مجله مهندسی آبیاری و آب ایران
پیاپی 54 (زمستان 1402)

Step spillways are an example of these massive hydraulic structures that, in addition to passing the excess water of the dams, also cause the consumption of flow energy downstream of the dams. Considering the complex hydraulics of the flow on these spillways and the presence of nonlinear limitations, their optimal design is a very difficult problem. In this study, a new framework based on Metaheuristic algorithms, including Harris's hawk Optimization (HHO), gray wolf Optimizer (GWO), invasive weeds Optimization (IWO) and water cycle Algorithm (WCA), considering the minimization of the amount of concrete used in spillway and the maximization of energy dissipation in Spillway toe were developed as objective functions to design these spillways. Algorithms' performance was first checked and validated on basic functions. Then, to achieve the objectives of the study, the spillway of the Siah Bisheh dam was selected as the study dam and the efficiency of the developed models based on the four mentioned algorithms was evaluated on it. The results showed that, in addition to improving the current spillway design in terms of construction costs and dissipation energy, the HHO-based model has good accuracy and convergence compared to other Metaheuristic algorithms. As the comparison of the design obtained from HHO with the current spillway design showed, in addition to a 35% reduction in the volume of concrete consumed, the amount of energy dissipation increased by 15%, which indicates the success of the design model developed in a multi-objective manner using HHO.

However, several factors affect the corrosion of a marine structure. Investigating each of the factors involved in the corrosion of a structure in the environmental conditions of sea water is very difficult and complex, and each of the researches that have been carried out on the corrosion of these structures, often on one type of corrosion and also on one or more metals and or alloy is done. In this research, the monthly changes of sea surface temperature and sea surface, as two important properties of sea water, have been studied using the MITgcm model, which is a three-dimensional and non-linear model, with the most accurate bathymetric data and with a spatial accuracy of 2 minutes. For this purpose, the data of temperature, salinity, evaporation rate minus precipitation, wind, net heat flux with a time accuracy of one month and a spatial accuracy of one degree were introduced to the model as initial data. The results of the last year of modeling show that the highest values of sea surface salinity (SSS) at the value of 37.3 PSU and sea surface temperature (SST) at the value of 32.2 degrees Celsius occur in the summer season near the southern coast of Iran. On the other hand, the intensity of winds in the Arabian Sea is higher in the summer season than in other seasons of the year, and the intensity of the surface currents is also higher.

Energy dissipation due to impinging jets in a confined space is used in many industrial and civil applications. In this research, using Flow-3D software, a numerical simulation of the flow of impinging jets has been carried out. To investigate the jet's position, the inlet jet to the chamber is placed in 4 different positions. Also, the effect of the height of the inlet jet to the chamber and the diameter of the inlet pipe on the parameters of the jet velocity in the axis of the turbulent kinetic energy and the amount of energy loss has been investigated. In these simulations, the inlet jet to the waste chamber has been investigated at 4 different depths and with 4 nozzle diameters. The obtained results show that when the jet stream enters the chamber, two velocity regions of the potential core and the radial decrease of the velocity are formed. Also, energy loss increases significantly by reducing the diameter of the inlet pipe. However, by reducing the diameter of the inlet pipe too much, the chamber will not perform properly. Also, the amount of energy loss increases with the increase in the depth of the foundation. The results of investigating the position effect also showed that the highest energy loss is related to the placement of the jet tube in the tank adjacent to the outlet tube of the waste chamber.

Cavitation is one of the most common and destructive causes of spillways and water conveyance tunnels. One of the most effective ways to prevent the cavitation is to aerate the current, provide the pressure and prevent excessive suction. The longer is the separation length downstream of the air entrance to flow, the more efficiency of cavitator. Conventional types of aerators (cavitators) in hydraulic structures including ramps, steps, grooves, and their combinations. In this research, the performance of 19 cavitators with different geometries in a pressurized flow inside a box tunnel, for 5 discharges with/without aeration were investigated. All experiments were performed for 3 times to validate the experimental results and reduce the experimental errors. Statistical analysis of the experimental results showed that the type of cavitator had considerable effects on the separation length. In spite of the positive effects of ramp height and discharge on separation length, the angle of ramp, step height, and groove depth had non-significant effects on separation length. Finally, two combined aerators were proposed, which in practice had better results in comparison with conventional aerators in hydraulic structures.

The hyporheic zone is a region immediately beneath the riverbed where surface and subsurface water mix, this research seeks to identify methods to increase the sedimentation rate in sedimentation basins. To this end, this study aims to (i) examine the effect of creating submerged walls on the efficiency of sediment trapping compared to a simple sediment basin, (ii) evaluate the influence of variation in wall height on sediment trapping efficiency, and (iii) study the effect of the number of walls on sediment trapping efficiency.The laboratory flow's length, width, and height were 5 m, 30 cm, and 0.5 m, respectively. The experiments were performed at Gorgan University of Agricultural Sciences and Natural Resources on a one-, two-, and three-step gabion spillway. Notably, three distinct basin lengths were used in the 3-step case test. Afterward, numerical modeling was employed to analyze the experimental findings.According to the results of the gabion spillway, as the number of steps increment, sedimentation rate, sequestration, and consequently flow retention time increase. Analysis of dimensionalized total flow rate (q*) in all three spillways revealed that this parameter decreases as the Reynolds number increases. In addition, the obtained power law for this parameter in terms of Reynolds number demonstrated correlations of 81, 88, and 98 for one-step, two-step, and three-step spillways, respectively.This study demonstrated that the presence of a hydraulic jump alongside a gabion stabilizer increased hyporheic interactions. As a result, increasing the flow rate increases the hyporheic interaction rate while decreasing the flow retention time.

Cucumber (Cucumis sativus L) is one of the most important greenhouse products in Iran and the world, which is very sensitive to soil moisture changes. In order to model the effect of mixing soil with sawdust on the yield of greenhouse cucumber under moisture stress conditions, an experiment was conducted in the form of a completely randomized block design with three replications. The treatments included no sawdust (S0) and a combination of 5 (S1), 10 (S2), 20 (S3) percent of sawdust, and the moisture stresses were considered at the level of no stress (I1), 45 (I2) and 65 (I3) percent of field capacity depletion. Using the SALTMED model, the results showed that the water consumption efficiency results for the treatment I1S4, I1S3, I1S2, I1S1 were estimated as 22, 13.6, 14.8 and 14.8 (kg m-3), respectively, and the greenhouse results of these treatments were estimated as 25, 13.5, 15.2 and 15.3 (kg m-3). In the treatments exposed to water stress and in the I2S4, I2S3, I2S2, I2S1 treatments, the water consumption efficiency calculated by the model was estimated as 32, 22, 29 and 28 (kg m-3), respectively, and the greenhouse results of these treatments were equal to 29, 23, 19 and 22.5 (kg m-3), In treatments I3S4, I3S3, I3S2, I3S1 the water consumption efficiency were calculated by the model were equal to 32, 29, 15 and 23 (kg m-3), respectively, and the greenhouse results of these treatments were 33, 23, 11.4 and 13 (kg m-3), respectively.

The main purpose of this research is to investigate the effect of rotation factor, rotation speed and irrigation duration on Wind Drift and Evaporation Losses (WDEL) of impact and gear driven sprinklers. Experiments were carried out in the research farm of Kurdistan University and in an area of 3600 m2 by single sprinkler method on two Komet R8 and Luxor sprinklers. The results showed: 1- Up to the wind speed of 11.5 km/h and the air temperature of 40 °C, there is no significant difference between the WDEL of sprinklers2- The average WDEL of Komet sprinkler in low wind speed is 8.5% and Luxor is 10.4% and their difference is not significant. With the increase of wind speed from low to moderate, increase in WDEL of Komet was 125% and Luxor was 21% and their difference was significant (P<0.05) 3- In both sprinklers WDEL increased with increasing working pressure, but this increasing was not significant 4- In both sprinklers, WDEL increases with the increase of vapor pressure deficit, but this increase was significant only in Komet and in the high range (P<0.05). 5- By increasing the irrigation duration from 1 h to 3 h, the WDEL of Komet decreased by 24%. 6- By increasing the sprinkler rotation speed from 1.5 Rpm to 3.5 Rpm, the WDEL of Komet decreased by 13.4%. In general, the Komet had more WDEL potential than the Luxor and in the irrigation events of farmers, the WDEL is lower than the reported values of the research.

By using the temperature of the canopy cover of the plant, a practical parameter called the crop water stress index (CWSI), it was determined that this index is one of the methods of checking the water requirement of the plant and it can be considered as a suitable tool for irrigation management in the field. Therefore, this research was carried out with the aim of determining the water stress index of sugarcane in two methods of surface irrigation (CI) and subsurface drip irrigation (SDI) at research station number one of Khuzestan Research and Training Institute for Development of Sugarcane and Related Industries, in June 2022. The fields included the third field culture (Ratoon 3), of the CP69-1062 variety, and were selected with four repetitions in both methods. First, the equation of upper and lower base lines for the surface irrigation method was determined as (Tc-Ta)ul=1.7 and (Tc-Ta)=-0.09VPD+1.27, respectively. Then, using the equations of the lines based on the surface irrigation method, the average of crop water stress index for subsurface drip irrigation method and surface irrigation was calculated as 0.28 and 0.66, respectively, and the equation was presented according to the irrigation scheduling of the Sugarcane in June.

The change of land use and the reduction of permeable surfaces due to urban development have caused an increase in the peak discharge and volume of runoff due to rainfall, which causes flooding of roads and damage to urban areas. By accurately estimating the amount of runoff and properly designing the urban drainage network, as well as managing this runoff, the damages of urban floods can be reduced. SWMM rainfall-runoff model is one of the most efficient models in the design of drains and urban runoff management. Since the hydrological models must be evaluated before use, in this study the SWMM model was evaluated using 6 rainfall-runoff events for the city of Shahrood and the efficiency of the urban drainage network for floods with return periods of 2 to 15 years was investigated. For this purpose, six flood hydrographs of precipitation events was measured at the two main outlets of the city. he results showed that the SWMM model with the mean square root of the normalized error (NRMSE) of about 20% and R2= 0.90 in the validation stage has a suitable efficiency in simulating the flood hydrograph. Also, also the examination of the performance of urban drains showed for precipitation with a return period of 2, 5, 10 and 15 years, 9.1, 31.8, 36.4 and 41% of the canals are flooded, respectively.

The purpose of this research is to analyze the quality of groundwater in Khanmirza, Lordegan, Borujen, Ardal, and Kiar cities based on WQI and GWQI indicators based on the Iran Standard and Industrial Research Institute (ISIRI) and World Health Organization (WHO) standard. In this research, 28 samples of groundwater (wells) were collected from different places in Khanmirza, Lordegan, Borujen, Ardal, and Kiar cities from 2020 to 2022 and 10 qualitative parameters HCO3, K, pH, TDS, EC, Ca, Na, Mg, Cl, and SO4 were chemically analyzed in the laboratory. After analyzing the data, the spatial distribution map of the index was prepared for the study area by using the inverse distance weighting interpolation method. The results showed that according to GWQI and WQI indicators, most of the samples were in the good quality category. By examining the Pearson correlation between WQI and GWQI indices and the parameters used, it was found that the two parameters TDS and EC with coefficients of 0.982 and 0.989 have the highest correlation at a significant level of 1% with the WQI index. Also, TDS and Ca parameters with coefficients of 0.975 and 0.979 have the highest correlation with the GWQI index at a significant level of 1%. The results of this research have shown that the combined use of GIS, WQI, and GWQI indicators in evaluating the quality of groundwater and their spatial distribution in the studied area is useful and effective in selecting water resources for drinking purposes.

Geoelectric harvesting was carried out in The Sammon-Jagr Strait in Kerman province in two stages and a total of 19 electric sondages with different distances were carried out in the area of the project. Then, the obtained data were processed using IPI2WIN software and finally the processed results were interpreted. After preparing geological, slope and land use maps of each region and combining them in ArcGIS software, using Boolean logic, areas that are geologically, slope and land use suitable for underground dam construction were identified in a hybrid map. The results showed that according to the results of geoelectric sondages and field evidences, the bet stone at the proposed option area has dense clay with many salts. And the depth of impact to the bet stone is measured at least 4.5 meters and a maximum of 17 meters. On the bed stone is a river alluvial layer which is divided into wet and dry horizons. Of course, due to horizontal changes in sedimentation of river bed sediments, river alluvial layers include sequences of layers with different aggregation and permeability that have limited expansion. According to the geoelectric data and topographic map of bed stone, the proposed sites are more suitable for the construction of underground dam in accordance with L6 and L8 sections.

For groundwater development, necessities are needed to detect different aquifer layers hydraulic parameters in an area , which can be used to explicitly define the type of aquifer and the thickness of its aquifer layer. Geoelectrical method is one of the most effective tools in determining and separating subsurface layers. The electromagnetic method as well as ,is a newer method that can play an important role in determining the potential of subsurface layers with acceptable accuracy. In this research, 10 electromagnetic logs were used to investigate the thickness and separation of the aquifer layer of 5 karstic springs in Famaseb, Faresban, Gian, Ghale Baroodab and Gonbad kabood in the Nahavand plain of Hamedan province. Logs were measured in the upstream of each spring, then the results of electromagnetic extraction were checked in different frequency ranges. Finally, the output of electromagnetic logs were compared with 5 logs of the Geoelectric method, which showed that the similarity in results of the two methods . The final results showed that there is an aquifer layer in Famaseb spring up to a depth of 6 meters, Faresban spring to a depth of about 20 meters, Ghale Baroodab about 10 meters appearing with joints and fractures in these springs, Gian to a depth of about 2 meters . The Gonbad kabood has an aquifer layer of up to 36 meters. The highest thickness of the aquifer layer was estimated in Gonbad kabood spring and the lowest in Gian spring.

In this research, two categories were used to investigate the effect of the change of clarion surface water of Khash plain. The data on 2010 to 2020 obtained from the Liz Hydrometer Station on the Syanjah River Khash Plain, on the other hand, the base rainfall data was obtained from the Khash Station. Based on the measured regression model, the base period of the relationship between Dubai and precipitation at the Khash basin level was modeled. With the implementation of the SDSM statistical microscale model, the simulated rainfall values were obtained in the statistical period of 2020-2040, under two lines of release 4.5 and 8.5, which was used as an input to the regression model for remodeling in the climate change period. The results showed that in the period of climate change 2040-2020, despite the fact that the rainfall of the Khash basin has increased in the cold months of the year, the simulated runoff of the period 2040-2020, in both RCP4.5 release trajectories and RCP8.5, has had a decreasing trend. The results indicated that the climate change period 2020-2040, in the RCP4.5 release, had reduced about 0.02 cubic meters per second to the base period, and in the RCP8.5 release track, this was a decrease of 0.016 cubic meters per second.

The aim of the study is to evaluate the changes of mean temperature and precipitation parameters using IPCC Sixth Report models (CMIP6) under SSP scenarios (SSP1-2.6, SSP2-4.5 and SPP5-8.5) during the period of 2022-2100 in Kashan Plain. The mean temperature and precipitation data was obtained from 7 stations (Kashan, Kavir-e-Hosseinabad, Kamu, Ardestan, Alavi, Noushabad and Sensen) in Kashan plain considering the base period of 30 years (1984-2014). Also, 7 models were selected from the models of the sixth report (CMIP6). The post-processing of the output of the models was carried out using the linear ratio method. Nash-Sutcliffe indices (NSE), root mean square error (RMSE) and correlation coefficient (r) were used to determine the accuracy of the models. The annual trend of changes was investigated using Mann-Kendall test. Finally, the mean of IPSL-CM6A-LR and BCC-CSM2-MR models outputs was used to simulate mean temperature and precipitation changes in the future period. According to the results, in all of the studied stations, precipitation in the coming period will have a decreasing trend compared to the base period. The mean temperature will also increase in the future period compared to the base period. In Kavir-e-Hossein Abad, Ardestan, Noush Abad and Sen Sen stations, the intensity of temperature increase will be higher than Kashan, Kamu and Alavi. According to the predicted conditions, it is necessary to pay attention to comprehensive policies in the field of adapting to climate change in Kashan Plain.

For the optimal management of the surface water, it is necessary to identify the effect of meteorological drought on the river flows in terms of time. In this study, the relationship of meteorological and hydrological droughts in Sufi Chai River basin of Maragheh (East Azarbaijan province) was evaluated using SPI, RDI and SDI. The daily weather data of the Maragheh synoptic station and the daily data of Tazehkand hydrometric station (upstream of Alavian dam) were used. The statistical period of 34 years were determined (1983-2017) and 3, 6, 12, 24 and 48 month time series were created. In RDI, ETO was calculated using FAO-Penman-Monteith and Hargreaves-Samani methods. The correlation of hydrological and meteorological indices was performed for 3 to 48 month time series without delay and with delay of one-five month. The results in without delay condition showed the highest correlation between the indices is belonged to the series with similar period. The correlation between the similar RDIFPM and SDI series were less than the ones corresponding to SPI and SDI, or RDIHS and SDI. It is concluded considering the other weather parameters, in addition to rainfall, for calculating the indices, results in reduction of the correlation between the meteorological and hydrological indices. Among RDIHS and SDI values with delay condition, in the 3, 6 and 12 time series, the greatest effect of the meteorological drought on river flow was observed with the 3 month delay and in the 24 and 48 month time series, this effect was simultaneous.

In the last two decades, Sistan region has been suffering from drought conditions. The fluctuation of the Hirmand River and the incorrect management of water resources in this region have caused the water crisis to intensify. In this situation, one of the solutions that can help to get out of the critical water situation is cooperative irrigation. Therefore, in this research, the feasibility of establishing water harvesting cooperatives in drought conditions in Sistan region with an entrepreneurial approach is considered. To achieve the mentioned goal, the model of similarity to the ideal option of the fuzzy logic bed has been used. To collect the necessary information, experts, experts and farmers were used through interviews and questionnaires. MCDMSolver 2018 software was used for modeling and solving the model. In this research, based on three economic, social, and attitudinal indicators, the sub-indices were divided into 12 items, and finally, the three options examined, the traditional system, the production cooperative system, and the rural cooperative system were prioritized and ranked. The results of the research showed that the production cooperative system with a weight of 0.56 was placed in the rejection rank. In the second place is the rural cooperative system with a weight of 0.40 and the traditional system with a weight of 0.29 is in the last place. According to the obtained results, water cooperative system should be given special attention in the form of production and rural systems.

The main purpose of this research was to investigate the water quality of Zarrinehrood and Siminehrood rivers for the year 2018 and in 13 and 6 stations of the two rivers, respectively. For this purpose, the unpublished data of Na+, Cl, SO4, TDS, pH, CO3, HCO, EC, Ca, Mg and SAR parameters from both rivers were used and presented in this paper. Graphical methods were used to determine the water quality of the rivers for various human uses based on drinking and agricultural standards, and to determine the water quality in terms of sustainability, Langelier, Ryznar and Pukorius indices were used. Also, the water quality conditions of the studied rivers were compared and studied with the national standards of Iran (1053), the World Health Organization, the United States, the European Union, and the water quality standards of Iran of the Environmental Protection Organization. The results indicate that the type and facies of water is calcium bicarbonate in study stations and water quality of most stations are suitable for drinking and agricultural usages. The SAR value in Shirin-Kond station is 1.51 mEq/L and the EC value is 1144 mmho/cm and its water quality is in class C3-S1 that can be used for agricultural purposes. According to the Results, water quality of studied stations is corrosive for industrial uses.

Wastewater from various industries is one of the main sources of environmental pollution, which has detrimental effects on the environment and the lives of living organisms. In recent years, adsorption methods using adsorbents to remove contaminants from water resources have been abundant. Solfounate and Pentaaza Tetra Ethylene supported Polyacrylamide (PAM-SO3-N5) as a novel adsorbent can be effective for removal of chemical pollutants of the aquatic solution. The purpose of this research is removal of Kalmagate using PAM-SO3-N5 as an adsorbent from polluted water in vitro. The effects of variables such as pH, contact time, initial concentration and adsorbent amount were observed to reach best adsorption conditions. Isotherms of Langmuir, Freundlich and Temkin have been fitted with the data of experiment. In addition, kinetics of pseudo- first order, pseudo- second order, intra-particle diffusion and Elovich were also fitted with the experiment data. Also, the results indicated that the best conditions for removal of Kalmagate dye were: pH= 2, removing time= 60 minutes, adsorbent dosage= 0.014 g and initial concentration of dye= 360 mg L-1. For PAM-SO3-N5, Freundlich isotherms showed a good agreement with the experimental data. Using this model to maximize absorption capacity of 1732.5 (mg g-1) for PAM-SO3-N5. Absorption rates showed a quick responses which was less than one hours. Based on these results, the adsorption kinetics of pseudo- second- order was more consistent with the experimental data (R2=0.97). The results show that PAM-SO3-N5 absorbent is effective in removing Kalmagate contaminants from the aqueous solutions due to its high

In this research, nine numbers of systems were built and urban water flow was established continuously from December 2019 to June 2014. All systems were planted in the soil with different densities of 10, 20, 30 and 40 cm. The selected hydraulic retention time was 5 days, and for each retention time, this experiment was repeated in three stages, for six months. The concentration of calcium, magnesium, potassium, chlorine, carbonate, bicarbonate and EC input to the systems and their output were measured and the concentration changes were compared using SAS statistical software. The comparison results of the average density of plant cultivation, changes in temperature, month, and their interaction in the efficiency of removing salinity parameters were observed to be significant at the 95% confidence level. Comparing the average effect of temperature on salinity removal showed a significant difference between the efficiency of salinity removal in some months of the year. The interaction effect showed that the highest salinity removal efficiency equal to 17.75% was obtained in the retention time of five days in the soil cultivation system and in July. According to the results, it can be said that the highest average for the EC parameter occurred in December at a density of 40 cm and the lowest average value for a density of 20 cm occurred in April.

Access to safe water is one of the main components of sustainable development, and monitoring of water resources used by humans is necessary and essential. In order to better understand the water quality of human societies, the analysis of physical and chemical parameters of water resources is done with the help of indicators and statistical methods. In this research, the quality of urban water resources of Nahavand was investigated and zoned with the help of nitrate parameter interpolation methods. For this purpose, 48 samples of drinking water from 16 districts of Nahavand city were taken randomly and pH, EC and No3 parameters were measured in them. Wilcox, WQI and NPI indices were used to determine the quality of water sources. The comparison of the values of the studied parameters with the WHO standard and the national standard of Iran was done by a one-sample t-test. Nitrate zoning map and WQI index in Nahavand urban water sources were also prepared by using Kriging method. Based on the obtained results, there was a statistically significant difference between the values of the investigated parameters with the national standards of Iran and WHO (p<0.05). So that the average pH and No3 were lower than the standard limits and the average EC was higher than the standard limit and according to the Wilcox classification, 44% of Nahavand city water samples were in medium salinity condition and 56% of the remaining samples were in medium salinity condition.