Prediction of Hydraulic Jump Characteristics on Rough Bed Using Artificial Neural Network and Genetic Programming
text
article
2014
per
In the present research the hydraulic jump characteristics such as depth and length of the jump on rough beds as functions of roughness height and initial Froude number were simulated using artificial neural network (ANN) and genetic programming (GP) models. In the experiments, initial Froude numbers and roughness ratios were in the range of 1.9 to10 and 0.085 to 2.025, respectively.
Totally, 454 sets of the observed data were used in training and testing process of the proposed ANN and GP models. The results of the both artificial neural network and genetic programming models had good agreements with the measured data. Also the results of these models were compared with the known empirical equations for rough beds. It was shown that the ANN and GP models had less computational errors than the empirical equations. Also, the outputs of the GP model were presented in the form of mathematical equations and tree graph.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
1
10
https://water-soil.tabrizu.ac.ir/article_1661_ce5ded3a4f04e19a7decb4e53feeec43.pdf
Modeling Scour around a Spur Dike in Bends Using Fuzzy Logic
and Artificial Neural Network
Mehdi
Daryaee
author
S Mahmood
Kashefipour
author
Alireza
Faghiheslam
author
Javad
Zahiri
author
text
article
2014
per
Spur dike is a structure made of stone, sand, rock, soil or concrete, which is usually built with an angle relative to the bank to divert the flow from the banks and concentrate it towards the centerline of the river in order to prevent bank scouring. One of the main problems regarding this structure is its stability due to possibility of the scouring around the nose of structure. Therefore modeling the amount of the scouring around the structure according to the flow conditions is important and essential. In this research the laboratory data of scouring around a spur dike for different flow conditions in a 180° bend were applied for modeling this phenomenon using Fuzzy Logic model (FLM) and Artificial Neural Network (ANN). The scour was modeled as a function of the length and the installation angle of spur dike in bend, and the upstream Froude number. The results showed that the ANN and FLM models were able to predict the amount of scouring, accurately. A regression equation was also developed for describing the amount of scouring around the spur dike using the corresponding measured values empolyed for producing and calibrating the pattern of the ANN and FLM models. The results obtained from ANN, FLM and regresion models were then compared together using another series of existing data, which had not been applied for developing those models.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
11
20
https://water-soil.tabrizu.ac.ir/article_1662_871dfcc5d5be170bb8190e81d3309b76.pdf
Experimental Investigation of the Effect of a Semi-Cylinderical Structure on increasing Pressurized Sediment Flushing Capacity in Reservoirs of Dams
Moahammad Naser
Mohammadi
author
Farzin
Salmasi
author
Ali
Hosseinzadeh Dalir
author
Hadi
Arvanaghi
author
text
article
2014
per
Pressurized sediment flushing is one of the methods for removing deposited sediment in reservoirs of dams. In this method, by opening the bottom outlet, deposited sediment in the vicinity of the bottom outlet is flushed out. In this study by performing experiments on a physical model, the effect of a semi-cylindrical structure in front of a bottom outlet on increasing pressurized sediment flushing capacity was investigated. The Semi-cylinderical structure used in the experimnts was closed at the upper side and had an opening width equal to the bottom outlet diameter at the upstream. Also in the all experiments the height of the structure was six times greather than the bottom outlet diameter and the level of the sediment layer was tangent to the bottom outlet. The experiments were conducted with four different discharges released from the bottom outlet, three water depths above the bottom outlet and four diameters of the semi-cylinderical structure. The results of the Experiments indicated that using a semi-cylinderical structure can increase sediment flushing capacity up to 10 times in contrast to nonstructured case. For a fixed depth of water, an increase in outflow discharge increased scour cone depth. Also for a fixed amount of outflow discharge and structure diameter, changes in water depth had almost no effect on scour cone depth. Also the results indicated that at a constant water level for each outflow discharge there was a proper diameter for the semi-cylinderical structure.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
21
30
https://water-soil.tabrizu.ac.ir/article_1663_69b061c290ad0329b8f72b6b57e65958.pdf
Effect of Freeze - Thaw Cycles on Hydraulic Conductivity of Compacted Clayey Soil and Geosynthetic Clay Liner (GCL)
Kazem
Badv
author
Mehdi
Gholikhani
author
text
article
2014
per
The effect of freeze-thaw cycles on hydraulic conductivity (HC) of compacted clay liner (CCL) and geosynthetic clay liners (GCLs) in water retaining structures and municipal solid waste landfills is a key issue in designing barrier systems in those structures. In this study the effect of freeze-thaw cycles on the hydraulic conductivity of a compacted clayey soil from Nazlou Region of Urmia City and a geosynthetic clay liner; and the impact of effective stress on the hydraulic conductivity change of clayey soil in these cycles were investigated. A flexible-wall triaxial hydraulic conductivity apparatus was used to measure the HC of the specimens subjected to freeze-thaw cycles. During the freezing process ice lenses grow in soil sample and when the ice lenses melt, a network of cracks is left and the HC increases. Increasing the effective stress reduces the increased hydraulic conductivity due to freeze-thaw cycles. The results show that on the contrary to compacted clayey soil, the application of intermittent freeze-thaw cycles does not significantly affect the HC of GCL even when GCL sample is subjected to extreme climatic conditions during which it continues to exhibit good performance as a hydraulic barrier.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
31
40
https://water-soil.tabrizu.ac.ir/article_1664_d7e6a4480010bc80f592f2a5e628727d.pdf
Relation between Atterberg Limits and Interrill Erodibility
of Semi-arid Area in East Azerbaijan Province
Abbas
Ahmadi
author
Elham
Talaie
author
Reza
Soukoti Oskoui
author
text
article
2014
per
Atterberg limits are indicators of soil moisture that show consistency of soil at various states. This study was conducted to investigate the relationship between interrill erodibility and soil Atterberg limits. For this reason 26 soil samples with contrasting properties were collected from four regions of East Azerbaijan province. The sand, silt and clay fractions were determined by the combined sieve- hydrometer method. Atterberg limits were determined according to the standard ASTM method (by Casagrande and hand rolling methods). A rainfall simulator with drainable tilting flume (1×0.5 m) at slope of 9% was employed and interrill erodibility coefficient of the soil (Ki) was calculated at 20, 37, and 47 mm/h rainfall intensities. Results showed that the effect of rainfall intensity on soil interrill erodibility coefficient was insignificant (P˃0.05). Regression relations between Ki and Atterberg limits and other soil properties were developed by STATISTICA software. Ki was estimated using clay, soil organic matter (SOM), sodium adsorption ratio (SAR) and pH as predictors and this regression model could explain 75% of the variance in Ki. Results also showed that there was a direct positive relationship between Atterberg limits and SOM and clay content of the soil. According to the results, the Atterberg limits couldn’t be a suitable predictor for estimating the interrill erodibility coefficient of the soils.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
41
51
https://water-soil.tabrizu.ac.ir/article_1665_53ae33697ead19c3148715e5d0f87e08.pdf
Effect of Water Deficit Stress at Various Growth Stages on Yield, Yield Components and Water Use Efficiency of Five Rapeseed (Brassica napus L.) Cultivars
AliAkbar
Sadeghinejad
author
S Alimohammad
Modarres-Sanavy
author
S Ali
Tabatabaei
author
S Morteza
Modares Vaneghi
author
text
article
2014
per
In order to study the effect of water deficit stress at various growth stages on yield, yield components and water use efficiency of rapeseed (Brassica napus L.) cultivars, a field experiment was conducted as split-plot in a randomized complete block design with three replications during 2009-2010 growing seasons in Abarkouh, Iran. Full irrigation based on four different soil water depletion regimes were applied to the main plots including: 40% of available water depletion (AWD) during full growth period (I1), 80% of AWD during stem elongation stage to maturity (I2), 80% AWD from flowering stage to maturity (I3) and 80% AWD from seed filling stage to maturity (I4). Five rapeseed cultivars as sub plot units including: Hayola401, Zarfam, Modena, Sarigol and Option500 were investigated. Analysis of variance showed that there were significant (P≤0.01) differences among irrigation levels for yield, yield components and water use efficiency. In this study, insufficient soil moisture at the three growth stages, reduced yield components such as seed number per pod and 1000-seed weight by 13.3% and 15.6%, respectively, and led to reduced seed yield as much as 21.4% compared to the control. Reduction of seed yield in each three treatments I2, I3 and I4 was mainly due to reduction in pods and seeds per pod. Water use efficiency decreased more in I2, I3 and I4 treatments than the control. Among the cultivars, Hayola401 had the highest water use efficiency. Statistical comparisons showed that Zarfam cultivar produced the highest seed yield (4006 kg ha-1) and Option500 produced the lowest seed yield (2515 kg ha-1).
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
53
64
https://water-soil.tabrizu.ac.ir/article_1666_9b7ff82c681d5e8b75062c1a9c9a095b.pdf
Taxonomic and Genetic Pedodiversities on Different Geomorphic Units in Marand Region, East Azarbaijan
Ayda
Abbasi
author
Aliasghar
Jafarzadeh
author
Mostafa
Karimain eghbal
author
Shahin
Oustan
author
Ahmad
Jahangiri
author
text
article
2014
per
In this research work, taxonomic richness and pedodiversity were used for studying soil evolution on rock pediment, mantled pediment, piedmont plain and alluvial plain geomorphic units and genetic richness was also used to evaluate the effect of classification system on genetic pedorichness in Marand region. 26 pedons were excavated and sampled in different geomorphic surfaces. Calculation of indices was done considering soil individuals and soil type areas at different levels of USA Soil Taxonomy System (order, family) as well as diagnostic horizons. Soil richness at the level of order increases from rock pediment to alluvial plain and alluvial plain with four suborders is the richest geomorphic unit. The index shows only a little difference between great group and subgroup in mantled pediment and piedmont plain and at the family level, indices increase in all geomorphic units except alluvial plain. The number of taxa increases from order to family level and rock pediment has the least richness by impossibility of deposition processes. The taxonomic diversity index on each geomorphic unit increases from order to family by increasing in taxa richness and diversity indices calculated based on pedon numbers are higher than those based on area coverage. Cambic horizon is the most dominant horizon in the study area and piedmont plain is genetically the richest geomorphic unit. Genetic pedodiversity depends on soil classification system and soil taxonomy system tries to homogenize the soils in geomorphically active regions.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
65
79
https://water-soil.tabrizu.ac.ir/article_1667_18d4da8b5d48deb84934f3b86160e48a.pdf
Effects of Upward Seepage on Scour Depth Downstream of the Free Falling Jets
Mahmood
Shafaei Bejestan
author
S Mojtaba
Razavi Nabavi
author
text
article
2014
per
In the present study the effect of upward seepage on scour depth downstream of the vertical jet such as grade control structure has been experimentally investigated. To reach such goal two series of tests without and with the presence of upward seepage using three different sediment sizes, three different flow discharges and three different tailwater depths were carried out at the hydraulic laboratory of Water Research Organization. For the second series of tests five different upward seepage discharges ranged from 1.5 to10.5 liters per second were applied. The resulting data showed that by applying upward seepage, the scour depth decreased. The amount of decrease was found to be dependent on the sediment size, tailwater depth and upward seepage discharge. The rate of decrease for higher seepage discharge, lower tailwater depth and small particle size was high. The present results were compared with the results of previous research on horizontal jet without horizontal apron and was found in good agreement due to flow pattern similarity while our results were in disagreement with the results of previous research on horizontal jet with horizontal apron. To find the reason, three components of flow velocities inside the scour hole were measured using a Magnetic Doppler velocity meter for both cases of with and without upward seepage. The plots of the vertical flow velocity component showed that when the upward seepage was applied, the down flow velocity near the bed decreased up to 47%. The decrease of this velocity component could cause the lift force to decrease which eventually could reduce the scour depth. Relations for scour depth prediction under the effect of upward seepage were presented.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
81
92
https://water-soil.tabrizu.ac.ir/article_1668_38744a668540e093c0b0cf38c6056ee0.pdf
Land Suitability Evaluation for Alfalfa in Khajeh Region Using the Parametric Square Root method and Fuzzy Set Theory
Moslem
Servati
author
Aliasghar
Jafarzadeh
author
Mohammadali
Ghorbani
author
Farzin
Shahbazi
author
Naser
Davatghar
author
text
article
2014
per
One of the best agricultural policies in developing countries for food security is the evaluation of arable lands and agricultural potential to support the current and future agricultural uses. FAO framework for lands suitability evaluation uses a Boolean mapping approach which has been criticized by a number of authors, because the Boolean representations ignore the continuous nature of soil, landscape variation and uncertainties in measurement. In this research, the parametric Square Root Method via a Fuzzy Set Theory was used to evaluate the suitability of alfalfa for 7335 ha lands in Khajeh region located in East Azerbaijan province. The analysis was done with MATLAB analytical software. The results revealed that, calculated correlation coefficients values between the land index and yield with fuzzy method was (r= 0.917) more than that with the Parametric method (r= 0.685) and relatively large difference in calculated correlation coefficients revealed that, there was a need for calibration of the Sys proposed tables about requirements of the climate, landscape and soil in this region. Based on the suitably selected transition zone, MATLAB Software was able to accurately estimate the weights. Although the fuzzy approach provided better results than the parametric square root method, but its results surely depended on the type and determination of the transition zone and membership functions.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
93
105
https://water-soil.tabrizu.ac.ir/article_1669_9734de457dc3e8627574d307fde331ce.pdf
Assessment of Some Heavy Metals in Paddy Soils and their Accumulation in the Organs of Rice in the Lenjan Area of Isfahan Province
Ghasem
Rahimi
author
Amin
Charkhabi
author
text
article
2014
per
In recent years, the accumulation of toxic heavy metals in grown rice at contaminated soil has led to a major concern. Accordingly, the quantities of heavy metals (Cd, Cu, Fe and Mn) were measured in soil, water and different parts of rice plants (Oryza sativa L.) cultivated (90, 6 and 41 samples, respectively) in Lenjan region. The studied area is located in Esfahan province and is exposed to various contaminants. The results showed that the concentrations of Cd in the water samples (0.005 mg/L) were less than the standard level (0.01 mg/L). However, its long term cumulative effects should be considered. The concentrations of Cu (23.4 mg/L), Fe (12708 mg/L) and Mn (108.9 mg/L) in roots of rice plant were higher than their standard limits (20, 450 and 100 mg/kg, respectively). Also, the concentrations of Cd in the root, straw and grain (1.6, 1.1 and 1.3 mg/kg, respectively) of rice were higher than the standard limit (0.3 mg/kg), so it is more important for consumers, particularly local residents, to pay special attention to that. Transfer factors (TF) of Cu and Mn ions in different parts of rice plants showed that they were probably controlled by external factors such as atmospheric deposition in the region, because their mobilities were relatively low in the plants. The accumulation of Cu was the highest in the aerial part of rice plants in Chamgordan region which could be due to short distance of the region from the foundry smokestacks. Therefore, in addition to the effect of soil properties, human activities have a significant impact on the concentrations of the studied metals, which should be considered to achieve sustainable agriculture in the area.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
107
120
https://water-soil.tabrizu.ac.ir/article_1670_33495edef1be9c2cffebfd6c7e8d44fc.pdf
Rainfall-Runoff Simulation Using Grey System Theory (Case Study: Lighvan Watershed)
Reza
Mokarian
author
Ahmad
Fakherifard
author
Mohammad ali
Ghorbani
author
text
article
2014
per
Grey system theory plays a role in prediction of events which have less observational statistics noting its mathematical basis, and in hydrology it might remove the problem of data insufficiency. In this study, the simulation of rainfall-runoff process was done by Grey system theory with the Mathematica software using the data of six corresponding events of rainfall-runoff hyetographs and also hydrometric data of Tabriz station in Lighvan zone. We used the least sum of squares method to calculate the differential and hydrological Grey Model equation (DHGM) and Grey parameters ( and and ). We found the mean values of those parameters as 0.1012365, -0.07836 and 0.200251 respectively. Simulated results were evaluated for the events that had happened in the dates of 25 May 2003 and 21 June 2003 and we obtained (R2, RMSE, VE %) parameters as (0.89, 0.22, 42%) and (0.75, 0.12, 38%) respectively. Using the obtained parameters, the model was tested for two additional events. The comparison between the obtained results by the correlation coefficient index and the least-squares error indicated good efficiency of the Grey model in simulation of rainfall-runoff process.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
121
133
https://water-soil.tabrizu.ac.ir/article_1671_8c6d1214a401d5219a4375ccff3ccae8.pdf
Hydrodynamic Analysis of Turbidity Currents Measured in Dez Dam Reservoir
Mohammadreza
Zayrie
author
Mehdi
Ghomeshi
author
text
article
2014
per
Dez Dam is one of the most important dams in Iran. The total initial storage volume of the reservoir was 3.3 Billion cubic meters. To find the characteristics of the turbidity current that may occur in the reservoir and understand its effects on sedimentation, measurements were made in this reservoir from 8th December 2002 to 30th June 2003. During this period, seven events of turbidity current events were recorded. Focusing on the velocity profiles results showed that generally the measured water entrainment coefficients (Ew) were higher, as compared with the existing laboratory data. This state strongly depended on the non-uniformity of the cross sections, tortuosity of the channel and bed roughness that increased the water entrainment. Also, a statistical analysis was performed on the dimensionless velocity profiles using SPSS software, and the results were compared with the experimental data.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
135
145
https://water-soil.tabrizu.ac.ir/article_1672_1338f7b747071948465f00ef4364822f.pdf
Effects of Light Intensity and NaCl Salinity on Yield and Uptake of Some Elements in French Tarragon (Artemisia dracunculus L.)
Mohammad
Ghoily Kylaneh
author
S Jalal
Tabatabaie
author
Sahebali
Bolandnazar
author
text
article
2014
per
Salinity is the most important factor limiting plant growth; light intensity is also a prominent factor affecting the response of plants to salinity stress. In order to investigate the effects of light intensity and salinity on yield and concentrations of some elements of tarragon plant, an experiment was carried out. The experiment was laid out in split plots with a randomized complete blocks design at 4 replications in soilless culture. Treatments consisted of two light intensities as main plots and five NaCl levels (0, 20, 40, 60 and 80 mM) as subplots. At the beginning of flowering, plants were harvested and shoot fresh and dry weights and elements concentrations were measured. The results showed that the salinity increase and in light intensity decrease led to shoot fresh yield and dry weight decrease. With increase of salinity more than 20 mM sodium chloride in solution, sodium concentration in leaves increased and this increment in shade was more than that in full light conditions. In the shadow conditions, first, increasing salinity caused K+ concentration to remain constant; then it decreased. Salinity reduced leaf nitrogen concentration, which was more pronounced in lower light conditions. Leaf P concentration was reduced under saline conditions. Salinity levels higher than 20 mM led to leaf calcium concentration to be reduced.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
147
158
https://water-soil.tabrizu.ac.ir/article_1673_13f282f73c57cc975e6c04b7fa5b2542.pdf
Leaching of Nitrogen in the Presence of Zeolite Enriched with Ammonium
in Two Soil Textures under Wheat Cultivation
Narghes
Mehrab
author
Mostafa
Chorom
author
text
article
2014
per
Leaching of fertilizers, nutrients and insecticides from soil is an important factor to change the surface and ground water quality. Studies show that some percentage of nitrogen fertilizers leaching from the soil profile joins the groundwater or rivers. The aim of this study was to investigate the effect of raw and ammonium-enriched zeolite on reducing nitrogen leaching from the soil under wheat plant cultivation. In this greenhouse experiment, effects of one level of fertilizer application (100 kg/ha), two levels of raw zeolite (5 and 10% wt) and NH4+-zeolite (5 and 10% wt) added to the clay loam and sandy loam soils and one level of leaching (30% of net irrigation depth) on nitrogen leaching in eight consecutive irrigation events were studied. Nitrate concentrations in sandy loam and clay loam soils treated with the chemical fertilizer were more than those in zeolite treatments at the all irrigation period. The lowest concentrations of nitrate and ammonium in the drainage water were observed in the treatment with 10% zeolite enriched with ammonium. The quantities of the ammonium and nitrate leached from the sandy loam soil were more than those from the clay loam soil. The nitrate outputs from the clay loam soil with 10% raw zeolite and 10% zeolite enriched with ammonium were 43% and 72% less than those with the chemical fertilizer treatment, respectively. Comparison of the raw and enriched zeolite with ammonium showed that the ammonium-enriched zeolite stored the nitrate and reduced the pollution more effectively.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
159
170
https://water-soil.tabrizu.ac.ir/article_1674_958e598f6db7574e3248dc4728aa8929.pdf
Influence of Restricted Hydraulic Parameters on Optimal Design
of open Channels Sections
Kumars
Roshanghar
author
Siamak
Talat-Ahari
author
Ayda
Noori
author
text
article
2014
per
Artificial open channel structures are expensive infrastructures in terms of their materials, construction and maintenance. Design of a minimum cost channel section involves minimization of the sum of costs per unit length of the channel, subject to uniform flow condition in the channel. In this research, the objective function was expressed using the cost per unit length of the channel for lining, the depth-dependent unit volume earthwork cost, and the cost of water lost due to seepage and evaporation. A general resistance equation was used as an equality constraint. Optimal design of trapezoidal channel sections using genetic algorithm with depth, bottom width and side slope variables was accomplished. Two methods and several Models were evaluated including no restriction and restriction on normal depth, velocity of flow, side slope and top width. Restricted depth, velocity and side slope resulted in higher costs. However restricted top width resulted in lower costs comparing with other models. Also, another model was employeed which used the Manning equation as an equality constraint.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
171
182
https://water-soil.tabrizu.ac.ir/article_1675_481de43b34f765acd006ae6e23e16ef3.pdf
Investigating Groundwater Quality Parameters Using GIS and Geostatistics
(Case Study: Shahr-Babak Plain Aquifer)
Afshin
Jahanshahi
author
Einillah
Rohimoghaddam
author
Abdulhamid
Dehvari
author
text
article
2014
per
Groundwater is one of the most important water resources in arid and semi-arid regions. The main aim of this study was to evaluate the accuracy of interpolation methods for predicting the spatial distribution of some groundwater quality indices for Shahr-Babak Plain in Kerman Province. First of all, the water quality data of about 56 wells in the period 2011-2012 were selected; based on their accuracy and scattering in 2011-2012; then the missing data were reconstructed and controlled. According to the Kolmogorov-Smirnov test, data were not normally distributed, so the logarithms of them were used. The results showed that for these water quality parameters, the best variogram models were the Spherical, Linear and Exponential ones. The variability of the data was investigated using different interpolation methods such as Kriging, Cokriging and IDW with powers 1 to 3. The results showed that the geostatistical methods had remarkable superiorities to the deterministic methods so that the Kriging method was the best one. For the parameters TDS, EC and Cl the lowest values of RMSE were calculated using Ordinary Kriging with the Spherical model, which were 844.6, 1214 and 10.61, respectively. Then the zoning maps of these three elements were drawn with the most appropriate method of ArcGIS software. The spatial and temporal variations of the most parameters were investigated and their correlations with the decreasing trends were shown during the period of the study. Also,the suitability of the plain aquifer water for agricultural and drinking uses was investigated with the Wilcox and Schoeller Standards. Wilcox standard results indicated that the water qualities of 30 wells were in unsuitable conditions, and the results of Schoeller diagram confirmed that in 49.3 percent of the plain area the groundwater was undirinkable.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
183
197
https://water-soil.tabrizu.ac.ir/article_1676_4e267e90afa65ebe6bcdea9b5b5f1690.pdf
Evaluation of Some Extraction methods for Determination of Corn Available Phosphorus in Some Calcareous Soils of East Azerbaijan Province
Mohammad reza
Maqsoodi
author
Adel
Reyhanitabar
author
Nosratollah
Najafi
author
text
article
2014
per
In this research, evaluation of Some Extraction methods for determining available phosphorus of the corn plant in 25 calcareous soils was implemented using surface soil (0-30 cm) samples. The experiment was carried out as a factorial in a randomized complete blocks design with cultivation of corn in three replications under greenhouse conditions. Methods of distilled water, calcium chloride, Paauw, Olsen, Colwel, Soltanpour, Morgan, Kelowna-2 and filter paper impregnated with iron oxide were applied, and the available P and the correlations between the resulted values with soil phosphorus fractions were investigated. The maximum and minimum amounts of P were extracted by the methods of Colwel and 0.01 M CaCl2 respectivly. Among the chemical extraction methods of P, the highest correlation was observed between the Colwel and Kelowna-2 methods. The Soltanpour method had the highest correlation with the paper strips method. Most of the extraction methods showed significant correlations with the labile organic phosphorus (LOP) and moderately labile organic phosphorus (MLOP) fractions, of which the maximum values were related to 0.01 M CaCl2 and distilled water methods, respectively. Also, all the extraction procedures, were, highly correlated with the dicalcium phosphate (Ca2-P) fraction among which the lowest belonged to the Paauw method. The amounts of total-P in soils were significantly correlated with the amounts of extracted P using all the extractants. In this experiment, the methods of Olsen and Colwel had the highest correlations with corn shoot dry weight, but due to the cost increase and longer time of extraction in the Colwel method, the Olsen method was introduced as the preferred one. The results of this study showed that although the paper strips method could predict corn growth parameters well, but the chemical extraction methods were superior.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
199
214
https://water-soil.tabrizu.ac.ir/article_1677_05af588204e4b617aa2eabd513d639af.pdf
Effect of the chute bed roughness height on the B-jump characteristics
Manoochehr
Shokrian
author
Mahmood
Shafaei Bejestan
author
text
article
2014
per
Rock and gabion types of chute structures are used in many natural and artificial channels. The excess kinetic energy downstream of this structure is dissipated through hydraulic Jump. One type of the hydraulic jump is the B-jump. A B-jump is defined as the jump having the toe section located on a positively sloping upstream channel and the roller length end on a downstream horizontal channel. Determination of hydraulic jump characteristics such as the sequent depth ratio, jump length and roller length which occur at the roughened bed chute can help to design a safe and economic stilling basin. In this study, to estimate sequent depth ratio on the rough bed, using Buckingham theorem and incomplete self similarity theory a general non-dimensional relation was developed. Also general equations were developed for estimating jump and roller lengths. Then tests were conducted for a wide range of relative roughness, flow discharge and Froude numbers. The results showed that relative roughness could reduce the sequent depth ratio, jump length and roller length.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
215
226
https://water-soil.tabrizu.ac.ir/article_1678_f4509a5215a6ec7f66664fd770e2c299.pdf
Effects of Different Soil Moisture Conditions and Zinc Sulfate and Monocalcium Phosphate Fertilizers on the Extractable-P in a Calcareous Soil
Rahim
Motallebifard
author
Nosratollah
Najafi
author
Shahin
Oustan
author
text
article
2014
per
For evaluating effects of different soil moisture conditions, zinc (Zn) and phosphorus (P) on extractability of P in a calcareous soil, two experiments were conducted as factorial on the basis of a completely randomized design with two replications under laboratory conditions in 2012. The first experiment was arranged with four factors, including Zn at two levels (0 and 20 mg Zn per kg of soil as ZnSO4.7H2O), P at two levels (0 and 60 mg P per kg of soil as Ca(H2PO4)2.H2O), soil moisture at two levels (0.6FC and FC) and incubation time at four levels (1, 10, 30, and 60 days) and the second experiment was accomplished with three factors of Zn and phosphorus at the above mentioned levels, and wetting-drying cycles at three levels (1, 10 and 20 cycles). The extractable soil- P values were measured at the end of each incubation period or wetting-drying cycle by Soltanpour and Schwab method. The results showed that application of P increased the extractable P in both soil moisture conditions. The extractable P significantly decreased with increasing duration of incubation, especially in the first 10 days and then remained constant for the rest of the period. The Zn supply decreased extractable P and this reduction was more pronounced with increasing incubation time. Increase in soil water content from 0.6FC to FC increased the extractable-P. The effects of wetting-drying cycles on the extractable-P were different with and without application of 60 mg P per kg of soil. Under no P supplying condition, wetting-drying cycles exhibited higher amounts of extractable P compared with incubation at constant moisture condition; while under P applied condition, imposing wetting-drying cycles led to a decrease in amounts of extractable P compared to incubation under constant moisture condition.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
227
241
https://water-soil.tabrizu.ac.ir/article_1679_aad0583718a3d91da0eba97302680a5e.pdf
Zone Classification of Soil Salinity in Maize Root Zone Under Different Irrigation Treatments Using Geostatistical Methods
Fatemeh
Karandish
author
Ali
Shahnazari
author
text
article
2014
per
This study was carried out as a complete block design with three treatments including, full irrigation, partial root-zone drying in two levels at 75% and 55% of full irrigation to evaluate three Geostatistical methods including Kriging, CoKriging and Weighting Moving Average for interpolating the values of soil electrical conductivity, as the best index for soil salinity. Soil electrical conductivity (EC) was measured using Decagon 5TE TDR sensors. Then zone classification maps of the EC were prepared using a linear relation between EC and soil water content values measured by IDRG SMS T2 sensors. Results of the variograms analysis showed that the effective range of variograms was higher than the maximum space between observed points in the all treatments. Comparing the observed and Geostatistical estimated values of EC based on the evaluation criteria including root mean square error (RMSE), mean bias error (MBE), mean absolute error (MAE) and index of agreement (d) showed that there was a good agreement between observed and estimated EC values. Duncan test at 5% probability level showed that values of the evaluation criteria for the Kriging method were significantly lower than those for the other methods at the all treatments, and CoKriging method ranked as the second method (p≤0.05). Also there was no significant difference between the Cokriging methods by simultaneous consideration of the electricul conductivity with one of the temperature or soil moisture covariates as the model input.
Water and Soil Science
University of Tabriz
2008-5133
24
v.
2
no.
2014
243
256
https://water-soil.tabrizu.ac.ir/article_1680_82516256b81060a96d94c2d1a0b17fcd.pdf