydraulic jump in a rectangular channel, While the negative step reduces the shear force coefficient, which has not been mentioned in any research. As can be seen from the results, the shear force coefficient, in addition to the landing number, also depends on the parameters of divergence ratio, relative step height and conjugate depth ratio.

In the present study, the velocity and shear force profiles in the hydraulic jump in an abrupt expanding channel with a negative step were investigated. In general, the shear stress coefficient of the bed increases with increasing Froude number. The values of shear force coefficient are presented using laboratory data as a function of landing number, divergence ratio and relative height of the step. The shear stress coefficient of the bed in an abrupt expanding channel with a negative step is 14 times that of the classical case. The velocity profiles at different stages of the hydraulic jump in an abrupt expanding channel with a negative step are similar to the classical mode. However, the maximum velocity in these experiments is higher than that of the classic wall jet, and the thickness of the boundary layer is greater when jumping in a sudden divergent channel with a negative step. The value of the dimensionless border layer (δ/b) in the present study was equal to 0.57, which is higher than the corresponding value in the classical case (0.16).

Given the fact that hydropower energy is the third largest source of electricity generation and also the most important renewable energy producer in the world, the optimal use of the huge and expensive source of water is essential. In this study, water cycle metaheuristic algorithm was used for optimization of the hydropower operation of Jiroft reservoir located in Halilrood basin (south of Iran) for a period of 223 months (from October 2000 to April 2019). The decision variables in the hydropower energy optimization model of the reservoir are the optimal release values of the monthly hydropower output from the reservoirs. After verifying the reliability of the WCA algorithm using several standard benchmark functions, a model was developed for optimal hydropower operation of the Jiroft reservoir. Also, the results of the algorithm were compared with the results of known metaheuristic algorithms of the Harmony search Algorithm (HS) and Imperialist Competitive Algorithm (ICA). The WCA, ICA and HS algorithms were capable to generate energy 7203, 273.66, and 7115.78 MW during the statistical period, respectively. Also, the objective function value for WCA, ICA and HS algorithms, was obtained 4.78, 5.82, and 8.63, respectively. The results revealed that the MSA algorithm was the superior algorithm in optimal hydropower operation.

A major part of the decision-making framework in the field of water resources management was dedicated to the development of quantitative-qualitative management models of river systems. In addition, river water quality control with economic approaches is an important part of quality management and environmental issues. Urban, industrial and agricultural wastewaters discharged into rivers with various pollutants are associated with adverse effects on the river ecosystem. These effluents increase the suspended solids in water and drastically reduce the dissolved oxygen in the water, thereby reducing or completely disrupting the possibility of river self-purification. Sustainable water quality management should be able to measure pollutants, predict the effects of pollutants on water quality, and determine the quality of water quality. Since the pollution and environmental problems of rivers have been higher in all countries, especially in industrialized and developed countries, a major part of the studies in the field of quality management of water resources has been devoted to the development of quantitative and qualitative management models of river systems. Accordingly, in this research, the management of the river system with the approach of pollution permit clearance will be studied. Moreover, considering the need for planning for the future, Iran is currently facing an environmental crisis, which doubles the importance of planning in the field of environmental protection. Today, most cities in Iran, including Khorramabad, face environmental pollution issues, including surface and underground pollution. The economic parameters resulting from the optimal utilization of the capacity to accept pollution of water resources systems and the reduction of pollution treatment costs are among the main objectives in the quality management of water resources. Optimal economic conditions in the quality management of river systems were considered between the pollution sources in the decision model. Therefore, in order to develop the decision framework, each source is assigned a permit to discharge the pollution. The trading theory provides incentives for pollution discharge sources in the sustainable river system and for technological initiatives to reduce wastewater discharge and reduce treatment costs. In this paper, a new structure for real-time pollution load in river quality management is presented so that while maintaining water quality at the desired level, the optimal trade model is presented and important uncertainties are considered.

The city of Khorramabad in Lorestan province, Iran is located at 48˚ 21” longitude and 30˚ 43” latitude with 35 km2 area and 1180 m height above sea level. Khorramabad city is considered as a semi-industrial city with 28% of all industries in Lorestan province. A large number of small and large industrial units are located around and near the Khorramabad River and along its route, which directly and indirectly cause its pollution. Some industries discharge wastewater directly into the river, while others discharge it into the river after incomplete treatment. In this paper, combined samples were prepared and analyzed from the pollutant of 9 important industries whose wastewater now enters the river (with or without treatment).Simulation model was used to predict the behavior of the system which is divided into four stages. In the first step, the necessary information was collected and summarized to enter the calibration model. In the next step, the governing equations of the system are formulated by MATLAB programming. The model was calibrated and verified based on the collected information. Finally, it can be used to simulate the effects of different plans on the water allocation strategies.In this study, the Trading-Ratio System (TRS) proposed by Hung and Shaw (2005) was used to trade pollution discharge permits. This system determines the TRS values by considering the rate of river self-purification and the pattern of pollutant distribution to present the optimal trade model with the application of genetic algorithm.Uncertain simulation models make it possible to consider the probabilistic properties of some system variables (such as river discharge and pollution loads). One of the accurate methods of uncertain simulation of water resource systems is multiobjective optimization. In this method, an initial values are randomly generated for each variable and the system is established based on the non-dominated theory and genetic algorithm. The output of the proposed model is two extreme points that are obtained by maximization and minimization of the objective function.

Results of calibration showed that the simulated BOD values were acceptable. The rate of BOD exchange between pollutant sources showed that location, distance and flow rate were significantly important in BOD exchange. Industrial towns have not played an effective role in increasing BOD exchange due to pollution control. Point pollutant sources can affect the flow of pollution in a shorter time and more quickly. The developed ratio-trade model is able to determine the optimal amount of wastewater discharge according to the flow conditions and the amount of pollutants in the form of an optimization model. In addition, the application of the maximum and minimum uncertainty model predicted the probability of each event based on the possible domain. The results of this forecast can determine the maximum risk available for each strategy and give the choice to the decision model. The economic evaluation of wastewater treatment showed that in the proposed model, treatment costs will be reduced by at least 11%.

An important consequence of this study is the development of a decision model that can be used for other chemical contaminants as well. Future research can be developed in the form of a probabilistic prediction model to involve different river flow regimes in the decision-making process.

Desertification is currently a problem in many countries of the world, including developing countries. The result of this phenomenon is the loss of renewable resources in each of these countries. One of the most important renewable sources is water, which is polluted in various ways today. Nitrate and phosphate are two important pollutants that are created by chemical fertilizers and pollute the environment, including water sources, and have harmful effects on human health. Sulfates are also another major ion found in natural waters and wastewater. There are common physical, chemical and biological methods in removing these pollutants from water sources. Due to the high cost and limited efficiency of physical and chemical methods, in recent years, suitable and inexpensive natural treatment methods such as Phytoremediation has been studied. The phytoremediation process is a natural way to purify contaminants that is very effective and inexpensive and can be performed for a long time. Due to the limited quantity and quality of water and soil resources and the need to provide food for the growing population of the country, today special attention has been paid to the production of agricultural products in soilless cultivation systems. Therefore, due to the fact that plants have different abilities in monitoring pollution, suitable plants should be used to clean polluted environments. Eucalyptus camaldulensis Dehnh. and Elaeagnus angustifolia L. plants are among the common and well-known species in Iran for planting along waterways with the aim of purifying crop water to prevent them from entering surface flows.However, as far as the comprehensive studies of the researcher in internal and international sources show, no study has been done on the removal of nitrate, phosphate and sulfate by Elm and Eucalyptus., this research can be the first research in this field to purify polluted resources in Iran. The present study was conducted in the greenhouse of Isfahan University of Technology at a temperature of 40 degrees. In First, to study and compare phytoremediation of nitrate, phosphate and water sulfate using Eucalyptus camaldulensis Dehnh. and Elaeagnus angustifolia L. tree species. seedlings of these trees were planted in plastic pots with a cover of washed pebbles. Overall, The pots were 54 and had a volume of about 10 liters and a diameter of 12 cm. Thus, in 27 pots of Eucalyptus and 27 other species of Elaeagnus were planted. At the beginning of planting, the seedlings were impregnated with hydroponic solution (with a volume of 2 liters) and about 2 times a week, hydroponic solution was added to each pot. after establishment of plants, solutions containing nitrate, phosphate and sulfate prepared in the laboratory was added to the culture in three replications with concentrations (0,30,60 mg /l) for phosphate and sulfate and concentrations (0,50, 100 mg /l) for nitrate. Three chemicals, potassium nitrate KNO3, monosodium phosphate NaH2PO and sodium sulfate Na2SO4 , were used to prepare nitrate, phosphate and sulfate contaminants, respectively. This experiment was performed for four months in the natural resources greenhouse of Isfahan University of Technology in March 2017. The experiment was performed factorially and in the form of a completely randomized design. In order to measure the nitrate, phosphate and sulfate of the samples and evaluate the effect of phytoremediation on the uptake of these contaminants, samples of the culture medium were transferred to the laboratory every month with contaminated water. Data were collected and recorded for at least 3 months and the uptake of nitrate and phosphate in the leaves of the plant was examined by sampling and analysis in the laboratory during each month. Plant parameters were harvested every week. In this regard, the effect of different concentrations of nitrate and phosphate contaminants on some physiological factors of the plant (stem diameter, plant height, stomatal exchange and chlorophyll content) were measured. also all data were measured by statistical analysis using SAS statistical software with version 25. Finally, analysis of variance was performed by ANOVA test and mean data were compared by LSD test. The results of the analysis of variance, for nitrate, phosphate and sulfate removal showed a significant difference at 99% level. The results of analysis of variance showed the highest percentage of removal was to Eucalyptus species with 86.26% nitrate, 95.34% phosphate and 86.8% sulfate and to Elaeagnus species with 83.72% nitrate, 88.55% phosphate and 90.73% sulfate. As a result, Eucalyptus specimens showed a higher ability to remove nitrate and phosphate pollutants and Elaeagnus species a higher ability to remove sulfate. The results also showed that the correlation and interaction of species on physiological traits (stem diameter, plant height, Chlorophyll content and stomatal exchange) was very significant due to differences in species and different concentrations of pollutants. Also, the results of mean comparison showed that no significant differences were observed between the traits of Eucalyptus and Elaeagnus species.

The hydraulic jump is often applied as an energy dissipator below weirs or spillways of dams, chutes, gates, drops and other structures might be utilized in this regard. In the hydraulic jump, the water depth increases abruptly and some of the kinetic energy is transformed into potential energy, with some energy irreversibly losses through the turbulence. Determining the dimensions of the stilling basin is an important task for the hydraulic engineers to design a safe and economical energy dissipator and to reduce the construction costs of stilling basin, a change in the plan and profile sections of the basins can be useful. Arbhabhirama and Abella (1971) studied radial hydraulic jumps in a gradually expanding channel of rectangular cross section with divergence angles from 0 to 13°. The results showed that the divergence of the walls causes reductions in the sequent depth and the length of jump and an increase in the energy loss as compared to the hydraulic jump in a straight rectangular channel. Ead and Rajaratnam (2002) conducted an experimental study of the hydraulic jump on corrugated beds and specified that the reduction of the tailwater depth depends on increasing of bed shear stresses, which in turn are generated by interaction of the supercritical flow with the bed corrugations. Channels with trapezoidal cross-sections was carried out by Omid et al (2007). They found that the sequent depth and the length of the hydraulic jump decreased, whereas the energy loss increased with the increasing bottom width. Abbaspour et al. (2009) investigated the effect of sinusoidal corrugated bed with different wave steepness on the basic features of the hydraulic jump. They showed that the length ratio and the tailwater depth ratio of the jump on corrugated beds are smaller than that of the corresponding jump on a smooth bed. Chanson and Carvalho (2015) using an integral form of the continuity and the momentum principles, proposed an equation for calculating the sequent depth ratio of the hydraulic jump in an irregular channel. Daneshfaraz et al. (2018) studied the effect of sand bed with median size 1.9 cm on S-jump characteristics. The results showed that the abruptly expansion stilling basins with a rough bed in all the expansion ratios reduced the depth ratio and average jump length compared to an abruptly expansion stilling basins with smooth bed. The main purpose of this research is to study the effects of expansion ratio of the side walls channel and the discrete roughness elements height on the characteristics of the hydraulic jump such as the sequent depth, the jump length, the energy dissipation and the bed shear stress.

The experiments were conducted in a hydraulic laboratory of the University of Tabriz in a metal-glass horizontal rectangular flume. The facility had been relatively large-size channel 0.5 m wide, 0.5 m high and 10 m long. The sidewalls had been made of glass for observational purpose with 0.5 m high and 2.1 m long. The inflow conditions were controlled by a vertical sluice gate with a semi-circular rounded shape (Ø = 0.2 m) and the downstream coefficient of contraction was about unity. Also, the downstream flow conditions were controlled by a vertical gate. The upstream gate opening was fixed (2.1 cm) in all of the conducted experiments. To investigate the effect of roughness, discontinuous dissipative elements of lozenge shape with two heights (1.4 and 2.8 cm) were installed on the horizontal bed. Three glass physical models were built with divergence ratio (B = b1/b2) of 0.4, 0.6 and 1 (where b1 and b2 are the widths of the stilling basin in upstream and downstream of the hydraulic jump, respectively). During the jump, flow depths were measured using ultrasonic sensors Data Logic US30 with operation range of 10–100 cm and accuracy of ±0.1 mm that were mounted above the channel. The length of the hydraulic jump was measured by a fabric ruler with a reading accuracy of ±1 mm installed along the channel.

In this paper, the main features of a hydraulic jump under both the effect of the height of bed roughness and expansion of basin walls condition were investigated. Experimental observations showed that installing roughness elements stabilized the hydraulic jump on the channel. Equations (8), (9) and (10) were proposed for estimating the sequent depth ratio (y2/y1), the relative length of the hydraulic jump (Lj/y1) and the relative loss of energy (EL/E1), respectively. The Equation (8) shows that the sequent depth ratio increased with the increasing inflow Froude number and the divergence ratio. Also, the sequent depth ratio decreased as the roughness elements ratio increased. The relative length of the hydraulic jump for a given inflow Froude number, decreased as the roughness elements ratio increased. A comparing between the measured values of EL/E1 and those calculated by Equation (10) showed that, Equation (10) allows an estimation for calculating the relative energy loss in expanding basin with roughened bed. Also, the results indicated that the value of ε in the hydraulic jump on rough beds is increased compared with the smooth bed in all expansion ratios. Furthermore, the roughness height of 2.8 cm is more effective in creating high turbulence, force and increasing the coefficient of bed shear force.

Shortage of fresh water resources and salinization of aquifers are two major development challenges in arid and semi-arid regions. Population growth, industry development, agricultural development in order to provide the required food resources and climate change has increased the uncontrolled abstraction of groundwater resources, which in turn has led to a decrease in groundwater quality, especially in arid and semi-arid regions. The purpose of this study is to investigate the main reasons for salinization of Kashan aquifer, one of the critical aquifers in Isfahan province, which is located near the salt lake. For this study, 53 wells located in Kashan aquifer were investigated. After selecting wells with suitableconditions, 74 water samples were collected from selected wells and chemically and ionically (EC, Na +, K +, Ca2 +, Mg2 +, Cl-, HCO3-) were studied. According to the results, the direction of groundwater flow in this aquifer is from the west to the east of the aquifer, with the exception of the northeastern region of the aquifer where there is a return flow from the salt lake to the inside of the aquifer. The results of this study showed that salinity of Kashan plain aquifer in different regions has two main reasons: in the central and southern regions of the aquifer, the reason for salinity is the uncontrolled abstraction of groundwater from exploitation wells, conical rise of saline water and the occurrence of upconing phenomenon. In the northeastern regions of the aquifer, there is a return flow from the salt lake and the intrusion of salt water into the aquifer.