Original Article
Irrigation network management
Atena Hazeri; RASOOL Ghobadian; Mohammad Mehdi Heidari
Abstract
Background and Objectives: Proper design of technical and hydraulic parameters plays an essential role in the success of a pressurized irrigation or urban water distribution project and its economy. Therefore, engineers should be able to select the best solution in different stages in terms of design, ...
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Background and Objectives: Proper design of technical and hydraulic parameters plays an essential role in the success of a pressurized irrigation or urban water distribution project and its economy. Therefore, engineers should be able to select the best solution in different stages in terms of design, construction, maintenance and operation according to the existing limitations and make the necessary decisions.The ultimate objective of such decisions is to minimize costs or maximize benefits by considering limitations.The objectives defined for each system may be different but it is certain that in today's engineering world, one-sided objectives are never defined.Today, meta-exploration optimization methods for the optimal design of irrigation and water supply networks have been considered.It is not possible to compare one-objective and two-objective methods in appearance. But in the two-objective method, one of the objectives is defined in such a way that it eventually goes to zero this comparison is possible.Materials and Methods: Hence in the present study, the optimal design of a pressurized network with one-objective binary genetic algorithm and two- objective NSGAII has been done.Genetic algorithm is a method that evaluates different designs through trial and error with analogy criteria and maintains the best designs and eventually achieves the proper design. Multi-objective optimization is a sub-branch of the MCDM multi-criteria decision-making set that takes place among an unlimited set of possible solutions. In such cases unlike single-objective optimization problems, due to the existence of several conflicting goals, a set of answers is obtained instead of just one answer. In order to compare the two methods in terms of accuracy of results and speed of calculations the second objective function in NSGA-II was defined as the sum of the pressure deficiencies in the network. Observance of minimum pressure constraints in the network causes the value of this objective function to reach zero and the results of the two methods are comparable. In order to analyze the network and obtain the pipe flow and pressure in the system nodes, the matrix shape of the gradient method was used. Computer code was developed for single-objective (GA) and multi-objective (NSGAII) optimization methods in VB programming environment. Also, the simulation code according to the matrix shape of the gradient method was prepared in this programming environment. Finally, All the codes were linked to each other.Result: In order to validate the NSGA-II developed cod, its ability to solve several constrained and none- constrained multi-objective mathematical problems was proposed. The results showed that there is a very good agreement between the results of the present model and the results presented by previous researchers. In order to validate the genetic algorithm model, the model was used to solve the linear and nonlinear constrained optimizations problems that have analytical solutions. it has been shown that the results obtained from the model are exactly equal to the results of analytical solutions. After verifying the prepared codes from a programming point of view, a proposed two-loop network consisting of 7 pipes and 8 nodes whit one earth reservoir was designed with both GA and NSGA-II algorithms. The result showed, estimated cost of implementing the studied network by tow method was the same and with a difference of less than 1%, while the cost of calculations in NSGA-II method was estimated to be about 2% of the genetic algorithm method. That is, the time to reach the optimal answer in NSGA-II method is 50 times faster than GA method. Conclusion: Given that the cost of calculations in the NSGA-II method is much lower than the GA method, the use of this method to optimal design of water presuurized network is recommended, Provided that in this method the second objective function is defined in such a way that if all the constraints are observed, its value will be close to zero. For this purpose, the objective function of the sum of pressure deficiencies Was deemed appropriate.
Original Article
Pressurized Irrigation Systems
Omid Orojian Mashhadi; Seyed Majid Mirlatifi; Hosein Dehghanisanij
Abstract
IntroductionGrapes are planted throughout the world and are used to produce dried fruit (raisins), grapes for fresh market (table grapes) and juice. Development of effective methods to improve water productivity in Agriculture is necessary due to the shortage of water resources. Water productivity is ...
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IntroductionGrapes are planted throughout the world and are used to produce dried fruit (raisins), grapes for fresh market (table grapes) and juice. Development of effective methods to improve water productivity in Agriculture is necessary due to the shortage of water resources. Water productivity is a momentous index to assess water saving and to gain more turnover for each unit of water used. Improving water productivity in irrigated agriculture decreases the demand for additional water sources and is thus a solution to the shortage of water resources. One of the efficient methods to improve water productivity is to use micro irrigation systems, which may help to reduce water used to increase yield. Subsurface drip irrigation (SDI) has been used in various countries for over 30 years especially in the regions encountering water scarcity. The results of the implementation of this method were identified in terms of increasing yield, reducing applied water, fertilizer and weed control costs, improve crop quality and water productivity. This study was conducted with the aim of evaluation of water productivity of grapes in two different plantation systems under SDI and furrow irrigation systems.MethodologyIn order to evaluate the effects of a Subsurface Drip Irrigation (SDI) on two varieties of grapevine; Sultani and Fakhri, this experiment was carried out based on completely randomized design with three replications during 2019 growing season in two vineyards with Bowed trellis (A) and Creeping (B) plantation systems. In vineyard A, laterals of SDI system were installed 50 cm below the soil surface and 50 cm from the grapes rows and in vineyard B, 30 cm below the soil surface and 60 cm from the grapes rows. Irrigation water requirement was calculated by P.M.E to meet full grapes water requirement using daily weather information data collected at Malekan weather station. Irrigation management of the furrow irrigated rows in both vineyards were controlled by the owner of the orchard. Except for the difference in irrigation, the vineyard’s grown vines were established and treated similarly (row spacing, training, pest control, canopy management, fertilization and pruning).Result and DiscussionAt the end of the growing season Water productivity, Yield and some physiological traits such as: number of clusters in tree, berry weight, number of berries in cluster, length of cluster were measured. Analysis of variance showed significant difference (at 1% level) between water productivity of different irrigation methods in both vineyards. The SDI method in vineyard A and furrow method in vineyard B had the highest water productivity (5.39 kg/m^3 and 3.7 kg/m^3, respectively). The comparison of interaction effects between irrigation methods and cultivars in vineyard A showed that the water productivity of Sultani variety under SDI irrigation (7.23 kg/m^3) was higher than other treatments and in vineyard B water productivity of Sultani variety under furrow method (5.17 kg/m^3) was higher than other treatments. SDI treatment in vineyard B, which was previously furrow irrigated and therefor roots had spreaded out into a larger volume of soil than that wetted by the SDI system, wasn’t capable to adequately supply Crop water requirement which manifested in crop yield reduction.ConclusionsThe SDI system in Bowed trellis plantation was able to adequately replenish Crop water requirement which enhanced crop yield. Implementation of the SDI system in vineyard A increased yield (28.4% in soltani variety and 32.4% in fakhri variety) and water productivity (42% in soltani variety and 47% in fakhri variety). Studies indicate that in Creeping plantation due to lack of proper distribution of moisture in the root zone, needs further investigation. In order to increase yield and water productivity of vineyards with bowed trellis systems, the installation of SDI system is recommended.
Original Article
Irrigation network management
Shirin Ostovari; Mohammad Javad Monem; Mehdy Hashemy
Abstract
IntroductionThe experience of irrigation networks in recent years shows that traditional operation methods are not able to implement proper water delivery in water scarce periods and enhancing is unavoidable. In many cases, delivered water does not match water requirement, and it causes decreasing water ...
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IntroductionThe experience of irrigation networks in recent years shows that traditional operation methods are not able to implement proper water delivery in water scarce periods and enhancing is unavoidable. In many cases, delivered water does not match water requirement, and it causes decreasing water productivity and farmer’s dissatisfaction. (Sadeghi and Monem, 2014)Irrigation delivery under these conditions is a complex process. Optimization techniques have limitations in the above situations (Santhi and Pundarikanthan., 1999)Monem et al. showed that using hydrodynamic model and unsteady flow analysis is a suitable approach to determine appropriate operation, and performance improvement of irrigation networks under harsh circumstances. (Monem, et al., 2005)In this paper, the main goal is improving the operational distribution management in irrigation networks in water scarce situation. At the first step, the water delivery and distribution status in Eastern Aghili secondary canal is evaluated for full discharge, 20% and 40% water scarce situation (as scenario 0). At the second step, four management scenarios have been defined, and are simulated to manage water scarcity.MethodologyAghili Irrigation Network is located in Gotvand irrigation area in Khuzestan. In present study, the East Aghili secondary canal is selected. This canal is a concrete lined canal having trapezoidal cross section with side slope of 1:1, and length of 16.215 km. The bed width of the canal in the first half is 1.5 meters and for the second half is 1 meter. For clear presentation and discussion of the results, the 9 km of the canal which has 13 outlets is simulated. Simulations are done using ICSS hydrodynamic model. The ICSS model simulates steady flow by solving gradually varied flow equations proposed by Henderson, and unsteady flow by solving St.Venant equations proposed by Sterlekof. It can simulate different structures with the wide range of operations. Performance indicators proposed by Molden and Gates (1990) are used for evaluation of the scenarios. Delivery efficiency, adequacy, and equity indicators, are calculated and discussed for scenarios. In this paper four scenarios are defined for three irrigation level of 100%, 80% and 60% of the required discharge for 24 hour delivery period. The scenarios are:1. The volume of water delivered to all outlets have been decreased proportionally to the shortage of water at the head of canal. The operation of structures are done at the same time. (Scenario 1)2. The second scenario is defined by a Prioritization based on cultivation pattern. Outlets number 3, 6, 8, 10, 11, are considered to have priority for water delivery. So, these outlets receive full discharge, and water shortage is distributed to other outlets (Scenario 2)3. In this scenario the outlets are divided into two groups, which in both groups, sum of the required discharge is equal. In the first 12 hours the first group (outlet numbers 1 to 5) receive their full required discharge, and the second group receive decreased discharge proportional to remaining water left in the canal. At the second 12 hours, the water distribution and corresponding operation is done reversely. (Scenario 3)4. In this scenario, also, the outlets are divided into two groups, which in both groups, sum of the required discharge is equal. In the first 12 hours the first group (outlets number 1 to 5) are closed, and water is delivered to the second group of outlets. At the second 12 hours, the water delivery and corresponding operation is done reversely. (Scenario 4)Results and DiscussionThe result of zero scenario shows that under 20 percent water scarcity, the Adequacy Index is less than 90% for five outlets, and 38% outlets have medium adequacy. The Equity Index is 0.07. For 40 percent water scarcity, 9 outlets (70%) have a medium and poor adequacy, and the equity index is 0.13. This results show that in water scarce situation, not only the adequacy is decreased, but also the equity of water distribution is harmed.After the use of four defined scenarios, the results indicate acceptable improvement in all scenarios, under both 20 % and 40 % water scarcity. Under 20% water scarcity the first scenario, and for 40% water scarcity, the fourth scenario has the highest performance indices. For 20% scarcity, the priority of the scenarios are, scenario no. 1, 4, 3, and 2. For 40% scarcity the priorities are, scenario no. 4, 3, 2, and 1. ConclusionWater shortage without appropriate management actions, will cause poor performance not only from adequacy point of view, but also from equity aspect. According to the results, all proposed management actions, have acceptable effect in water delivery improvement under both 20% and 40% water scarcity with little differences. For selection of the scenarios in addition to hydraulic performance, operational efforts and social acceptance of different scenarios should be considered as well.
Original Article
Hydraulic
Rasoul Daneshfaraz; Mahdi Majedi Asl; Mohammad Jafari
Abstract
Introductions In the early 21st century, vertical screens downstream of small hydraulic structures were proposed as energy dissipators by Rajaratnam and Hurtig (2000). Extensive studies were then performed on thickness, porosity, pore shape, flow angle, and multiple flow currents. The results of these ...
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Introductions In the early 21st century, vertical screens downstream of small hydraulic structures were proposed as energy dissipators by Rajaratnam and Hurtig (2000). Extensive studies were then performed on thickness, porosity, pore shape, flow angle, and multiple flow currents. The results of these studies showed that the screen with 40% porosity and square hole shape creates the highest energy dissipators.Since the distance of the horizontal screen from the edge of the vertical drop can also affect the hydraulic parameters and flow energy dissipation, so in the present study, for the first time, the effect of the location of the horizontal screen from the vertical drop edge on hydraulic parameters and vertical drop dissipation has been investigated and evaluated.Methodology A laboratory flume 5 m long, 0.3 m wide, and 0.45 m high with zero floor slope and two pumps were used to perform the experiments of the present study.The vertical inclinator at the beginning of the flume was made of glass with a height of 20 cm. Screens made of polyethylene with the shape of circular holes with a diameter of one centimeter, with the zigzag arrangement and two porosities of 40 and 50 percent were prepared and placed at distances of 5, 10, and 15 cm from the edge of the drop, respectively. The flow upstream of the drop was considered subcritical. In all laboratory models, the flow discharge was between 200 and 800 liters per minute and the downstream valve was considered fully open. Results and DiscussionLaboratory observationsIn all experiments and at a constant discharge, it was observed that with increasing distance of the screen from the edge of the drop, climate interference is reduced. Also, for the case where the distance of the screen from the edge of the Inclined was more than half of the height of the drop (S = 15 cm), the screen acted as a flow attenuator and the whole length of the screen was submerged by the current. The flow is transmitted downstream along the length of the screen with short waves.Wet lengthScreens with 50% porosity have the lowest relative wetting length compared to 40% porosity. Horizontal screens with 40% porosity increase the relative length of wetted plates by 30% compared to 50% porosity. On the other hand, it was observed that in both porosities of the screen, with increasing the relative critical depth to the location of the screen, the relative wetting length of the plates increased.Pool depthIt was observed that the depth of the pool increases with the increasing relative distance of the screen from the edge of the drop. In addition, by increasing the angle of impact of the jet planes with the bed, the return flow to the inclined wall increases and increases the depth of the pool. Also, by comparing the depth values of the pool in two porosities and at a constant relative distance, it is inferred that the porosity of the screen does not have a significant effect on the depth of the pool.The length of the turbulence Because the length of turbulence is a function of the relative wetting length of the screen, so decreasing and increasing the wetting length of the screen is effective on the amount of turbulence length created. Since the screen with 50% porosity and relative distance of 0.25 have the lowest wetting length of the plate and also the screen with 40% porosity and relative spacing of 0.5 has the highest relative wetting length, therefore the lowest and highest length values Turbulence is specific to these two models. In general, for the screen with 50% porosity, increasing the screen distance from 0.25 to 0.5 increases the turbulence length by 14%. For a 40% mesh screen, increasing the relative screen distance increases by 10%.Total energy dissipationBased on the studies of previous researchers and the results of the present study, it can be found that none of the parameters of orifice diameter, slope placement, screen, dual horizontal screen, and distance of plate from the vertical edge of the drop does not affect depreciation. It does not exist and only increases or decreases climate interference.ConclusionsThe results showed that with increasing the relative distance of the inclined, the discharge, and decreasing the porosity of the screen, the wetting length and the turbulence length of the screen increase. In addition, in examining the depth of the pool, the results showed that increasing the relative distance of the plate from the edge of the drop led to an increase in the depth of the pool in both pores of the screen. Finally, although increasing the relative distance of the plate from the edge of the drop reduced the climatic interference, they still did not affect the energy dissipation of the flow.
Original Article
River engineering
mohammad ali solbi; mehdi meftah halaghi; Amir Ahmad Dehghani; abdolreza zahiri
Abstract
Abstr AbstractIntroductionMasonry check dams are small structures that are built to reduce the slope of the canal, reduce the flow velocity as well as control bed erosion. The distinguishing feature of Masonary check dam and other similar structures is the presence of pipes in the body of check dams. ...
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Abstr AbstractIntroductionMasonry check dams are small structures that are built to reduce the slope of the canal, reduce the flow velocity as well as control bed erosion. The distinguishing feature of Masonary check dam and other similar structures is the presence of pipes in the body of check dams. This adds to the complexity of the hydraulic conditions of these structures. As the flow overflows through the Masonry check dams, only some of the kinetic energy of the flow is dissipated in the stilling basin and the excess kinetic energy is occurred downstream of the structure. This situation can cause erosion of the riverbed downstream of the structure. Various methods are designed and implemented to control this excess energy. These methods include changing the height of the bottom bed, roughening the bed and creating a protrusion at the end of the stilling basin in order to create a submerged hydraulic jump into the stilling basin. Due to the fact that the stilling basin used in the main structure is USBR type 1 and in this type of basins, no baffles or end sills are used to dissipate the flow kinetic energy, embedding a sill at the end of the stilling basin is one of the innovations of this research. Also, using a physical model of mortar stone dams has not been reported anywhere and hence, this is also one of the innovations of this research. Therefore, using the physical model of "Tol Beneh" mortar rock dam can help to better understand the impact of scour reduction methods in the main structure constructed on the Gorgan Ziarat River and similar structuresMaterials and Methodsin order to identify scour in Masonary check dam and its control methods, a physical model with a scale of 1:20 was developed. The flow rate in all tests was 25 l/s At first First, experiments were performed to determine the amount of scouring at the stilling basin. The results of these experiments were used to compare with the remaining test conditions. In the second series of experiments, to create a rough bed, the 54 cm long distance (equal to the length of the stilling basin) was covered with materials with a median diameter of 2.5 cm. three heights of 3, 6 and 9cm were used to model the increase of bed elevation (third series experiments). In the fourth series of experiments, to create a sill at the end of the stilling basin, a plastic blade 3 cm high was used in four stages. In the first stage, only a 3 cm sill was installed at the end of the stilling basin. In the second stage, the height of the bed bottom increased by 3 cm along the length of 54 cm. It should be noted that the average diameter of bed particles in these two methods was 4.5 mm. In the third stage, the roughness thickness of the bed materials increased to an average diameter of 2.5 cm without increasing the bed height. In the fourth stage, in addition to increasing the roughness of the bed material, the height of the bed also increased by 3 cm along the length of 54 cm.Results and DiscussionIn the stilling basin model, the scour depth was 130 mm without any obstacles. In other words, this magnitude represents a scour of 2.60 meter in the prototype. The presence of the end edge at the end of the stilling basin as well as raising the end of the channel causes a submerged hydraulic jump and consequently reduces scouring. If it is used in combination with these two methods, the effect will be greater. The results show that the presence of the end edge at the end of the calm pool shows a greater scouring reduction than increasing the height of the bottom,Keywords: scouring, stilling basin immersion, masonry check dam, stilling basin
Original Article
River engineering
Mostafa Heydari; mohammad bahrami yarahmadi; Mahmood Shafai Bejestan
Abstract
IntroductionAccurate estimation of flow resistance, such as Chezy coefficient, is important for calculating the hydraulic flow conditions and sediment transport in open channels. Chezy coefficient is affected by various factors: bed particles size, vegetation, irregularity of waterway cross-section, ...
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IntroductionAccurate estimation of flow resistance, such as Chezy coefficient, is important for calculating the hydraulic flow conditions and sediment transport in open channels. Chezy coefficient is affected by various factors: bed particles size, vegetation, irregularity of waterway cross-section, irregularity of waterway path, scour and sedimentation, presence of obstructions, suspended and bed load, and bed form (Bahrami Yarahmadi & Shafai Bejestan, 2010, 2011). Previous researches, Talebbeydokhti et al. (2006), Omid et al. (2010), Nasiri Dehsorkhi et al. (2011), Chegini & Pender (2012), Kabiri et al. (2014), and Kwoll et al. (2016), have shown that the bed forms can affect the hydraulic or sediment transport characteristics. However, there is a lack of study to investigate the effect of bed forms with different sediment sizes on the Chezy coefficient. Therefore, the present study aims to conduct experiments on a straight channel whose bed is covered with the artificial bed forms made from P.V.C sheet, and on its surface is glued sediment of different sizes in the range of 0.51 and 2.18 mm.MethodologyThe experiments were performed in a straight flume of 12 m in length and 0.30 m wide (Figure 1). In this study, different flow discharge of 10, 15, 20, 25, and 30 l/s and different bed slopes of 0, 0.0001, 0.0005, 0.001, and 0.0015 were tested. Two series of experiments were carried out: plane bed or bed without form and bed covered with form. Each form was made in a triangular shape with a P.V.C sheet. The form's length and height were equal to 20 and 4 cm, respectively, and the angles of its upstream and downstream to the horizon were selected as 16.4 and 32 degrees, respectively. After each form was built, the desired sediment size was glued to their surface. This study used two types of uniform granulation with average sizes (d50) of 0.51 and 2.18 mm. The total number of experiments in the present study was 100. Since in alluvial rivers with bed form, the resistance Chezy coefficient includes the grain Chezy coefficient and the form Chezy coefficient. A formless bed, covered with the same sediment size, was tested to determine the grain Chezy coefficient ((C_b ) ́). The bed with the form was used to determine the total Chezy coefficient (C_b) and the form Chezy coefficient (C_b^''). Ripple and dune form is formed in a lower flow regime, in which the Froude number of the flow is less than 1 (Shafai Bajestan, 2008). In this study, the Froude number values in all tests with bed form were 0.435 to 0.6, indicating a lower flow regime.Results and discussionFigure 3 shows the changes in the total Chezy coefficient (C_b) against Froude number for sediment-covered substrates of 0.51 and 2.18 mm. It can be seen that as the Froude number increased, the total Chezy coefficient (C_b) increased. In addition, increasing the longitudinal slope of the bed decreased C_b.Figures 4, 5 and 6 illustrate the effect of sediment particles size on (C_b ) ́, C_b^'', and C_b. These figures show that (C_b ) ́, C_b^'', and C_b decreased with increasing particles size. In addition, Figures 5 and 6 show that with increasing R/∆, the total Chezy coefficient (C_b) and the form Chezy coefficient (C_b^'') increased. Calculations showed that the value of C_b^'' in beds with a sediment size of 0.51 mm for slopes of 0, 0.0001, 0.0005, 0.001, and 0.0015 was, on average, 14, 12, 12, 15, and 16.4% more than 2.18 mm sedimentary beds, respectively. In addition, the value of C_b in beds with a sediment size of 0.51 mm for slopes of 0, 0.0001, 0.0005, 0.001, and 0.0015 was, on average, 15, 13, 13, 16, and 16.5% more than 2.18 mm sedimentary beds, respectively.The results of Table 1 shows that the grain Chezy coefficient ((C_b ) ́) for particles with sizes of 0.51 and 2.18 mm was, on average, 98 and 93% more than the total Chezy coefficient (C_b), respectively. In addition, The form Chezy coefficient (C_b^'') for particles with sizes of 0.51 and 2.18 mm was, on average, 16 and 17% more than the total Chezy coefficient (C_b), respectively.Conclusions The results of this study shows that generally with increasing the bed slope and the bed particle size of movable bed sediment channel, the flow resistance increases or the total Chezy coefficient , the form Chezy coefficient and the grain Chezy coefficient decreases. Increasing the bed particle size from 0.51 to 2.18 mm reduced the coefficients of Cb ́, Cb'', and Cb by 15.14, 12, and 12.9%, respectively. Moreover, the value of Cb ́, Cb'', and Cb in sedimentary beds with particles of 0.51 mm were, on average, 18, 14 and 15% more than sedimentary beds with particles of 2.18 mm, respectively.Keywords: Bed form, Chezy coefficient, Dune, Resistance to flow, Ripple.
Original Article
Efat Mohamadi; omolbani mohammadrezapour; Parviz Haghighatju; Abolghasem Haghayeghi
Abstract
Estimation of the virtual water content of some livestock products (milk and meat) in Khorasan Razavi provinceIntroduction:Virtual water in Tony Allen's definition is the amount of water that consumes during agricultural or industrial products and services (Sadek, 2011; Mousavi et al., 2009; Mohammadi, ...
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Estimation of the virtual water content of some livestock products (milk and meat) in Khorasan Razavi provinceIntroduction:Virtual water in Tony Allen's definition is the amount of water that consumes during agricultural or industrial products and services (Sadek, 2011; Mousavi et al., 2009; Mohammadi, 2012; Agahi et al., 2011; Mehdi Zadeh, 2014; Mokhtari, 2013). The population growth, water crisis, global warming increases the challenges of food security. Therefore, it is essential to consider enhancing water productivity as well as reducing virtual water. Livestock is a kind of activities that consume a considerable amount of water. Some previous studies have been done to the estimation of virtual water in the livestock industry in India (Brindha 2017) and in Saudi Arabia (Shakhawat Chowdhury et al., 2017) in recent years. Moreover, Ibidhi and Salem (2020) reported the water footprint of livestock products strongly related to the water footprint of forage and other kinds of livestock nutrition. Although Iran located in an arid region and the Khorasan Razavi province has an active livestock industry, there were not any surveys in the virtual water trend of live stocks in Khorasan Razavi province. Accordingly, in this study, the virtual water of the purebred, hybrid and native cows has estimated in each city of Khorasan Razavi province.Methodology:The virtual water content of livestock products was calculated based on Chapagin and Hokestra (2003). At first, the water requirement of purebred, native and hybrid cows was calculated with CROPWAT software for three consecutive years from 2015 to 2017in 28 cities of Khorasan Razavi province. Then the virtual water content of live cows was calculated. Finally, the virtual water of milk and meat was calculated separately for each city.Results and discussion:The results showed that the highest values of milk’s virtual water, related to hybrid dairy cows with 1590 cubic meters per ton (m3 ton-1) in in Gonabad and Bajestan cities and the lowest one related to native dairy cows with 309 m3 ton-1 in Mashhad. Moreover, the highest amount of virtual water of meat production belonged to hybrid dairy cows with 52350 m3 ton-1 in Gonabad and lowest was for purebred 9232 m3 ton-1 in Mashhad. Therefore, it would be recommended to produce milk from native cows and meat from purebred. Compared to world average values, virtual water of native cow’s milk in Mashhad was 68.8% lower while in Gonabad it was 60.6% higher. Therefore, it could be recommended to produce milk from native cows and meat from purebred.Conclusion:Livestock feed compositions are one of the most influential factors on the total amount of virtual water in livestock products. In accordance with the previous studies, it could be suggested, the most milk should be produced in industrial conditions as well as should produce in cities which have advantages in producing fodder, based on virtual water aspects. It also might suggest changing the cultivation patterns of the province with less water consumption such as clover, fodder peas, fodder beet and sorghum. Other influential factors in the total amount of virtual water are cattle breeds and the value of milking. Virtual water for milk and meat productions in Gonabad city had the highest values in all three types of livestock and was the lowest for Mashhad and Quchan cities, so it might be better to grow more dairy cattle in Mashhad as well as to decrease the livestock productions and development in Gonabad and similar areas. Calculating the virtual water trends for the whole country also are deeply recommended in order to achieve a better vision for water resource management. Keywords: Virtual water, Khorasan Razavi province, Animal feed, Milk and meat, CROPWAT
