فرزین سلماسی

Accurate knowledge of where jets hit downstream of dams helps designers a lot in locating plunging pools. The purpose of this study is to investigate experimentally and numerically the trajectory of pressurized jets through the gates and to determine their location downstream of the dam. Ansys - Fluent software was used for numerical simulation. The results showed that there is a significant difference between the experimental values and the values extracted from the jet projectile equations for predicting the path of the pressurized jets, and this discrepancy may be due to the effect of air resistance on flow. The existing jet trajectory equations don’t consider air resistance. To minimize this difference, the projectile equation was modified. Also, the effect of changing the diameter of the dam gate and the discharge on the point of impact of the pressurized jet on the ground surface was examined. By increasing the diameter of the dam outlet at a constant discharge, the location of impact of the impinging jet to the ground from the dam toe decreases, and with increasing discharge at a constant diameter of outlet, the place of impact of the pressurized jet to the ground from the toe of the dam increases. In addition, the numerical simulation results showed that the dynamic pressure as well as the velocity at the point of impingement of the jets on the river bed have the maximum value that should be considered in designs. The dynamic pressure as well as the velocity of the jet coming out of the gate hit the ground with an average increase of 145% and 242% relative to the end edge of the gate, respectively. In addition, the breaking length of the pressurized jet was investigated in this study, and it was found that the breaking length of the pressurized jet increases with the increase in the initial velocity of the water jet.

Weirs are one of the types of hydraulic structures in water projects that with different cross section have been widely used as flow measuring, controlling and regulating of upstream water surface for turnouts devices, in conveyance water canals or body of dams. In this study, the hydraulic characteristics of flow over broad-crested weirs including the effects of different configurations of sloping crest and upstream and downstream ramps using of finite volume method (FVM) by the ANSYS FLUENT software was investigated. Numerical simulations were validated by experimental results. The results showed that discharge coefficient (Cd) for the BCW-UR-PSC and BCW-UDR-NSC weirs are higher than the BCW-UDR-HC weir. The average increase of Cd in BCW-UDR-NSC respect to BCW-UDR-HC in such a way that θ=-4.76° and- 9.46° is 18% and 25%, while the average increase of Cd in the BCW-UDR-PSC respect to the BCW-UDR-HC for same condition (θ=+4.76° and+9.46°) is 10% and 18%. It was found that both of the BCW-UDR-NSC and BCW-UDR-PSC, the Cd increases with steeper of the crest slope (or increasing θ). Also, the results showed that for BCW-UDR-PSC, value of Cd is 0.35≤Cd≤.47, however for the BCW-UDR-NSC, values of Cd are between 0.42≤Cd≤0.48. This shows that the Cd is affected by the sloping of the crest in such a way that negative slope respect positive slope has more impact in this increase. The average increase of the Cd in BCW-UDR-NSC respect to the BCW-UDR-PSC is approximately 8%.

Accurate determination of the discharge coefficients plays an important role in estimating the discharge of the weirs. As a result, it is significant to estimate the discharge coefficients correctly. The purpose of this study is simulation and estimation the discharge coefficients of the broad-crested weirs. Hence, numerical simulation of hydraulic characteristics of these weirs were performed by ANSYS FLUENT software and results were obtained. Then, three intelligent models of ANN (MLP), GEP and RF were used to determine the discharge coefficients and the results of these models were compared. Assessment of the results were carried out using the statistical indices as R2 , RMSE, KGE, and graphical diagrams. The amounts of R2 , RMSE and KGE for ANN (MLP) were 0.906, 0.016, 0.927, for GEP 0.790, 0.025, and 0.780, and for RF 0.898, 0.013, and 0.841 were obtained, respectively. Due to the statistical criteria results and the range of RE% (∓5%), the ANN (MLP) was selected as the superior model. Violin plot illustrates a great and close agreement between the probability distribution of estimated data with ANN (MLP) and the obtained data from the numerical simulation using the finite volume method. Furthermore, the probability density function plot of residuals in ANN (MLP) model was closer to the normal distribution function, compared with the other models in this study.

Broad-crested weirs can be used to make discharge measurements in irrigation canals; the entrance of stepped weirs or chutes is sometimes designed as a broad-crested weir structure. These structures are also sometimes used for the dam body. In this study, the Artificial Neural Network (ANN) and M5 model tree methods are used to predict discharge coefficients (Cd ) for broad-crested weirs. The results from these two models are compared with nonlinear regression equations. Four series of data obtained from different rectangular broad-crested weirs have been used and important dimensionless parameters have been defined. Results show that the ANN procedure is superior to the M5 model and regression approaches. The accuracy for ANN is quantified by R=0.966 and RMSE=0.038. All three methods are able to provide a reasonable prediction for Cd ; the M5 model tree provides four linear equations that can be used to estimate Cd . The shape of the Cd contours shows that the effect of weir height (P) exceeds that of the weir length (L).

Weirs are structures that are important for measuring flow and controlling water levels. Previous studies have shown that the discharge coefficient is not constant and depends on the weir crest length, the height of weir, the upstream head, and the weir upstream and downstream slopes. In this study, the effect of these parameters on the discharge coefficients (Cd) are investigated by numerical simulation. Results showed that the downstream face slope has little effect on Cd. For 0.1<H1/w<0.4 by decreasing the upstream slope, Cd increases, where H1 is the water head on the weir crest and w is the length of the crest. Also, for the same range, by decreasing the height of the weir (p), the Cd increases. For 0.16<H1/p<2, as the length of the crest decreases, the Cd increases. By comparing the numerical simulation results to physical measurements, determination coefficient (R2) was between 0.71-0.86. In addition to Cd, extraction of other more detailed information such as water level profiles and velocity profiles at different locations are provided and comparison with other studies was carried out.

This study investigated the performance of a labyrinth weir with a trapezoidal cross-section at different heights. For this purpose, the geometry of the weirs was designed in Inventor software, and simulation was performed in Flow3D software. Validated the model with laboratory data, and the results of the model were in good agreement with the results of laboratory data. Examined the numerical model at three heights of 10, 14 and 18 cm and three different angles and two apex widths; Analysis of the results showed that with decreasing the weir height (P), the discharge coefficient (Cd) increases. Reducing the weir height by 44% increased the average discharge coefficient by 2 to 3%. In all simulated models, with decreasing relative water head, the decreasing trend of discharge coefficient was also reduced. During the constant crest length, with a 100% increase in the weir angle, the discharge coefficient of all three weir heights increased by 20 to 25%. A 40% increase in crest length at a fixed angle increased the average discharge coefficients of all three heights by 12 to 15%. As a result, at a constant angle, the increase in crest length is greater than the second case (constant crest length and increase in weir angle) on the flow rate; This is important in designing labyrinth weirs to have a maximum discharge coefficient and should be considered.

Water pumping stations usually use fixed speed pumps that have a good efficiency over a small range of pressure and flows. If different flows and pressures are required, unsuitable pump speeds will yield excessive energy losses. This imposes additional costs, especially on pressurized irrigation systems, which are constantly changing their irrigation needs, sometimes monthly. In pressurized water distribution systems, a constant speed pump is often used because of its simplicity. However, constant speed pipes are not easily able to deal with changing demands in water flows. When the demand for the discharge differs from the design discharge, the required demand (discharge and head) could be met by changing the pump speed without making any special changes in the system. Using an electronic drive circuit, the electrical frequency can be changed and the rotation speed of the pump motor can thus be modified. In this study, the application of variable speed pumps in pressurized irrigation systems is investigated. Two pumping station scenarios including a fixed speed pump and a variable speed pump are considered. The results show that using a variable speed pump increases the average pump efficiency by 18.7%. In addition, the variable speed pump system reduces the electrical consumption 57.6 % compared to a fixed speed pump. Therefore, the use of variable speed pumps in pressurized systems is recommended.

In design of hydraulic structures cutoff walls are needed for reduction of uplift force and exit hydraulic gradient. Upstream cutoff wall is used for reduction of the uplift force and downstream cutoff wall is used for reduction of the exit hydraulic gradient. This study tends to numerically investigate the double-cutoff beneath the hydraulic structures with variation in their location, distance and depth. Governing equations with boundary conditions are solved using the finite element method (FEM). Results showed that if the downstream cutoff wall is deeper than upstream cutoff wall, the resultant of uplift force would be more than the uplift force without cutoff walls. With a constant value for hydraulic structures width (B), decreasing in distance between two cutoffs (L), results the reduction in uplift force. Increasing in impermeable depth (D) and reduction in B, yields lower uplift force. Increasing in downstream cutoff depth (d2) and L, results reduction in exit hydraulic gradient (GR). When the two cutoffs are located in the end of the hydraulic structure, GR is lower than that when the downstream cutoff is located in L/B=0.33 and L/B=0.66 from upstream cutoff. Comparison between the available analytical solutions for two equal ending cutoffs with FEM, showed that FEM can predict PC and GR with maximum 5% error.

Weirs are common hydraulic structures that can be used in conveyance water canals for increasing the water depth upstream of turn outs or measurement of flow discharge. In this study the effect of hydraulic parameters and creation conditions of undular flow in broad crested weirs were investigated numerically using the finite volume method and the results were evaluated by the experimental method of other researchers. Results indicated that discharge coefficient (Cd) for experimental data are between 0.321-0.332, whereas Cd for numerical simulation (using ANSYS FLUENT) are between 0.301-0.354. Over the crest where the minimum water depth (dmin) is happen, when Fr1 is less than 1.5 (Fr10.1. Thus it can be resulted that long broad -crested weirs (H/L

In this study, flow characteristics and pressure parameters of hydraulic jumps has been investigated in a laboratory flume. The results for different incident Froude numbers (Fr1), at the downstream of an Ogee spillway on the typified USBR II stilling basin bed were compared with the USBR type I basins. Dimensions of the Ogee spillway and stilling basin were designed according to the USBR criteria. The pressure data of the points on the basin bed were recorded using pressure transmitters with 20 Hz frequency. Experimental parameters including flow depth and velocity at the start and end points of free jumps (Y1, Y2, V1 and V2), and submerged jumps (Y3, Yt, V3 and Vt) were measured. In the present study, dimensionless parameters of energy dissipation efficiency (εt), mean pressure head (Ψ*X), standard deviation of pressure fluctuations (Φ*X), maximum positive pressure fluctuation coefficient (CP+), maximum negative pressure fluctuation coefficient (CP‒), total pressure fluctuation coefficient (CP) and skewness coefficient (Ad) were investigated. Pressure parameters are dependent on Fr1, the point position (Γ*X), and the submergence degree (S). The results showed that by reducing the values of Fr1, parameter εt decreases. The parameter Φ*X max in the USBR type II basin decreases around 30% compared to the type I basins in free jumps. The reduction of Φ*X max values in the submerged jump with S=1.4 is about 29% than free jumps. The values of CP+max and |CP‒|max coefficients in the submerged jump with S=1.4 in comparison with free jumps decreases about 15% and 17%, respectively.

Accurate prediction of pore water pressure, settlement, soil stress and pore water pressure coefficient (Ru) in the body of earth dams during construction is one of the necessary measures in the management of earth dam stability. In the present study, which is a case study, a three-dimensional numerical simulation was performed using the Plaxis software for the Kabudval Dam located in Golestan province, Iran. The values obtained from the numerical simulation were compared with the corresponding measured values using the dam instruments. Calibration was carried out using back analysis method (BAM) and some dam geotechnical parameters were corrected based on BAM. The results showed that the hardening soil (HS) model with the statistical indicators of R2, RMSE and GMER is more accurate compared with the Mohr- Coulomb (MC) model. The results of the numerical model were calibrated at the end of construction for Kabudval Dam and showed that the maximum increase in pore water pressure, stress, settlement and horizontal displacement occurs in the central part and its value in the axis and middle part of the dam is more than its sides. The middle part and close to the dam axis have similar changes with the fill process of the dam body; while with moving away from the dam axis due to the transfer of stresses to the sides, they have less impact from the dam filling process. In addition, in the central part, the effects of filter and drainage is low.

In this study, different components that affect energy dissipation on flow over gabion-stepped spillways were investigated using physical models, and comparisons were made with the other studies. Flow over gabion spillway was conducted in both through flow and overflow simultaneously. The discharge is in the range of 5 to 65 liters per second.  Uniform particles with three medium diameters of 10, 25, and 40 mm were used. The height and width of the physical models were 60 and 40 cm, respectively, with 3 steps and the downstream slope of weirs was 1:1, 1:2, and 1:3 (V: H). Tow end sills including rectangular and inclined shapes were used. The results showed that the effect of end sills in gabion-stepped weirs with lower slope is more than that of weirs comprising higher slope. The effect of the end sills on the energy dissipation in the weir for d50=40 mm and S=1:2 is about 10% more than the weir with d50=10 mm and S=1:1. In weir including d50=10 mm and S=1:2 is about 30 to 35 percent more than the weir with d50=10 mm and S=1:1. Therefore, the existence of end sills in the weirs with the body of materials of d50=10 and 40 mm have the highest and the least effects on the energy dissipation. On the other hand, the effect of the rectangular end sill on the energy loss is about 3-4% more than that the effect of the triangular end sill.

The purpose of this study is to provide an equation for prediction of discharge coefficient (Cd) for triangular plan sharp-crested weirs. Using laboratory data, a regression equation was presented based on h/p and α parameters with a reasonable accuracy. In addition, the performance of artificial neural network (ANN), gene expression programming (GEP) models and regression models (MR-linear and MR-nonlinear) in the estimation of the h/p was investigated. The stage-discharge relationship for triangular sharp-crested weirs was investigated. The results were evaluated using statistical criteria R2, RMSE, NSE and RE%. The values of the R2, RMSE, NSE and RE% were respectively, 0.998, 0.0076, 0.997 and 1.74% for ANN, 0.983, 0.0301, 0.998 and 6.86% for GEP, 0.986, 0.0196, 0.985 and 4.09% for MR-linear and 0.987, 0.0197, 0.984 and 4.09% for MR-nonlinear. The results of statistical criteria indicated the superiority of ANN as compared to other methods. In addition, results showed that based on the angle of the triangular sharp-crested weirs, the Cd is increased from 1 to 8 % respect to the normal sharp-crested weirs with identical width (suppressed weirs). In a situation where the head on the crest of these weirs is low, they will show better performance.

Discharge over the ogee weir is related to the length of crest, upstream total head and discharge coefficient. Also discharge coefficient is influenced by several factors. In this study, some parameters that are affecting the discharge coefficient in ogee weir are investigated. These are: ogee weir upstream slope, apron elevation and downstream submergence. In this regard, some ogee weir physical models were fabricated. These models include: (1) ogee weir with vertical upstream face; (2) ogee weir with inclined upstream face (18, 33, and 45 degrees); (3) ogee weirs with downstream apron elevations (3, 5, 7, and 10 cm thickness) in free flow; and (4) ogee weir with vertical upstream slope in submerged flow condition. Results show that in all the ogee weirs, the discharge coefficient (C) increases with increasing (P/He), and then remain constant. The value of discharge coefficient decreases from 2.25 (in free flow) to 2.15 (in submerged flow). For a constant value of head over ogee weirs (He), the discharge coefficient decreases with increasing in downstream apron elevation and submergence. The relative discharge coefficient has constant trend at beginning with parameter (hd/He), then has decreasing trend. The threshold value for submergence (hd/He), is 0.75 in ogee weir in this study. With increasing relative submergence (hd/He) from 0.75 to 1, the relative discharge coefficient (Cs/C0) decreases from 0.88 to 0.24.

In this study, the effects of diameter and location of drain pipes in uplift force, exit hydraulic gradient and seepage in the foundation of gravity dams are investigated. For this purpose, the SEEP/W software as a subgroup of Geo-Studio software is implemented and foundation of a gravity dam is simulated. The results showed that the existence of drain pipes under the gravity dam, reduce 4, 6, and 9 times of uplift force, exit hydraulic gradient and seepage respectively. Installation of two drain pipes with 0.25L distance from each other and in depth of 0.26D near the dam heel, presents more suitable position respect to uplift force reduction (D is the pervious foundation depth). Also, by defining the best position for the location of drain pipes, it was observed that drainage pipes in these situations reduce 41-67% in the volume of the studied dam and increase the safety factor up to 2 to 3 times against the dam overturning. It is also found that the drainage pipe diameter has less effect on uplift force, exit hydraulic gradient and seepage and and is controlled by the rules of the executive. For validation, the numerical method used in this study was compared with the laboratory method by others and a suitable match was observed.

The triangular in plan sharp-crested weirs do not have a direct and straight edge and are in good agreement with the broken line. The aim of the present study is to provide an equation for discharge coefficient (Cd) for these types of weirs. Cd is between 0.53-0.88 based on the observed data. For =15 degrees Cd has highest value and thus weir can convey maximum discharge. Using laboratory data based on h/p and α parameters, a regression equation was presented. The results of the regression equation were compared with the results of the numerical model (Ansys Fluent) and the results showed the high precision of this equation. Ansys Fluent software works based on finite volume method. The numerical simulation is 3D. In addition, the performance of MR-Linear and MR-nonlinear regression models on the application of the stage-discharge equation the triangular in plan sharp-crested weirs were investigated and indicated that the result of this equations is very similar to results of the experimental data. The results also showed that due to the angle of the triangular in plan sharp-crested weirs, the Cd is increased from 1 to 8 % to the suppressed weir. In a situation where the head on the crest of these weirs is low, they will show better performance.

Due to heavy rainfall, underground water level and pore water pressure increase each year, which can cause failure of the earthen slopes. Retaining wall is one of the main structures that is used to increase the earthen slopes stability. In the present study, the stability of earthen slopes relative to the critical hydrological cases was simulated by Slope/w software and the pore pressure behind the retaining walls over 10 meter height which causes to instability was simulated using Seep/w software. The studied parameters are: precipitation intensity, soil type, position and the diameter of drainage. Also the kind of drainage has been considered as a variable parameter and horizontal and chimney drainages were used. Results showed that for fine grained soils with intensive rains condition, using of one horizontal drainage could not provide the stability of retaining wall. While in the same conditions, for coarse grained soils, the retaining wall will be stable by using of one horizontal drainage and drainage will be able to discharge all of the excess water behind the retaining wall. Also the chimney drainage system provided the best results and the stability of the retaining wall did not face any danger under the worst circumstances. For overturning moment and water pore pressure behind the wall, linear and non-linear regression relations were produced in dimensionless form. The accuracy of the regression relations were proper and the acceptable results could be expected.

Weirs are one of the most important hydraulic structures for flow control, water measurement, and regulating of upstream water elevation in canals, irrigation networks, and rivers. For a given channel width, inclined weirs have a longer effective length in comparison with the usual rectangular sharp-crested weirs, and this could be effective on their discharge coefficients and efficiency. In the present study, the effect of the geometrical parameters on the hydraulic properties of the flow in inclined weirs was investigated using 3D Ansys Fluent software. Numerical simulations were validated by laboratory results. Weir height (P), weir angle with channel wall (α), water height above the weir (H), and effective length (Le) were investigated. The MR-linear regression model performance in applying the inclined weir discharge coefficient was investigated. The results indicated that this relation is very similar to the numerical model results. The numerical model results were also compared with those of the other researchers. Inclined weirs discharge coefficient at different effective lengths decreases by increasing H/P, and at a constant H/P, by increasing the weir effective length, the discharge coefficient decreases, and the flow rate increases. Increasing in weir height results increasing in discharge.

In this study, the effects of diameter and location of drain pipe in uplift force and exit hydraulic gradient in the foundation of gravity dams are investigated. For this purpose, a numerical model of gravity dam foundation is simulated using finite elements method. The results indicate that drain pipe under the gravity dam reduces the uplift force and exit hydraulic gradient. Location of the drain pipe in 0.25L (L is the dam width), and 0.75L from the dam heel, causes to reduce for uplift force and exit hydraulic gradient in minimum value, respectively (optimum place). In addition with increasing the depth of drain, the uplift force at first decreases and then increases. The drain pipes diameter has little effect in uplift force and exit hydraulic gradient and thus its selection is dependent to construction cost considerations. By defining the best position for the location of drain pipes, it was observed that drainage pipes in these situations increase the safety factor up to 1.5 to 2 times against the structural overturning.

The purpose of this study is to generate the relationships to directly calculate waterfall height at the downstream of the spillway to form a jump at the toe of the spillway and to prevent erosion and destruction of the downstream river bed or body of the spillway in a submerged and free hydraulic jump.

The purpose of this study is to provide a relationship to directly calculate the waterfall height (h) without the need for a trial and error procedure. For this purpose, the application of the momentum relationship between two sections (1and 2) yields the waterfall height (h) according to Eq. (1).   h=y1 .....   (1) Since in Eq. (1), Fr1 and y1 are themselves a function of the waterfall height (h), so this equation must be solved by trial and error or by using design charts provided by other researchers. To calculate the waterfall height in oscillating jump conditions (2.5<Fr1<4.5) and also for steady and strong jump conditions (4.5<Fr1<15.5), by assuming different values ​​for p, y0, yt and C (where C is the discharge coefficient), 300 and 1146 series of numbers have been generated by trial and error, respectively. Then, the parameters in Eq. 1 (y1, Fr1) were also calculated. The final waterfall height (h) was obtained for each series of numbers. Using the existing variables, dimensionless parameters ( ) and Fr1 were extracted. Then, multiple linear and nonlinear multiple regression relationships were tested for direct calculation of . Finally, the best relationships with the least error were selected. The results of multiple regression (MR) relationships are also compared with the results of ANN and SVM methods.

The proposed non-linear multiple regression relationship (MR-3) shows higher accuracy in estimating the waterfall height, compared to MR-1 and MR-2 regression models based on three statistical indices (RE%, RMSE, R2) for 2.5<Fr1<4.5 and 4.5<Fr1<15.5. Therefore with having the Froude number related to the initial hydraulic jump depth (Fr1), tail water depth (yt), weir height (P) and initial jump depth (y1), the calculation of waterfall height (h) will be possible using MR-3 model without any trial and error procedures. Moreover, the results show that among the intelligent models, the ANN model has very close results to the proposed nonlinear regression relation (MR-3) based on the statistical indices.

A new method for calculating the height of a waterfall at the toe of the ogee spillway was presented to control hydraulic jump. To calculate the height of the waterfall directly, multiple nonlinear regression (MR) relationships were presented for two ranges of different Froude numbers. The MR, ANN, and SVM models showed good performance in predicting the height of the waterfall downstream of spillways, but the ability of the two MR and ANN models were better than the SVM.

In this study, the effect of soil material parameters including soil specific weight (γ), cohesion (C) and angle of internal friction (∅) and geometric parameters of slope including angle with the horizontal (β) and slope height (H) on factor of safety (Fs) are investigated. Slope factor of safety is considered in two scenarios: (i) slope with dry condition and (ii) slope with steady-state saturated condition that comprises water level drawdown circumstances. In addition, the type of slip circle investigated. For this purpose, the limit of equilibrium method (LEM) is implemented. Results indicated that, decreasing of water level and omitting the hydrostatic pressure on the slope, would result in safety factor decrement such a way that with drawdown of 5.5 m water level, the factor of safety decreases about 41.42 % and also the type of slip circle is changed. Comparison of the plane and circular failure surfaces showed that plane failure method has good results for near-vertical slopes only. Determination of clip type showed that for β〖60〗^o only toe circle can happen. Application of the LEM in Bishop’s method resulted the values of R2 and RMSE equal to 0.93 and 0.121, respectively that the error of this method is 1.3% respect to other methods, which can be neglected in comparison with the complex and accurate methods.

Rainfed cultivation is one of the best ways to rich the sustainable development with optimal use of green water. About 75 percent of the world's cultivated areas are rainfed, which forms important part of the international economy. For a long time rainfed cultivation has been a common method in low-rainfall areas of Iran and mentioned method is one of the main ways of producing crops yet. Rainfall is an important factor in rainfed agriculture, so its limitations and non-conformity with planting season can reduce the production efficiency. Wheat growing period consists of three seasons of the year. Rainfall in spring, fall and winter is effective on wheat growth. Cereal grains, especially wheat, are the most important food source in the world. After cereals, legumes are considered to be the main human food source and have significant nutritional and agricultural importance. In addition to being high in quality and valuable, suitable and complementary protein for cereals in the nutritional pattern, lentils are also among the legumes that stabilize the air nitrogen in the soil, which lends itself to crop rotation. Thus, intermittent cultivation of rainfed wheat with rainfed lentil is an important factor in stabilizing production in the developing countries. Given that Iran is in arid and semi-arid regions and its population is growing, it is important to plan, and evaluate the past in order to predict the future. Zanjan province is the fifth country with 6.9% of total grains production. In this study, the effect of precipitation in water requirement of these two important products and their water stress has been studied in the climatic conditions of Zanjan plain. Zanjan province is located at the longitude of 47º 10' to 50 º 5' East and the latitude of 35º 25'37º10' North. The area of Zanjan province is about 39369 square kilometers. According to the De Marten climate classification, the tropical, temperate and subtropical climatic zones can be identified at the applied level. Average rainfall over the past decade has been reported as 301 mm. For conducting this study, statistical data including meteorological and crop yield data 2004-2014 obtained from the Meteorological and Agriculture-Jahad Organization, respectively. Zanjan synoptic station with the latitude and longitude of 48º 31' East and 36º 39' North, respectively, is located 1663 meters above the sea level. In the last 50 year, the annual precipitation trend has been decreasing and this trend is affecting the water availability of rainfed plants in the region and can decrease yield of crops. Although in the long term the average temperature trend is slightly constant, the yield has also declined with decreasing rainfall. Regarding the importance of wheat and lentil in arid lands of Zanjan plain, these two main rainfed crops were investigated in this study by determining the regression relationship between yield and evapotranspiration with precipitation and water stress coefficient. The results showed that the average evapotranspiration values of wheat and lentil for Zanjan plain during the study period were 398 and 262 mm and the mean temporal stress coefficients were 36 and 33%, respectively. Regression analysis showed the highest correlation between actual evapotranspiration and yield. The highest correlation was observed between temporal stress coefficient and yield of rainfed wheat. But, in lentils this trend was different and the correlation between water stress coefficient (Ks) and yield was more than the precipitation and lentil yield. For 25% decrease in precipitation, wheat yield reduced almost 18%. Generalizing this issue, the response to water stress coefficient of the product or Ky become 1.14. The regression equation also indicated that in case of being precipitation about 300 mm, wheat yield in the area will be near one tone. For 25% decrease in precipitation, wheat yield reduced about 22%. According to figures, the fitted model was significant and well-acted; and during the growth period of these crops, lack of water supply caused water stress as well as severe yield loss. The occurrence of high tension time percentage of 25% for wheat and 20% for lentil in all years of the study period confirms that the climatic potential of the region does not reach the standard requirements of plants, so it is not possible to achieve optimal performance. Hence, new methods of tillage, conservation agriculture and supplemental irrigation are recommended for achieving high yield, as well as the expected cultivation method for crops.

The correct identification of the uplift force plays an important role in the stability analysis of gravity dams. For this purpose, a numerical model of the foundation of a gravity dam of the Guangzhao, China was made using finite element method. After simulation, the uplift force values were obtained in different positions of drainage. Require experience, the timing of calculations and the accurate determination of the boundary conditions in numerical models, have caused to the development of the tendency to use intelligent models. For this purpose, in addition to the Artificial Neural Network model (ANN) with three-layer that consists of 4 input neurons, 1 hidden layer (with 8 neurons), and 1 output neurons, a new hybrid model of Artificial Neural Network-Whale Optimization Algorithm (ANN-WOA), was developed. The values of R2, RMSE and RE% for the ANN-WOA model, were 0.998, 0.021 and 3.3%, respectively, and for the ANN model were 0.995, 0.261 and 4.67% respectively, that indicate the higher accuracy of the ANN-WOA model in the estimation of the uplift force than the ANN. In addition, the density plot box and the violin plot indicate that the point density and the probability distribution estimated data with the ANN-WOA model is very similar to that the data obtained from the numerical simulation compared with the ANN model.

In recent decades, the optimal use of dam reservoirs among water resource management researchers has been of great interest. So, due to the high performance and capabilities of evolutionary algorithms, in this study, using gray wolf optimizer algorithm (GWO) to predict Urmia Shaharchay dam reservoir and present a short-term forecast program for next years. The gray wolf algorithm imitates the hierarchy of leadership and the mechanism of hunting gray wolves in nature. In this algorithm, four types of gray wolves consists of alpha, beta, delta and omega have been used to simulate the hierarchy of leadership. In this study, considering the annual planning and monthly intervals, GWO algorithm was firstly evaluated for prediction storage of Urmia shaharchay reservoir during 2006-202014 years and the results compared with ICA algorithm. The results showed that GWO algorithm, with a high accuracy of 90%, provides better results in finding optimal response, convergence rate and lower computational cost compared to ICA algorithm. The results of this study indicated that GWO algorithm, an appropriate algorithm to solve the optimal operation of dam reservoir system problem.

In the present study, the flow pressure fluctuations have been measured on the bed of the USBR Type II stilling basin downstream of an Ogee spillway using pressure transducers. The experiments were carried out in a laboratory flume under different flow conditions. In addition, the pressure field in submerged hydraulic jumps was investigated to help better understanding the energy dissipation process and optimum designing the stilling basins. Using the dimensionless parameters, the submergence effect on the longitudinal distribution of the mean pressure and the pressure fluctuations intensity were evaluated. Pressure data acquisition was conducted for different incident Froude numbers (Fr1), ranged from 6.4 to 8.3, and submergence factors (S) in the range of 1 to 1.4. Based on the dimensional analysis, the values of the intensity coefficient of pressure fluctuations (CʹP) were a function of parameters of Fr1, S and the relative distance from the beginning of the basin (X/Y1). The results showed that the maximum values of CʹP coefficient for the Type II stilling basin decreased around 30% compared to the smooth basins. The mean values of CʹP in submerged jumps decreased around 25% compared to the free jumps at the downstream zone of the stilling basin (X/Y1>10).