Research Article
S. Esfandyari; hossein dehghani; A. Alizadeh; K. Davary
Abstract
The present study was aimed to determine the effect of drip irrigation methods and nitrogen levels and their interaction on corn root development and study of the root movement model. For this purpose, a split plot field experiment based on randomized complete block with irrigation method in two levels ...
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The present study was aimed to determine the effect of drip irrigation methods and nitrogen levels and their interaction on corn root development and study of the root movement model. For this purpose, a split plot field experiment based on randomized complete block with irrigation method in two levels (surface and subsurface drip) as main treatment and Nitrogen fertilization in two levels (50 and 100% of fertilizer requirement) as sub main treatment at 3 replications was conducted at Agricultural Engineering Research Institute, Karaj, Iran using corn variety 370 double-cross. Monitoring of root depth was performed by digging trenches and observation of soil profile. The samples were collected during the growing season with 10 day intervals (8 times totally) and root weight in different soil layers was measured by harvesting of soil monoliths and washing in plastic filters under water pressure. Results showed that the depth of root development up to 20 days after planting was significantly more in surface irrigation method compare to subsurface drip irrigation method; but it was not significant in 30 to 80 days after planting at 5% level. The depth of root development was not significantly different in different nitrogen levels in fertigation method at 5% level. Interaction of irrigation methods and nitrogen levels also didn’t show significant effect on depth of root development at different corn stages growth at 5% level. Root width development was not significantly different in all treatments. The most root distribution observed at 20 to 40 cm and 0 to 20 cm of soil layer in subsurface drip irrigation and subsurface drip irrigation methods, respectively. The lowest root density was observed at 40 to 60 cm soil layer in both studied irrigation methods. Also the roots were more uniformly distributed in soil in subsurface drip irrigation method compare to surface drip irrigation method. The most accurate root depth estimation was achieved by the linear, Borg & Grims and Cropwat models, respectively.
Research Article
S. Beygi; O. Bozorghaddad; M. Khayatkholghi
Abstract
In recent years, limitation of water resources and the increasing trend of population growth cause the quantity issues on water supply. On the other hand, permanent and sudden pollution of waters as a biological threat has always been of high importance, because occurrence of biological pollution in ...
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In recent years, limitation of water resources and the increasing trend of population growth cause the quantity issues on water supply. On the other hand, permanent and sudden pollution of waters as a biological threat has always been of high importance, because occurrence of biological pollution in water systems produces national crisis. However, since there are various and contradictory goals and utilities in reservoir systems, making proper decisions considering all aspects is a complex issue. A good strategy to compromise between the contradictory goals and utilities would be conflict resolution methods. To perform this study the allocations of drinking and agricultural waters of the Karaj dam, as one of the most strategic dams in Iran in the case of quality attacks, has been used. In this study, Nash model has been used as the conflict resolution method. According to the results, when there is a decrease in the quality aspects of water, Nash model assigns the priority to the quantity ones and allocates low-quality water to the consumers. Thus, a new conflict resolution method has been developed so that the allocations are modified according to the quality aspects. Thus, low-quality water is less allocated while more allocation is made along with an increase in the quality utility.
Research Article
H. R. Boostani; abdolmajid ronaghi
Abstract
Sewage sludge (SS) as a source of required plant nutrients has been utilized in many countries for crops production. for investigation of SS application affect in compared to chemical fertilizer treatment (F), on dry matter yield (DMY) and concentration of some macro and micro nutrient in corn, a greenhouse ...
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Sewage sludge (SS) as a source of required plant nutrients has been utilized in many countries for crops production. for investigation of SS application affect in compared to chemical fertilizer treatment (F), on dry matter yield (DMY) and concentration of some macro and micro nutrient in corn, a greenhouse experiment (5 × 3 factorial) arranged in a completely randomized design with three replicates was conducted. The first factor included SS levels (0, 10, 20, 40 and 80 gr kg-1 soil) and the second factor was soil textural classes (clay loam, sandy loam and sandy). A chemical fertilizer treatment was also used to compare its affect with that of SS application levels on growth and chemical composition of corn. For comparison of applied SS levels (one factor) with chemical fertilizer treatment in each soil textural classes was used from a completely randomized design with six treatment and three replicates. The results indicated that addition of SS significantly increased DMY of corn in all textures. Application of SS significantly increased N, P, Fe, Zn, Cu and Mn concentration in corn aerial parts and nutrients deficiencies symptoms disappeared. Nutrients concentrations in corn plants did not reach to toxic levels even at high rates of SS application and concentration of Cd and Pb were negligible and not detectable in shoot corn. Based on nutrient deficiency in calcareous soils especially Zn and Fe, application of SS for contrasting with shortage of these elements can be effective way to eliminate these nutrients shortage. In general, application of SS was superior to chemical fertilizer treatment in increasing concentration of nutrients and DMY of corn. Prior to any SS recommendations the results of this experiment needs to be verified under field conditions.
Research Article
H. Rezaei; J. Behmanesh; S. Besharat
Abstract
With respect to necessity of the optimum use of water resources and existence of many various optimization methods, in this study 3 kinds of heuristic algorithms have been used including Particle Swarm Optimization, Genetic Algorithm and Simulated Annealing to optimize the operation of Shaharchai dam ...
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With respect to necessity of the optimum use of water resources and existence of many various optimization methods, in this study 3 kinds of heuristic algorithms have been used including Particle Swarm Optimization, Genetic Algorithm and Simulated Annealing to optimize the operation of Shaharchai dam reservoir as an application. The optimization was carried out considering the probability of inflow for a period of 5 years. In order to obtain the best operation of reservoir, monthly release was defined as a second order polynomial according to storage volume and inflow, and different parameters of these algorithms have beenadjusted to minimize the objective function in which supplying the required demand of downstream was defined as the target. The best state of each algorithm is selected through 10 times running of programs (due to intrinsic random behavior of algorithms) and the results comparison leads to realization of which method can perform the best. According to the results, Particle Swarm Optimization method operates more effectively and produces the best results in solving reservoir operation problems. So as an application, control curves of release and storage volume have been extracted for Shaharchai dam reservoir using this method.
Research Article
A. Emadi; S. Kakouie
Abstract
Poor delivery and distribution water in irrigation canals will cause the discontent of farmers, disrespect of equity in water delivery and increase operational losses. Therefore optimal water delivery scheduling will increase performance condition network, considerably. With the spread of computers and ...
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Poor delivery and distribution water in irrigation canals will cause the discontent of farmers, disrespect of equity in water delivery and increase operational losses. Therefore optimal water delivery scheduling will increase performance condition network, considerably. With the spread of computers and mathematical methods, it is possible that develop simulation and optimization mathematical models for optimal operation. In this study, Ants Colony System (ACS) optimization algorithm is used for development optimal water delivery in BP14 canal of Fumanat irrigation network in west of Gilan province. This canal has a length of 6852 meters with a trapezoidal cross section and capacity of 2.5 m3/s and land cover area of 2100 ha. The optimal delivery schedule canal is derived for two cases; single objective, canal capacity minimization and two objective including minimize canal capacity and delivery time. Comparison of the research with results obtained from Genetic Algorithm (GA) showed that ACS algorithm to GA in single objective state resulted in less canal capacity (90 l/s) and more irrigation schedule complement duration (10 hours). Also, the number of upstream gate regulations and water delivery deficiency obtained 1 and 0.04 percent, respectively. In two objective state, ACS determined less canal capacity (105 l/s) and more irrigation schedule complement duration (41 hours).
Research Article
A. Atefi; ali asghar ghaemi
Abstract
The aim of the present research is to study the effect of both different irrigation water quality (treated wastewater and urban water) and N. P. K fertilizer via Tape subsurface micro irrigation on the soil chemical properties in the test area was investigated in Fras Bajgah Region in 2010. In this study, ...
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The aim of the present research is to study the effect of both different irrigation water quality (treated wastewater and urban water) and N. P. K fertilizer via Tape subsurface micro irrigation on the soil chemical properties in the test area was investigated in Fras Bajgah Region in 2010. In this study, the impact of treated Shiraz urban wastewater under micro irrigation in broccoli cultivation on the soil chemical properties was evaluated. According to the results of this research, Electrical Conductivity to a depth of 30 cm of soil was increased significantly due to irrigation with wastewater and irrigation fertilizer comparing to urban water. Also, using wastewater increased pH in surface layer of soil. Although, considering the buffer wastewater and soil environment and its resistance to ph variations, there was little increase. Moreover, the treatment containing the wastewater was led to increase Sodium Absorption Ratio (SAR) in the surface layer of soil. However, this effect was more in treatments which that have benefited the fertilizer and wastewater. Also, variations of Bicarbonate , Sulfate and accumulation B , sodium;Na, ferro;Fe, zinc;Zn, copper;Cu, potassium;K and magnesium;Mg, to a depth of 30 cm of soil and also the accumulation of nitrogen, calcium, phosphorus in the depth of soil in an area under studying was increased significantly due to irrigation with wastewater and irrigation fertilizer comparing to urban water. As expected, using the wastewater increases the concentration of heavy metals of nickel, lead and cadmium in under studying soil area.
Research Article
H. Asakereh; R. Khoshraftar; F. Sotudeh
Abstract
Rainfall and debit of rivers are two tempo-spatial non-linear and changeable factors. One way to study and analysis these parameters is investigate appearance and latent oscillations. Spectral Analysis is a useful technique to reveal these oscillations in time series. In this paper it has been attempted ...
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Rainfall and debit of rivers are two tempo-spatial non-linear and changeable factors. One way to study and analysis these parameters is investigate appearance and latent oscillations. Spectral Analysis is a useful technique to reveal these oscillations in time series. In this paper it has been attempted to detect cycles in rainfall and debit time series at Mashinkhaneh station in Talesh (Garakanrood) catchment’s during Mehr 1354 to Shahrivar 1386 in the three time scales (annual, seasonal and monthly). Accordingly, the discharge and precipitation data at Mashinkhaneh station in Talesh (Garakanrood) catchment from Mehr 1354 to Shahrivar 1386 have been used. The results of applying the spectral analysis procedures to discharge and rainfall time series in each three category of time scales, suggested the absence of significant non-sinusoidal (trend) in the 95% confidence level. However, significantly sinusoidal cycles various in the two time series were extracted. The 2-4 year cycle, and 4-5.3 years have the most occurrences in the both time series. In the annual scale, 6.4 years cycle, 2-5.3 years, 7.7 years seasonal and 2-4, 4- 5.3, 6.4, 8, 10.7 and 16 year in the monthly scale cycles has been extracted. Studies carried out by many researchers indicate that the mentioned cycles are in relation with oscillation periods of ENSO, NAO and QBO in other parts of the world.
Research Article
S. Abdollahi; M. A. Delavar; P. Shekari
Abstract
Increasing soil pollution due to heavy metals is a major concern of present day soil research. This study conducted to know intensity and spatial pattern of soil heavy metals pollution in a 10,000 ha area of Anguran region near Zanjan. A number of 315 surface (0-10 cm) samples collected at nodes of a ...
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Increasing soil pollution due to heavy metals is a major concern of present day soil research. This study conducted to know intensity and spatial pattern of soil heavy metals pollution in a 10,000 ha area of Anguran region near Zanjan. A number of 315 surface (0-10 cm) samples collected at nodes of a 500 meter equilateral grid. Beside HNO3-extracted Pb, Cu, Ni, Cd and Zn content, EC, pH, OC and CaCO3 of the samples were determined. To classify data in taxonomic space, a fuzzy c-means with extragrades clustering algorithm ran on the data using several fuzziness exponents (Φ). Plausible fuzzy clusters obtained at Φ=1.3. To find eight as the optimal number of classes from a 2-10 assemblage, fuzziness validation functions F, H, and S were used. Scrutiny of class centroids and membership values revealed that though number of variables was not numerous, the algorithm clustered data sensitively. Spatial distribution of classes mapped through geostatistical analysis of membership values. Though extragrade class embraced extreme values, still all centroids of regular classes showed severe pollution. Most polluted classes C, E, F and H located at center to southeast, while A, B, D and G covered northern and western parts of the study area. Extragrade class widely spread in the area that confirmed interspersed outliers among all others. Major part of extragrade class lied across southeastern part of the area. Results of the study showed that numerical classification of soil pollution is rather realistic, thus provides a pragmatic approach to the problem.
Research Article
M. Ghaemi Baygi; mahmood raeini; M. Mousavi Baygi
Abstract
Evapotranspiration is one of the important elements of the hydrologic cycle in agricultural projects. Energy balance (the bowen ratio) is a method for estimating evapotranspiration of plant which is based on measurements of temperature and humidity gradients in two different heights of a plant. An experiment ...
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Evapotranspiration is one of the important elements of the hydrologic cycle in agricultural projects. Energy balance (the bowen ratio) is a method for estimating evapotranspiration of plant which is based on measurements of temperature and humidity gradients in two different heights of a plant. An experiment was conducted in agriculture faculty of Ferdowsi university of Mashhad by using three Lysimeter to estimate evapotranspiration of Gascogne wheat and the resulting were compared with direct method. Required data for measuring the amount of evapotranspiration using energy balance method was obtained throughout plant phenology with one hour intervals using energy balance (model 5200 – DIK) estimation device of evapotranspiration was daily calculated. The rate of daily evapotranspiration that obtained by using energy balance method amounted to 2.4 mm which is in a high correlation (0.98) with the Laysimeter result that was 2.4 mm. The range of Bowen ratio changes was between -1.5 to 1.9 during the day which the negative values occurs after sunset that is the sensible heat flux begins to decrease. The value of Boven ratio gradually increase so that it's maximum value between 8 AM to 9 AM, and then followed a decreasing trend until the afternoon.
Research Article
M. Heydarizad; Hossein Mohammadzadeh
Abstract
Abstract
Karde river is one of the most important river in Khorasan Razavi province which provides potable water for 3 million inhabitant of Mashhad city. The following research shows seasonal and spatial fluctuation in water quality. Investigating the chemical analysis of Karde rivers water shows that ...
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Abstract
Karde river is one of the most important river in Khorasan Razavi province which provides potable water for 3 million inhabitant of Mashhad city. The following research shows seasonal and spatial fluctuation in water quality. Investigating the chemical analysis of Karde rivers water shows that precipitation chemistry doesn't have significant role in the chemistry of river because there is no industrial activity in the region when the Anthropogenic recourses caused by (agricultural fertilizers and sewage) and lithology of the basin have their own roles. Anthropogenic resources has dominant role in late spring and summer when the concentration of NO3-, SO42- and Cl- increases dramatically by chemical fertilizers used in the basin. On the other hand, the concentration of the Ca2+, Mg2+, SO42- and HCO32- in water analysis, Factor analysis and hydrochemical graphs show that dissolution of the carbonate minerals in Mozdooran formation and evaporative and silicate minerals in Shorije formation plays dominant role in the chemistry of the Karde river. Identification of dissolved Carbonate and silicate minerals with ion activity(α) and Log(aCa2+/a(H+)2) versus Log(aMg2+/a(H+)2) graph for Carbonate minerals and Log(aMg2+/a(H+)2) and Log(aCa2+/a(H+)2) versus Log (aNa+/a(H+)2) for silicate minerals show that carbonate minerals " Calcite and Dolomite" and silicate minerals " Kaolinite, Laumontite and Clinochlore beside sulfate mineral "gypsum" are the dominate dissolved minerals in the river.
Research Article
A. Mohseni; H. Mirseyed Hosseini; F. Abbasi
Abstract
Fertilizing method plays an important role in fertilizer and water use efficiency and plant yield and losses fertilizer. A field experiment was carried out at 16 treatments with factorial a complete randomized block design during 2010 for free drainage furrows. First factor was four levels of water (60, ...
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Fertilizing method plays an important role in fertilizer and water use efficiency and plant yield and losses fertilizer. A field experiment was carried out at 16 treatments with factorial a complete randomized block design during 2010 for free drainage furrows. First factor was four levels of water (60, 80, 100 and 120% of full irrigation) and second factor was four levels of fertilizer (0, 60, 80 and 100% of required fertilizer) for fertigation method. The 16 treatments mentioned above, were compared with common fertilizing method. Nitrogen requirement was applied in four stages of the growth: before cultivation, in seven leaves, shooting and earring stages, the first portion (before cultivation) was applied by manual distribution and others by fertigation. In conventional treatment, the whole of required fertilizer was used in two split applications (before planting and in seven leaves). Results showed, the highest yield, yield component and use efficiency of corn was obtained on 100% irrigation and 100% fertilizer treatments. While the highest amount percolation of nitrate into soil was related to conventional treatment.
Research Article
S. Fallah; Fayez Raiesi
Abstract
The effects of organic and inorganic N sources on nutrient (N and P) efficiency under the water-stressed conditions have not yet been determined. Thus, a field study was conducted to determine the influence of N from different sources along with drought stress on nutrient efficiencies of maize. Main ...
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The effects of organic and inorganic N sources on nutrient (N and P) efficiency under the water-stressed conditions have not yet been determined. Thus, a field study was conducted to determine the influence of N from different sources along with drought stress on nutrient efficiencies of maize. Main plots consisted of two irrigation treatments (i.e., optimum irrigation and cut-off irrigation at silking stage for two weeks), and subplots comprised N fertilizers (cattle manure: 40.8 Mg ha-1, poultry manure: 13.3 Mg ha-1, urea fertilizer: 435 kg ha-1, cattle manure + urea fertilizer: 20.4 Mg ha-1and 20.4 Mg ha-1, respectively) and control (without fertilizer). Results indicated that the imposition of water deficit and fertilizer type had a significant effect on N uptake while P uptake was significantly affected only by fertilizer type. The highest N and P uptake were obtained with poultry manure. Similarly, significant differences in N and P use efficiency and N physiological efficiency were observed between the water deficit and fertilizer type (P
Research Article
R. Mansouri; K. Esmaili; A.N. Ziaei; Hossein Ansari; S. R. Khodashenas
Abstract
In arid and semi-arid regions, collection of surface and subsurface waters in small seasonal rivers is very crucial, particularly in dry seasons. The cost of construction and maintenance of classical water intakes makes them inappropriate for these rivers. In this study a rather new method to divert ...
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In arid and semi-arid regions, collection of surface and subsurface waters in small seasonal rivers is very crucial, particularly in dry seasons. The cost of construction and maintenance of classical water intakes makes them inappropriate for these rivers. In this study a rather new method to divert surface and subsurface water is experimentally evaluated. In this kind of intakes, a couple of trenches are excavated and the drain pipes are installed in them and then filled with very porous materials. Indeed the system acts as a river drainage network. This method not only reduces the construction and maintenance costs but also minimize the disturbance of river topology and morphology. Therefore this intake is also suitable for rivers with high sedimentary loads. In a few small rivers in Khorasan Razavi province, Islamic republic of Iran, such systems have been installed but their design and applicability have not been evaluated. In this research, experimental model of the intake to collect flow was built for flow diversion and flow rate deviation examined. Results showed a direct relationship between flow diversion with water level and with increasing distance between the drainages, the drainage flow increases. Drainage flow in the porous medium is initially decreased and then increased and drainage flow is the lowest in the middle drainage. In the review drainage arrange, the drainage of two deep with shorter porous medium is more suitable. Finally, regression mathematical model for the structural design of the intake subsurface with porous medium and drainage system were presented.
Research Article
S. M. Hosseni; A. Mosaedi; K. Naseri; A. Golkarian
Abstract
Rill erosion due to run off on hill slopes is a kind of water erosion which causes the highest soil loss in world-wide scale. Since the length of hill slope is one of the most effective factors in erosion, in this research, the variation of width, depth, cross-section, and frequency of rills were evaluated ...
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Rill erosion due to run off on hill slopes is a kind of water erosion which causes the highest soil loss in world-wide scale. Since the length of hill slope is one of the most effective factors in erosion, in this research, the variation of width, depth, cross-section, and frequency of rills were evaluated on the length of hill slops. In addition, soil components were evaluated due to the variation of hill slope length. Some hill slopes with pronounced rills were chosen in Ahmad-Abad location and on each slope, fifty-meter –transect was selected with the distances of 10, 20, 30, 40 and 50 meters and the features of rills were measured. As the routine models of linear regression have not been fitted to the observed data, the incomplete gamma function was used to obtain logical relation between hill slope length and mentioned parameters. Therefore, this model were fitted well to all parameters, except to the frequency of rills and the mean amounts of clay (p
Research Article
Sh. Kiani
Abstract
A pot experiment was conducted to elucidate the effects of nitrification inhibitor (NI) 3, 4-dimethylpyrazole phosphate (DMPP) on the nitrogen uptake, yield components, yield and grain protein content of spring wheat (Triticum aestivum L.) cv. Bahar during 2011 at ShahreKord University. A factorial experiment ...
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A pot experiment was conducted to elucidate the effects of nitrification inhibitor (NI) 3, 4-dimethylpyrazole phosphate (DMPP) on the nitrogen uptake, yield components, yield and grain protein content of spring wheat (Triticum aestivum L.) cv. Bahar during 2011 at ShahreKord University. A factorial experiment in randomized complete block design was carried out with two factors of type of N fertilizer (1- control with no added N fertilizer, 2-urea 3- ammonium sulphate nitrate (ASN) and 4- ASN plus DMPP) and soil type (10 soils) with three replications. The results indicated that application of nitrification inhibitor DMPP with ASN led to significant increase (P
Research Article
M. J. Nasr Esfahani; M. Shafai Bajestan
Abstract
Abrupt drop is a sudden lowering of the channel bed which is done for reduction of hydraulic jump length and to ensure that the jump will not be shifted outside the basin for various flow conditions. This type of basin is used in irrigation and drainage networks as an effective measure for dissipation ...
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Abrupt drop is a sudden lowering of the channel bed which is done for reduction of hydraulic jump length and to ensure that the jump will not be shifted outside the basin for various flow conditions. This type of basin is used in irrigation and drainage networks as an effective measure for dissipation of kinetic energy. Since the roughened bed of basin also can reduce the stilling basin length, the use of both abrupt drop on bed and roughness can reduce the jump length even more. Therefore it is the main goal of this study to conduct experimental tests on a large scale model to see how the roughness can affect on jump characteristics. To reach such goal tests conducted on a flume of 80cm wide, 15m long and 60cm high. The flow discharge ranged from 56lit/sec to 230l/sec providing Froude number in the range of 2.5 to 9.0. The results of this study show that the jump length reduces to about 36% of classical jump length. In comparison with jump in smooth bed of abrupt drop, the amount of reduction reaches as high as 53%. The observation al results show that the location in which the jump starts, is almost constant in all tests and the sequent depth ratios have almost the same value as in classical jump.
Research Article
Z. Rashidi Koochi; I. Esfandiarpoor Borujeni; A. Abbaspour; A. Kamali; A.A. Naderi
Abstract
Geopedology is a systematic approach to analyze the geomorphic levels for soil mappingwhich organizes natural terrains in a hierarchical order in accordance with their scale. Hereon, the effect of mapping scale and kinds of soil classification system on the reliability of the geopedologic approach was ...
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Geopedology is a systematic approach to analyze the geomorphic levels for soil mappingwhich organizes natural terrains in a hierarchical order in accordance with their scale. Hereon, the effect of mapping scale and kinds of soil classification system on the reliability of the geopedologic approach was investigated. In view of that, after air-photos interpretation (1:55,000 and 1:40,000 scales) of an area (1500 ha) on the east of Damavand, two similar delineations (named A and B) were selected on the geoform map. Then, some pedons were dug in the similargeoforms based on semi-detailed soil surveys. The pedons were classified up to the family level according to Soil Taxonomy and up to the subunit level (including suffix and prefix qualifiers) based on WRB soil classification systems. This was the conducted when description and sampling from all genetic horizons and physical and chemical analyses had been already done. The results showed that mapping scale affected the results of the geopedologic approach significantly, so that relative similarity in all taxonomic levels was lower in 1:40,000 scale than the 1:55,000 scale for all studied pedons. Besides, Soil Taxonomywas more adaptable than WRB in predicting the relative similarity among soils in the same geoforms. On the whole, the geopedologic approach is still not able to estimate and determine the complete variability of soils and define their chaotic nature precisely, and the performance of this approach is limited to semi-detailed surveys and smaller ones.
Research Article
V. R. Verdinejad; H. Ebrahimiam; H. Ahmadi
Abstract
A transient drainage simulation model, SWAP, was used to evaluate the performance of subsurface drainage system. SWAP model was calibrated by measured daily data including water table depth, drain discharge rate and soil and water drain salinity collected from Behshahr Ran drainage system for 120 days ...
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A transient drainage simulation model, SWAP, was used to evaluate the performance of subsurface drainage system. SWAP model was calibrated by measured daily data including water table depth, drain discharge rate and soil and water drain salinity collected from Behshahr Ran drainage system for 120 days during 1385. Calibration of SWAP model was done by inverse modeling via linking with WinPEST model. In order to calibrate drainage quantity parameters, two objective functions were defined to minimize difference between measured and simulated values of the water table depth and drain discharge rate, simultaneously. To calibrate drainage quality parameters, another objective function was also defined to minimize difference between measured and simulated values of soil salinity. There were good agreements between measured and simulated values of drain discharge rate and water table depth. The absolute error of estimation was 7 and 4 % for water table depth and drain discharge rate, respectively. Measured cumulative drainage was 7.5 % (5.3 mm) greater than its simulated value. The SWAP model could also simulate soil and drainage water salinity with a reasonable accuracy. The results of this study indicated that the performance of the SWAP model could be considerably improved using inverse modeling.
Research Article
M. Ghorbani Aghdam; yaghoub dinpazhoh; A. Fakheri Fard; S. Darbandi
Abstract
Having a correct view of the effective factors on climatic changes by explanation of a considerable part of the total variance in data with limited number of principal components the analytical methods of decreasing data dimensions, such as PCA are important tools in water resources planning. In this ...
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Having a correct view of the effective factors on climatic changes by explanation of a considerable part of the total variance in data with limited number of principal components the analytical methods of decreasing data dimensions, such as PCA are important tools in water resources planning. In this study factor analysis method as a tool for projecting the information space on the limited and specific axes, has been applied. The main aim of this study is regionalization of Urmia Lake basin from the view of drought using factor analysis. For this purpose monthly precipitation data of 30 weather stations in the period 1972-2009 were used. For each of the selected stations three and twelve months SPI value were calculated. Factor analysis conducted on SPI values to delineate the study area with respect to drought characteristics. Homogeneity of obtained regions tested using the S-statistics proposed by Wiltshire. Resultes of factor analysis of 3 (12) months SPI values showed that 5 (6) factors having eigen values greater than 1 acounted for 68.08 (78.88) percent of total variance. Urmia Lake basin delineated to 5 (6) distinct regions considering the eigenvectors following rotation using the 3 (12) month time scale. Results of homogeneity test indicated that all of the obtained regions were homogeneous.
Research Article
M. Aghajani; Maryam Navabian
Abstract
Water for rice cultivation is one of the main inputs. The new administration of irrigated rice is increase water efficiency and water conservation in the paddy fields. In this research, for optimization of intermittent irrigation management in proportion to water requirement of different stages of rice ...
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Water for rice cultivation is one of the main inputs. The new administration of irrigated rice is increase water efficiency and water conservation in the paddy fields. In this research, for optimization of intermittent irrigation management in proportion to water requirement of different stages of rice growth was present an optimization- simulation model to maximize irrigation water, transpiration and evapotranspiration productivity Indexes. Irrigation water depth in stages of tiller, vegetative, maturity, harvest and irrigation intervals were selected as decided values in optimization model. Simulation of plant growth stages, using the hydrological model SWAP and genetic algorithm was used to solve the optimization model to maximize agricultural productivity. Finally, the optimum amount of irrigation water productivity, transpiration and evaporation - transpiration were obtained 1.60, 2.90 and 1.33(kg/m3) respectively. Results showed, irrigation water productivity index has more harmonize with Sefidroud irrigation network. Also the index is user-friendly in applying and calculating. So according to maximizing of water productivity index irrigation depth was recommended 51, 29, 39 and 11 mm respectively in stages of tiller, vegetative, maturity, harvest and and 8 days period of irrigation intervals to improve water productivity index in Hashemi variety in Rasht. Optimization results showed optimal intermittent irrigation is successive compared with flood irrigation in rice.
Research Article
R. Ghafourian; A. Bagherian kalat; A. Gord Noushahri
Abstract
Part of water flowing downstream in rivers, infiltrates into the bed river. Infiltrated water depends on morphologic and hydraulic characteristic of the rivers. Planners and managers want to know the amount of water infiltrates into the bed and consequently recharges ground water. In this study three ...
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Part of water flowing downstream in rivers, infiltrates into the bed river. Infiltrated water depends on morphologic and hydraulic characteristic of the rivers. Planners and managers want to know the amount of water infiltrates into the bed and consequently recharges ground water. In this study three rivers of Kashaf rud river basin, namely Ferizi, shandiz (Zoshk) and Golestan, were selected and their discharges were measured during period of 2009-2011 at the beginning and the end of a selected reach in each of the mentioned rivers by a current meter. Then transmission losses (TL) of the reaches were computed by subtracting the measured discharges. By surveying longitudinal profile and cross sections of the reaches and running the Hec-Ras model, wetted perimeter was determined for every discharge measurement for three selected reaches. Analysis of data showed that there is a significant exponential relationship between TL and the measured discharge at the beginning of the reach and wetted perimeter for one kilometer of the reach. The results showed that the percentage of TL decreases with increasing of the discharge in each river. As well as TL rate decreases from west to east; on the other hands in Ferizi river is the most and in Golestsn river is least. Developing an exponential model which is independent of the wetted perimeter, is one of the other results of the research.
Research Article
H. Naveh; K. Khalili; M. T. Alami; J. Behmanesh
Abstract
One of the important tools in modeling and forecasting of hydrological processes, is using and analysis of time series. The generated river flow series by using time series models have been used in many researches such as drought, flood periods, reservoir systems design and other purposes. The use of ...
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One of the important tools in modeling and forecasting of hydrological processes, is using and analysis of time series. The generated river flow series by using time series models have been used in many researches such as drought, flood periods, reservoir systems design and other purposes. The use of nonlinear time series is very useful in river flow forecasting because of nonlinear river flow behavior in different spatial and time scales. The purpose of this study is to investigate the efficiency of bilinear nonlinear time series model in river flow forecasting. In this research monthly flow of Shahar-Chai and Barandouz-Chai rivers located in West Azarbaijan for duration of 31 and 39 years respectively were used. Despite of simplicity of bilinear nonlinear model, the results showed that this model had high efficiency in modeling and forecasting of two rivers and presented best results from ARMA model. The error of fitted model of Barandouz-Chai (1.605) was less than the model fitted for Shahar-Chai river (1.920). The reason may be due to longer data period for Barandouz-Chai river or it’s recharge from springs and ground waters.
Research Article
A.A. Abbasi; M. Malek Nejad Yazdi
Abstract
In river engineering, determination of flow resistance is essential. Various empirical methods have been suggested for estimating bed roughness coefficient by researchers. However, these methods can only be applied to Special River. In this study, flow conditions and river geometry data were obtained ...
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In river engineering, determination of flow resistance is essential. Various empirical methods have been suggested for estimating bed roughness coefficient by researchers. However, these methods can only be applied to Special River. In this study, flow conditions and river geometry data were obtained from the Ferizi river. In this section flow must be uniform, turbulent, hydraulically roughness and without vegetations or obstacles and bed forms, until could ignore from effects of this cases and could assume that the flow resistance is only due size of particle sediment. The result showed in addition particle sediment the hydraulic behavior is effective on calculating for flow resistance coefficient. For this reason after the dimensional analysis the flow resistance coefficient (n) will be inversely proportional to the Froude number. Also the relation is obtained estimate the flow resistance coefficient (n) with more accuracy (R2=0.993).
