JWSS - Journal of Water and Soil Science

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Effect of different times and levels of nitrogen fertilizer application on growth and grain yield of spring wheat cultivar “Ghods” was studied during 1993-1994 growing season at Karkadj, Agricultural Experiment Station, College of Agriculture, University of Tabriz, using a split plot design with three replications. Main plots were assigned to five levels of N fertilizers (0, 40, 80, 120 and 160 kg/ha) and subplots to five times of applications [all of N fertilizer at planting (T^₀) 1/2 at planting + 1/2 during tillering stage (T₁), 1/2 at planting + 1/2 during heading stage (T₂), 1/3 at planting + 1/3 during tillering and 1/3 at heading stages (T₃) and 1/4 at planting + 1/4 at tillering + 1/4 at stem elongation and 1/4 at heading (T₄)]. Results showed that different levels of N applications affected grain yield and biological yield significantly, while the effect of split application and also N levels × times of application interaction on these two traits were non-significant. Growth stages of wheat were not significantly affected by different N Levels and times of application. Dry matter accumulation, leaf area index, and crop growth rate, in response to growing degree days during growing season, increased when higher levels of N fertilizer were applied. Leaf area index and crop growth rate initially increased up to anthesis and then decreased. Crop growth rate decreased to zero level at soft dough stage and then became negative. Variations in relative growth rate and net assimilation rate, in relation to growing degree days, decreased when different levels of N fertilizer were applied at early part of growing season it was maximum while at later growth stages decreased and finally became negative, Times of N application and level × time interaction during growing season did not affect the growth indices significantly.

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In order to study the genetic variation among local varieties of onion in Iran, an experiment was conducted in the Research Center, Faculty of Agriculture, Tabriz University. Sixteen populations were evaluated for agronomic characteristics and also total seed proteins via SDS-PAGE. Cluster analysis and principal component analysis were used to group the onion populations under study.

 Analysis of variance showed significant differences among varieties for leaf color, leaf length, texture tightness, onion yield per plant, and number of edible layers. No significant differences were observed for the number of twin onions, bulb diameter, and onion dry weight. Hamadan (98-148), Arak (98-95, 98-96, 98-97, 98-103), and Zanjan (98-223) populations acquired the highest onion yield per plant. The significant differences between populations for the majority of characteristics proved the existence of genetic variation in the Iranian onion germplasm. The results from cluster analysis for agronomic characteristics were the same as those from the cluster analysis for the onion yield per plant. The 16 populations were divided into 4 groups. Cluster analysis for the electrophoresis banding pattern resulted in two groups, which was not similar to the dendrogram of agronomic traits. Using principal component analysis, the first principal components determined 97.57% of the total variation. Onion yield per plant was the most important trait in the first principal component and onion dry weight was the second trait in the rank.

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Artemisia is the major component of the vegetation of a large portion of arid lands in Iran. Determining the utilization rate is an essential element in the management of these rangelands. Methods of determining the utilization regime for woody plants and shrubs include clipping and weighing, reference unit, ocular estimate, twig length, branch diameter and production index. These methods were used in Chahlor winter range in Jarghoyeh, 250 Km southeast of Isfahan. Clipping and weighing is the most accurate although the most time-consuming method. In this research, means of utilization percentages obtained from the above methods were compared with the mean obtained from the clipping and weighing method using T-test.

Data obtained from reference unit, twig length, and branch diameter methods were not significantly different from those of clipping and weighing method (P>0.0l). Since reference unit was the least time-consuming among these methods, it was selected as a proper method of utilization measurement of Artemisia stands.

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Changing agricultural experts' attitude toward sustainability principles and perceptions is essential to create sustainable agriculture. Various studies had shown that permanent changes are not easily accessible to maintain ecological values. Therefore preparing effective information channels and precautions leading to communication system firmness are important challenges ahead. The purpose of the present research was the evaluation of caricature effects on attitude change of Jihad Agriculture Organization experts concerning sustainable agriculture in Shiraz. A Quasi-experimental research method was devised for three groups consisting of two experimental and one control group. A Pre- and a Post-test were also administered. Eighty experts from Jihad Agriculture Organization were selected in a simple randomized sampling manner. Based on research theories, questions were devised and data were collected through a questionnaire. Its validity and reliability were determined by specialists and Cronbach's Alpha, respectively. The results indicated that workshops had changed experts' attitude toward sustainability principles and perceptions and workshops with caricature had the most influences on the change of attitudes. Thus the use of caricature is significant to establish sustainable agricultural principles and perceptions in experts at local level conditions.

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The reaction of forty two barely landraces, mostly from Azarbijan Province and a susceptible cultivar, Zarjo, was studied under greenhouse conditions in the presence of four highly virulent isolates of Pyrenophora graminea, i.e. Marand 3, Ajabshir 2, Khasseban-Tireh, and Bostanabad. The experimental design was a split-plot based on randomized complete blocks with three replications. Landraces were considered as sub-plots and the isolates as whole plots. The seeds were inoculated by the sandwich method and responses of the landraces were evaluated by the method of Mathur and Bhatnagar. The resistance of landrace #1 to the isolates of Marand 3 and Ajabshir 2 and that of landrace # 27 to the isolate of Ajabshir 2 was observed. These landraces could be used as a source of vertical resistance in barley. Landraces 6, 8, 11, 12, 13, 15, 17, 25, 27, 28, 29, 31, 33, 34, 36, 37 and 41 were classified within the range of partial resistance to partial susceptibility, which may be utilized as the sources of horizontal resistance.

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The fire blight with the bacterial causal agent, Erwinia amylovora (Burrill) winslow etal. is one of the most important diseases of the pome fruits that causes the economical losses to quince, pear and apple productions, respectively, in some parts of country. To determine the infection severity of the 43 raturally infected pear cultivars in collection of karaj horticulture research division and also for studing the reaction of these cultivars against disease, the evaluation was performed by the USDA standard system for these cultivars in collection. In this study, although the most of cultivars had been infected on the natural conditions, but disease severity was significantly different between them. By the USDA system, pear cultivars were divided in the 2 classes. Percentage of pear cultivars in very susceptible and moderately susceptible classes were 81.4 and 18.6 respectively. Also for dividing the pear cultivars, beside of USDA method, SPSS software and the cluster analysis were also by the UPGMA method and cultivars were divided into 3 clusters, but it seems that the classification of cluster analysis did not conform with USDA system. Correlation of I.V.S in the artificial tests and the disease severity by natural infection was very significant (r= -0.83).

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Saline soils and halophytic vegetations are common features and part of the habitat pattern in deserts and steppes. The saline area is developing in arid lands. Investigation effects of halophytes on soil characteristics and adaptive mechanisms of the various halophyte types is essential for controlling saline environments. Juncus gerardi is a perennial grass-like halophyte and Halocnemum strobilaceum is a succulent halophyte shrub. The distribution of these species is mound like in the field. The soil samples of the mounds for investigating the effect of these species on plant root environment were compared with near regions in Korsiah saline area in Darab. Also the consentration some ions of live and dead organs and tissues of these species were studied for recognition of their adapive types. The results show that Juncus gerardi decrease salinity in 0-30 cm of topsoil, therefore the Ec decreased 37%. But salinity increased significantly in 30-60 cm depth. The identification of ions in plant tissues showed that the concentration of ions is low in dry matter. This is 0.33% of dry matter for Sodium. This is a way to rescue from dry conditions by selective absorption of ions. The comparison of root environment of Halocnemum strobilaceum with near regions showed a significant decrease in salinity in 0-30 cm and 30-60 cm depth decreased 27% and 40% respectively. The identification of ions concentrations in plant tissues reflect the high amounts of ions, therefore the plant tissues composed of 8.18% of Sodium. The comparision of ion concentrations in different live and dead tissues of plants a Significant increase of the amounts of ion in the dead tissues in comparison with the live tissues. Therefore this species excrete much quality of salts in their dead tissues and organs and so combat this problem.

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During years 2000 and 2001, biology and population changes of two- spotted spider mite (T. urticae) was studied on five bean cultivars of two species at 25±1ºC temp., 45±4% RH and 15: 9 (L:D) photoperiod, using leaf disks made from 2-, 6- leaf and flowering stages of the plants. The mite mass rearing was carried out on tomato plants under the same environmental conditions and the effects of feeding on 4 cultivars of phaseolus vulgaris namely Chiti Var. Zanjan, Picher, Sunray, Contender and Vigna unguiculata, Var. Kameran as host plants. Biological features as fertility, percentage of egg hatch, duration of embryonic and larval development, percentage were also Studied of lraval mortality, duration of nymphal stages, developmental period from lava to pre- oviposition stages, oviposition period, adult mite longevity, number of progenies, their percentage mortalities, and sex ratios were determined. The results indicated that the two cultivars Chiti Var: Zanjan, Contender, and species Vigna unguiculatat Var. Kameran at 2- leaf stage appeared to be suitable hosts causing higher egg production and hatches, lower embryonic and larval developmental time and lower rate of larval mortality, lower nymphal developmental period, lower duration from larval stage to preoviposition, extended oviposition period and higher adult longevity. In contrast, the cultivars, Sunray and Picker were shown to be unsuitable hosts. Regarding 6- leaf stage, the cultivar Contender and Vigna unguiculatat, were considered as suitable hosts in relation to embryonic developmental time, number of larvae, duration of larval stage, and rate of mortalities, nymphal developmental time and duration from larval stage to pre- oviposition, extended oviposition stage, sex ratio and adult longevity. But the cultivars Chiti, Picker and Sunray appeared to be unsuitable hosts. In relation to the number of eggs and percentage of egg hatch, number of larvae and nymphs, nymphal mortality rates and sex ratio, the cultivars, Picker and Sunray were considered as suitable hosts at their flowering stage but Vigna unguiculatat and Contender were identified as unsuitable ones.

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Rape seed (Brassica napus L.) containing more than 40 per cent oil is one of the best oilseeds for cultivation in Iran. Sclerotinia stem rot is one of the important diseases of the rape seed, the causal agent being Sclerotinia sclerotiorum. The aim of our study was to assess the effect of the disease on the quantity and quality of the extracted oil and remaining foodstuff in a field experiment. In this research three cultivars including Okapi, SLM046 and Talayeh were examined under field conditions using a factorial design (cultivars and inoculations were two factors under study). The cultivars were inoculated with SK₄ isolate of S. sclerotiorum. The inoculation was done on the plant stems at 30 cm height above the soil using Lewartosca method during mid flowering stage. One thousand- seed weight and glucosinolate, erucic and oleic fatty acids contents of the seeds were determind after the harvest. The results indicated that the infected plants in comparision with the controls had a lower 1000- seed weight and oleic acid content and a higher glucosinolates and erucic acid contents. There were significant differences among the genotypes in respect to all the studied traits except 1000- seed weight. Inverse correlation was observed between 1000- seed weight and erucic acid content or oil glucosinolates contents. It was concluded that the disease can reduce quantity and quality of seed oil and other nutrient contents.

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The study was conducted to compare the efficiency of diets containing various levels of calcium(0, 1, 2, 3 and 4 percentage) in feeding freshwater crayfish, Astacus leptoductylus. 150 cray fish (10 individuals per tank) with mean weight of about 8-9 gram were stocked in each of 15 tanks, containing 100 L of water. In this research, The results showed that the mean values of some parameters such as weight gain (WG), weight increment rate (WIR), length increment rate (LIR), specific growth rate (SGR), biomass increment (BI), food efficiency rate (FER) and survival rate (SR) of animal fed on different diets were 0.75-1.46gr, 9.8-24.54%, 6.57-15.33% and 0.12-0.29% respectively. However, the diet with high levels of calcium (3-4%) showed the good weight and length increment, but there were no significants difference among these indices using different trial diets. The biomass of crayfish increased with increasing of calcium concentration. So, the highest biomass (11.65gr) of crayfish was observed in the diet containing calcium about 4%. Optimal calcium requirement in the freshwter crayfish was estimated about 3.4% with broken-line regression analysis. The lowest survival rate (30%) was obtained in the diet containing 2% calcium level. There were significant differences among survival rates in various experimental diets (p<0.05). These results indicate that the dietary calcium supplement is nesessary for crayfish. The diets with high levels of calcium had a good efficiency in freshwater crayfish feeding. So it is recommended to use 3-3.5% of calcium in formulated diets for freshwater crayfish

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  Parsi Zira, Bunium persicum (Boiss.) B. Fedtsch., which is called Mountainous or Black Zira, is one of the most important medicinal plants with high economic importance. Generally, there is a little information about in vitro culture of Bunium persicum. Fragmented embryo was used as an explant in Bunium persicum regeneration. In this method, a great callus induction and regeneration only on the same medium without any subculture occurred because of being young and having better interaction with medium, leading to reduction of tissue culture time, infection and chemical consumption. In this research, B5 media containing different concentrations of plant growth regulators, NAA and 2,4-D only or together with Kin, were used. The experiment was conducted using completely randomized design with 30 treatments and 10 replications per treatment. The highest callus number was obtained from the treatment containing 0.1 mg/l 2,4-D and 2 mg/l Kin or 1 mg/l NAA and 2 mg/l Kin. Regeneration occurred in some treatments without Kinetin, showing that Kinetin is not essential for Bunium persicum regeneration. The treatment containing 0.1 mg/l NAA and 4 mg/l Kin was the best one for regeneration. The best treatment for somatic embryogenesis was 2 mg/l 2,4-D.

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In order to evaluate effect of planting date and plant density on grain yield, yield components and some quality and morphological traits of chickpea (Cicer arietinum L.), an experiment was conducted at the research center of agricultural and natural resources of west Azerbaijan in Urmia rain-fed research farm during 2005-2006 growing season in a split plot arrangement, based on a completely randomized block design with four replications. The cultivar of chickpea (Qazvin local mass) was planted in three sowing dates (mid November, mid March and mid April) in main plots, and four plant densities (intra row space: 7.5, 10, 15 and 20 cm) representing (45, 34, 23 and 17 plant/m2) in sub plots. Yield, number of pod per plant, seed protein content, plant height, number of secondary branches and 100 seed weight were evaluated. Results indicated that date of sowing had a significant effect on the yield, number of pod per plant and seed protein content but was not significant for plant height, secondary branches and 100 seed weight. Highest number of pod per plant was obtained in mid November sowing (37.69) and high protein content (22.63) in mid March. Different plant density effects were also not significant on yield, plant height, secondary branches and 100 seed weight but the effect of density on the number of pod per plant and seed protein content was significant. Highest number of pod per plant was obtained in the third density (31.5), and highest protein content in the first density (22.31). The results of study indicated that between mid March planting in the density (45 plant/m2) had highest yield (1042.08kg/ha) and protein content compared with the other planting dates.

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Tracer experiments are very important in the studies related to aquifer contamination for determination of dispersion coefficient. In this study, the effect of sampling method on the dispersion coefficients of two simulated sandy aquifers was examined. The physical model was made from Plexiglas material with inner length, width and height of 72, 10 and 120 cm, respectively. A solution containing 9 g/l sodium chloride (Ec = 14 ds/m) was used as the non - reactive (conservative) contaminant. Homogeneous sands with coarse and medium particle sizes were used as media for the simulated aquifers. The experiments were carried out in the aquifers with various thicknesses from 20 to 100 cm with 10 cm thickness increment. Point and mixed samples were taken through all experiments. The results of the study showed that (1) for both simulated aquifers, the dispersion coefficient values obtained by point sampling method were close to the values obtained by other researchers from laboratory experiments (2) In all the experiments, the dispersion coefficient values obtained by mixed sampling method were higher than those obtained by the point sampling method (3) with increasing the aquifer thickness, the dispersion coefficient values obtained from the mixed samples varied but did not have a uniform trend which could be due to the unavoidable experimental errors and (4) there was no difference between the breakthrough and pore volume curves of various aquifer thicknesses obtained from point and mixed samples. Overall, based on the results obtained from this research, in studies related to aquifer contamination, it is recommended to take point samples instead of mixed samples to obtain more precise results.

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Salinization and alkalization are considered spatiotemporal dynamic soil degradation processes. In order to investigate the effects of agricultural activities on land degradation and soil salinity, Shamsabad area in Qom province was selected. Aerial photos (1955) and satellite images (1990-2002) were used to examine the changes in land use. Soil samples were collected from 25 locations in the study area from 0-50 cm and 51-100 cm depth at each location. For comparative purposes, sampling locations in this study were similar to locations used for salinity study in 1983. For each sample, pH, electrical conductivity (ECe), base saturation percentage, exchangeable sodium, lime and texture were measured. Land use and salinity maps were created by using geographic information system (GIS) softwares. Results revealed an increase of 9.5 times in cultivated lands in 47 years. Increase in agricultural activities in the study area has also intensified the pressure on water resource in the area, lowering ground water tables and degrading water quality. In the 0-50 cm soil depth, the average soil ECe was 6.5 dS/m in 1983, which increased to 10.7 dS/m in 2005. If soil salinity trend and pressure on water resources continue, large part of Shamsabad area is expected to change to desert in near future years.

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Eight multiparous Holstein dairy cows with 634±44 BW, 57±6 DIM, and 46.7±3.1 kg daily milk yield were assigned to a duplicated 4×4 Latin square design for 21-day periods (adaptation, 14d sample collection, 7d). The treatment diets were: 1) no pistachio by-product (control), 2) 5% of pistachio by-product, 3) 10% pistachio by-product and 4) 15% pistachio by-product. Corn silage in control diet was replaced with pistachio by-product. The blood metabolites (2h after feeding), DMI, daily milk yield and milk compositions were not affected by the treatment diets. The economically corrected milk (ECM) and fat corrected milk (FCM) were decreased linearly by increasing pistachio by-product in the diet (P<0.1). By increasing the by-product level in the diet, digestibility of DM, OM, NDF and ADF were decreased linearly (P<0.05). Daily rumination and chewing activity alone or per DMI, NDFI or ADFI were linearly decreased when the by-product level increased in the diet (P<0.1). The results showed that the pistachio by-product does not seem to be suitable for complete replacing of the roughages in the diet and it can be used as a part of forage in the diet up to 10% of DMI.

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Reservoir sedimentation is an unavoidable problem which has unsuitable effects on reservoirs such as decreasing of reservoir useful volume, decreasing of dam stability, unsuitable operation of operational gates and penstocks and decreasing of flood control volume. The minimization of reservoir sedimentation is a nonlinear and constrained optimization problem. Constrains imposed include reservoir storage level and releases in each time, and reservoir storage level in the end of operational period. In this study, after calibration of GSTARS3 software, one of the newest mathematical model for simulation of river and reservoir sedimentation developed by USBR, for region of Voshmgir dam, results of running of software were converted as a part of data file to an optimization model by a mediator computer program. After running the optimization model, results were converted to GSTARS3 by another mediator computer program. Then, GSTARS3 was run again with new data file, obtained from running the optimization model. Results of running of GSTARS3 were converted to the optimization model again. The continuation of this process (loop) finished when the desired accuracy was obtained. In other words, the optimum condition was obtained when the running of this loop finished. The constrained optimization problem changed to unconstrained problem using penalty function method. The Powell method, a method of direct search methods, was used to solve this unconstrained optimization problem. Capabilities of the model were demonstrated through its application to the Voshmgir dam in Gorgan for a 12 month period to obtain the optimal operation policy for minimization of reservoir sedimentation.

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The determination of air temperature is important in the energy balance calculation, hydrology and meteorological studies. In this regard, the limited number of meteorological stations is one of the serious problems for air temperature determination on a large spatial scale. The remote sensing technique by covering large areas and using updated satellite images might be appropriate for estimation of this parameter. In this research, the negative correlation between land surface temperature and vegetation index (NDVI) has been used for air temperature estimation through TVX method in which the inference of air temperature is based on the hypothesis that the temperature of the dense vegetation canopy is close to air temperature. For investigation the performance of TVX method, images of MODIS sensor have been applied for the Sefidrod River basin in the years 1381- 1382-1384. The spilt window technique which was developed by Price has been used for land surface temperature calculation. The mean difference between observed and estimated land surface temperature using Price algorithm was about 6.2Co. This error can affect the air temperature values. Because of using NDVI index in TVX method, this method has the sensitivity to the vegetation density, though in the parts with sparse vegetation, the value of error increases. 4 percent variation of air temperature against the 0.05 increasing of maximum NDVI indicates the high performance of TVX method for air temperature estimation in large areas.

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This study was conducted to determine some mineral content concentration in soil and plant of three elevation classes (1500, 2200 and 3000m) and two phenological stages of flowering and seedling start in north-facing slopes of Sabalan rangelands. Soil samples from the depth of 20cm and plant samples using 1×1m plots with 10 replications were collected. After sample preparation, the concentrations of minerals such as calcium, phosphorous, sodium, potassium, ion, copper, zinc and magnesium were determined using spectrophotometer and flame photometer. Data was analyzed by SAS9.1 software using Completely Randomized Design with a Generalized Linear Model procedure. Results showed that elevation had a significant effect on Ca, Fe, Cu, Zn and Mn of soil and P, Na, K, Mg and Mn of plants in the study areas (P&le0.05). Growing stages had a significant effect on all elements of plants except Ca (P&le0.05). Moreover, results showed that in three elevation classes the high demand minerals’ concentration was higher at the starting seedling stage in comparison with the flowering stage. In contrast, the low demand minerals’ concentration in three elevation sites was higher in the flowering stage in comparison with seedling stage. Interaction effect of elevation and growing stage was also significant in relation to all elements except Ca (P&le0.05).

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Construction of a dam in the upstream of Tajan basin, as one of the human activities in order to provide drinking water, hydropower, agriculture, flood control or other purposes, can be effective on other sectors such as water resources. The purpose of this study is investigating the impact of Rajaei dam on groundwater resources in Sari-Neka plain during 26 years period (1985-2011) using geostatistical method, parametric and non-parametric tests. The results of statistical tests showed that groundwater table variation during 26 years has experienced insignificant upward trend. Quality factors such as EC, TDS, TH, Cl, SO₄, Mg, Na and SAR had significant downward trend at 5% confidence level for Pearson and Kendall test. The Quality changes of groundwater resources in the region had good condition due to construction of dam. The results of spatial analysis for the study area using Kriging interpolation method in the three years for 1985, 1999, 2011 showed that in 1999 (the year of exploitation of the dam) most of the quality factors had reached the highest level from 1985 until the dam operation (1999) and then decreased to 2011. The results of this study showed that, agricultural activities after dam construction, operation of irrigation system and drainage network design of Rajaei dams, have raised the water table in northern part of the region and consequently had a significant impact on the quality of water resources.
 

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Hydraulic jump is the most common method of dissipating water’s kinetic energy in downstream of spillways, shoots and valve. In this paper, Support Vector Machine (SVM) method, as a machine learning method, have been used to estimate hydraulic characteristics such as the sequent depth ratio, jump length and energy loss in three different sudden expansions stilling basins, and the rate of influence of input parameters in each jump has been analyzed. In order to evaluate the performance of proposed method, 936 sets of the observed data have been used for training and testing process of three kinds of expanding channel models. Furthermore, a comparison between semi-theoretical approaches and the data obtained from the best SVM models have been carried out. The results confirmed the efficiency of SVM method for estimating the hydraulic jump characteristics and proved that this method performed well in comparison to the semi-theoretical relationships. The obtained results revealed that the superior model for the sequent depth ratio and relative energy dissipation was the model with (Fr₁,h₁/B) parameters and the superior model for the length of hydraulic jump prediction was the model with (Fr₁, h₂/h₁) parameters.