ADVANCED TECHNOLOGIES IN WATER EFFICIENCY
Year:2024 | Volume:4 | Issue:3|Papers Count:6

IntroductionThe effect of salinity stress on plants is very wide, and it can cause a decrease in growth, damage to the roots, decrease in yield and even death of plants by reducing the absorption of water and nutrients, reducing enzyme activity, and disrupting the physiological processes of plants such as photosynthesis and respiration (Gupta and Hong, 2014 and Awaad, 2023). Rapeseed oil, as one of the most important sources of vegetable oils in the world, is very important in various economic, agricultural, industrial, and health sectors. With the ability of growing in different climatic conditions, having low water requirement and good relative resistance to various environmental stresses, rapeseed is known as a suitable plant for crop rotation (Raboanatahiry et al., 2021). The effects of salinity on the characteristics of the rapeseed plant in the stages of germination, vegetative stages and seed ripening have been proven. Considering that different rapeseed cultivars are different from each other in terms of their susceptibility to salinity stress in different stages, a detailed assessment on the effects of salinity stress on rapeseed and the adoption of appropriate strategies to manage and reduce this stress can help in better cultivation and optimal management of rapeseed; Therefore, evaluating the response of different rapeseed cultivars to salinity stress is of particular importance in order to introduce salinity-tolerant cultivars MethodologyExperimental modelIn order to evaluate the response of winter rapeseed (Brassica napus L.) cultivars to different levels of salinity, an experiment was conducted in a greenhouse at the Research Greenhouse of Payame Noor University of Gandaman (Chaharmahal and Bakhtiari province). The experiment was arranged as a split-plot design within a completely randomized design with three replications. The first factor was four levels of salinity, including S0 (2), S1 (10), S2 (20), and S3 (30) (dS/m), where S0 was the Hoagland's solution as the control, and other salinity levels were the result of mixing sodium chloride (NaCl) and calcium chloride (CaCl2) at a ratio of 20 to 1 moles in the Hoagland's solution, respectively. The second factor comprised eight winter rapeseed cultivars including (Licord, Okapi, SLM 046, Modena, Opera, Symbol, Fornax and Elite). The experimental units included 40 × 40 cm pots, 35 cm in height, containing completely homogenized washed sand. Due to lack of absorption and less the plants' need for a complete nutrient solution, the pots were irrigated every other day with a solution containing half the concentration of nutrients found in the Hoagland's solution (Dehdari et al, 2005). Two weeks after establishment, the plants were thinned from 15 to 8 plants per pot to achieve the desired plant density. From the 20th day after sowing (the four-leaf stage of the plants), salinity levels were gradually applied to acclimate the plants, such that all pots, except for the control level, received incremental salinity levels of 25% of each level in four irrigation shifts, thereby applying the total salinity treatment for each level. Collecting and preparing plant samplesThe salinity treatment continued at the specified ratios until the end of the growth stage. In this study, the traits of seed yield, dry matter traits, thousand seed weight, oil yield and oil percentage were measured. At the end of the growth stage (90 days after sowing), to measure the seed yield, dry matter traits, thousand seed weight and oil yield, six plants in each pot were randomly selected, harvested, and the above parameters were measured and calculated. Oil percentage was calculated with a Soxhlet apparatus (Joshi et al., 2008). Statistical Analysis Statistical Analysis Finally, data were analyzed using SAS software (version 9.1). Mean comparisons were conducted using Duncan's multiple range test at a 5% probability level.  Results and discussionIn the present study, all the traits under investigation were affected by salinity. An increase in salinity levels across all evaluated cultivars resulted in a significant reduction in all examined traits. Based on the results, it can be inferred that the rapeseed cultivars evaluated in this study can produce an acceptable yield up to a salinity level of S1 (salinity of 10 dS/m). At this salinity level, the cultivar SLM 046, with a seed yield of 22.78 grams per pot and an oil yield of 7.97 grams per pot, was identified as the most successful cultivar. Conversely, the Okapi cultivar, with an average seed yield of 11.99 grams per pot and an oil yield of 3.71 grams per pot, was the most susceptible cultivar. Therefore, according to the findings of this study, the SLM 046 cultivar was determined to be the most tolerant to salinity at all levels tested, while the Elit cultivar was assessed as the most susceptible to salinity. Since the primary goal of producing canola oilseeds is oil production, cultivating the evaluated cultivars under salinity conditions of S3 (salinity of 30 dS/m) and higher is practically ineffective. ConclusionsExposure to environmental stressors, including salinity and drought stress, directly and indirectly causes a portion of the assimilates produced by the plant to be diverted from growth and production processes towards coping with and mitigating stress conditions (Ahmed & Umar, 2011). It has been stated that with increased salinity stress, the stressed plant experiences reduced activity and degradation of cellular biomolecules, lipid oxidation, protein structure alteration, enzyme deactivation, chlorophyll bleaching, and nucleic acid degradation, resulting in the limitation of the plant's photosynthetic system (Ahmed & Umar, 2011; Al-Sharari et al., 2023). In the present study, increasing the intensity of salinity stress from S0 (control) to S3 (30 dS/m) caused the highest percentage reduction in all evaluated traits, including seed yield and oil yield, across all tested cultivars. The results indicated that the SLM046 cultivar, with the highest harvest index (0.29) and seed yield (10.52 grams per pot) at the highest salinity level (S3), and the lowest percentage reduction in harvest index (25.64%) compared to the control, performed better in mitigating the effects of salinity stress compared to other cultivars. In salinity stress conditions, salinity-tolerant cultivars like SLM046, which can allocate remaining assimilates effectively despite limitations in phloem transport and new physiological demands due to salinity stress, are more successful. By maintaining an appropriate harvest index and directing resources towards economic yield, these cultivars produce satisfactory yields (Ahmed & Umar, 2011; Khalid et al., 2015).

IntroductionPopulation growth and changes in the pattern of needs in accordance with economic growth and lifestyle changes have increased the need for suitable water sources. Treatment and reuse of wastewater is very important in order to reduce the water crisis and prevent the pollution of surface and underground water sources and ecological destruction caused by the discharge of sewage and preserv human health. Conventional wastewater treatment methods have many implementation limitations, including high cost, complex operations and maintenance, etc. For this reason, it is not possible to implement conventional and high-tech methods everywhere. While natural wastewater treatment systems have lower technology and less need for trained labor and at the same time have high efficiency. Among the solutions for green wastewater treatment, we can mention phytoremediation and artificial wetland system. An artificial terrestrial wetland that removes pollutants by creating a saturated porous environment and providing the conditions for the occurrence of physical, chemical and biological processes. Phytoremediation is a biological treatment method in which a plant reduces the pollutants by selective absorption of pollutants and accumulation of them in its tissues. In this method, various factors such as retention time, pollutant concentration, environmental factors (acidity, temperature) and plant characteristics (species, root system, etc.) are important. Since the artificial wetland is similar to a black box whose processes cannot be predicted, simulation models are used to design them with the aim of achieving the highest pollutant removal efficiency. The HYDRUS-2D model is an advanced two-dimensional model related to the simulation of water movement and solute and heat transfer in saturated and unsaturated porous media. In this model, Richards and dispersivity-diffusion equations have been used respectively to simulate water movement and solute transport, as well as features such as spatial distribution of plant roots, water absorption by plant roots, various equations of hydraulic properties of porous media and various initial and boundary conditions, the possibility to provide the simulation of an artificial wetland with plants. MethodologyExperimental site and Measuring TDSTo collect the information from the model, six artificial wetland systems, including three vertical subsurface flow systems and three horizontal subsurface flow systems were constructed at the sewage treatment plant located in Fakhb, Rasht. From the three systems that were constructed, one system was considered without plants and the other two systems contained Reed and Typha plants.  The wetlands were filled with Gravel in diameter of 5 to 25 mm. To adapt Plants with the cultivation environment and wastewater quality, the plants were irrigated by wastewater about three months. After the three months, the main data collection was done by sampling and checking the performance of the systems. Collecting data was for 9 months. During experiment, the raw wastewater sample was entered into the wetland systems and after the hydraulic retention time (about one month in winter and one week in spring and summer), were sampled from the outlet of the wetlands and the parameter of total dissolved solids measured.  Calibration and Validation HYDRUS-2DIn this research, the HYDRUS-2D model was used to simulate the processes governing the movement of water and transport of solutes and its absorption by plants. S-ship model was used to estimate water absorption by Reed and Typha plants. The effective parameters of water movement and transport of solutes, including saturated hydraulic conductivity, longitudinal and transverse dispersivity, and diffusion of the wetland bed, were estimated using the inverse solution method, respectively, using the output flow data and the total dissolved solids of the output wastewater. Statistical indices were used to evaluate the accuracy of the model in the simulation of the purification process in the wetland. The data of days 112, 125, 131, 140, 146 and 152 from the start of the experiment were used for calibration and the data of days 187, 208, 215 and 222 from the start of the experiment were used to validate the wetlands. Results and discussionComparison of the saturated water conductivity value estimated by the HYDRUS-2D model with Sheykhan et al.'s research (2019) showed that the model was able to estimate the hydraulic properties of the bed properly. The longitudinal and transverse dispersivity coefficients in the horizontal wetland were found to be almost half of the vertical wetlands, which is in line with the lower saturated water conductivity and as a result, the lower velocity of the wastewater in the pores in these wetlands compared to the vertical wetland. Dispersion coefficient was a more important factor in solute transport than dispersivity coefficients. On average, in vertical wetlands, the model was able to estimate the amount of reduction of total dissolved solids with about 2% less than the values measured in wetlands under plant cultivation, while in the horizontal wetland, this amount was between 3 and 5 percent. ConclusionsAccording to the results of statistical indices, the estimated values of the total dissolved solids of the artificial wetland system under Reed cultivation were more consistent with the measured values than other wetlands. The results showed that the model has a suitable ability to simulate the movement of solutes and total dissolved solids, which means that it can be used in the design process of treatment in the wetland.

IntroductionOne of the water level control and regulation structures is lopac gates, which is known as a dam or flow depth control structure. lopac gates are in the form of two rectangular sheets that are connected to the channel wall. This structure has the ability to adjust the water level upstream of the valve and regulate the distribution of passing water downstream of the valve in different flow rates and openings. lopac gates are divided into rectangular and elliptic categories. Methodology Experimental modelThe experiments conducted by (Pilbala et al, 2021) were conducted on an open rectangular channel with a length of 10 meters, width and height of the laboratory channel equal to 0.8 meters, with a horizontal rectangular channel bed slope and at Shahid Chamran University of Ahvaz. In total, the laboratory model in 45 tests considering three flow rates (25, 35, and 45 liters per second), five opening angles (35, 40, 45, 50, and 52.5 degrees), and three intake ratios (70, 80 and 90 percent) by (Peel Bala et al., 2021).  Verification of the physical modelIn this research, in order to validate and increase accuracy in numerical simulation results of a rectangular Lopac gate (Pilbala et al, 2021) with a flow rate of 25 liters per second, an opening of 35 degrees and an extraction rate of 70% in the number of mesh cells and different turbulence models were simulated in Flow3D and compared with laboratory data. The results show that among the simulations regarding the selection of the number of meshing cells and different disturbance models, the best performance, compared to the measured laboratory data, is by RNG models, and the number of meshing cells is 1000000. The RNG disturbance model and the number of meshing cells used for all simulations were used in the results of this research. Also, according to the convergence diagram, 40 seconds of time was used for the purpose of simulation. Results and discussionThe effect of changes in Froude number (Fr) on maximum velocity (V max)When using multiple elliptic lopac gates in submerged flow mode, the range of velocity distribution and numerical values of velocity are reduced compared to multiple elliptic lopac gates in free flow conditions. It can be seen that with the increase of the Froude number in fixed openings, the maximum velocity value has increased, and also with the increase of the opening angle of the valve (reduction of narrowness), this parameter has been continuously increased. It can be seen that the maximum velocity value has an inverse relationship with the absorption percentage. In such a way that with the increase in the absorption percentage of the current, the maximum velocity decreases continuously. Investigations show that the maximum flow velocity created on multiple elliptic lopac gates in submerged flow conditions is far lower than when multiple elliptic lopac gates are used in free flow conditions. Effect of dimensionless opening (bg/B) on discharge coefficient (Cd)It can be seen that the value of the flow coefficient during the operation of multiple elliptic lopac gates in submerged flow conditions was lower than that of multiple elliptic lopac gates in free flow conditions. Evaluations show that when multiple elliptic lopac gates are used in submerged flow conditions, compared to multiple elliptic lopac gates in free flow conditions, the flow coefficient at the opening of 30 degrees, on average, in flow rates of (20, 40, and 60) liters per second for the absorption rate of (70, 80 and 90) percent, respectively 8, 26 and 45 percent, in the opening of 45 degrees, in the flow rates of (20, 40 and 60) liters per second for the absorption rate of (70, 80 and 90) percentages are 16, 34 and 49%, respectively, and at 60-degree opening, at flow rates of (20, 40 and 60) liters per second, for the amount of absorption (70, 80 and 90)%, respectively, 17, 36 and 54%  will be reduced. Flow pattern in multiple elliptic lopac gates It was found that when multiple elliptic lopac gates are used in free flow conditions, high-strength vortices are formed compared to multiple elliptic lopac gates in submerged flow conditions. This phenomenon can cause problems such as increased energy loss, reduced water absorption rate, reduced efficiency of hydraulic machines, and their improper performance. However by examining the flow pattern of multiple elliptic lopac gates in submerged flow conditions, the size of the vortices has decreased and as a result, its strength has decreased. ConclusionsIn this research, using laboratory data and Flow3D software, the effect of using multiple elliptic lopac gates in submerged flow conditions compared to multiple elliptic lopac gates in free flow conditions, maximum flow velocity, flow coefficient, and flow vortices were evaluated. The results showed that the maximum velocity have a direct relationship with the Froude number and the opening angle. Investigations showed that the flow coefficient (Cd) has a direct relationship with the flow rate and gate opening value. The results showed that the flow is diverted to the center or around the channel when passing through multiple elliptic lopac gates, which creates large vortices with high longitudinal elongation near the flume wall.

IntroductionGlobal solar radiation (GSR) is an important parameter for designing and developing different solar energy systems (Tris et al., 1997). The concept of solar radiation means that during a certain period of time, how much solar energy is absorbed by a horizontal surface in an area (Almoroux and Hontoria, 2004; Wang et al., 2011). Iran is a sunny country, and, the optimal utilization of solar energy can be necessary for furure enenrgy development (Jafarkazemi and Mardi, 2019). MethodologyIn the present study, solar radiation was investigated in five climates. In this way, the two stations of Ramsar and Rasht represent the very humid cool warm climate, the three stations of Kermanshah, Mashhad and Shiraz represent the very hot semi-arid climate, the three stations of Tabriz, Zanjan and Urmia represent the semi-arid climate. Cold-warm, Birjand, Kerman and Isfahan stations were investigated as representatives of warm dry climate and Ahvaz, Booshehr and Bandar Abbas stations as representatives of warm dry temperate climate.Daily measured data of wind speed (U), maximum temperature (Tmax), minimum temperature (Tmin), average air temperature (Tave), average relative humidity (RH), sunshine hour (N) and precipitation (R) As independent variables and the amount of solar radiation (RS) as a dependent variable, for each of the mentioned stations, it was prepared from the National Meteorological Organization during the years 1986 to 2010.After preparing the data and their quality control, solar radiation was estimated using multivariate linear regression fitting under SPSS software. Empirical relationships were calculated for each climate separately.For this purpose, by applying the ranges, restrictions and characteristics of radiation, regression analysis was performed in the Solver environment of Excel software.In order to evaluate the research, the results were measured based on the error measurement indices of the mean squared normal error (nRMSE) and mean bias (MBE). Results and discussionAccording to Table (2), the meteorological parameters of maximum, minimum and average temperatures, hours of sunshine and wind have a positive correlation with solar radiation, that is, with the increase of each parameter, the amount of radiation also has an increasing trend, except precipitation and relative humidity, which have a negative correlation with radiation. It shows the reverse relationship between these two parameters with solar radiation. The highest correlation between relative humidity and solar radiation (-0.485) and the lowest correlation between precipitation and radiation with a value of -0.048 is in the hot dry climate. The best regression equations obtained from meteorological parameters using SPSS software for different climates are given in Table (3). in which the amount of error between the available parameters has been calculated for each of the stations.The relationships presented for five climates show that the maximum amount of error based on nRMSE and MBE index in hot dry climate is 11% and -1.15 megajoules per square centimeter per day, respectively. On the other hand, the lowest amount of error based on the two mentioned indicators is in the hot and cold semi-arid climate, which is 8.5% and 0.50 megajoules per square centimeter per day, respectively. To estimate the regression equation in hot and cold semi-arid climates, as the results show, the variables included in the best regression equation in hot and cold semi-arid climates were: maximum temperature, precipitation, minimum temperature, sunshine hour, wind speed and average temperature In hot dry cool climate, the maximum, minimum and average temperature, relative humidity, sunshine hour and wind speed were used. Precipitation, minimum temperature, wind speed and solar hour are used in very hot semi-arid climate, in hot dry climate, maximum and minimum and average temperature, relative humidity, wind speed and solar hour are used, finally in moderately hot dry climate. Precipitation, maximum and average temperature along with wind speed, sunshine hour and relative humidity were used. In very humid, cool, hot, semi-dry, very hot, and dry, moderately hot climates, it is observed that the accuracy of radiation estimation between meteorological parameters is almost within the same interval of change (about 9%). From the MBE index provided between the meteorological parameters, we find that the minimum overestimation value is 0.02 megajoules per square centimeter per day in very humid, cool, hot climates, and the maximum value is (0.50) in the semi-arid, cold, hot climates. be Figure (3) shows the time series graphs of the investigated stations during the relevant statistical period. In general, the estimation of solar radiation using regression equations based on the investigated error measurement indices, which has the least amount of error and, conversely, the highest amount of accuracy, is in the semi-arid, cold, hot climate, because the accuracy is 8.5% based on the nRMSE index. The high accuracy of the equation is used to estimate the radiation, and its MBE value is 0.50, which proves the overestimation of the presented equation.Meteorological parameters were examined on a daily basis to obtain the regression equation in the years 1986 to 2010 in a very humid cool hot climate as mentioned in Table (4), and in the time series graph, the observed radiation values are more than Radiation values are estimates from regression relationships. The very hot semi-arid climate shows that the estimated radiation values have almost a constant range of changes and its maximum value is approximately 2000 megajoules per square centimeter per day, but the observed radiation value is more than this value. According to the diagram and table (4), the semi-arid, cold and hot climate has MBE value of -0.501 MJ/cm2/day among the parameters, and the estimated amount of radiation has not exceeded 2000 MJ/cm2. In some statistical years, the observed value is more than the estimated value. The time series of the hot and cold semi-arid climate is the same as the rest of the climates and it is higher than the mentioned value, and in the cool and hot dry climate, which has MBE with a value of -1.15 MJ/cm2/day, it is among the meteorological parameters. It is also mentioned in Table (4), and in some of the investigated periods, the amount of observations is more than the estimate, and there is a large fluctuation between the amount of radiation estimated and observations, and the estimated amount is up to about 4000 megajoules per square centimeter per day. is Finally, the hot temperate dry climate with MBE, -0.558 megajoules per square centimeter per day indicates the underestimation of solar radiation in this climate. ConclusionsIt is necessary to investigate the energy of solar radiation as it is important and influential parameter on the processes on earth, including water resources. In this research, using the equations obtained from the regression model, the amount of solar radiation reaching the earth's surface was estimated in five different climates in the country, which includes 14 meteorological stations. It was seen that the amount of observed radiation in three climates, semi-arid, very hot, dry, cool, hot, and dry, moderately hot, is lower than the observed amount, and in two climates, very humid, cool, hot, and semi-arid, cold, hot, it is higher than the estimated amount of radiation. According to the regression equations, the amount of error obtained in the hot and cold semi-arid climate has the lowest amount of error and the warm and dry climate has the highest amount of error. The changes in the error percentage of the solar radiation estimation of the other three climates are not large and are about 9%. The meteorological parameters used in the semi-arid, cold, hot climate were temperature, precipitation, sunshine hours, and wind speed. Considering the limitation of measuring solar radiation in the country, the importance of estimating this meteorological parameter is essential in order to use it in the management of water resources by managers.

IntroductionWater, as one of the vital and fundamental resources in human life and ecosystem survival, is directly and indirectly affected by pollutants such as heavy metals, pesticides, agricultural toxins, soil erosion, animal waste, and human sewage. This issue has raised significant concerns regarding public health and environmental safety. Rivers, as one of the most important sources of freshwater, are heavily impacted by these changes, emphasizing the necessity of protecting their quality. This text examines methods for assessing water quality and demonstrates how the use of new technologies such as artificial intelligence and the Internet of Things can aid in improving the water quality assessment process. For example, calculating parameter values and converting them into qualitative values can be enhanced using artificial intelligence. According to Zhi et al.'s (2024) research, the determination of all water quality is characterized by traditional measurement methods, which may be time-consuming, expensive, and sometimes in the later stages of evaluation due to the large volume of non-constructible data. It is not reusable. Additionally, this text categorizes challenges and new requirements in this field, indicating that intelligentizing the water quality assessment process through the use of new technologies leads to significant improvements in this area. MethodologyThe methodology of this study consists of several important stages. Initially, by reviewing relevant literature and existing standards in the field of water quality assessment, the necessary foundations for the study were established. Subsequently, through the formation of a Delphi panel and using the snowball sampling method, the opinions of experts and specialists on issues related to water quality assessment were collected and analyzed. In the following steps, by creating a suitable portal for data collection and questionnaire, the required data were gathered from experts and specialists. Then, using the Delphi-fuzzy analysis method, the results obtained from interviews and questionnaires were analyzed by suitable softwares to gain a more precise understanding of the challenges and requirements in water quality assessment. This methodology employs a combined approach, which integrates literature review, expert and specialist participation, questionnaire data collection, and detailed result analysis. After that, we have proposed an IoT-based method for measuring some parameters in river for water quality assessment. The proposed system has been tested in a real environment.                              Results and discussionResults of the research indicated that heavy metal measurement emerged as the most important parameter in water quality assessment, while chlorophyll-a measurement was deemed as the least significant of all. Challenges associated with traditional assessment methods, including the need for expert personnel, costly and time-consuming task, and potential outdatedness of results, were identified. Furthermore, the inadequacy of water sampling conditions underscored the necessity for more online assessment methods. Experts recommended using new technologies such as artificial intelligence and the Internet of Things (IoT) for data collection, storage, processing, and pattern extraction. Based on these findings, a proposed IoT-based system for river water quality assessment was designed, comprising hardware and software components across four layers: perception, network, platform, and application. This system aims to address the limitations of traditional methods while meeting the emerging requirements driven by artificial intelligence. ConclusionsWater quality assessment, especially the quality of river water, is a highly important process that is traditionally and often manually conducted by some organizations, such as environmental agencies, water and wastewater authorities, and fisheries departments. In this process, experienced experts are dispatched to predetermined locations along the rivers at specific time periods, where some parameters are measured on-site while others are sampled by water and analyzed in laboratories, ultimately resulting in water quality assessment. This paper employed the Delphi-Fuzzy methodology to prioritize influential parameters in water quality and identify existing challenges in the manual water quality assessment process through the assistance of selected experts and professionals via questionnaires and interviews. The analysis of the gathered data revealed that heavy metal assessment parameter holds the highest importance, while chlorophyll-a parameter, holds the least significance in water quality assessment. Furthermore, the challenges in traditional water quality methods, which require sending expert water specialists with suitable equipment to relevant locations at the right time, incurring high costs and time-consuming procedures, were highlighted. Additionally, the results obtained from assessments may become outdated in some cases and lack necessary valuable data. Moreover, water sampling in certain circumstances occurs under unsuitable conditions, necessitating a greater emphasis on online monitoring. Furthermore, experts believed that, considering the aforementioned needs, new technologies such as artificial intelligence and the IoT should be utilized for data collection, storage, processing, and pattern extraction. Based on the conducted research and its outcomes, an IoT-based system for river water quality assessment was proposed. This system comprises a collection of hardware and software in four layers: perception, network, platform, and application. Various sensors in the perception layer are utilized to measure priority parameters. The collected data in the platform layer are processed by different algorithms, and suitable patterns can be extracted using artificial intelligence algorithms and data mining techniques. This proposed system, besides addressing the challenges of traditional methods, possesses the capability to meet the new requirements based on the utilization of artificial intelligence.

IntroductionIn nature, different types of river bends such as simple, complex, sharp, mild, etc. can be seen. The hydraulic behavior of the flow in the place of water intake from the river bends is more complicated than the straight path. Due to the presence of secondary flow in the bends, the outer wall of the bend is a suitable place for taking water from the river.MethodologyUsing SRH-2D numerical model, the behavior of flow in a 180-degree bend with side intake and three ratios of bend radius to channel width (R/B) were investigated. In this way, three ratios of bend radius to the channel width, equivalent to 2 (sharp bend), 3 and 4 (mild bend) were used. The hydraulic parameters such as flow velocity and streamline and spanwise water level were taken for sections of 100, 110, 115 and 125 degrees along the main channel and one section at the beginning of the side channel.Results and discussionValidation of the numerical model was done using the laboratory data of previous research. The results showed that the model correctly simulates the different parts of the flow in a bend with the presence of a side intake. The calculated and measured velocity values have an R2 coefficient equal to 0.94. According to the results obtained from this research, in the 115-degree section which corresponds to the axis of the side intake, with the increase of R/B ratio from 2 to 4, the velocity of the flow entering the intake increases by 6%. In the area of the outer wall of the bend, before the water intake, flow velocity in the sharp bend is higher than in the mild bend, and in the section immediately after the water intake, the flow velocity in the mild bend is higher than in the sharp bend. Regardless of the relative radius of the bend, before the water intake opening, the position of the maximum flow velocity is in the vicinity of the outer wall of the bend, while after the intake opening, it is drawn towards the inner wall of the bend. In the 125-degree section, with the relative radius of the bend increasing from 2 to 4, the flow velocity in the outer wall has increased by 5%, but in the inner wall, the average velocity has decreased by 4%. At the 115-degree section, the maximum amount of water level can be seen around the center line of the bend, and the sharper the size of the bend, the higher the amount of water level rises around the center line of the bend.ConclusionsAccording to the obtained results, the SRH-2D model was able to simulate well the flow in a 180-degree bend with a lateral intake. Also, the different flow areas including the point of stagnation, the minimum velocity after the intake which tends to the inner wall bend, the minimum velocity, the separation zone and the maximum flow area inside the intake channel were correctly modeled. In taking and deviation of water from a mild bend, the entering velocity into the intake is higher than that from a sharp bend, which can be effective in reducing sedimentation in the intake opening. In the cross-sections before and after the lateral intake, the highest value of flow depth occurs near the outer wall of the bend and the lowest value occurs near the inner wall of the bend. The sharper the bend, the greater spanwise slope of the water surface.