WATER AND SOIL SCIENCE (AGRICULTURAL SCIENCE)
Year:2018 | Volume:28 | Issue:3 |Papers Count:15

Due to the rapid movement of water and contaminants through preferential flow paths, in this study kinematic– dispersive wave model as an appropriate method to simulate this motion was used. This model had three unknown coefficients which were determined using particle swarm optimization (PSO) method. Four different rainfall intensities of 56. 97, 107. 64, 133. 01, and 161. 71 mm h-1 were applied on the surface of a soil column and output water fluxes from the bottom of the soil column versus the soil mobile moisture amount in the column were recorded. Model coefficients were calculated by minimizing the error function between the observed values and the equation of the flow flux prediction. To achieve the best results and the minimum amount of error function, several solutions were evaluated and different values for c1 and c2 that control the best personal and global, respectively and interfere to make the next generation of results were tested. The best values for c1 and c2 were 1. 2 and 2. 4, respectively. Also to find the best results, several equations as the inertia weight, to control the particles velositeis in the search spaces, were tested and finally the linear decreasing inertia weight was chosen. Generally the results showed that the used algorithm could define the coefficients of kinematic– dispersive wave model in a short time and with a reasonable accuracy.

Water stress is one of the factors whish reduces the amount of nutrient uptake, greatly. In order to study the effect of foliar application of iron and manganese on yield and yield components of the mung bean (Vigna radiata L. Parto) under water deficit stress, an experiment was conducted as a complete randomized block design with split plot arrangement in three replications. Main plots were three levels of irrigation stoppings (With out stopping irrigation, with one irrigation turn stopping at each of the primary growth and the production stages, respectively) and submain plots were combination of foliar iron and manganese applications. The levels of foliar application were no foliar application (as control), water foliar application, iron sulfate 1%, iron sulfate 1. 5%, manganese sulfate 0. 5%, manganese sulfate 1%, iron sulfate 1%+ manganese sulfate 0. 5% and iron sulfate 1. 5%+ manganese sulfate 1%. The results showed that the treatment of water deficit stress at the vegetative and production stages had a significant effect on yield and yield components of the varieties of the mung bean. The hightest effect of water stress was related to the production stage. The combined foliar application of the iron and manganese significantly increased the grain yield, number of the pods per plant, grain weight, plant height, leaf area index, and grain iron and manganese content. However, drought stress reduced the studied traits, but foliar application of iron and manganese resulted in plant resistance that caused delay in appearance of the water stress in plant and thus improved the production performance.

Water leakage from dam reservoir and body is one of the most concerning issues in establishment of such large projects, which in addition to wasting costs brings lots of negative social and environmental consequences. One of the dams of Urmia lake catchment area, which suffers leakage phenomenon being unusable, consequently, due to not doing exact geotechnical studies is Arbatan reservoir of Heris town. Investigation of the dam establishment site shows that the dam reservoir has been placed on evaporative sediments and water penetration has resulted in formation of some sinkholes and water escape channels in the lower substrates and the dam discharge. So the aim of the present research study is to evaluate use of clay blanket for covering the reservoir floor and its restoration. To do so, after identifying subterranean features of the reservoir using SEEP/W numerical model and bent method, leakage amount of water was determined under clay blanket application state. Results of the two numerical and bent methods indicated that leakage amount of the dam reservoir covered with clay blanket are 23569 and 584000 cubic meter, respectively, within 180 days. So, with huge amount of leakage, efficiency of the method will not be effective and a good solution for the dam restoration. In general, such amount of leakage might result in repeated rapture in the dam body and clay blanket. So under such conditions, success of every investment related to this dam will confront high level of uncertainty.

Flow Simulation and discontinuous shock capturing are important in shallow water equations. Common numerical schemes such as finite difference Preissmann scheme, without performing some modifications, cannot simulate discontinuities. Finite volume methods using Riemann solvers by taking advantage of the characteristics of solving the smooth areas as well, have the ability to simulate discontinuities. In this paper, the second order Roe model of Riemann solver was employed by applying the limiting functions to eliminate the spurious oscillations of the numerical simulation in the surface and subsurface flows (Saint-Venant equations in surface flow and Kostiakov-Lewis in subsurface flow). A Fortran code was developed for Roe-TVD method, the presented model was evaluated using the Preissmann scheme (an implicit finite difference scheme) and two sets of field data (Printz-323 and Walker) based on Root Mean Square Error (RMSE), Standard Error (SE) and Determination Coefficient (R² ). It was concluded that Roe model showed better results comparing to the Preissmann scheme in all of the simulations, particularly in outgoing runoff, RMES was improved up to 62%. The applied model was an explicit method and reduced running time and had the ability of application under different field conditions.

Estimation of total suspended solids in upland watershed of reservoirs using simulation models is a vital key to manage reservoirs water quality. It is consequently essential that these models undergo calibration and uncertainty analysis before their application. In this study, Soil and Water Assessment Tool model was applied to estimate stream flow and total suspended solids for Sofichai Watershed upstream of the Alavian Reservoir located in East-Azarbayjan province. The Generalized Likelihood Uncertainty Equation (GLUE) and Sequential Uncertainty Fitting (SUFI-2) were used in this study to calibrate and analyze the uncertainty of SWAT model. The performance of the GLUE and SUFI-2 was evaluated using four objective functions namely: Nash– Sutcliffe Efficiency (NS), coefficient of determination (R2), RMSE-observations standard deviation ratio (RSR) and the adjusted R2 coefficient (bR2). Uncertainty statistics used were the P-factor and R-factor. SUFI-2 proved to be a very efficient optimization algorithm for Calibration and uncertainty analysis. The model calibrated with SUFI-2 can therefore be applied confidently for water resources management, for quantification of scenarios of climate and land use change, and for estimation of the Best Management Practices efficiencies in the watershed.

In order to study the effect of apple (Golden delicious variety) pruning residue biochar on chemical forms of Cd, Pb, Cu and Zn in a contaminated soil, an experiment was conducted as a factorial in a completely randomized design (CRD) in three replications with 4 levels of biochar (0, 2, 5 and 10 %) and 4 levels of incubation time (1, 2, 4 and 8 weeks). Chemical distribution of metals in soil was determined using Tessier sequential extraction method during the mentioned incubation times and the reduced partition index (IR) and mobility factor (MF) of the metals were calculated. Application of the biochar significantly (p ≤ 0. 05) decreased the exchangeable and carbonate fractions and increased organic and iron and manganese oxide bound fractions in comparison to the control treatment. With increasing the biochar level and incubation time, the IR values were increased, but MF values decreased, demonstrating a decrease in the mobility of metal in soils. It was concluded that the addition of the apple biochar in soil may led to transformation of the metals from unstable forms (e. g. exchangeable and carbonate forms) to stable forms (e. g. iron and manganese oxide bound and residual forms), and consequently decreased the mobility of the metals in soil.

Nickel (Ni) is an element that has recently been added to the list of essential micronutrients of plants. On the other hand, accumulation of Ni in soils and plants has increased concerns about humans and other living organisms for toxicity of Ni. To study the effect of Ni and iron (Fe) on the growth characteristics of corn (Zea mays L. ) plant in the soil a factorial experiment on the basis of randomized complete blocks design with three replications was carried out under greenhouse condition in a calcareous soil. The factors included the concentration of the applied Ni at four levels (0, 10, 50 and 100 mg Ni kg-1 soil) as pure nickel sulfate (NiSO4. 6H2O) source and Fe at five levels of 0, 10 and 20 mg Fe kg-1 soil, as iron sulfate (FeSO4. 7 H2O) and commercial Fe sequestrene (FeEDDHA). According to the results, at the applied levels of 50 and 100 mg Ni kg-1 soil, the shoot dry weight was decreased by 21. 1 and 31. 9%, and the relevant decrease of root dry weight was 30. 8 and 28. 5% respectively, as compared to the control. Stem height was decreased by 2. 1% in the presence of 100 mg Ni kg-1 soil, as compared to the control. Chlorophyll index was decreased by 32. 4 and 40. 5% in levels of 50 and 100 mg Ni kg-1 soil, respectively, as compared to the control. Increasing Fe levels of the two applied Fe sources significantly increased the shoot dry weight. But the shoot dry weight was decreased by 81. 9 and 29% at 20 mg Fe level of Fe-EDDHA, as Ni was increased from the levels of 10 to 50 mg and from 50 to100 mg, respectively.

Nowadays, Labyrinth and piano key weirs are suggested as appropriate options for modification of those weirs which are faced with the problems as passing the probable maximum flood. Piano key weirs (PKWs) have been developed for the substitution of Labyrinth weirs which their footprint areas are restricted. In this study, to evaluate the hydraulic efficiency and discharge coefficient of the PKWs, totally 377 experiments are conducted on the 18 physical models in both contracted and not contracted PK weirs. From the experimental results, in all PKWs, the discharge coefficient and the efficiency of the cycle by increase of the head water ratio (HT/P), first increase and then decrease. Nonetheless, discharge coefficient of the modified PKWs (modified by increasing and reshaping the weir crest as well as installing the fillet) was increased by 10% when compared to the non-modified weirs. In the contracted PK weirs, the PK₁ weir at HT/P≤ 0. 18, has the highest discharge coefficient, but with the increasing of the discharge, the discharge coefficient decreases and at HT/P≥ 0. 3 reaches to the lowest magnitude. Nonetheless, in contrary to the non-contracted weirs, increasing Wi/W₀ leads to discharge coefficient reduction in the contracted weirs.

Tagetes erecta is an annual plant from the Asteraceae; commonly cultivated as an ornamental and medicinal plant and has a widespread use in landscape designing. An experiment was conducted as factorial based on randomized complete block design to evaluate the effects of salinity (0, 7. 5, 15 and 22. 5 dSm-1) and zinc sulphate foliar application (0, 100 and 200 mgL-1) on some physiological traits of T. erecta. The results revealed the interaction effects of salinity and Zn foliar application on flower, leaves and stem dry weight, as well as on Zn concentration and ion leakage were significant (P≤ 1%). The highest flower (0. 46 g) and stem (0. 54 g) dry weight, as well as the greatest amount for Zn concentration (60. 0 μ g g-1DWt) belonged to 200 mgL-1 Zn foliar application. Salinity stress significantly influenced the leaves Relative Water Content (RWC) and the highest data for this trait was measured in control treatment. Salinity stress had a positive meaningful influence on Na+ concentration, ion leakage, proline content and also malondialdehyde content of the plants and the top-recorded quantity of these traits belonged to the highest salinity level i. e. 22. 5 dSm-1 NaCl. Salinity stress increased the catalase enzyme activities in 15 and 22. 5 dSm-1salinity treatments. In total, Zn foliar application had partial positive effect on the amelioration of salinity effect on the plant.

In this study, for investigation of Tabriz droughts, monthly precipitation data (1951-2015) were used. Three drought characteristics, including drought duration (Ld), severity (Sd) and magnitude (Md) were extracted from observations. Data of every characteristic fitted with the most suitable statistical distribution. Then five hundred artificial series with the same length of the observed precipitation were generated for each of the characteristics. Two thresholds were considered for drought analysis, including average of annual precipitation and average of annual precipitation minus its standard deviation. The results of first threshold showed that the maximum of Ld, Sd and Md were 7 years, 500 mm and 71 mm/yr, respectively. Poisson, Pearson type 5 and Wakeby distributions were recognized as the most suitable fitted distributions for to the Ld, Sd and Md, respectively. Quantile 90% for Ld, Sd and Md were obtained as 5 years, 443 mm, 103 mm per year, respectively. The maximum and minimum of Ld in Tabriz were between 14 and 71 mm/yr. The second threshold results were showed that the maximum for Ld, Sd and Md were 2 years, 76 mm and 38 mm/yr, respectively. Uniform, Burr, and Generalized Extreme value distributions were recognized as the suitable distributions, for duration, severity and drought magnitudes, respectively. In this case, quintile 90% for drought duration, severity, magnitudes were obtained as 2 years, 51 mm and 38 mm/yr, respectively.

Turbidity current phenomenon is one of the most important factors in reservoir sedimentation and sediment distribution, which causes management and operational problems and decreases dam’ s useful life. Study and investigation of progressive section (head of turbidity current), as the most significant and considerable section is essential for sustainable management of dam reservoirs. So far, most of the studies have been conducted under experimental conditions on rigid beds. But in this study, in order to achieve more realistic results regarding natural conditions in rivers and reservoirs, the experiments were carried out on an erodible and mobile bed. So dynamic of turbidity current head was analyzed on rigid and erodible beds for different effective hydraulic conditions. It was shown that erodible bed increased the head velocity of turbidity current and Keulegan coefficient up to about 20% and also, increased the relative forehead height up to about 40% with increasing flume bed slope. In addition, in order to estimate the averaged head velocity, an equation with correlation coefficient of 0. 86, was developed using multivariate linear regression and effective dimensionless parameters. Finally, sensitivity analysis of the equation’ s dimensionless parameters showed that the most effective parameter in estimation of the head velocity average is Richardson number.

Haftcheshmeh Cu-Mo deposit is located in East Azerbaijan province, Iran, with 28 km distance in North west of Varzeghan Area. In order to evaluate the hydrogeochemical properties and concentrations of heavy metals in water resources of the studied area, 14 samples of groundwater (springs and the leakage levels) and 10 samples of surface water area were collected. Samples were analyzed for major anions and cations, anion and some heavy metals including Zn, Cu, Pb, and Mo and. This qualitative study showed that majority of samples collected from the range of deposit, under the impact of low pH, caused the release of elements of minerals and change water quality for drinking, agriculture and industry. But at farther distance deposits in the flow direction with decrease of contaminants the quality of water in these resources increased. Concentrations of Pb and Mo were higher than standard values in the sample near the deposit, whereas the concentrations of Cu and Zn were lower than standard values in all of the samples. Determination of “ Heavy metal pollution index” (HPI) and “ metal index” (MI) revealed that samples of groundwater and surface water near the deposit were not suitable for drinking and it could be harmful for the human health. Spearman correlation analysis of metals showed that the all elements except Mo were negatively correlated to pH, reflecting different geochemical behavior of Mo. The results of this research showed that it was necessary to be studied the environmental effects of this deposit before start of mining.

Management of manure and chemical fertilizers application in the soil in terms of environmental impacts and performance of plants is important, especially in arid and semi-arid regions of Iran. A split plot experiment was carried out in a randomized complete block design with three replications at the research farm of Shahrekord University in 2014. Main factor was consisted of three levels of irrigation regimes including 100% (I1 or control), 75% (I2) and 50% (I3) of water requirement while 6 levels of manure application including 1) no amended fertilizer (control), 2) 25% urea fertilizer + 75% cattle manure 3) 50% urea fertilizer + 50% cattle manure 4) 75% urea fertilizer + 25% cattle manure 5) 100% urea fertilizer and 6) 100% cattle manure, were considered as subplot factor. Results showed that irrigation regime of I3 caused decreasing an contration of chlorophyll a, b and total, essential oil yield of flowering branch, leaf and stem while in caused 83 and 13. 5 percent increase in the amount of carotenoids and proline compared to control, respectively. Fertilizer treatments, 25% urea fertilizer + 75% cattle manure, 50% urea fertilizer + 50% cattle manure, 75% urea fertilizer + 25% cattle manure, 100% urea fertilizer and 100% cattle manure caused significant increase in carotenoids content compared to control whereas the maximum carotenoids content with the average of 1. 35 mg g-1 was obtained from the 25% urea fertilizer + 75% cattle manure treatment. A significant positive correlation was observed between chlorophyll a, b, total, essential oil percentage, essential oil yield of leaf and essential oil yield of flowering branches. Therefore, in order to obtain the maximum essential Moldavian balm under Shahrekord climatic condition, application of 50% urea + 50% cattle manure and full irrigation is recommended.

In the present study, the information of 31 synoptic weather stations in the period of 1987-2010 were used to delineate Iran’ s precipitation regions. For this purpose, each month’ s data were standardized and written in the (n*m) matrix, where n is the number of stations (31) and m is the number of months (12). Principal component analysis was conducted on the mentioned matrix. The main components were determined according to the criterion of having an eigen value greater than one. Then principal components scores were calculated for the selected components. These valeus were used as an input for Ward method of cluster analysis. Then according to the cluster diagram, precipitation climates of the country were identified. The Procrustes analysis (PA) was used to answer the question of which stations could be considered as the indicator of rainfall climates? Furthermore, from this method those months, which their precipitation can be recognized as an indicator of annual rainfall, were selected. Results showed that the first three components incorporated more than 97% of total variance. Based on the selected components the six distinct precipitation regions were distinguished across the country. Furthermore, PA results indicated that the precipitation of May, August and December approximately had whole of the annual precipitation information. Moreover, it was found that seven stations located in different points of the country namely Zahedan, Tehran, Urmia, Ilam, Yasooj, Gorgan and Rasht could be considered as the indicator stations. These stations incorporated over 87 percent of total variance of data of all selected stations in the country.

In this research work taxonomic distance and clustering performance for understanding of relation and correlation between calcareous, gypsiferous and saline soils of East Azerbaijan semi-arid and arid regions were studied based on soil taxonomy (ST) and world reference base (WRB) systems. The taxonomic distance by R software and Numerical Taxonomy in Excel and clustering using R and SPSS softwares were calculated and their relationship in two systems was investigated. Then using the average amount of physicochemical quantitative data, the results of calculation and clustering compared with each other and so with opinion of the experts, that there was a good quantitative correlation between salids and salonchaks, salonetz, gypsids and gypsisols, argids and luvisols, xerepts and calcisols and gypsisols. The obtained results of four methods were almost similar and identical with each other, but use of each one had its own limits and skills. The conceptual method was based on the dominant qualitative identifiers (soil-forming factors or processes, diagnostic horizons and in general dominant morphological properties of calcareous, gypsiferous and saline soils) and coding of them, that sufficient information or knowledge and skills are necessary to achieve a good accuracy in this method. The quantitative physicochemical data were used in the centroid-based approaches numerical taxonomy and clustering and results of these methods are more reliable. The easiest method was Numerical Taxonomy, which with simple options and without any programing, forms matrix and by normalizing data, the Mahalanubis equation makes the taxonomic distance easily available. In general, these tools and calculations are useful for finding the relationship between soils in different classification systems, and quantitatively numerical findings for their correlation and association in classification systems, especially ST and WRB, which are widely used in Iran are recommended.