مجله مهندسی آبیاری و آب ایران
پیاپی 42 (زمستان 1399)

In this study, a new structure called that the butterfly gate is introduced to control and measure the flow in canals, which is usually a parabolic or semicircular cross section. For this purpose, the hydraulic performance of this gate and the effect of flow parameters and gate opening angle on the flow depth have been investigated in a semicircular canal.  Also in this study, with using a data collection system and recording of the pressure data at different point in canal determined the depth flow while providing the stage-discharge relationship curves for different opening angles, two methods are presented for estimation of flow discharge through the butterfly gate. This estimation can be used both as a separation technique of each angle and as a data aggregation technique. The precision of these methods have been evaluated by using the statistical indices. The results show that, the each method with a high accuracy 95% can estimate the discharge through in canal.

A fundamental solution to save fossil fuels and to avoid air pollution is using small water turbines. In this study, an example of a hydrodynamic turbine that can generate electricity in low-flow and low-velocity flows is proposed. After extensive research on the problem's theory, the 3D shape of the turbine blades was modelled in SOLIDWORKS software and introduced as an input in the FLOW-3D model. For each turbine with different blade angles and for different depths of flow, the interaction between the fluid and blades were evaluated and analyzed to determine the turbine that has the highest torque and angular velocity. The basic premise of this study is that the turbine, which has the maximum angular velocity and torque speed, without oscillation and mutation and without the changes of torque direction, certainly has more power and has the optimal blade angle and flow conditions. All turbines had the highest torque and angular velocity at a discharge of 20  and at the depth of 5 cm and therefore had more power. Accordingly, it was concluded that the most suitable location for greater efficiency and greater power of the turbine is its location near the flow surface. Also a turbine with a blade angle of 70 degrees had the best efficiency among the turbine blades with respect to the created torque and angular velocity.

One of the key factors affecting leakage in water distribution systems is network pressure management. The main objective of pressure management in water distribution system is to minimize water leakages along with maintaining the required pressure at every node. A common way to reduce pressure is to locate flow or pressure reducing valves (PRV) and optimal regulation of these vales in water networks.This study aimed at investigating optimal pressure management problems so as to minimize leakage in water distribution networks. To do so, a two-phase approach was proposed for both optimal positioning and setting of pressure reduction valves (PRVs), where location optimization was addressed at the first stage and optimal operation issue of valves was considered in the next step. In the present research, in order to resolve these problems, an optimization model—a simulation based on an emerging algorithms inspired by honeybees’ behavior called as Artificial Bee Colony (ABC)—was utilized. In this model, ABC optimization in MATLAB environment was integrated with hydraulic simulation of EPANET model. In the next step, the obtained results were compared with those of the previous studies. The results revealed that in case all the limitations of the problem are observed, employing this method to determine the position of the pressure reduction valves and regulate them lowered the mean leakage rate of the network from 82.28 to 72.15 lit/sec by 14.75% in three phases of maximum, average and minimum aquatic need periods.This means that the proposed method was effective in regulating the pressure level to minimize leakage in networks. Comparing the results of the present method with those of the previous approaches revealed that GA algorithm reached better response in fewer times than ICA, CA and ABC methods.

Urban rivers as one of the natural structures of the city are important cities sources because of their environmental, economic and cultural values and the provision of ecosystem services. The purpose of this study investigate the role and importance of Tajan River ecosystem functions as one of the most important rivers of Iran in Mazandaran province, Sari. In order to achieve this purpose, multi-criteria decision models includes Entropy to calculate functions weight of the river ecosystem and Technique Order of Preference by Similarity to Ideal Solution (TOPSIS) and the Simple additive weighting (SAW) to prioritize functions. In this study, research data were extracted from field survey, random sampling and from 239 questionnaires completed by Sari citizens in winter 1397 and spring 1398 to show which of the ecosystem functions of the Tajan River, including regulatory, habitat, productivity and information functions, is importance for Sari citizens. Analysis of weighting Tajan River ecosystem functions in Sari with Entropy technique showed that habitat, productivity, information and regulatory functions gained 0.2511, 0.2501, 0.2500 and 0.2488 weights, respectively. According to the results of the prioritization Tajan River ecosystem functions with TOPSIS and SAW models, habitat, productivity, regulatory and information functions take the first to fourth priority respectively.  Also, the results showed that habitat function for 39% of the citizens, productivity function 27% of the citizen, regulatory function 25% of citizen, information function 9% of the citizen had priority. By identifying and determination the priority of Tajan River ecosystem functions, it is suggested that the results of the present study used as a model for designers and decision makers of river engineering and improvement of urban river landscape, and projects be done for the balance of the river ecosystem and the sustainability of the quality of the urban environment.

To obtain in a laboratory retention curve is not cost and time effective. So estimation of soil moisture using basic soil properties is of importance. The objective of this study was to calculate the soil-water retention curve using the readily available parameters of soil, fractal geometry. In order to calculate the fractal dimension in the TW type( )  model from readily available parameters of soils, four methods were used based on (1) clay percentage with non-linear equation, (2) clay, sand and silt percentage, (3) clay percentage with logarithmic equation, and (4) the fractal dimension of particles obtained from clay, silt and sand. 30 soil samples with different texture including loam, clay loam, clay, sandy clay loam, silty loam and sandy loam from the northern part of Iran were used to evaluate fractal functions.  had the maximum value of 2.909 in clay soil and the minimum value of 2.731 in sandy loam soil and average of 2.817. The average fractal dimension obtained by the first, second, third and fourth methods were 2.84, 2.86, 2.75 and 2.82, respectively. NRMSE value of the first method was 0.0160, the second method was 0.0093, the third method was 0.0216 and the fourth method was 0.0089. The results showed that except for the method based on the percentage of sand, silt and clay, the results of the other methods are close to each other.

Generally, due to the presence secondary flows in the curvature of the river, the outer wall in the bend is always subjected to degradation and erosion. These streams divert the surface flow lines towards the outer wall and the flow lines close to the substrate to the inner wall. Therefore, studying the flow in the meandering channels in order to prevent erosion is of particular importance. One of the simplest, yet most economic methods to cope with outer wall erosion is the use of spur dike. For this purpose, in this laboratory study, the effect of the presence and absence of series spur dikes on longitudinal velocity components in a channel meandering with sloped erodible wall is investigated. The results showed that the presence of simple series spur dikes cause reduced the flow velocity in the outer wall of the bend. Therefore, the average highest velocity reduction between the second and third spur dikes and the lowest velocity reduction between the third and fourth spur dikes was performed. Also, the studies showed that with the increase of 33% of the discharge, about 5% were added to the performance of the spur dikes in reducing the flow velocity in the outer wall of bend.

Regarding climate change, and consequently the decrease in the Gergranod River catchment area, as well as the sharp decrease in the volume of water stored behind the Golestan dam in recent years, a review of the water allocation problem is necessary. Therefore, in this research, the optimal values of water harvesting from the Golestan dam reservoir are calculated using the colonial competition algorithm (ICA), which is one of the interconnected algorithms based on socio-political evolution. In this study, the proper parameters of the colonial competition algorithm were calculated with try and error, and then in five times the implementation of this algorithm in the first run in the 1240 repetition of 2,363.2 million cubic meters for the target function, in the second run in repeat 1256, the value of the target function 4947/2 Million cubic meters, in the third run in Repetition 1271 the value of the objective function was 1,971.1 million cubic meters, the 1300 repetition in the fourth run was 304.1 million cubic meters for the target function, and in the fifth implementation and repeat 1450, the value of the target function was 1,2473.1 million cubic meters Come. The comparison between the values of the objective function indicates that with increasing the number of repetitions, the value of the objective function is reduced. The results indicate that this algorithm is good. The optimal release values obtained from the algorithm have always fluctuated during the statistical period, so that in the first three years of the increasing trend, the fourth and fifth declines, the sixth and seventh increases, the eighth and ninth, and finally increased again in the tenth.

Baseflow separation is one of the important topics in hydrology and water resources management. Different methods have been used to baseflow separation in the river and karstic springs. In this study, the wavelet transform was used as a new tool to baseflow separation in Gamasiyab spring in Nahavand County and Kahman spring in Aleshter County. In this study the data of the 49 years period for the Gamasiyab spring and data of the 27 years period for the Kahman spring were used. For evaluation of this tool, the Hydrochemical method was used by sampling quality data in water year of 2017-2018 for the two springs. The results showed that, in Gamasiyab spring, wavelet function Db4 at level 6 has the best performance. This best performance has the adjusted R2 of 0.96, and RMSE of 0.651 (m3/s). The best performance in Kahman spring related to wavelet function Db2 at level 5, that has adjusted R2 of 0.99, and RMSE of 0.187 (m3/s). Generally, the Wavelet Transform has high accuracy in baseflow separation.

Quality and quantity of drainage water in saline lands, which require primary leaching is continuously changing from the beginning of irrigation and drainage network operation before reaching a more or less equilibrium state. The time to reach a state of equilibrium in areas with saline groundwater may take several years. Therefore in this paper, the system dynamics technique that is one of the object oriented approach was used to simulate farms of irrigation and drainage network, and determine model performance to simulate the drainage water salinity and discharge of subsurface drains. To validate the results of the model, data collected in the 2004 and 2005 cropping years from ARC2, ARC4, ARC6 and ARC8 farms was used in the research area of ​​Sugar Center Research Center (Amir Kabir Agro Industrial Development Unit of Sugarcane Development Company, Khuzestan Province). To statistical analysis and calculating, the root mean square error (RMSE), standard error (SE) and correlation coefficient (R2), were used. In this regard, the RMSE statistical index for drainage discharge of ARC2, ARC4, ARC6 and ARC8 farms were 6639, 8546, 7950 and 8207 m3/day respectively. Also, the RMSE for drainage water salinity of the farms were 2.25, 4.86, 2.04 and 7.98 dS/m respectively. The results showed that the model is capable of simulating the drainage outflow and its salinity in saline and shallow water table region

One of the concerns of the human society is that the changes caused by global warming change the frequency and amount of precipitation and temperature. This study was conducted to investigate the trend of annual, seasons of cultivation, seasonal and monthly temperature and precipitation changes using the Mann-Whitney test at Ahvaz Meteorological Station. The study period consisted of two 31-year periods from 1957 to 2018. The results of this study showed that the minimum temperature had more changes compared to the average and maximum temperatures in the first 31 years (1957-1987) compared to the second 31 years (1988 to 2018). Mean comparison of minimum temperature and average temperature for the two periods showed that there was a significant difference at the 5% of probability level.  The means of the minimum and average temperature increased from 12.1 to 14.9 and 24.9 to 26.9°C, respectively. Mean comparison of the maximum temperature and precipitation for the two periods showed that there was no significant difference at the 5% of probability level. The averages of the maximum temperature and precipitation decreased from 37.5 to 36.8°C and 226.9 to 188.8 mm, respectively. Also, the study of precipitation trend in the two studied periods showed a high distribution of this climate parameter and a small change in the amount of this factor.

Drought is one of the natural events that has a great impact on the environment. The severity and duration of drought are two important characteristics for the detection of drought and are usually derived from the weather data such as precipitation. In this study, two-dimensional copulas were used to construct bivariate distribution of drought characteristics for Sanandaj and Saqez stations located in the western part of Iran. Two important characteristics of drought including; duration and severity were derived from the standardized precipitation index (SPI) time series. In order to use copulas functions, Spearman’s rho and Kendall’s tau correlation coefficients were first calculated to assess correlation between variables of severity and duration of drought for both of considered stations. The results showed that there is a significant correlation between severity and duration of drought. After determining the best fitted marginal distributions on drought characteristics, the fittness of five different copulas for developing the bivariate distribution of severity and duration of drought was examined and the dependency parameter of each copula was calculated using the inference function for the margins technique (IFM). The results showed that for both stations (i.e. Sanandaj & Saqez) Frank copula function, due to having the highest log-likelihood (-328.9137 & -339.3758) and NSE (0.9393 & 0.9174), and the lowest values of RMSE (0.0655 & 0.0763) and AIC (695.8280 & 680.7516), is the most appropriate function for constructing the bivariate distribution of duration and severity of drought. Finally, the conditional probability of drought, joint and conditional returns periods of drought were calculated. The obtained results can provide useful information for planning and management of water resources over the studied area.

Evaporation from the surface of water reservoirs leads to loss of water used in agriculture, industry and drinking. One of the methods of controlling evaporation is the use of physical coatings. In this research, polystyrene sheets, pieces of wood, and honey-bee wax sheets were used as physical coatings on the surface of the water to reduce evaporation from standard buried Colorado evaporation pans. The effect of each coating with three replicates (in three separate pans) was investigated and also three pans were considered as control. Evaporation was measured daily from all pans for 4 months. Results of the experiment showed that polystyrene, wood and wax coatings reduced evaporation by 54, 19 and 18%, respectively. Next, to estimate the percentage of evaporation reduction, decision tree M5, least squared support vector machine (LSSVM) and artificial neural network (ANN) were used. Meteorological data of Semnan synoptic station was used as input data for all the three models. All three methods were highly accurate in the training period. During the test period, the LSSVM method, decision tree M5 and ANN were more accurate, respectively. The values ​​of R2, RMSE and MAE of the LSSVM method at the test step were 0.9834, 2.3718, and 1.7212, respectively. The general results of this study showed that using polystyrene coating can have proper function in controlling evaporation from reservoirs and water storage pools.

In this research, water productivity of annual crops in Moghan plain using physical and economic productivity indices were evaluated and the relationship between physical and economic productivity based on field data has were analyzed. The physical productivity of wheat, canola, soybean, rice, corn, forage, corn, melon, alfalfa, tomato, barley, nectarine, watermelon, cucumber and sugar beet were 1/27, 0/5, 0/67, 0/069, 4/5, 0/45, 3/2, 0/25, 3/46, 1/19, 0/55, 3/1, 0/42 and 5/5 (kg / m3), respectively. Also, Economic water productivity of these crops were 1098, 572, 702, 313, 542, 2286, 322, 97, 832, 685, 547, 279, 267 and 1111, respectively. (Tomans/m3). The results of the interaction matrix and the density of the physical and economic water productivity showed that barley, rice, alfalfa, nylon, cucumber and canola are relatively weak or weak based on physical and economical water productivity indices. Forage, melon and honey physical productivity was in good condition, while in terms of economic productivity, the situation is relatively weak. Among the studied crops, only Sugar beet and tomato water productivity were at a good or good situation for both indices. In general, the results of the research showed relatively poor water productivity at the plain. Also, the findings showed that there is no logical and mathematical relationship between the two indices of physical and economical productivity water. Depending on the water productivity index, the proposed management approaches will be completely different. Hence, both indices should be evaluated in each region and differences of indices should be noticed in water planning.

One of the most important tools for water demand management is water and energy tariff changes. The aim of this effort was to study the level of groundwater in Mehran plain using the system dynamics method under different scenarios of energy carriers price changing. the conceptual model was designed, dynamic hypotheses were explained and simulation was performed. After calibration and verifying the model, the research purpose was evaluated in terms of applying 12 scenarios combining energy tariff increases and water tariff increases. According to the results the effect of changing energy tariffs on changes in aquifer volume and groundwater level was more than the change of water tariff. The results also indicated that the increase of water and energy tariffs could reduce harvest from the groundwater, and in all scenarios an increase in energy tariffs of 80 percent of the current tariff and increasing the surface water tariff  of 50 percent of the current price and Performance of the Right to Supervision would have the greatest impact on the stopping of the decline in groundwater levels and its significant increase

Considering the vital role of water all over the world particularly in arid areas and the non-uniform distribution of resources and water users, inter basin water transmission projects are becoming more and more important. To economize water transmission projects, using the potential of hydropower energy could be considered an effective option. Gross head and discharge play important roles in potential of power generation. In this paper the importance of gross head considering its effective factors, pipe size, internal coating, are evaluated. The water transmission project from Safaroud dam to Kerman is considered as a case study in which internal coating as the main component of head issue is particularly evaluated as the important criteria to make decision for economic aspects of the projects. Also, using both cement lining (standard and non-standard) and epoxy as internal coating are compared technically and economically. The results show an increase of about 1.2 MW in power generation capacity in case of using epoxy which is caused by decreasing friction factor and head loss. As a result, pipe internal coating and even how implementing has to be considered an important criterion in design and implementation of projects. In addition, considering the long paths in water transmission projects, accuracy of head loss calculation can significantly affect the economic justification of such a projects.

Checking of flow meters and increasing their accuracy will increase the efficiency of the water distribution network, optimal use of water resources and decrease the amount of Non-Revenue water. This study was carried out to identify the amount of Non-Revenue water due to the inaccuracy of the flow meters of subscribers in the villages of Birjand. In this research, a systematic random sampling method of 1007 flow meters was used. This is equivalent to 5% of household subscribers in the villages of Birjand. Taking into account the lifetime of the flow meter, the flow meters were divided into six groups of 1-3 years, 6-4 years, 9-7 years, 10-12 years, 13-15 years and 16-18 years. The results of this study showed that 75.3% of the flow meters had an error in the allowed range and 24.7% had a higher error than the permitted range, 19.5% of them had a positive error and 5.2% had a negative error. By increasing the life of the flow meter, the precision of the flow meter is reduced and the volume of the actual flow of water is mostly recorded. According to the expenditures of 1396, the average weight of the corrected coefficient of the tested meters was 1.049 and the application of this coefficient in the consumption of the year studied subscribers and the recalculation of water bills, increased by 4.7 percent of the cost and 16.98 percent of revenue It was a company. Also, with these correction coefficients in total water consumption in 1396, the total subscribers of the province, it was found that the volume of Non Revenue water due to the lack of  precision of the meter consumed 2.97% of the volume of producing water and 4.9% of the volume of allowable consumption of the company's revenue.

In the cotton planting region of northern Khorasan (Iran), the late stages of growing season of autumn crops (wheat) are overlapping with the early stages of spring crops (cotton). The urgent need of both plants for irrigation during this period (cotton need it for emergence and deployment, and wheat need it to develop its the most sensitive stage of growth, the flowering stage). Limitation in water rights of farmers causes them to postpone the irrigation of wheat and use it for cotton. This reduces the wheat yield in the region. Using any technique that help to conquer irrigation overlap of two crops during this period is vital without reducing the yields.  No need for cotton irrigation in the methods of wet planting of seeds and seedling planting can be used as a solution for this problem during this period. Accordingly, an experiment was carried out with three treatments and three replications in the form of strip plot in a randomized complete block design in the marginal lands of the Atrak River in the cropping season of 2016-2017. In each treatment, both wheat and cotton plants were cultivated. Treatments included: 1- Planting cotton as seed and cutting the irrigation of wheat (control). 2- Cotton wet planting and 3- Planting the seedlings of cotton after the last irrigation of wheat. Saved water in irrigation of the corresponding wheat was used in cotton wet planting and seedling planting. The results showed that cotton wet planting and seedling planting, can increase water utilization efficiency 47% compared to seed planting method

Additionally drought, unused management methods in applied of water resource in agriculture lead to shortage of water in different subjects such as farm and garden management. One of the solutions water source management about shortage water problem in agriculture is applied urban wastewater. This research was conducted to investigate the effect of urban wastewater management and water deficit method on the yield and physiological characteristics of millet. Therefore, a Completely randomized block design with split plot arrangement with Irrigation source is at three levels (I1 and I2 and I3: wastewater, the well and the well-wastewater alternate respectively, irrigation at three levels (C1, C2 and C3: irrigation with 100%, 50% and 30%water requirement respectively), with three replications at the research farm of the water and sewage company of Birjand. The result of this research was indicated that using of urban wastewater as irrigation source had significant effect on physiological characteristics of millet such as plant performance, 1000 seed weight and water use efficiency. The plant height value in alternative treat with the best yield to test treat was indicated 20% increasing of variation of course under deficit irrigation in 30 level percent demand water was observed 5 % decreasing of variation. The weight of each cluster (gr) in wastewater treat to test treat had 18 % increasing of variation. Also, under deficit irrigation, the water use efficiency of the well-wastewater alternate to test had increased to 5 at the 50 and 30 level percent demand water. The obtained results represent the effective role of urban wastewater with the well on growth of the plant millet grass that lead to improve physiological characteristics and also increase yield of millet. So, use of urban wastewater is a valuable to Management of water resources in agriculture.

In this study, combined numerical Eulerian-Lagrangian method was used to simulate the movement of and assess the fate of oil spills. Momentum and continuity equations of two-dimensional horizontal flow and transport equations of oil pollution were obtained from Eulerian and Lagrangian methods and solved by a two-dimensional horizontal flow model, Telemac-2D. The finite element method was used for discretizing the governing equations.At the simulation stage of transport process, oil spill velocity which is depended on wind and current speed was computed from net transport model and then substituted into stochastic advection-diffusion model by Lagrangian approach. As a result, the location of the oil spill was provided at different times. It is necessary to point out that the effect of the waves was ignored based on the assumption that coastal currents were weak. At the simulation stage of weathering processes, Fay model was used to model spreading as the most important factor considering gravity and viscosity effects. Then, the surface area of the particles was calculated to solve the evaporation equation. Here, the final evaporation equation was described as a function of oil boiling point and its type. Comparison between results of the present study and Goeury et al. shows that Root Mean Square Error (RMSE) calculated for two-dimensional model in gasolineoil evaporation and dissolution problems are 0.414 and 2.97 respectively which is shown its reasonable accuracy.

The goal of this research is assessment spatial and temporal distribution of groundwater quality in Sirjan plain using Arc GIS software. For this purpose, groundwater quality data were collected from Kerman province of water and wastewater company from1381-1397 years. Simple Kriging, ordinary Kriging and IDW method were used to predict spatial distribution of groundwater quality parameters (12 parameters). The variogram of each parameter was drawn using GS+ software for fitting the best interpolation model. Then, spatial distribution maps of groundwater quality were drawn using Arc GIS. Results showed that ordinary Kriging was the best interpolation method for most of the parameters and spherical and exponential models were the best variogram model. According to spatial distribution maps, concentrations of ions were increasing during the years studied and pollution was aggregated in west and south parts of Sirjan plain which agreed with well locations and using groundwater for agriculture in those zones.