فهرست مطالب amir hamzeh haghi abi

Stepped spillways are used in hydraulic engineering projects such as small and large dams. The inception point of aeration on such hydraulic structures is essential in determining the zones of single and two-phase flow. In this study, the effect of the surface roughness of steps on the location of IFPA on a stepped spillway is investigated. This paper investigated the effect of the surface roughness of steps on the location of the inception point of flow aeration (IPFA). For this purpose, a laboratory model of Ogee-stepped spillway was designed based on the maximum energy dissipation guidelines and its steps were roughened with gravel (with a specific grain size). The experiments were conducted in a channel with a longitudinal slope of 0.001, length of 12m, width of 0.5m, and depth of 0.8m on a stepped spillway with a height of 0.6m that has 9 steps. The flow discharge ranged between 6 (l/s) and 16(l/s). It was found that aeration starts from about 12 times the critical depth and by doubling the critical depth, its distance from the crest increased up to 50 percent. Notably, roughing the step surface reduces the length of the non-aeration area by about 15%.

Calculation and estimation of evapotranspiration is one of the most important parameters of water management in agricultural engineering projects. The aim of this study was to evaluate the models of gene expression programming (GEP), group method of data handling (GMDH), and Multivariate adaptive regression spline (MARS) to estimating daily reference evapotranspiration. For this purpose, daily data recorded during the last 25-year period (1993-2017) of Aligudarz region (located in the east of Lorestan province) were used. 80% of the data were used for training and the remaining 20% for testing the models. The modeling results showed that only with the maximum temperature and average wind speed can evapotranspiration be estimated with very good accuracy. The error indices of GEP model in testing stage are , the error indices of MARS and GMDH models are .  Comparing the performance of the models showed that the March model performed better than the other models.

Obstacle usually blocks the current and it has been found by other researchers an obstacle with a height more than two times of body height of flow is necessary to fully block the density current. The construction of an obstacle with this elevation creates problems in terms of performance and sustainability as well as the accumulation of sediments behind it.Rottman et al. (1985) solved the analytical solution of the two-phase current in a horizontal slope with an obstacle in the steady and unsteady flow and concluded that if the height of the obstacle is twice the body height of the density current so the density current is completely blocked. Prinos (1999) conducted studies on the effect of the shape of the obstacle on the current control. In his experiments, he used two semi-circular and triangular obstacles with the same height and concluded that the shape does not have a significant effect on the control of high current. Also, in the range of densimetric Froude number, 0.7 < Frd < 0.8 if the height of the obstacle is twice the height of the body of the density current, the current will be fully restrained. As it has been stated, for a complete block of density current, based on the results of previous investigators, the height of the obstacle should be at least twice the height of the body.The purpose of this study is to use successive obstacles with lower height, with greater sustainability and lower cost, in controlling density current. For this purpose, in different conditions, in terms of slope and concentration, three rows of obstacles with different heights and also different distances were used to control sedimentary and salty density current.

Investigation of floods as one of the most common natural destructive phenomena is very important. Due to the problem of deficiency and defect of hydraulic data in most hydrometric stations in the country, flood hydrograph simulation by hydrological and hydraulic models is helpful. There are several hydrological and hydraulic models to simulate flood hydrographs. The present study has investigated the performance of Advection-Diffusion relationships of 36 flood phenomena in 5 study reaches of Kashkan river and its tributary. Physical properties related to the studied periods and hydrometery data related to each flood phenomenon, including discharge and scale of the input and output station, were used to determine the Manning roughness coefficient and flood simulation. Evaluation of obtained hydrographs indicates the acceptable accuracy of the model in term of simulating values of flood trends and discharge. In order to evaluate the accuracy of the model results, different coefficients such as: Nash-Sutcliffe, RMSE, Volumetric Efficiency, Kling-Gupta and R correlation coefficient were calculated. A value above 0.5 for the Nash-Sutcliffe coefficient in 29 flood phenomena out of 36 studied phenomena, and an acceptable range of other coefficients for all studied flood phenomena, indicates the verifiable results of flood hydrograph simulation using simplified propagation methods at reach scale for studied watershed. Therefore, Advection-Diffusion relationships can be used in similar watersheds to the study area to simulate floods.

In this paper, the quarter-circular crested stepped spillway (QCSS) is introduced and its hydraulic properties including the discharge coefficient (Cd) and energy dissipation of flow are investigated. The QCSS consists of a quarter-circular as the crest and a stepped chute. The Cd of QCSS variates between 0.9 and 1.4 considering the range of relative upstream head (hup/R) between 0.1 and 1.0, but at the same range of hup/R, the Cd of the broad crested stepped spillway (BCSS) changes between 0.9 and 1.0. The ratio of energy dissipation changes between 30% and 98% for both hydraulic models. Comparing the performance of QCSS and BCSS shows that in the skimming flow condition, the Cd of QCSS is about 30%more than the BCSS. Whereas, in the same flow regime, the energy dissipation of the flow on QCSS is a bit less than the BCSS about 10%.

Considering the increasing population and the growing need for food and drinking water, it is essential to explore and understand the factors of crop production, especially water resources. Today, the removal of undiluted water from underground water sources has produced qualitative issues, in addition to a few shortcomings. These issues are more significant in arid and semi-arid regions, which are more dependent on these resources. In these areas, due to lack of water resources, access to appropriate quality resources is important. The quality of groundwater undergoes spatial and temporal scales and cannot be assumed to be constant over time and place. Therefore, for the purpose of using groundwater resources and targeting for future uses, it is important to consider changes in the quality characteristics of resources over time and place. Therefore, studying the temporal and spatial variations of water quality is essential for properly and efficiently managing the use of these resources. In order to determine the process of time variation, different methods are used. One of the most common non-parametric methods is analysis of the trend in time series using the Mann-Kendall test. It is necessary to know the spatial changes of resources, to collect parameters in different locations, which requires a high cost and time. In such a situation, geospatial interpolation methods can be very efficient. Land use methods can reduce costs and increase the accuracy of estimation, due to the ability of reducing the number of samplings, application of the combination and providing more accurate estimation of variables location. The purpose of this research is investigation of groundwater quality in terms of agricultural use and its effect on permeability in Borujerd-Doroud Plain.

Boroujerd-Doroud Plain with an area of ​​2545.8 km2 is located in northeast of Lorestan province and northernmost part the large Karon Basin. the trend of changes in the parameters of electrical conductivity, calcium, magnesium, sodium and bicarbonate of plain resources during the period of time (1994-2016) was investigated by the Mann-Kendall test and for qualitative maps prepation based on the Permeability Index, Sodium Percentage, and Wilcox, the data of 41 groundwater resources in 2016 were used. The accuracy evaluation of any interpolation or selection of the appropriate parameter is necessary. In the present study, the RMSE index was used to determine the appropriate method. Among different methods, each one with less RMSE is selected as the appropriate method. Different methods of interpolation were compared for the zoning of the quality parameters. Regarding the results of this comparison, the conventional Kriging interpolation method was chosen as the most appropriate interpolation method due to lower RMSE. The permeability index is a parameter that is used to evaluate the quality of irrigation water. Sodium levels of water are important parameters for using water in irrigated agricultural land. Increasing of sodium in water decreases soil permeability. Wilcox classification is one of the most important classifications for determining the quality of agricultural water based on two parameters of electrical conductivity and sodium absorption ratio as alkalinity risk.

The results showed that the trend of changes in all parameters was reduced, which showed that the trend of changes in bicarbonate content was significant at 95% confidence level. In terms of permeability index, 85.84% of the plain has excellent irrigation water quality. Based on this classification, the water quality in northwest of the plain is poor, in southeast is moderate and in other plain areas is excellent for irrigation purposes. Based on the qualitative map of the percent of sodium, the irrigation water quality in northwest and southeast of the plain is excellent, and in the central area of the plain is allowable. The irrigation water quality in other areas of plain is good. The irrigation water quality based on Wilcox's method was classified in two C2S1 and C3S1 classes, which included 90.91% of the studied sources of C2S1 and 9.09% of the C3S1 grade.

The quality map based on this classification showed that 85.94% of the plain area has a good water quality. The Investigation of EC and SAR changes effects on soil permeability showed that the variations of these two parameters are not negative across the plain, and the region has a good and moderate permeability status, which is 26.8%.

Modeling the erosion and sediment transport is one of the major problems which discussed in river engineering projects such as river intake and dam construction. In some cases, careless estimation of the river sediment load causes failure of river engineering projects. Bed load of the river sediment is one of the main parameters for assessing the stability of river form and evaluating the river power flow. The bed load measurement has much more difficulty in comparison with the suspended load, so measuring the sediment load of rivers is limited to the suspended load measurement. Estimating the river sediment load is conducted with study on the river hydraulic, flow regime, river morphology grading materials of the sediment load. Control and minimization of defection to the hydraulic structure caused by the river sediment load needs to define the river flow regime, sediment motion, erosion and degradation mechanism. The erosion in river has several effects on the river flow regime such as descending the water surface elevation that may cause a decrease in the efficiency of hydraulic structures such as intakes and pump stations. River management, regarding to the sediment transport conditions, causes an increase in the operation period. Study on the sediment transport in rivers are usually conducted with laboratory experiments and field study. In this regard, due to the high cost of experiments and field study, researchers attempt to model the sediment transport using the mathematical approaches. In order to achieve the purpose, the flow equations for rivers such as Saint Venant equation is coupled by sediment transport equations such as Akers-White, Englund-Hansen, Laursen, Meyer-peter Muller, Tofaletti (field and laboratory) and Yang, and numerical is solved by advanced numerical methods. Free or commercial powerful software packages have been provided in order to facilitate the use of mathematical approaches. Mike 11, as commercial software, and HEC-RAS, SSIM, FLUVIAL and GSTARS, as free software, could be mentioned. Several studies are done using free software packages such as HEC-RAS. Jabary et al (2014) used the HEC-RAS software to model the sediment transport in Abhar River. They stated that the Yong formula is more accurate among the other empirical approaches to model the river bed elevation. They considered the graded material of sediments, river cross sections and flood hydrograph with 25 years return period as input parameters for the model. They stated that the HEC-RAS model has suitable performance for modeling the sediment transport in Abhar River. Alami (2003) used HEC-6, River Intake and GSTARS-V2 to model the sediment transport in reservoir of dams and stated that the GSTARS is more accurate in comparison with the other software packages. Seyedian et al (2006) used the GSTARS-3 to model the sedimentation of river load in the Voshmgir Dam and predicted the volume of sediments for the next seven years. Shahinejad et al (2009) used the GSTARS-2.1 to model the morphological variation of Karun River within the Ahvaz City. They evaluated the river bed elevation for the next seven years. Due to high important effects of modeling the river sedimentation on the success of river engineering projects, modeling the sediment transport in Telvar River using the GSTARS-3 is considered in this paper. The Telvar River is a main river in the Kordistan Province, western Iran. The catchment area of the Telvar River is about 147 Km2 and about 26.1 Km of the river was considered as case in this study. The GSTARS was developed by Molinas and Yang (1985) to model the alluvial rivers, this model has been modified with Yang et al (2006) and nowadays the GSTARS-4 is the last version of the GSTARS. The GSTARS is in involved four parts: First, using the energy and momentum equations for the water surface calculation. Second, using the concept of flood routing for routing the river sediment load. Third, using the concept of intensity of energy losses, in other words, using the minimum power flow theory for modifying the width and depth of flow and fourth, evaluating the Criteria of slope stability. The GSTARS included 14 equations for modeling the Non-cohesive sediments. The aim of this study is analyzing the longitudinal erosion of the river bed and also evaluating the cross section width variation and at the end, selecting the suitable empirical formula which has suitable performance for modeling the case study area. The model validation was conducted by a trial and error process because of evaluating the erosion such as sedimentation depends on the empirical formula and graded material curve. Therefore, a number of formulas which had more suitable performance were selected. During the model validation process the result of model was compared with the measured data which was recorded at the 2013 and found that the Yang method is more suitable for modeling the river bed elevation. The results of this study showed that the GSTARS model has suitable performance for modeling the erosion and sedimentation in the Abhar River, and this software can be used for modeling the cross section erosion and finding the area which has high potential for erosion and sedimentation.

One of the main goals of diverting water from bend of river is diversion the maximum flow discharge with the minimum rate of sediment to the intake mouth. Therefore, the position and diversion angle of lateral intakes in river bend with sediment control structures, are the major parameters that must be considered.In this study by experimental investigation in a U- shaped channel using compound structures of sill and 10 skimming wall in three diverted flow percentages of 17, 21 and 26, the effect of diversion angle on rate of sediment entering the intake, was investigated. The results showed that with decreasing of the angle of intake, the inflow Froud number decreases. Also with increasing the angle of intake from 45 to 75 degrees, the rate of sediment entry to intake increases, so that by combining of sill and skimming wall 10ᵒ, the sediment transportation into intake mouth decreases more in comparison with basic state. By increasing the angle of flow diversion in all percentages of flow diversion, the width of separation zone at water surface decreases. By investigation of power of secondary flow along the intake mouth it was found that in all experimental states, decreasing the angle of flow diversion from 75 to 45 degrees, causes less decreased power of secondary flow and consequently less sediment entry into the intake mouth.

Several types of sediment transport equations have been developed for estimation of the river sediment materials during the past decades. The estimated sediment from these equations is very different, especially when they applied for a specific river. Therefore, choice of an equation for estimation of the river sediment load is not an easy task. In this study 10 important sediment transport equations namely; Meyer-Peter and Muller (1948), Einstein (1950), Bagnold (1966), Engelund and Hansen (1972), Toffaleti (1969), Yang (1996), Van Rijn (2004), Wiuff (1985), Samaga et al. (1986) and Beg (1995) are used to estimate sediment load of the Karun River in Iran. The estimated sediment load compared with the measured field data by using statistical criteria such as root mean square error (RMSE), mean absolute error (MAE) and correlation coefficient (R2). Results showed that Engelund and Hansen formula can provide reliable estimates of sediment load of the Karun River which have high suspended sediment load concentration with RMSE of 3725 ton/day, MAE of 1058.82 ton/day and R2 of 0.41. Bagnold and Wiuff formulas estimated the total sediment load 280 % and 700% more than the measured values and the Van Rijn, Tofaleti and Bagnold formulas estimated the sediment load 99 %, 71% and 93 % lower than the measured values, respectively. The comparison indicated that Samaga, Einstein, Tofaleti and Yang equations with low accuracy are not suitable for estimation of sediment load of the Karun River. The main reason for this difference is related to fact that the Karun River carries fine sediment (wash load) which these equations not considered it.

Water supply networks account for a major portion of the urban infrastructure requiring sizable funds for their construction and operation. This has encouraged many researchers to focus their efforts on optimizing water distribution networks. In most recent research in the field, stochastic meta-heuristic algorithms have been employed to address the problem. Given the many inadequacies of stochastic algorithms, the present study explored the application of a novel deterministic algorithm for minimizing pipe-sizing costs in water distribution systems (WDS). The algorithm used in this study is a modified version of the central force optimization algorithm called CFONet which is used for solving water distribution system problems. The performance of the proposed method was evaluated by optimizing pipe-sizing in two benchmark WDSs. For this purpose, both CFO and CFONet methods were written in MATLAB and interfaced with the hydraulic simulation model EPANET. Application of the two methods mentioned above to two different water supply systems revealed the superior performance of the proposed CFOnet over its CFO counterpart. Thus, CFOnet yielded an optimum response for the deisgn of a double ringed system equal to US$419,000 after 12,432 runs of objective function estimations. Moreover, the optimum design of a CAdo system was obtained to cost 126,535,915 In. Ruppes after 259,476 runs of objective function estimations. Comparison of the results obtained in this study with those reported in the literature on other stochastic optimization algorithms showed that the proposed method yields satisfactory solutions for WDSs optimization problems while it also enjoys the merits of a deterministic optimization method.

Weirs have widely been used for the flood flow, flow measurement, flow diversion and control of water levels in dams, rivers and open channels. This study was curried out to investigate the hydraulic characteristics of flow over the sharp-crested triangular plan form weirs for different apex angles. Three-dimensional flow field over the weirs 30, 60, 150 and 180 degrees was numerically simulated based on the RNG turbulence model using the software Flow-3D version 10.0.1. The results showed as the apex angle increases, the interference of the longitudinal and lateral falling flows decreases and in turn leads to less disturbance and vortex flow. Also, in downstream, the flow surface knob of the longitudinal profile and height difference between the transverse cross-section profile becomes less and velocity and Froude number increase, whereas the pressure on downstream bottom decreases. The results show that the RNG turbulence model for determining water surface profiles along the channel downstream of the weir of appropriate accuracy.

Distribution of velocity of flow in compound open channel due to interaction of floodplains and main channel is strongly non-uniform. Defining the distribution of flow velocity is an important factor in calculation of sediment transport and estimation of flow discharge. One of the correction factors in calculation of flow discharge and shear stress are momentum and energy  coefficients. In this study, the effect of  and  coefficients on Froude number and specific energy are assessed. Stage-discharge relationship in compound open channel was assessed using some empirical formula including Single-Channel Method (SCM), Divided-Channel Method (DCM), and modified divided-channel method (MDCM) and compared with together. When the discharge only flows in main channel all the empirical has a same result whereas by increasing the discharge and covering the floodplains by flow the results of them are different. The highest value of outcome of empirical formula is related to the SCM. Results indicated that considering the energy and momentum coefficients have significant effect on distribution of Froude number and specific energy.
Distribution of velocity of flow in compound open channel due to interaction of floodplains and main channel is strongly non-uniform. Defining the distribution of flow velocity is an important factor in calculation of sediment transport and estimation of flow discharge. One of the correction factors in calculation of flow discharge and shear stress are momentum and energy coefficients. In this study, the effect of and coefficients on Froude number and specific energy are assessed. Stage-discharge relationship in compound open channel was assessed using some empirical formula including Single-Channel Method (SCM), Divided-Channel Method (DCM), and modified divided-channel method (MDCM) and compared with together. When the discharge only flows in main channel all the empirical has a same result whereas by increasing the discharge and covering the floodplains by flow the results of them are different. The highest value of outcome of empirical formula is related to the SCM. Results indicated that considering the energy and momentum coefficients have significant effect on distribution of Froude number and specific energy.

Allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. Side weir is one of the most common structures for this purpose. Study on the flow Hydraulic characteristics of this structure included two parts, defining the water surface profiles and estimating the discharge coefficient. To estimate the discharge coefficient, many ways as experimental formulas and artificial intelligent models are propose. The empirical formula for simplifying in developing process that assume by the authors, contained significant error so using the AI models are inevitable. In this paper, some of the famous empirical formula and AI models such as Multilayer neural network (MLP) and Adaptive Neuro fuzzy inference system (ANFIS) are assessing with a laboratory experiment. Among the experimental formula, Borghei formula is most accurate (R2=0.83) and the performance of the AI model in Training and testing stage is more suitable (R2=0.96).

Estimation of the sediment load which a specific flow is capable to transport, is one of the main topics of sediment researches. Abhar Rood River is one of the major rivers in Zanjan province which plays a big role in the agriculture of the region. In the present research, HEC-RAS 4.1 model is utilized to simulate the sediment hydraulic in Abhar Rood River. For this purpose, 730 sections along 50 km of Abhar Rood have been prepared by using the DEM map of the river (map scale 1:4000) in Hec-GeoRas extension of ArcMap, thereafter it was used to introduce the river geometry information to Hec-RAS model. Also the discharge amount with 25 years return period has been calculated in HYFA model using the 33 years flooding discharge data which was measured at the Ghorveh hydrometric station and used to simulate hydraulic flow of the Abhar Rood River. After calibrating the model for hydraulic conditions of the river, sediment boundary condition and bed gradation have been defined in model. Thereafter the sediment transport capacity of the river was calculated by transport functions at total cross sections. The comparison between the achieved results and measured data shows that, the Yang equation has minimum error compared with other equations. Therefore Yang equation due to its acceptable results is recommended to recognize the sediment transport capacity potential. In addition, to investigate the erosion and sedimentation status of Abhar Rood River, Hjulstrum and Shields criteria have been utilized. The hydraulic condition of this river shows the erosion status at the whole crosses of the river.

Water pollution in rivers is a complex process. Transmission of pollutant in river is one of the most important problems in Environmental Science. The governing Equation of transmission of pollutant in river is Advection Dispersion Equation (ADE). The ADE is Partial differential equation (PDE) that it’s one of the most important equation that used in fluid engineering Special water engineering، this equation named in general Convection equation. This equation has two part، Advection and dispersion term. To modeling of pollution transport in rivers needed to developing Numerical model for solving the ADE and calculating of Longitudinal Dispersion coefficient (LDC). LDC is one the important parameters in the Pollution transport simulations. Accurate estimates of this parameter increase the accuracy of the computer modeling. There are many methods to calculate the diffusion coefficient of the experimental and mathematical methods. The results of the experimental has significant errors because it’s based on indirect parameter in the simplification of modeling. So it needs to be calibrated with observational data or Methods that the Dispersion coefficient can be calculated directly. In this study، the routing method was used to calculate the Dispersion coefficient and the following a careful review was done on the empirical formulas. Final result shows that the intelligent method (ANN and ANFIS) is more accurate in compare with empirical formulas.