مجله مهندسی آبیاری و آب ایران
پیاپی 39 (بهار 1399)

Nowadays, the use of polymers and soil and water reclamation agents has a significant bearing on agriculture. Polyacrylamide is one of the most important polymers that reduces soil erosion and increases water penetration in the soil by the PAM brand. Research on the effect of using PAM on soil physical properties (such as saturated hydraulic conductivity) has not had the same results. In this study the effect of six concentrations 0, 5, 10, 15, 20, 25and 30 mg/l dissolved PAM on saturate hydraulic conductivity 3 different soil textures (sandy loam, loam and silty clay loam) were studied in laboratory. Saturation hydraulic conductivity was measured with constant head method. For each treatment five replications were considered. Results showed that PAM viscosity increased about 1.9 % relative to water for each mg/l increase in PAM concentration. In sandy loam soil, with increasing PAM concentration, the hydraulic conductivity of soil saturation decreased linearly and significantly. With increasing of 5 mg / l of PAM solution, the hydraulic conductivity of sandy loam soil 2.6 cm / h decreased. In sandy loam soil, the effect of increasing the viscosity of PAM solution passing through the porous medium was more evident than the effect of the bond between clay and PAM particles. In loamy and silty clay loam soil texture, the trend of saturation hydraulic conductivity changes was compared to the PAM concentration as a parabolic curve. In the loam soils up to 20 mg / l PAM concentration and in the silty clay loam soil up to 25 mg / l PAM, the hydraulic conductivity of soil saturation increased and in concentrations greater than these values, the saturated hydraulic conductivity decreased. For loam soil and silty clay loam with increasing concentration of PAM solution to the optimum amount, the effect of bond between clay and PAM particles and later on the effect of viscosity PAM solution was evident.

Creation and propagation of unsteady flow in irrigation canals causes changes in water delivery to canal intakes. Unsteady flow in irrigation canals usually form by operation of check structures. Up to now simulation of unsteady gradually varied flow in irrigation canals has been considered in various researches. Simulation of unsteady gradually varied flow mostly done using available hydrodynamic models, but these models can’t simulate unsteady rapidly varied flow. In this research, using MacCormack numerical method, a numerical model was developed to solve the governing equations for rapidly unsteady varied flows, and the TVD method was used to control unrealistic and non-physical oscillations. The model was developed in MATLAB programming environment to simulate positive waves caused by the suddenly closure of a gate at the end of the E1R1 canal in Dez irrigation network and a hypothetical channel. The results showed that the higher flow in the gate at the moment of gate closure causes the higher numerical solution errors. Also, the results showed that the simulation using MacCormack method would have a large error, but the simultaneous application of the TVD and MacCormack method could reduce the numerical solution errors and simulate the water surface fluctuations according to the reality.

In recent years, Lake Urmia has encountered with environmental crisis, due to poor management of water resources, increasing the agricultural land and over the construction of dams on feeding rivers. In this research, a 3D model (Mike 3 flow model FM) was applied to investigate the effects of changes in wind direction and construction of causeway on flow circulation and salinity distribution in Lake Urmia. The salinity data measured in two depths (near the water surface and close to the bed), and different locations were used to evaluate the calibration and verification of the model. The results of the present study showed that the wind speed and its direction are one of the important parameters that play a major role in flow circulation patterns, especially in the surface layer of the water, and salinity distribution in both cases with and without causeway. Moreover, three-dimensional simulation results revealed that the flow path and salinity distribution were different in surface and bottom layers, due to the wind direction and construction of the causeway.

Labyrinth weirs are some cost-effective structures, having trapezoidal, triangular and other formats, utilized for increasing the output efficiency in a limited width. Raising the capacity of labyrinth weirs via increasing their width is not always possible. The labyrinth weirs are used due to the increase in their efficient length on a given hydraulic height and width. The present study investigates the weirs having trapezoidal polyhedron format, on the wings of which some new labyrinth have been added so that their spillover discharge rate will be reinforced. The experiments in this study were conducted on 27 laboratory models having 9 different discharge rates, on whose wings double labyrinth have been added, totally through 243 experiment. Besides the spillover simulations were performed using the Flow-3D software. The results obtained from the numerical analysis for the determining the spillovers discharge rate coefficient were validated using laboratory data and it demonstrated a good correspondence between the numerical solutions and laboratory findings. It is also suggested that the Flow-3D software has a high potential in simulating the flow on labyrinth weirs. Laboratory results also indicated that, regarding all the compound polyhedron trapezoidal weirs, the parameter ratio, flow rate coefficient to ratio (Ht: total hydraulic load and P: spillways height) firstly raise and then start to reduce once they reach the maximum level. The spillover discharge rate increases for a given when the effective length of the weirs’ wing is raised. The discharge rate on the weirs having semi-circular compound format is better than this rate of ones having the square format and the ones having compound square format have spillover discharge rates better than the ones having simple trapezoidal format, in a manner that the discharge rate of the current flow is increased 15 percent more than the trapezoidal dam labyrinth spillways and flow rate coefficient interval increases from 0.4 percent of dam labyrinth spillways to 0.65 on the compound spillways.

In this study, the effectiveness of wheat straw mulch and wood shred was investigated in order to reducing runoff and sediment yield from unit source micro-catchments. Three micro-catchments (one for control and two others for treatments) were selected with an area of 1/ha for each wich are located in upstream of Gheshlagh Dam in Kurdistan province. After the implementation of treatments (application rate of 3 ton. ha-1), each micro-catchment was equipped with one flume at its outlet to measure the runoff rate and turbidity during storm events across one-year sampling from 2014-2015. The result of RRE and SLRE showed that straw mulch and wood shred have reduced runoff by 24.54 and 13.24 percent, and sediment yield by 58.75 and 44.10 percent in comparison to the untreated micro-catchment, respectively. Wheat straw mulch showed better performance in reducing runoff and sediment than wood shred. This might be due to the twisted fibers of straw mulch, the formation of barrier against the flow, and filtration of sediment particles by straw.

The increasing of urbanization and the increase of impervious areas in cities has as a consequence extreme flooding events, with increase in citizens’ problems and economical losses. In order to be able to overcome mentioned problems, computer models are an appropriate solution. The use of hydrological- model to simulate the runoff necessitates the proper calibration of the different parameters involved in the routed hydrograph. Therefore, In the present study, the Storm Water Management Model (SWMM5.0) was chosen to simulate quantity of runoff of an urban subcatchment, located in Neyshabur. Data from nine rainfall events were collected. the model was calibrated using six rainfall events and validated using three new events.  The model performance was evaluated based on the Normalized Root Mean Squared Error (NRMSE), Coefficient of Residual Mass (CRM), and EFFiciency of model (EFF). The results showed that the SWMM model could simulate accurately the shape of the hydrograph, the peak discharge and the time of peak. For validation events, values of NRMSE, EFF and CRM were 29.4%, 80% and -0.16 m3/s, respectively. Overall SWMM model was found to be a very useful modelling tool, which can be used for the simulation of urban runoff hydrographs. finally, the evaluated model used to simulate 2, 5 and 10-year return period flood.

The purpose of this study was to investigate the effect of seasonal, non-seasonal and combined differentiations on the time series stability of Dez River’s monthly discharge for 60 years. Also, the effect of the stability level on the performance of SARIMA models in the prediction of the time series is investigated from different aspects. Out of 720 data, 80% are taken into account for the calibration and the rest for the validation period. First, the stability of the variance of time series was investigated and the necessary transformations were applied to stabilize the variance. Then, with the help of seasonal Mann-Kendall test, the average stability was evaluated and its results have been used to assess the existence of the process and the need for differentiation. Using seasonal, non-seasonal and combined differentiations, three new series have been created, whose stability with the original series have been investigated by analyzing the ACF graph and the generalized Dickey-Fuller test. In the following, the type and number of parameters required in the models are determined for each scenario.  The results indicate that when using combined differentiation, the number of models needed for review is severely reduced so that for modeling of series with seasonal differentiation, 196 and for modeling of combined differentiation series, only 16 models need to be investigated. While the outcomes of the best model of both types of differentiated series were almost the same, the best model of the seasonal differencing series, with the criteria of the assessment of MAE= 92.4, RMSE = 154.4 and R = 0.61 showed its superiority over the other models. Finally, the selected model namely SARIMA (4, 0, 4) (1, 1, 1)12 has been used to predict the river flow in the next 24 months.

Estimation of reference evapotranspiration is one of the important components of water balance in each region and that is one of the effective factors in proper irrigation planning for improving water use efficiency. Among the methods that allow the estimation of variables on a regional scale, two methods of geostatistics and Theissen have key roles for land interpolation in extensive level. This study was conducted in Hamadan province. The best variograms was determined, which were the best fit for the exponential model in Kriging method. In the Theissen method's internal analysis, large values of errors are expanded for those stations located in the north-west and south regions, and the range of error variations is between 0.5% to 16%. But in the Kriging method, these errors are distributed in the north-west and south-west regions, while this method estimated better than Theissen's method, and the range of error variations is between 0% to 12%. Comparison of geostatistics and Theissen interpolation methods showed that in the scale of the seasonal, the geostatistical methods have a higher accuracy, but on an annual scale considering the ease of using the Theissen method, taking into account the accuracy required, there is the possibility of using Theissen's method.

Optimization of water distribution networks, regardless of uncertainties of effective variables in design of network is unrealistic. Therefore, developing method based on uncertainties variables in water distribution network design is necessary. In this research, a model based on simulation-optimization approach (combination of genetic algorithm and EPANET software) with fuzzy variables has been developed. Also, water distribution networks without causing disruption in their Performance with level-1 redundant have been optimized. In this model, fuzzy nodal demands and fuzzy available nodal heads are characterised by triangular membership functions. Furthermore, desirable nodal heads are also considered as fuzzy and relationship between fuzzy available nodal heads and fuzzy desirable nodal heads is used to convert fuzzy constraints to crisp constraints. For validation of model, the program has been implemented for optimization of level-1 redundant water distribution single network with fuzzy demands then paid to the optimization Jangal water distribution network with fuzzy demands (under one pipe failure condition) as a case study. The result of this model shows the cost of optimal design of Level-1 redundant water distribution networks model with fuzzy demands regard of scale of network 30% to 70% is increases due to providing nodal heads to offset the one pipe failure condition from network.

To assess the role of non-conventional water in arid regions, an Operational toolbox was designed comprising an integrated allocation model and a decision support module. The Water Evaluation And Planning System (WEAP) was used to define and calibrate the existing conditions. Possible scenarios for water supply (including conventional and non-conventional water) and consumptions (including drinking, agriculture and industry) where examined under current and potential future scenarios. A multiple attribute decision-making tool was utilised to rank various scenarios. The toolbox was used in an arid catchment of Iran, where indiscriminate use of conventional water resources, has posed a dominating water shortage.The results of the various scenarios showed that there is no scope to increase in agriculture allocation while the industrial allocation may be increased provided the non-conventional water is utilised to a certain extent. The results obtained from the toolbox has indicated that water transfer from other catchments is not an attractive option compared to the use of non-conventional water The results imply the effective role of recycling for the industrial water allocation, and desalination for the drinking water supply management.

Zayandeh-rud basin which is located in central Iran, is one of the areas with serious water instability problems. This research had studied water resources and the use of surface and underground waters on Zayandeh-rud Basin and its relation to instability of water resources in the basin. The method of this research is descriptive-analytic and is based on data analysis of water resources and water use. To evaluate water resources, water storage changes in Zayandeh-rud dam is studied, and the amount of drinking Water allocation, and also industry and agriculture sectors usage were studied. The research results show that Basin water resources have been decreasing in recent decades, while water consumption in the basin have had a different trend. Drinking water consumption has been increasing but water allocation to agricultural sector had substantially decreased. Instability of agricultural water resources has caused the river's course to dry out and also continuous flow of water is ceased and therefore many problems had arisen in relation to the allocation of water to agricultural sectors in the middle and lower area of the Basin. To compensate all of this instability and water shortage, farmers have drilled lots of wells and exploited too much underground water for agriculture, which has intensified the instability and shortage of water resources in the Basin. As this devastating cycle continues, environmental and human sustainability in the Basin will be in serious danger.

In traditional irrigation systems, inappropriate management of water allocation may lead to poor performance of the irrigation district, an increase in water losses, and a reduction in crop water productivity (CWP). Using optimization methods and nonlinear models along with the geographical information system (GIS) can improve the management of an irrigation district under uncertain condition. The objective of this study is to investigate the optimal water allocation and reasons for the CWP reduction in irrigation distribution district. To do so, in the first stage, those sites of water distribution district with the highest effects on CWP variability were identified. Then, the CWP was increased, later. For this purpose, fuzzy programming models and the possibility theory are used to prepare a water allocation plan for the irrigation system of Sistan Dam. The results show that the highest CWP of irrigation district for wheat fields is 0.45 kg/m3, which exist at the sites by the range of discharge losses in 360 to 400 L/m/hr. The analysis of these critical spots shows that the CWP values do not necessarily depend on crop productivity but they may depend on the management factors of irrigation district and the cultivated areas. Therefore, the spots with an optimized CWP could be considered as suitable patterns for increasing the management efficiency.

Gradual or sudden subsidence of Earth's surface is one of the natural hazards with catastrophic consequences. Due to excessive extraction of underground water resources and the drop in piezometric levels in many of aquifers, ground subsidence is occurring at different speeds. InSAR techniques in areas where sufficient land is not available geodetic data, the way they move vertically as well as a wide range of displays. In this study of one coherent pair image of Sentinel 1 with an interval of 11 months was used to check the rate of subsidence in the plain of Semnan. After securing the high correlation between the two images, the original interferogram were prepared and the removal of unnecessary phases, phase shift is calculated and then became vertical component. The results show Semnan plain in most cases is more than 10 cm of subsidence. Generally, areas with high rates of subsidence near the city of Semnan in the East and South are up to 10 kilometers away from the city have been located. Because of this phenomenon centered in Semnan, it would be proper management of water resources in the region quickly reduce this phenomenon.

Coastlines are one of the most important phenomenon in the surface of the earth, with a dynamic nature. Monitoring of coastal area is an important parameter for sustainable development and environmental protection. Coastal area monitoring requires the extraction of coastlines at different times. Today, data collection is considered as the most efficient source of information for the study of coastal landforms, tidal levels, coastline variation, and depth of the water. The purpose of this study was to estimate the changes in the coastline of the Miankaleh gulf area that is located on the southeast coast of the Caspian Sea, using remote sensing techniques. This study examines the qualitative and quantitative interpretation of coastline changes in the 44 years period. The main research tool is the MSS, TM, RVB, OLI and ETM+ Land Rover satellite images. The results of net changes show that, a deramatic rise was occurred in the gulf of Miankaleh. But after year of 1977, this trend was reversed. The coastal variation line with estimation of mean weighted suggests that, the study area was appears to be moderately antecedent, in the period of 44-year.

In the present research, the climate change effect on groundwater resources of Miandoab plain in West Azerbaijan province was investigated. In this direction, the scenarios including A1B, A2 and B1 via LARS-WG downscaling model and with applying the HadCM3 general circulation model and artificial neural network model in two different periods (2046-2065, 2080 -2099) were studied. For this purpose, monthly groundwater depths data of 25 piezometric wells in the Miandoab plain with a 10-year statistical period (2005-2014) and daily and monthly data of rainfall, minimum and maximum temperatures and sunshine hours of the Miandoab synoptic station in a 20-year statistical period (1995-2014) were used. The evaluation results of the observed and simulated data by the LARS-WG model, using different statistical indices indicates that there is no significant differences between simulated and observed values. The performance analysis of the artificial neural network model shows that the mentioned model has good and suitable accuracy in simulating the changes in groundwater depth in the studied plain. The results showed that the average depth of groundwater level in the first period (2046-2065) and the second period (2080-2099) increases 2.87% and 9.3%, respectively. In fact, considerable augmentation of temperature and consequently increasing the groundwater consumption cause to deeper depth of the groundwater.

Water scarcity especially in Iran and the recent drought, achieving a water policy is of important particular. Optimal water collocation under controlled and climatic and real conditions, in the past two decades, it has been one of the major concerns of researchers and engineers. The main purpose of this research is to use the imperialist competitive algorithm (ICA) to estimate and water allocation. the imperialist competitive algorithm is a new optimization algorithm and compared with other optimization has par or even higher ability to optimize a variety of issues. This algorithm for finding the optimal solution is speed. In other words, an optimal convergence rate is high and can find global optimized in optimization problems. In this study, ICA was used for optimizing water resources values from 1991 to 2003 agriculture years about the Sofi-Chay drainage network to achieve the most optimal policy. The results of the application of the ICA to the issue of water allocation and compared with genetic algorithm results indicate that the proposed method is very successful. The results showed that the results of the implementation of the ICA algorithm in comparison with the genetic algorithm are very close to the measured values of water allocated. The results showed that the results of the implementation of the ICA algorithm compared with the Genetic algorithm is very close to the measured values of water allocated. Also, the results showed that the lowest amount of water allocation in the 4th study area in 1997-2003 and the highest amount of water allocation in the 1st study area in 1991-1994 and 1998-1999. The results showed that the results of the implementation of the ICA algorithm in comparison with the genetic algorithm are very close to the measured values of water allocated. Also, the results showed that the lowest amount of water allocation in the 4th study area in 1997-2003 and the highest amount of water allocation in the 1st study area in 1991-1994 and 1998-1999. The results also indicate that generally, optimal water resource allocation between different parts (agriculture and services), 40% of the proceeds is recovering from the current situation.

Optimal water consumption and the supply & demand management would require a better focus on the economy of water resources. This study evaluates the effects of virtual water on the economic value of water resources using a mathematical model. The model has been applied to the Arak Plain, central Iran, for four strategic crops of wheat, barley, alfalfa and corn with three weighting methods of “cultivated area”, “water consumption volume”, and “income”. Meteorological and agricultural data, water consumption data as well as incomes and expenses of the water section in 2015-2016 were used in this research. Results show that the economic value of agricultural water resources in the Arak Plain increased for all the three weighting methods by considering the virtual water that led to substituting the products. Replacing alfalfa with sorghum would increase the economic value of water resources by 36.0%, 28.0%, and 40.5%, using the three weighting methods of “cultivated area”, “water consumption volume”, and “income”, respectively. Increasing the economic value of water resources is one of the main ways towards sustainable development and food security.

The water requirement of the urban district of Zahedan City in Iran is met by the transfer of water from Sistan Chah-Nimeh reservoirs that are themselves suffering from severe water crisis. So, the prediction of the urban demand for drinking water can greatly help managers and users of urban water systems to use sound management practices. The present paper uses the artificial neural networks of GMDH and RBF, as two vigorous tools for the analysis and modeling of nonlinear relationship, to estimate monthly demand for drinking water in Zahedan in 2017. The selected parameters include mean monthly temperature, relative humidity percentage, mean precipitation, sunny hours, and previous-month consumption rate. The results of comparing MSE and MAE indicators show that after studying different structures with various number of neurons and hidden layers, the GMDH neural network with three hidden layers that has one neuron in layer 1, three neurons in hidden layer 2, and three neurons in hidden layer 3 yields the best results for the predication of short-term demand for drinking water. The comparison of linear and nonlinear activity functions reveals that in output layer of GMDH and RBF neural models, the nonlinear functions outperform linear functions. As well, among the GMDH model, the models with nonlinear output show better performance than those with linear output. Also, it is shown that the expansion of the network structure cannot improve the results considerably.

Groundwater resources are considered as the most important sources of drinking water, agriculture and industry. investigation of quality changes and decreases is necessary in groundwater level due to excessive exploitation of these resources.In this research, investigated the spatiotemporal variations of groundwater quality parameters for drinking and agriculture in 18 wells during the statistical period of 1991-2015 in Lordegan plain of Chaharmahal and Bakhteyari province.The studied parameters were including Cl-, TH, TDS, Na+, SO4-2, SAR and EC. In order to estimating the semivariance model and determining the best interpolation method used the GS+ 5.1.1 software and RMSE and MBE criteria. Finally, spatial variation of parameters was calculated using IDW method in ArcGIS10.3 and parameters variations trend investigated using nonparametric Man-Kendall test in MAKESENS 1.0 software. The results showed that the TDS and TH parameter is better condition in plain than Cl-, Na+ and SO4-2 Also; in agricultural aspect the SAR and EC parameters have a very good condition during the statistical period in this plain. Trend analysis results showed that the TDS, TH, EC, SO4-2 and Cl- parameters have positive and SAR and Na+ have descended trend.

The water shortage and the recent droughts have revealed the necessity of paying attention on increasing the water productivity, more than done in the past. In this regard, using pressurized irrigation systems is recommended as alternatives for surface irrigation systems. So this study, in order to assess the system performance and water productivity in such systems, nine and ten of the existing sprinkler irrigation systems (constant classic and wheel move) were evaluated in Isfahan and Hamedan Provinces, respectively. The Potential and the actual application efficiency of the low quarter, the distribution uniformity and the Christiansen's coefficient of uniformity were determined. The Averages of PELQ, AELQ, CU and DU in Isfahan province were 61.5%, 58%, 66.8% and 75.8%, respectively and those of Hamedan province were 53.9%, 44.8%, 71.1% and 81.1%, respectively. By determining the average of water consumption and the crop yield, the averages of water productivity in Hamadan and Isfahan provinces were found 6.6kg.m-3 and 6.3kg.m-3, respectively. The averages of water consumption in the irrigated potato fields in Hamadan and Isfahan were 6745 m3/ha and 6298 m3/ha, respectively. The results of this study showed that in most of the studied fields, deficit irrigation has been happened. From the results of these assessments, it can be deduced that the main problems in the implementation of these systems are: inaccuracy of design, the mismatch of design criteria with the implementation phase, incorrect performance, insufficient users' knowledge and the lack of accordance between the amount of water used and the crop water requirement.