جستجوی مقالات مرتبط با کلیدواژه « یکنواختی توزیع » در نشریات گروه « آب و خاک »

The Water Productivity (WP) of the Darbasti Irrigation System (DIS) was evaluated in Alfalfa cultivation in the Markazi Province. The evaluation included three patterns of sprinkler placement: 8x8 meter (SS-88), 8x10 meter (SS-810), and 8x12 meter (SS-812). The Distribution Uniformity (DU), Coefficient of Uniformity (CU), Application Efficiency of Low Quarter (AELQ), and WP were determined in the years 2018 and 2019, after the third (HA-3), fourth (HA-4), and fifth (HA-5) yield harvests. The results showed that the average CU in the SS-88 pattern was 84.76% in the first year and 86.34% in the second year. This pattern had the highest CU compared to the other two patterns. The DU in SS-88, SS-810, and SS-812 patterns in the first and second year was 77.3%, 79.31%, and 75.38%, 77.66%, and 70.11%, 70.88%, respectively. These results indicate very good, good, and relatively good performance in each of the patterns, respectively. Moreover, there was a significant difference at the one percent level in the AELQ between the first and second year for all three patterns. The results showed a significant difference at the level of one percent between the SS-812 model and the other two models. The WP of alfalfa was 1.84 kg/m3, 1.87 kg/m3, and 2.28 kg/m3 for SS-88, SS-810, and SS-812 patterns, respectively, in the first year. In the second year, this index was 2.43 kg/m3, 2.3 kg/m3, and 2.4 kg/m3 for the same patterns, respectively. Generally, the SS-810 pattern of sprinkler placement is a suitable choice based on performance indicators.

Oxygation is a variant of subsurface drip irrigation in which ambient air is injected through the system via a venturi, thereby plant roots receive air and water simultaneously. The objective of this research was to study the effect of two surfactants and certain ratios of them on the uniformity distribution of emitter air flow rates along lateral pipes in an oxygation system.

Two non-ionic surfactants, namely, Triton X-100 and Tween 80, and three mixtures of them with different ratios including 2:1, 1:1, and 1:2 were added to irrigation water and the results were compared to the case where no surfactant was used. For statistical analysis of data, the Kolmogorov–Smirnov and Friedman tests along with Christiansen Uniformity Coefficient were used.

In the absence of surfactants, Christiansen uniformity coefficient (CUC) for emitter air flow rates was -67 percent. The relative increase in CUC, when Triton X-100, Tween 80, and the ratios 2:1, 1:1, and 1:2 were applied, amounted to 211, 162, 210, 213, and 206 percent, respectively.

The results of this research clearly indicates that application of surfactant mixtures with synergic interaction will effectively enhance distribution uniformity of emitter air flow rates.

Evaluating the performance of pressurized irrigation systems is one of the important strategies for managing farm water consumption. In this study, 5 sprinkler irrigation systems, 5 drip irrigation systems and 2 tape drip irrigation systems were selected for technical and hydraulic evaluation in agricultural lands of Hamedan. Evaluations were based on the Merriam and Keller method. Measured indices for sprinkler irrigation systems included Christiansen uniformity coefficient (CU), distribution uniformity (DU), potential application efficiency of low quarter (PELQ) and application efficiency of low quarter (AELQ). Also, Indicators measured for drip irrigation systems included uniformity factor (EU), efficiency reduction factor (ERF), potential application efficiency of low quarter and application efficiency of low quarter. The values of CU, DU, PELQ and AELQ for sprinkler irrigation systems were 65.6-80.1, 53.1-65.4, 31.1-55.7 and 28.3-52.5 percent, respectively. Also, the values of EU, ERF, PELQ and AELQ for drip irrigation systems were obtained in the range of 43.4 to 65.7, 0.8 to 1.3, 39.1 to 59.1 and 34.0 to 73.0 percent respectively. The results showed that in all systems the efficiencies under study were lower than expected, which can be attributed to improper design, the difference between the implemented system and the designed system, the impact of climatic factors such as high wind speed, operational problems such as the lack of adjust pressure by farmers, the use of inappropriate equipment and the lack of periodic reviews due to low levels of awareness, the lack of education and economic failures.

The main problem in surface irrigation systems is the low irrigation efficiency due to poor management, inaccurate estimation of design parameters and inadequate design. Losses in surface irrigation include deep infiltration and runoff, which is one of the ways to increase the efficiency of border irrigation, using closed-end mode in irrigation systems. This research was conducted to evaluate the effects of geometrical variables (slope and length of border) and flow control (inlet flow rate and cut-off time) on application efficiency and uniformity of water distribution in closed-end border irrigation system. The length, slope, inflow rate, and cut-off time are considered as the decision-making variables for developing the multi-objective genetic algorithm based on the non-dominated sorting. For this purpose, three irrigation borders with closed-end system were considered in the Ramshir network. The optimization algorithm for calculating the objective functions involves maximizing the minimum water depth and minimizing the infiltration depth in a modeling loop. The optimization algorithm was linked to WinSRFR 4.1.3 software to calculate the objective functions. The results showed that the best combination of inflow rate and the cut-off time for 75 mm of required water depth was 1.9 lit/s/m and 150 min, respectively, which increased application efficiency and distribution uniformity to 79 and 78 percent. Furthermore, the application efficiency in the closed-end border irrigation system is higher (30% to 50%) than the open end method in different scenarios.

This study was conducted to evaluate the performance of the classic sprinkler irrigation system and identify the exploitation challenges. The assessment included the measurement of the uniformity coefficient of Christinean (CU), distribution uniformity (DU), potential effeceincy of the low quarter (PELQ), and application effeciency of low quarter (AELQ). The average wind drift and evaporation losses was 19 and 16 percent in selected farms in Isfahan and Fars provinces, respectively. The average amount of DU and CU for selected famrs in Isfahan provinces was 55 and 63 percent and for Fars provinces was 64 and 76 percent, respectively. The average amount of PELQ and AELQ in Isfahan province were 45 and 38 percent and that was 53 and 46 percent in Fars province. The average amount of PELQ in selected farms in Fars province was 18 percent higher than that in Isfahan province. The potential effeceincy of the low quarter was lower than the acceptable range in evaluated irrigation systems. It was attributed to the low uniformity of water distribution, the wind drift and evaporation losses and as well as, inappropriate working pressure due to the improper irrigation system design and operation. Considering the encountered areas with water and energy shortages and most importantly, climatic constraints (extreme heat and existence of severe wind on most agricultural areas), a medium pressure sprinkler systems(small sprinklers), drip irrigation system or low pressure systems were suggetced for these provinces.

Semnan province faces water and soil limitations due to its geographical location, desert and semi-desert climate. Pressurized irrigation methods are used as one of the options for improving water use efficiency in this province. In this study, sprinkler irrigation systems were evaluated in Semnan province. For this purpose, 6 sprinkler irrigation systems including wheel move, classic with portable sprinkler, and center pivot systems were evaluated in different farms. Potential and actual application efficiency (PELQ and AELQ), uniformity, and distribution coefficients (CU and DU) for wheel move systems were 40.7%, 29.6%, 57.2% and 52.7%, respectively, and for classic systems with portable sprinkler they were 54.8%, 54.8%, 75% and 65%. For center pivot system, these parameters were 83%, 79.6%, 5/94%, and 91%, respectively. In center pivot system, these parameters were the best. Good designing, new and appropriate sprinklers, and low height of sprinklers were the factors causing better operation of this system. Next to center pivot, the classic system with portable sprinkler had better performance. New and appropriate sprinklers, low height of sprinklers, and appropriate pressure in this system increased the efficiency in farm No.4, while in farm No. 5, inappropriate sprinklers distance decreased efficiency of the classic system with portable sprinkler. In other farms, low pressure of sprinklers, decreasing the discharge and spray radius of sprinklers relative to nominal values and high pressure difference in the system caused low efficiency of wheel move system.

The aim of this research was evaluate end connection types of drip irrigation system laterals affecting on uniformity of water distribution. To carry out research, a drip irrigation system was installed on flat plot with dimensions of 80m × 90 m in Zanjan University Research Farm. Experiments was carried out in 3 different treatments including conventional laterals layout (C.L.) connecting laterals end as pairs (P.C.), and loop (L.C.). Also 3 different input pressures i.e., 0.5, 1.0 and 1.5 bar were used. Results showed, at 0.5 bar input pressure, emitters average discharge ( a q ), variability coefficient (Cv) and Christiansen’s uniformity coefficient (Uc) were 2.9LPH, 11.0% and 92% (respectively) for P.C., 3.0LPH, 10.7% and 91%, for L.C. and 2.8LPH, 13.1% and 89 % for C.L. At 1.0 bar input pressure, Cv in C.L., P.C. and L.C. were obtained 9.1%, 5.7% and 4.9% (respectively), and a q and Uc for 3 different connects were 4.8 LPH and 92% for C.L., 4.1LPH 96% for P.C. and L.C. for C.L. (for both). At 1.5 bar input pressure, due to inflict excess pressure to the system, a q were calculated 5.0 (C.L.), 4.9 (P.L.) and 5.0 (L.C.) LPH. In this input pressure, Cv values for C.L., P.C. and L.C. were 9.7%, 8.4% and 5.5% (respectively), and Uc were 93%, 94% and 96% (respectively). As the results of the research in the case study site, connecting of lateral ends (as pair or loop) were improved and increased water distribution uniformity compared conventional connecting which the increasing was more for loop connection.

Practical problems such as rushing roots toward pot, difficulty of manually filling with water and deficit irrigation due to permeation from regular pots prevents the development of pot irrigation. With regard to increasing irrigation efficiency importance and preventing water loss to fix the problems of this irrigation method.Changing physical structure of pot could solve many problems and issues which this irrigation technique is facing. Comparison of the two major characteristics of localized irrigation hydraulic characteristics (coefficient of variation and distribution uniformity) and also using gravity pressure can achieve a solution for water and energy shortage problems. So far, with knowledge of the role of water pressure at gravitational pressures in hydraulicproperties of these methods, some effective features in these methods application is specified.
Material and This study was carried out in randomized complete block at water engineering department of Sari Agriculture Science and Natural Resources university laboratory from September to December 2015. In this study, in the form of randomized complete block, hydraulic specifications of three treatments of pot irrigation, gravity drip irrigation and porous pipe irrigation investigated under water pressure of 0.5, 1.5 and 3 m. In each of the water column pressure, output water volume from 10 samples of each irrigation method treatments calculated from 7 replicates during one hour in about two months. Porous pipes which used in this study were imported 16mm sample pipes from Anahita Company. GDI gravitational emitter model, porous pipe and containers made of cellulose clay pots in the form of cylinder shape with diameter of 15 cm were used. Thus, within one hour of irrigation, water volume withdrawn from tested samples under constant pressure of irrigation were collected by suitable containers and measured by graded container and flow rate of each samples were calculated. Christensen distribution uniformity coefficient was calculated with Christensen distribution uniformity coefficient formula. Based on USA agronomical engineers, a pointed emitters with variation coefficient less than 0.05 is good, with cv of 0.05-0.10 is medium and with cv of 0.10-0.15 is weak. After calculating evaluation parameters, the results were analyzed with SPSS statistical software and Tukey test at 1 %and 5 % level of probability.
The results of statistical analysis of randomized complete block design and mean comparison of different level of treatments effects with Duncan test (irrigation method treatment and water pressure treatment) at 5 %level of probability showed that maximum distribution uniformity achieved in gravitational drip irrigation among samples. With increasing pressure, coefficient of variation was less affected and at lower pressures, coefficient of variation among tested samples were more evident. In addition, it is indicated that increasing pressure have maximum effect on flow rate and distribution uniformity increment while with increasing pressure, minimum changes observed in coefficient of variation. Therefore, among possible gravitational pressures in each project, maximum pressure should be selected for design and implementation. Result showed that in porous pipes and in pressures of 50, 150 and 300 cm, average flow rate were 0.31, 1.4 and 4.2 liter per hour in meter, average coefficient of variation were 0.88, 0.61 and 0.83 and average distribution uniformity were 2.2, 6.2 and 1.6 percent, respectively. In the main-treatment and in each pressure sub-treatment, samples flow rate changes at different replicates is so high that coefficient of variation was more than conventional coefficient (more than 0.6) and thus classified in unacceptable emitters. In this treatment, distribution uniformity was so low that using this irrigation method at gravitational pressures range cannot be recommended. Based on statistical analysis results, it is indicated that increasing pressure in gravitational drip irrigation have maximum effect and in pot irrigation, have minimum effect on flow rate changes, and in addition, maximum distribution uniformity among samples was in gravitational drip irrigation while in porous pipe irrigation besides high coefficient of variation, minimum distribution uniformity among samples were observed.
Due to the high influence of pressure changes in gravitational pressures on hydraulic characteristics of mentioned three irrigation method, among investigated gravitational pressures in this study, pressure of 3m as appropriate pressure at gravitational pressures and among localized irrigation methods, gravitational drip irrigation were recommended. It is recommended to paying attention to the development of gravitational drip irrigation application in large-scale garden and agriculture projects with positive approach.

The major problem in surface irrigation methods is low irrigation efficiency which is mainly caused by the lack of suitable irrigation management. Noting the cost of pressurized irrigation systems and restrictions of applying them in some circumstances, it is necessary to improve surface irrigation methods. This study aimed to assess the current situation of furrow irrigation management, identifying weaknesses and ways to improve water consumption in four sugarcane agro-industries of Dehkhoda, Amirkabir, Hakim Farabi and Karun. In this study, the amount of water used, irrigation scheduling parameters, irrigation application efficiency and water distribution uniformity of the studied farms were evaluated. At total, 37 cases were evaluated at different stages of growth in the studied sugarcane agro-industries. In each of the studied farms, soil texture, bulk density, advance and recession times, inflow rate, soil moisture content (before and after the irrigation), two points of soil moisture characteristic curve, field slope, furrow cross section, and irrigation time were measured. Results showed that irrigation interval in the studied farms was short, irrigation time was long, and water consumption in most of the evaluated farms was more than the required water. Soil moisture before irrigation at depths of 33-66 cm and 66-100 cm and sometimes at depth of 0-33 cm in the most of the studied fields was close to field capacity (FC) or even it was more than it. Irrigation gross water depth ranged from 70 to 319 mm and application efficiency varied from 7 to 100 percent, average was 42.5%. Unlike application efficiency, water distribution uniformity was acceptable in the studied farms and its average was approximately 92%. Water losses in the studied farms were mainly due to deep percolation.

Evaluating the implemented sprinkler irrigation systems, made it possible to determine these systems level of success; and presented practical solutions to improve the efficiency of these systems and offered suggestions for future systems. The main objective of this study was to evaluate the status and performance of the implemented center pivot systems in the study area. In this study, 5 center pivots were chosen in alfalfa, maize and sugar beet fields in Moghan Agro-Industry and Livestock. Each system was evaluated in 3 experiments. The results showed that, average distribution coefficient, distribution uniformity, PELQ, AEQL, evaporation and wind drift losses are about 47.5, 60.4, 50.1, 50.1 and 7.6, respectively. Analyses of these evaluation parameters showed that the existing center pivot systems in the study fields were not efficient. The Low efficiency of these systems was results of improper management and technical issues that were not considered. The reason for the low amount of AELQ and PELQ was improper designing and operation of these systems that should be considered and revised.

The objective of this study was to evaluate how the design and the management of solid set sprinkle irrigation systems in Koohdasht plain of Loreistan province. For this purpose, 10 solid-set sprinkle irrigation systems were evaluated .For evaluating of the selected systems, some performance indicators were used such as Christiansen’s coefficient of uniformity(CU), distribution uniformity(DU), potential application efficiency of low-quarter (PELQ), application efficiency of low-quarter(AELQ), wind drift and evaporation losses(WDEL), deep percolation losses(DP) and adequacy of irrigation(ADirr). The mean values of these parameters were obtained 70.84, 43.64, 46.85, 38.01, 8.77, 31.02 and 64.66%, respectively. All of systems have low PELQ values and also water distribution uniformity of them were lower than recommended values by Merriam and Keller. In 4 systems out of 10 systems, irrigation is complete and deficit irrigation occurred in the other systems so AELQ values were equal to PELQ. Unsuitable design and implementation of the systems were recognized as the most important reason of low PELQ. Synchronic utilization of many sprinklers and using rather than one sprinkler on lateral also were the most important reasons for low water distribution uniformity. In general, the results of this study showed that however in many of cases the design and executive problems were exist; but, a big share of the reason of low performance of sprinkle irrigation systems in koohdasht plain are the weak managing and operation of the systemsThe objective of this study was to evaluate how the design and the management of solid set sprinkle irrigation systems in Koohdasht plain of Loreistan province. For this purpose, 10 solid-set sprinkle irrigation systems were evaluated .For evaluating of the selected systems, some performance indicators were used such as Christiansen’s coefficient of uniformity(CU), distribution uniformity(DU), potential application efficiency of low-quarter (PELQ), application efficiency of low-quarter(AELQ), wind drift and evaporation losses(WDEL), deep percolation losses(DP) and adequacy of irrigation(ADirr). The mean values of these parameters were obtained 70.84, 43.64, 46.85, 38.01, 8.77, 31.02 and 64.66%, respectively. All of systems have low PELQ values and also water distribution uniformity of them were lower than recommended values by Merriam and Keller. In 4 systems out of 10 systems, irrigation is complete and deficit irrigation occurred in the other systems so AELQ values were equal to PELQ. Unsuitable design and implementation of the systems were recognized as the most important reason of low PELQ. Synchronic utilization of many sprinklers and using rather than one sprinkler on lateral also were the most important reasons for low water distribution uniformity. In general, the results of this study showed that however in many of cases the design and executive problems were exist; but, a big share of the reason of low performance of sprinkle irrigation systems in koohdasht plain are the weak managing and operation of the systemsThe objective of this study was to evaluate how the design and the management of solid set sprinkle irrigation systems in Koohdasht plain of Loreistan province. For this purpose, 10 solid-set sprinkle irrigation systems were evaluated .For evaluating of the selected systems, some performance indicators were used such as Christiansen’s coefficient of uniformity(CU), distribution uniformity(DU), potential application efficiency of low-quarter (PELQ), application efficiency of low-quarter(AELQ), wind drift and evaporation losses(WDEL), deep percolation losses(DP) and adequacy of irrigation(ADirr). The mean values of these parameters were obtained 70.84, 43.64, 46.85, 38.01, 8.77, 31.02 and 64.66%, respectively. All of systems have low PELQ values and also water distribution uniformity of them were lower than recommended values by Merriam and Keller. In 4 systems out of 10 systems, irrigation is complete and deficit irrigation occurred in the other systems so AELQ values were equal to PELQ. Unsuitable design and implementation of the systems were recognized as the most important reason of low PELQ. Synchronic utilization of many sprinklers and using rather than one sprinkler on lateral also were the most important reasons for low water distribution uniformity. In general, the results of this study showed that however in many of cases the design and executive problems were exist; but, a big share of the reason of low performance of sprinkle irrigation systems in koohdasht plain are the weak managing and operation of the systems of the systemsof the systemsof the systemsof the systemsof the systemsof the systems.

Water is wasted during the storage, distribution and application in the field. In sprinkler irrigation systems Wind Drift and Evaporation Losses (WDEL) are known as the main part of losses due to the impact of climate variables on the droplets dispersed in the air. In arid and semi-arid and windy regions WDEL is high and lead to reduce the efficiency and performance of the sprinkler system. This study investigated the WDEL on classic sprinkler irrigation system in Dehgolan plain located in Kurdistan province. The experiments were done with three replications at the University Research Farm of Kurdistan in the Sarab village using the two sprinklers VYR-35 (3.96×2.38mm) and ZK30 (8×3.6mm) sprinklers with two riser heights (1 and 1.5 meters) at day and night irrigation times. Results showed that riser height, day and night irrigation and interaction between riser height and irrigation time had a significant effect on WDEL. So that, WDEL percent was 22.53 % and 6.94% for day and night irrigation, respectively. According to these results, nightly irrigation will help to improve irrigation efficiency. Also based on the results in the same conditions, riser height should be 1 meter.

One of the main purposes of sprinkler irrigation is the uniform distribution of water in the farm in order to supplying crop water and preventing wasting water. Travelling Gun irrigation system is a kind of sprinkler irrigation that is always mobile and irrigates farm in border-like manner. Esmatyeh Farm is one of the dedicated lands of Holly Shrine of Hazrat Fatemeh Masumeh where Travelling Gun irrigation system has been implemented. This irrigation system is 290-85 TX model with the diagonal of 85 mm Polyethylene and length of 290 m. The employed sprinkler is BIG GUN-SR 150 model, nozzle size of 17.8 mm made by NELSON Corporation. For the performance evaluation of this system, in the summer, June 2013, an investigation was carried out in two ways: Fixed Cart (3 repetitions) and Mobile Cart (4 repetitions). Therefore, coefficient of uniformity, distribution of uniformity, adequacy of irrigation, application efficiency of low quarter, application efficiency and wind drift and evaporation were determined. The results showed that in fixed Cart way, the deep of water on the ground decreases to the distance of 10 m from the Cart centre. Within the distance of 10-20 m from the Cart, the amount of water on the ground increases and will have the maximum amount in the distance of 20-30 m. The average of coefficient of uniformity in fixed Cart way was 61 percent and the average of distribution of uniformity was 44.8 percent. The average amount of water on the ground was 10.1 mm and the average of wind drift and evaporation in Trimmer method was 1.4 percent. In mobile Cart way, the difference between wind drift on the left and right side of the Cart indicate the effect of wind on the water distribution on the ground. The average of wind drift and evaporation in Trimmer method and fixed Cart way was 1.6 percent and in the mobile Cart way was 2.5 percent. The average of coefficient of uniformity was 65.1 percent and the average of distribution of uniformity was 48.3 percent which indicate that coefficient of uniformity is appropriate in Esmatyeh Farm. The average of distribution of uniformity in aforementioned farm is not appropriate and indicates of inappropriate of water distribution in the farm. The average of adequacy of irrigation was calculated as 66.7 percent. The average of application efficiency of low quarter calculated 24.7 percent and application efficiency was 48.8 percent.

The most common of irrigation method in the world is surface irrigation, so that 94 percent of land is irrigated by this method. Many researchers say that low-efficiency surface irrigation is not related to the type and nature of surface irrigation, but also of weaknesses in the design, implementation and management. Many researchers say that low-efficiency surface irrigation is not related to the type and nature of surface irrigation, but also of weaknesses in the design, implementation and management of it. Management of surface irrigation is a complex engineering problem due to spatial and temporal variation of several affecting parameters. However researchers have individually studied the influence of each parameter on the efficiency of surface irrigation systems, but the combined effects of the parameters have not been investigated. Therefore, this study was conducted to evaluate the efficiency of the border irrigation system under simultaneous variation of two input parameters using Full Hydrodynamic Method of SIRMOD model in a silty loam soil. SIRMOD requires input parameters that measurement accuracy of this is effective on the accuracy of the simulation model. The unit flow rate, slope, length and cutoff time were used as input parameters. In order to assess the performance of the model unit flow rate, slope, length and cutoff time were changed ±25% and ±50%. About cutoff time, because of it must be the correct fraction of a day, therefore cutoff time 2, 3, 4, 6 and 8 hours in a day were considered. Also, to evaluate the efficiency of border irrigation, the Ea and DU indexes were used. The results of the study showed that the highest Ea (94.8%) was obtained for the unit flow rate of 1.5 (lps) and cutoff time of 180 minutes. The maximum DU (98.6%) was obtained for the two-parameters of cutoff time of 480 minutes and a slope of 0.006 (m/m). The influence of the unit flow rate on the performance of border irrigation was higher than other parameters. The results showed that can be considered value 2 (lps) and 240 meters as the unit flow rate crisis and length crisis for a silt loam soil respectively. The combination of unit flow rate and cutoff time can be selected as optimal combination to achieve high efficiency in border irrigation.

The importance of proper management of water resources in Kerman, because of limited and water resources crisis is very high. This research has been based on two farm included two center pivot systems in Kerman’s Bardsir and Rayen. For this purpose, the evaluated parameters included Application Efficiency (AE), Potential Application Efficiency of Low Quarter (PELQ), Actual Application Efficiency of Low Quarter (AELQ), and Distribution Uniformity of low quarter and half quarter (DU), Christiansen’s Uniformity coefficient (CU) and adequacy of irrigation is calculated. The result of comparing two Center pivot systems is that Rayen’s Center pivot system with a CU, Adequacy of irrigation and also DU are higher, but AELQ is lower than the recommended value and the difference between AELQ and PELQ shows weakness in design, performing of the system and supervision. Otherwise because of proximity between AELQ and PELQ at Bardsir’s center pivot system indicated purposely paucity in terms of management.

Among surface irrigation methods, furrow irrigation is most common and adaptable method. Longitudinal slope in furrow irrigation is generally uniform and constant along the furrow. In order to access more application efficiency and more uniformity of water distribution and control runoff and deep percolation in furrow irrigation, several techniques such as surge irrigation and cut-back irrigation is used that all is need applying special equipment during operation. This study was conducted to investigate the effects changing of longitudinal slope furrow from linear to planar (concave or convex) on the parameters of the furrow irrigation. In this way an experiment with completely randomized design with three replications was taken place in the experimental field of Shahrekord University during the summer 2010. The treatments were furrows with uniform, concave and convex longitudinal slope. Indexes such as time advance, time recession and outflow was measured. Coefficients of infiltration equation were calculated by two-point method of Elliott – Walker. The indexes such as application efficiency and uniformity of water distribution in all treatments were calculated and compared statistically by SAS software. The results of this study shows application efficiency and uniformity of water distribution in the concave slope treatment was 73 and 92 percent, respectively. Corresponding values of control treatment (70 and 90 percent) were significantly different and so on that of convex slope treatment with quantity of 63 and 86 percent, respectively. Therefore it can be concluded that in furrow irrigation the assessment indexes and productivity are improved by applying the longitudinal concave slope.

In this study, Hydraulic properties of low pressure drip irrigation systems were studied under laboratory conditions and using of the pipes that exist in Iran. Therefore, effect of various heads from 0.45 to 1.8m was evaluated for lateral pipe with outside diameter 32mm and length of 16, 30, 60 and also the lateral pipe with length 16 and outside diameter of 16, 20, 25 and 32mm, on hydraulic characteristics consist of average emitter discharge, variation coefficient, uniformity and loss. Emitters used in this study were micro-tube with length of 0.7m and outside diameter of 3mm that inserted to the lateral at 1m intervals. Results showed low pressure trickle irrigation system supplied necessary discharge in all of the lateral length and diameters to the end of it. Moreover, examine effect of lateral length and diameter on emitter coefficient uniformity indicated that desirable uniformity obtain in the lateral with length of 89m and outside diameter of 16mm and also the least head.

Since trickle irrigation system efficiency depends on the physical and hydraulic characteristics of the drippers and specially water application uniformity, therefore evaluation of drippers as the most important section of a trickle irrigation system will be very important to have an efficient irrigation system. The objective of present study was to measure discharge rates of three different kinds of emitters (including Siplast, Inline168 and Katif8) at four different pressure levels of 50, 100, 150 and 200 kPa to assess the hydraulic performances, calculating the coefficient of manufacturing variation, water distribution uniformity of emitters and emitter discharge exponent, in order to establish the emitter´s flow rate sensitivity to pressure and comparing the results to the manufactures´ specifications. Based on results, Katif8 was classified as pressure compensating and inline168 and Siplast were classified as non-compensating pressure as expected. All three emitters distributed water uniformly at all operating pressures. Results indicated that designing trickle irrigation specially relationship between discharge and pressure should be based on reliable test data, not on manufacturer´s supplied data.