Spur dikes are river training structures that developed from the natural river banks with proper length and angle from the flow dominant direction, cause to divert the flow attack at the riverside and the critical regions and directs the flow to the river central axis. There are several researchers focused on the effect of the spur dikes angles on the flow pattern however there is not any study on hockey spur dikes angle on scouring patterns. In present study, the effects of the hockey spur dikes angle on scouring and the bed topography was carried out experimentally while the results were compared to those provided for L-shape. The experiments were conducted on a series of hockey spur dikes also the L-shape in three various angles equal to ,  and  (towards the downstream channel lateral walls) inside a laboratory flume in 10.5m length, 0.5 width and 0.5m height under the clear water conditions. The results revealed the scour hole parameters including the length and thickness of the sediment hill are lower in hockey spur dikes than the L- shape by increasing the spur dikes angle. Furthermore, the maximum scour depth, mean area and volume of scouring are increased by 41.4, 41 and 75.5 percent in hockey and by 33.8, 39 and 73 percent in L-shape through increasing the angle from   to , respectively. Also, no scouring was taken place in the vicinity of the channel lateral walls downstream the hockey spur dikes, hence, those beter act against the destruction also in protection of river beaches against the erosion, with respect to the L-shape.

It is expected that due to the value of water in the agricultural sector and the reduction of water resources in recent years, methods of adaptation to the conditions ahead will be investigated. A study was carried out to investigate the effects of deficit irrigation on yield components of rice (Binam variety). The experiment was run in the form of a randomized complete block design with nine treatments and three replications in the Babolsar city of Mazandaran province in year 2020. The treatments were regulated deficit irrigation (RDI) and partial root zone drying (PRD) in three drought stresses of 10, 30 and 60 kPa (RDI10, RDI30, RDI60, PRD10, PRD30 and PRD60) and full irrigation (FID). Drip tape irrigation system was used as irrigation method. Flood irrigation system was used as an irrigation (FI1) and weed (FI2) control treatment. Soil water deficit was measured by a tensiometer and Volumetric meter was used to calculate water consumption. Flood irrigation treatment had the highest yield of rough rice and water consumption (6442 kg / ha and 10886 m3 / ha). The lowest rice yield was for RDI60 treatment with 2998 kg / ha and the lowest water consumption was corresponded to PRD60 treatment with 2111 m3 / ha. According to the results, the applying of PRD method in addition to higher yield than RDI, saved 76.33% in water consumption. The PRD method could be recommended for the region.

Put critical situations. Decline of groundwater level in Urmia plain and declaration of this plain as one of the forbidden plains of West Azerbaijan province; It has caused the rehabilitation of the aquifer and planning to prevent its decline and increase its level to be among the priorities of the executive plans of the Ministry of Energy in this area.In this study, in order to rehabilitate the aquifer and in parallel, the effect of annual rainfall parameters and reduction of groundwater abstraction on changes in the aquifer level of the Urmia plain was investigated using the fuzzy TOPSIS technique. In this regard, the effectiveness of the measures taken based on 4 management scenarios, a questionnaire with 18 options in the form of three criteria of implemented measures, short-term proposed measures and long-term proposed measures were prepared. Given the breadth and multiple interactions between the criteria and the leading measures, the fuzzy method to express the effect of each option quantitatively and the TOPSIS fuzzy analysis method to analyze the opinions of experts with the aim of ranking the options of each scenario in Problem solving was used. The results indicate that increasing rainfall and consequently decreasing groundwater abstraction is still the most effective factor in the relative improvement of the quantitative status of the aquifer. Meanwhile, by examining the amount of rainfall in the last few years in the Urmia plain, it can be stated that in addition to changing the amount of rainfall as the main factor, the effectiveness options of patrol and inspection groups (Ch6), feeding the aquifer by releasing water from the dam Tea city (Ch7) and river blockage in non-crop seasons and feeding the aquifer through the main river (Ch4) are among the measures of the rehabilitation and balancing plan (implemented) in improving the groundwater level. Given the breadth and multiple interactions between the criteria and the leading measures, the fuzzy method to express the effect of each option quantitatively and the TOPSIS fuzzy analysis method to analyze the opinions of experts with the aim of ranking the options of each scenario in Problem solving was used.The results indicate that increasing rainfall and consequently decreasing groundwater abstraction is still the most effective factor in the relative improvement of the quantitative status of the aquifer. Meanwhile, by examining the amount of rainfall in the last few years in the Urmia plain, it can be stated that in addition to changing the amount of rainfall as the main factor, the effectiveness options of patrol and inspection groups (Ch6), feeding the aquifer by releasing water from the dam Tea city (Ch7) and river blockage in non-crop seasons and feeding the aquifer through the main river (Ch4) are among the measures of the rehabilitation and balancing plan (implemented) in improving the groundwater level.

When the dam reservoir exceeds its capacity, the spillway, as one of the most significant water-dependent elements of dams, safely conveys the oncoming flood flow to the dam reservoir. Dam safety is inextricably linked to sufficient spillway capacity. Therefore, one of the most pressing issues in all dams is ensuring the accuracy of structures and the hydraulic operation of spillways. In the present study, the hydraulic parameters of the flow on the spillway for the flood discharges with 50 and 10,000-year return periods were simulated using WS77 and Flow3D softwares in order to evaluate the factors affecting the destruction of the concrete panel of the Bukan Dam spillway. Various known factors in the destruction of spillway floor concrete panels such as cavitation, pressure fluctuations, uplift pressure and hydraulic jacks were also investigated. As shown in the results, the minimum cavitation index in selected floods of 50 and 10 thousand years is 0.31 and 0.275, respectively, which is more than the critical value of 0.2. Furthermore, at the maximum values estimated in the two floods, the failure potential index is 111 and 198 (2.5 cm offset) respectively, which is much below the value of the destruction threshold of 500. However, the results show that increased pressure owing to the hydraulic jack phenomenon, as well as uplift pressure to values greater than the concrete panel weight component and anchor strength, has resulted in spillway floor concrete panel displacement.

The aim of this study was to investigate the effect of using each of the surface, sprinkler and drip irrigation methods on the condition of Zayandehrud basin. For this purpose, water, energy, food and carbon nexus approach was used for a comprehensive study. In the nexus approach, considering their interactions, efforts are made to increase productivity and ensure the security of the region. In this study, this approach has appeared in the form of a newly developed index called water, energy, food and greenhouse gases nexus (WEFGN) and considering ten indicators including inputs of crop production, energy consumption for irrigation, food self-sufficiency, economic efficiency and carbon emissions were studied for irrigation methods that could provide a comprehensive view of managers and decision makers. The results of the study of irrigation methods in 2020 showed that by changing the current irrigation method to drip and sprinkler irrigation due to reduced water consumption (17 and 4.84 percent (483.7 and 138.5 million cubic meters per year, respectively)) the condition of the basin improves, but in the sprinkler method more energy is needed for irrigation (280.5 percent (112415.8 thousand kcal per year)) and the carbon released due to the increase in irrigation energy also increases to 87432.5 tons per year (73.7 percent). Therefore, the WEFGN index score for each of the drip irrigation, sprinkler and current status methods was 0.86, 0.31 and 0.47, respectively, and the best irrigation method in Zayandehrud basin in terms of nexus approach was drip irrigation.

In the design of embankment dams, the vertical or inclination of the core has its own advantages and disadvantages according to technical and economic considerations. In each of these options, it is necessary to pay attention to the amount of seepage, deformations and stresses created in the body and foundation of the dam, as well as stability. In addition, the control of the arching caused by different stresses and subsidence in different levels and areas, which can lead to hydraulic failure of the dam, should also be considered. In this study, while analyzing the static behavior of the "Azad" dam in real condition (with a vertical core) in GeoStudio software, analysis of seepage, stress-strain, arching and slope stability with different core inclination (zero , five, 10, 15, 20 and 22 degrees relative to the vertical) at end of construction and steady-state seepage have also been studied and compared. The results showed that for a given depth, with increasing the angle of inclination of the core from the vertical position, the seepage through the dam body and foundation (especially for angles greater than 15 degrees) and the vertical displacement of the core central line increased. Also with increasing the angle of inclination, the average stability safety factor of the downstream slope of the dam increased imperceptibly but for the upstream slope especially for angles greater than 15 degrees, there was a significant decrease of 22.6 percent. The trend of increasing the total vertical stress along the central core line with increasing depth for different angles of the core did not change significantly. In the case of arching, except in the height range of 0.3 of the height of the crest, the probability decreased with increasing inclination angle of the core.

Geometric and morphological characteristics of each river are its main characteristics by which the management planning of the basin and the conservation of natural resources around it is done. Estuaries are formed at the mouth of rivers in a border area between sea and land. Deformation of estuaries due to sedimentation and erosion changes the pattern of river flow. In this research, the hydrodynamic model (HD) is used to calculate the flow rates and velocity and the sediment transport model (ST) is used to calculate the suspended load and bed level. The results of the hydrodynamic model showed that the maximum speed at 17 km of Shalmaneh station (beginning of the third interval) is approximately 4.7 m /s. This value decreases to about 1.5 meters per second as we approach the end of the estuary. Due to the importance of the role of floods in bed changes, the model was implemented using the 25-year flood discharge of Shalmanrood River (355 cubic meters per second) for a period of one year. After that, the river route was divided into three parts and the behavior of Shalmanrud river was studied according to the deformation created in the sections of each part. The maximum amount of sediment in the first part is 0.41 m in non-flood condition and 1.1 m in flood condition. In the second part, sedimentation increases and in non-flood state reaches 0.8 meters and in flood state reaches 2 meters. In the third part, the amount of sediment will be more than the first and second parts. The maximum amount of sediment in this part is 0.53 m in non-flood condition and 1.4 m in flood condition.

Due to the increase in greenhouse gases and numerous water and climate crises, accurate prediction of  the changes groundwater levels is very important and vital in the  water resources management. Therefore, in this paper,the  climate changes of Talesh plain is studied under RCP scenarios using Lars-WG and its water sources from SVR and ANN models. Also,aquifer pumping parameters, evapotranspiration potential, minimum and maximum temperature and  precipitation are used from (2021-2030). The results of the mean minimum and maximum temperature changes under RCP scenarios indicate the temperature increase by 0.9 and 0.69 °C. Also,studying  the accuracy of SVR and ANN models shows that the AUC in the training and testing phase in the ANN model, the maximum AUC values ​​were calculated as 0.876 and 0.769, while the SVR model, the maximum values ​​were equal to 0.867 and 0.819.Thus SVR has better predictive accuracy.In addition to that  during the time period (2005-2019) the groundwater level has decreased by 10 cm and in the SVR and ANN models by an average nine and six cm respectively more ever during in the time period(2021-2030) ground water levels have decreased in by 18, 20 and 21 cm, 20, 21 and 23 cm under the scenarios RCP2.6, RCP4.5 and RCP8 5 in SVR and ANN models,respectively.Therefor it is suggested that in Talesh plain considering the cultivation pattern appropriate to water resources in different parts of the plain should be the  priority for agricultural planners.

The scarcity of available water resources, on the one hand, and the increase in water demand, on the other, have upset the balance between water supply and water demand systems. Consequently, it is necessary to prevent the destruction of this valuable ecosystem and its adverse effects by considering the principles of the integrated water resources management program, determining the environmental status of wetlands such as Amirkalayeh wetland, and improving its water resources management. The main purpose of this study was to investigate different allocation scenarios for the provision of wetland ecosystems based on the principles of integrated water resources management. To aim this purpose, the water resources system of the wetland and its catchment area were simulated with the WEAP model. First, the model was calibrated for the current condition of the wetland in the reference scenario at the water years 2011-2020 whith R2 and RMSE statistical indices of 0.99 and 0.1 for the wetland volume and 0.95 and 0.3 for the creek discharge, respectively. Therefore, water shortage values were estimated to achieve the minimum and optimal ecological conditions of the wetland. Then, the effect of the management strategies on the balance of water resources of the wetland was investigated by compiling different management scenarios. The results showed that the implementation of scenarios at the wetland scale and its catchment would increase the volume of water in the wetland between 0.5 to 4 and 0.3 to 1.7 million cubic meters, respectively. Furthermore, simultaneously implementing scenarios of increasing the volume of the wetland’s reservoir could provide the wetland's water requirements by constructing a levee, increasing irrigation efficiency, and eliminating the occupation of agricultural lands in the wetland bed and its margins. Also, when agricultural water requirement is provided, the water requirements of the wetland will be met so, even at a higher level.

Planning for the best use of water resources in agriculture is inevitable. In this regard, the method of subsurface drip irrigation can, in addition to reducing the amount of irrigation water, increase crop yield. This study was conducted to investigate the different levels of under-irrigation and over-irrigation on yield indices and plant traits of sweet corn cultivar CHASE, under subsurface drip irrigation system in a randomized complete block design with four treatments of 20 Percent over-irrigation, equal to water requirement, 20 and 40 Percent under-irrigation in four Repeated. The results showed that in general, the effects of under-irrigation and over-irrigation on cob yield, 1000-seed weight, uncovered cob diameter, pod-free cob length, number of cob rows and number of seeds were significant. Also, based on the results, it can be stated that by reducing the amount of water consumption, the yield of the product decreases linearly. The highest and lowest cob yields were obtained in over-irrigation treatments and 60 Percent of water requirement with an average of 30.4 and 19.9 tons per hectare, respectively. Accordingly, with a 20 Percent reduction in water consumption compared to full irrigation, only 4.72 Percent of the crop is significantly reduced. This is while with a 20 Percent increase in irrigation water, the yield of cob increases by 10.54 Percent. 1000-seed weight in full irrigation and 20 Percent low irrigation treatments was 375.7 and 372.6 g, respectively. There was no significant difference between over-irrigation and 20 Percent under-irrigation treatment. There was a significant difference between the means of ear yield indices, length and number of seeds per ear row in all irrigation treatments.

Determination of the environmental flow of rivers using hydrological and hydraulic methods has received more attention due to the available information and less cost and time. The important point in using these methods is to consider the natural conditions of the river by eliminating the effect of upstream withdrawals. To investigate the necessity of naturalization of the flow and its effect on determination of the ecological water supply of Zayandehroud river at the location of the Sad-e-tanzimi station (before major drinking, industrial and agricultural harvests) and Varzaneh station (near Gavkhuni wetland and after harvest and water infiltration) has been selected as a case study. Based on the Tennant method, using the observed and naturalized flows at Varzaneh station, the ecological watercourse showed that if the observed flows are used, it will obtain about 0.6 cubic meters per second. It turned out that there would be practically no water flowing in the river. If naturalized flow is used, 16 percent of the basin runoff potential will be allocated to the environment. The environmental flow obtained from the wetted perimeter method with the curved slope algorithm at the Sad-e-tanzimi and Varzaneh station has estimated 13 and 16 percent of the annual average natural flow, respectively, which is within the acceptable results of the modified Tennant method. Has been located. As a result, the use of the modified Tennant method is recommended due to the ease of calculating and providing the monthly distribution of environmental water, provided that the naturalized flow time series is used at the study stations.

In order to understand the mechanism of flow patterns in vegetated channels, the flow located in a rectangular channel was numerically investigated by using OpenFOAM software. Firstly, two solvers of that software (i.e. icoFoam and pimpleFoam) were used to calculate the velocity profiles in both longitudinal and cross-sectional directions for four selected sections in a rectangular channel with a square cylinder. By comparing the simulation results with the available data, the icoFoam solver with a better performance (six Percent Error) was selected for the next developed model. A new model was then created with two tandem square cylinders with spacing ratios of two and a half and five. Flow patterns, velocity distribution and pressure characteristics in the channel with different inlet flow velocities were investigated for two cases. It was observed that a flow field disturbance occurred in all simulations and the current changed from steady state to unsteady one at a critical velocity. This instability occurred in a distance between the cylinders for the spacing ratio of five at an average Reynolds number of eight, while for the ratio of two and a half it is occurred at an average Reynolds number of 32. The maximum values ​​of longitudinal and transverse velocity timelines in a period of 200 seconds for four states (including two Reynolds numbers and two different spacing ratios) were plotted in two spatial ranges and fully investigated. According to the results, it can be said that the overlap has an important role on the flow characteristics in tandem arrangements and by increasing the distance ratio between the cylinders by 55 percent, the critical velocity value decreases by 74 percent.

One of the ways to reduce water consumption and increase water productivity is to simultaneous use mulch and deficit irrigation. For studying the effect of mulch and different levels of irrigation on water use efficiency of Basil, a split plot experiment based on randomized complete block design was conducted. The experimental treatments consisted of four different irrigation levels; and two soil factors in two seasons of cultivation. The elasticity theory was used to determine the maximum product yield and water productivity. In the theory of elasticity, marginal water consumption efficiency index and elasticity index are determined by deriving from the production function. The results of the first season showed that in the conditions of maximum yield, the yield of the product in mulched soil was about 19% higher than the normal soil, while water consumption was reduced by 28% in the mulch, and in total about 50% of water productivity has increased. In deficit irrigation condition, the best dry matter yield, water requirement and water productivity were 118 gr/m2, 67 mm and 67.1 gr/lit in soil covered with mulch respectively; while these values for uncovered soil were 96.7 gr/ m2, 80.2 mm and 21.1 gr /lit respectively. The results in the second season of cultivation were similar to those of the first cultivar and indicated that the yield of the product, water requirement and water productivity in the mulch was increased. The results of the experiment showed by applying mulch on the soil surface and using deficit irrigation strategy, water use efficiency and yield productivity of basil increased.

Roof rainwater harvesting is considered an important alternative source where contaminated surface and groundwater resources are limited or not readily available. The aim of this study was to evaluate the quantity and quality of water extracted from rainwater harvesting systems for drinking water production at Sari Agricultural Sciences and Natural Resources University. To investigate the potential for rainwater harvesting within the university, one of the student dormitory buildings with a roof area of 850 m2 and a capacity of 300 students was considered. Daily rainfall data of Dasht-e Naz station in Sari in the period 2000 to 2018 were used as inputs of the water balance model to determine the appropriate volume of the rainwater storage tank. Also, in order to evaluate the quality of water collected from the roof, sampling from the roof outlet and some important physical, chemical and microbial parameters were measured. According to the results, the volume of the storage tank of 30 m3 in the dormitory with Volumetric and time reliability of 29 and 29.5 percent, respectively, was considered appropriate. The results showed that at the implementation of this system, about 309 m3 of town water consumption will be saved annually. The results also show that the direct use of collected water for drinking purposes is limited. Accordingly, according to the amount of water produced annually, it is recommended to use a UV system for disinfection and microbial purification while using a sand tank to improve physical parameters (turbidity).