Iranian Journal of Soil and Water Research
Year:2018 | Volume:49 | Issue:1 |Papers Count:20

Sugarcane bagasse is one of the agro-industry wastes that its maintenance and disposal makes some problems for the factories managers. In this research, the effects of lime and bagasse fly ash on the strength characteristics of a clayey soil were studied. For this purpose, 20 treatments were made by adding of different amounts of lime and bagasse fly ash to a high plastic clayey soil. In such a way four levels of lime including 0, 1, 3 and 4percent and five levels of bagasse fly ash including 0, 2, 5, 8 and 12 percent by dry weight of soil. In addition and bagasse were added to the soil with percentages of 2, 5, 8 and 12 for bagasse ash. Then, considering two curing times (7 and 28 days) and three replications, 6 specimens for each treatment and totally 120 specimens were made by using of Harward miniature compaction apparatus. The prepared samples were then tested for unconfined compressive strength at their curing ages. The results showed that the adding of Bagasse fly ash and lime increases the optimum water content and reduces maximum dry density of the clayey soil. It is also found Furthermore, The combination of 8% sugarcane bagasse ash with clayey soil has increased the compressive strength of soil by 92%. Moreover, addition of bagasse ash to the mixture of clayey soil-lime reduces the amount of unpressurised compressive strength and of the elastic modulus. According to the experimental mixtures, the combination of 2% sugarcane bagasse ash with 4% lime was obtained as the optimum composition.

There are several different hydraulic models to estimate unsaturated conductivity, but a few researches have evaluated the ability of these models for simulation of water movement in porous media. In this study, we evaluated the performance of 5 different hydraulic models, which used in HYDRUS-2D model (van Genuchten-Mualem, modified van Genuchten, Brooks and Corey, Kosugi and Durner) in simulation of water content profile in surface drip irrigation. Moreover, in order to improve results, a combinational averaging model using BMA method, based on weighting to the hydraulic models performance is presented. In this study, a sandy-loam soil was irrigated using T-Tape drip tubing. Two drip irrigation trials (8 and 24 hour) were carried out. Evaluation of simulated and measured soil water content was performed by using adjusted coefficient of correlation, RMSE and normalized root mean square errors (NRMSE). Based on the results, the NRMSE in soil water content prediction for 8 and 24 (hour) times was calculated in the range of 20 to 29 and 26 to 39 percent, respectively. In addition, the RMSE for 8 and 24 (hour) times was calculated in the range of 0. 04 to 0. 06 and 0. 05 to 0. 09 (cm3cm-3), respectively. The average regression coefficient for 8 and 24 (hour) times was calculated 0. 93 and 0. 89, respectively.

In the past decades, human activities changes the quality of water resources significantly so that water resources have been contaminated or to be contaminated in the future. In this way, agriculture has more contribution to reduce water quality and increase consumption of surface water than other activities. Agricultural management in river’ s watershed is one of the main approaches to improve the quality of water resources. Water quality simulation models in the basin scale, are the practical tools to simulate the impacts of various activities such as agriculture on the quality and quantity of water resources. In this study, the SWAT model to simulate the salinity load under two cycles, heavy metals and nitrogen in the catchment basin Navrood who represents the West Guilan, was used. The accuracy of the model to simulate the salinity in the two methods was compared. Calibration and validation of SWAT was conducted by data series of salinity and discharge during 2006-2013. To assessment the efficiency of model, two statistical indicators R2 and NS was calculated. The values of the indicators in simulating river flow were 0. 82 and 0. 58 respectively. In salinity simulation, these indicators were 0. 30 and-0. 71 under heavy metals cycle and 0. 61 and 0. 54 under nitrogen cycle, respectively. Therefore, the use of the nitrogen cycle in simulation of salinity load of Navrood basin is recommended.

Monitoring the quality of water resources and reservoirs is very important however water sampling is a very time consuming, costly and sometimes dangerous task. Satellite and aerial images from surface water could be applied to monitor water quality parameters of different water bodies effectively. In this research the possibility of estimating and monitoring chl-a concentration in Ekbatan reservoir is evaluated using Landsat 7 images. Different conversions were applied to bands reflectance and the relation between chl-a concentration with reflectance were examined and derived. Then the best model for estimating the concentration of chl-a was selected. The results of study showed that the equation based on the band ratio have the most precise estimate between all models. The value of R2Adj and SE were 0. 91 and 0. 04 respectively. The results show that using Landsat 7 images the concentration of chl-a could be estimated accurately.

biochar have the ability to remove organic pollutants from soil, water and sediments, and thus lowering their bioavailability and preventing toxic substances transferring from environment to plant and organisms. In this study, the ability of different biochars to adsorb the methylene blue (MB) was investigated. The biochars were produced from rice straw, rice husk, sugarcane bagasse and dicer wood chips in 300˚ C and 600˚ C temperature. Kinetic experiments were carried out to determine, optimum pH and adsorbent dosage. The adsorption isotherm was done using rice straw biochar (RSB) which is producing at 600˚ C. The results showed` that RSB600˚ C, had the most ability of methylene blue adsorption. Adsorption of methylene blue by RSB600˚ C was equilibrated after 300 min. The optimum pH and adsorbent dosages were 7 and 2. 5 g/L respectively. The methylene blue adsorption of RSB600˚ C was fitted to Langmuir isotherm and maximum adsorption capacity of RSB600˚ C was 27. 85 mg/g. Therefore it can be concluded that RSB600˚ C is a good reliable adsorbent for removal of MB from aqueous solutions.

Microorganisms are one of the important parts of soil, that their activity and population can be affected by the high levels of heavy metals such as lead (Pb). The objective of this study was to evaluate the changes of Microbial Indicators of inoculated fungi and bacteria in Hyoscyamus niger rhizosphere at different levels of lead (Pb). For this purpose, a soil was selected and various levels of Pb (0, 250, 500 and 1000 mg Pb kg-1 soil) were uniformly added to the soil. Then soil was sterilized and after soil inoculation with the mycorrhizal fungi (a mixture of Glomus intraradices, Funneliformis mosseae and Glomus fasciculatum species) and bacteria (species of Pseudomonas including P. putida, P. fluorescens, and P. aeruginosa), Hyoscyamus (Hyoscyamus niger L. ) was grown. This study was carried out under greenhouse condition as a factorial experiment based on a randomized complete block design and in three replications. Results showed that increasing of Pb levels at soil, led to a significant (P≤ 0. 05) reduction in the amounts of root colonization (41. 1 percent), soil bacterial population (52. 8 percent), soil microbial respiration, substrate induced respiration and microbial biomass carbon. While the metabolic quotient was not change significantly (P≤ 0. 05). The maximum and minimum of changes (at Pb1000 compared to Pb0) were observed in microbial biomass carbon at bacteria inoculation (83. 0 percent) and metabolic quotient at fungi inoculation (18. 9 percent), respectively. The amount of microbial biomass carbon in fungi treatment was greater (1. 28-2. 62 times) than that in bacterial treatment. Results of this study indicated high sensitivity of bacteria on high levels of soil Pb contamination as well as higher tolerance of the fungi.

in this study the efficiency and effectiveness of six PSB (Pseudomonas fluorescens Tabriz, P. putida Tabriz, Pseudomnas sp. C16-2O, Enterobacter sp. S16-3, Bacillus megaterium JK6 and B. firmus) in the basal formulation of rock phosphate (45 g), bagasse (30 g) and sulfur (15 g) after providing initial appropriate microbial population were evaluated. Also in this experiment, Pantoea agglomerans P5 bacteria which used in Barvar2 fertilizer was applied as a positive control. This experiment with 17 treatments in four replications was carried out. Treatments included: Negative control treatments (no microbial or chemical), positive control (triple super phosphate fertilizer based on soil test or TSP), PMF powder without adding bacteria, PMF related to any of six bacteria which prepared in equal (0. 6 g) and twice (1. 2 g) the amount of recommended TSP fertilizer. The results obtained from the greenhouse experiments showed that the microbial phosphate fertilizers significantly influenced on wet and dry weight of roots and shoots, chlorophyll index, and uptake of phosphorus in the root and shoot of corn S. C. 704. Inoculation with some of PMFs caused an improvement in the measured parameters. In most measured parameters Enterobacter sp. S16-3 and Pseudomonas sp. C162-O had a similar effect like Pantoea agglomerans P5 treatment, and these treatments had higher performance than TSP (except in the case of measuring element P). P. fluorescens and P. putida treatments were in the next order and they had similar effect on plant growth. It should be noted that the PMF produced by B. firmus in some cases and PMF made by B. megaterium in most parameters showed lower performance compared to the negative control and even lower than the treatment without No Carrier.

The present study was done to investigate a few decades application of raw municipal wastewater on soil physical quality and biological yield of wheat in Harsin. In this way, the main soil physical properties, which effect on soil physical quality, and total concentrations of some heavy metals in the soils of ten sites, that have been irrigated by wells water or wastewater, were statically analysed. The results showed that the use of wastewater, while added organic matter to the soil, improved aggregate stability, reduced soil bulk density, and increased other soil physical properties, including: saturated hydraulic conductivity, total porosity and saturation percentage. The total concentrations of Zn and Fe in the lands that had been irrigated by wastewater were significantly more than in the lands had been irrigated by wells water, while, concentrations of Cr, Pb and Ni were not significantly different. In general, application of wastewater improved the soil physical quality and meanwhile increased biological yield of wheat in the study area. .

The Clark Instantaneous Unit Hydrograph is getting popular because of its easy accessible parameters and application to ungauged catchments. This study focuses on simulating the unit hydrograph of Mohammad-Abad watershed, Golestan Province and analysis of relative and absolute sensitivity analysis of the Clark time-area model. The time-area histogram of the study area were identified using dimensionless Laurenson’ s method. The instantaneous unit hydrograph of study area was also calculated by the Clark model and then converted to direct runoff unit hydrograph. The sensitivity analysis of the Clark model has been conducted by changing the input model parameters (time of concentration and storage coefficient) to obtain the relative and absolute sensitivity of the model to estimate the unit hydrograph components. The observed index unit hydrograph were derived using S-curve method and the efficiency of Clark IUH model in predicting hydrologic watershed response hydrograph was evaluated by Nash-Sutcliffe efficiency criterion. The results showed that the model efficiency was 71% in predicting the response of unit hydrograph. The model sensitivity analysis indicated that the relative sensitivity of the Clark model to storage coefficient parameter was-0. 66 in estimation of peak discharge of unit hydrograph. Also the absolute sensitivity of the model was-2. 76 with respect to changes in concentration time. It can be concluded that the time of concentration was the sensitive parameter in accurate estimation of time to peak of unit hydrograph.

using of concrete lining for erosion control water conveyance channels in mountainous and impassable ways in many areas due to high cost of providing and transportation materials is not economical. This Parameter in gypsum soils due to the higher solubility and erosion is Very important. Previous studies show that additives cement and the other materials to Location soils, can increase compressive strength soils. The application of micro silica for stabilization gypsum soil and Evaluation of erosion and compressive strength could have major differences with previous research. In the present study, the erosion and compressive strength due to jet flow plane with samples analyzed. Results indicate that, the incipient erosion in samples dependent with speeds, angles and times of erosion. For samples with 10% micro silica, velocity 4 m/s and impact angle vertical (Ө =00) the mixture of 10% cement at 6 hours and the mixture of 12% cement at all of time (8 hours) and velocity 6 m/s and impact horizontal (Ө =900) both of mixture (10% and 12% cement) all of time (8 hours) of experiment were resistance to erosion.

Every year, long waves attacks such as tsunamis cause coastal erosion and destruction and bring irreparable damages to the life and properties of people. Recent approaches of coastal protection are based on environmental balance. Of the new methods of coastal protection against destructive force of waves is planting coastal forest known as green belt. Coast slope is one of effective factors which contributes with the wave breaking condition and wave run-up. Hence, the aim of present study is to investigate the effect of coast slope on solitary breaking waves attenuation by coastal forest. To this purpose, a sloping coast and a coastal vegetation model were installed in a flume equipped to a frictionless force measurement system. The experiments were conducted in four different coast slopes in both with coastal vegetation and without coastal vegetation mode. The results indicated that increase of the coast slope causes the waves to break faster into vegetation area, hence more wave force absorption. The amount of the wave force reduction in presence of vegetation in comparison with the non-vegetated condition in different coast slopes was 17 percent on average.

The presence of heavy metals in the environment, especially in water creates environmental problems. Effective technology to remove metals are using of adsorbents and some of adsorbents that economically, availability and high power to extract heavy metals better than others. In this study, sorption of Cd and Pb by diatomite (Iranian diatomite and French diatomite) from aqueous solutions, a batch experiment were conducted with various metal concentration (0 to 200 mg L-1) and 0. 03M NaNO3 were applied as a background solution. Scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray Fluorescence (XRF) were used to characterize the adsorbents. The cation exchange capacity (CEC) values for Iranian diatomite and French diatomite were 80 and 15 cmol kg-1, respectively and surface area of diatomites were calculated as 55 and 23 (m2 g-1), respectively. Adsorption data were fitted to Langmuir (R2=0. 89-0. 99), Freundlich (R2=0. 81-0. 98), Temkin (R2=0. 80-0. 98), Dubinin-Radushkevich (R2=0. 83-0. 97) and Elovich (R2=0. 26-0. 90) isotherm models. The results showed that the sorption affinity of Pb onto both adsorbents was greater than that of Cd. Also Iranian diatomite can adsorb more Pb and Cd than French diatomite. The maximum adsorption capacity (qmax) of Pb was 65. 8 and 41. 23 (mg g-1) for Iranian diatomite and French diatomite, respectively, and the maximum adsorption capacity (qmax) of Cd was 47. 30 and 35. 56 (mg g-1) for adsorbents, respectively. According to the results, abundant, locally available cheap minerals of Iranian diatomite showed a greater efficiency for removal of Cd and Pb from the aqueous solution, also can be used for water pollutants.

Awareness of the dominant patterns of radiation fluctuations in any region is important in terms of planning for the use of solar energy potential. In this study solar radiation time series’ signals has been investigated from a new perspective, based on the fractal geometery (self-similar). In this regard the fractal dimension of daily solar radiation time series was calculated with Minkowski-Bouligand method and with clearness index consideration used for classification the days of year in terms of radiation properties. Results showed that in the years of 2014, 2015 and 2016 the highest Probability of occurrence was belong to class 3 (overcast sky) with 55. 2%, 52. 07% and 44. 8% respectively. The Days belonging to class 1 (clear sky) and class II (semi-cloudy sky) are ranked second and third in terms of probability of occurrence in all three statistical years. The results of this new method, that classes the days of the year based on solar radiation behavior, can considered as an essential step in photovoltaic cells installation and performance analysis in one region.

To evaluate biomass production and lead (Pb) uptake and translocation in three varieties of cabbage a factorial pot experiment with completely randomized design and three replications was performed in the greenhouse conditions. The experimental treatments consisted of six levels of soil contamination to Pb (0, 50, 100, 150, 300 and 400 mg/kg soil using lead nitrate [Pb(NO3)2] as Pb source) and three varieties of cabbage (Brassica oleracea var. acephala L., Brassica oleracea var. italica L. & Brassica oleracea var. capitata L. ) which were examined in triplicate. The Analysis of variance of the data showed that the treatments had significant effects (P<0. 01) on fresh and dry weights of biomass, leaf surface area and the leaf chlorophyll index of all varieties of cabbage. With the increase in the levels of soil Pb, the accumulation of Pb in root, stem and leaf of the cabbage cultivars increased significantly. In ornamental and broccoli cabbage cultivars, the Pb concentration of root was more than that of aerial parts, but in leaf cabbage, the Pb concentration of aerial parts was more than that of the root. The highest Pb uptake was belonged to the cabbage (2. 64 mg per plot) and the broccoli cabbage and the ornamental cabbage were in second and third places respectively. The translocation factor for the ornamental and broccoli cabbage cultivars was less than one, but for the leaf cabbage was more than one. The bioconcentration factor for all varieties of cabbage was less than one. According to the standard (FAO/WHO) was observed that the lowest and the highest concentration of Pb in all three varieties was more than allowed critical. Therefore, is necessary in case of the cultivation in areas contaminated with heavy metals, be measured the concentration of metals in the food part they before supply these products to market.

Present research covers the results of a theoretical and experimental investigation on a circular and quadratic flap gate, which installed at the exit of a circular channel. This study would employ an experimental program in a horizontal channel of circular cross section of 200 and 300 mm diameters, equipped with either a circular or quadratic flap gate to explore the basic parameters affecting the flow discharge estimation of these devices. In this study, of three ways such of the first form Stage-Discharge technique, incomplete self-similarity theory and the second form Stage-Discharge technique have been used for estimating the discharge for circular and quadratic flap gate under free flow conditions. The research took the advantages the main difficulties during the experiments were the vibration of the gate as well as accurate measurement of gate opening. The use of second form Stage-Discharge technique would overcome such weaknesses. The most accurate of these methods is incomplete self-similarity theory. In this theory, mean absolute relative error for circular flap gate is equal to 3. 34% and for 4. 1% for quadratic flap gate.

Crop simulation models are valuable tools for quantifying crop yield response to water, and for devising strategies to improve agricultural water management. In this study, AquaCrop model was evaluated for simulation of potato biomass, yield and water use efficiency under different irrigation levels. To model evaluation was used from fields results of years 2013 and 2014 at research station of the SHahrekord CHahartakhteh. Field experiments included three irrigation levels; full irrigation (FI), 80% of the water requirement (I80) and 65% water requirement (I65). The model was calibrated and validated using data of the first and second years, respectively. NRMSE index was obtained for yield and biomass in FI, I80 and I65 treatments; 8. 5 and 9. 58, 18. 16 and 14. 42 and 30. 59 and 25. 08 percent, respectively. Was calculated R2 coefficient to compare of yield and biomass in validation step between 0. 92 to 0. 99, which showed the model accuracy for simulation. The model precision was the level lowest in I65 so that the index of agreement (d) was determined for biomass and yield 0. 79 and 0. 91, respectively. The difference percentage of between measured and simulated water use efficiency for treatments FI, I80 and I65 was calculated 9. 2, 11. 8 and 15. 1. In the end, the results showed that the model has less accuracy in I65 treatments

In this paper, the effects of various parameters on incipient motion of a repelling rubble-mound spur-dike are experimentally explored. To this end, the velocity of incipient motion is measured for a repelling rubble-mound spur-dike with various angles composed of 100, 110 and 120 degrees, various mean particles diameters (i. e. 3. 55, 7. 1 and 11mm) and various percentage of submergence (i. e. 31. 2, 50 and 68. 7%). To observe prone area of the spur-dike to failure during the experiments, all the process was recorded using a video camera. Moreover, a vectorino+ Doppler velocimeter was used to measure velocity field around rubble-mound spur-dike. Results show that 10% increase in repelling rubble-mound spur-dike installation angle results in 5. 35% decrease in failure threshold. It is also observed that the intersection of upstream or downstream sides with frontal side of spur-dike are prone area to failure. ADV measurement show that these areas are those areas where the highest values of turbulent kinetic energy and Reynolds stresses occurs. In fact, the highest value of in the interaction of upstream side and frontal side, along the shear layer happens which can cause spire-dike failure Moreover, negative values of and leads to stone accumulation behind the spur-dike.

Soil porosity plays the major role in relation with soil genesis, soil processes control and its interactions with the environmental factors and translocation of water and solutes. The heterogeneity of soil porosity components is simplified by considering some assumptions such as taking into accounr all of the pores do actively and are spherical. Micromorphological approaches by direct observation and determination of soil pores geometry prepares detailed characterization of soil pores. The aim of this study was quantifying soil pores geometric properties using flouerecent dye method. 39 undisturbed soil samples impregnated with a mixture of resin-acetone containing flouerecent dye, dryed out and cut. Then 40 digital images were taken from each sample under ultraviolet light. The images were thresholded until the soil pores distinguished as white from the matrix. The results of pores based on area, perimeter, elongation, compaction, roundness, ferret diameter, long and short axis diameters were classified visually. The quantitative results of pores area showed that the pores smaller than 100 μ m2 in the plough layer (depth < 35 cm) were less than 16% while it increases to > 29% in the plough pan due to compaction. Pores with > 100 μ m2 area in plough layer increases > 80% of total porosity. The dominant compaction class was the (0. 3-0. 5 unit less) that its maximum percent was (56. 94%) in the depth of 35-30 cm. According to the elongation index the most elongated pores (the class <0. 1) was observed in the surface layers (0-10 cm) while it decreased to 33. 8% in 30-35 cm. From the roundness point of view more than 55% of pores in all studied depths showed the roundness index of 0. 05-0. 1.

Today the main function of drainage, is not only out excess water, but its main purpose has changed to manage the water table. Controlled drainage is one of the procedures that can fulfill this goal. In this study, controlled drainage system in the lands of the Maghan plain was implemented to reduce the volume of drainage water, water table management, increase efficiency and productivity of water use efficiency in corn and wheat. This study was implemented in 40 hectares' area in three treatments and three repeated included free drainage (FD), controlled drainage with fixed control depth 70 cm (CD70) and controlled drainage with variable depth during plant growth (CDch). The collected information includes the discharge from drains, temporal and spatial changes in water table levels and production of corn and wheat crops in two consecutive seasons. The results showed that volume of laterals drainage in CDch and the CD70 treatment 51. 2 and 43. 8 percent in corn and 46. 6 and 33. 1 percentage for wheat declines into significant related to free drainage (FD). Investigation on water table fluctuation revealed that the free drainage has more frequency than the controlled drainage treatments. The wet forage in maize in the treatment of CD70 and CDch was to the 24. 9 and 19. 1 percent and in grain wheat increased 41. 3 and 26. 6% percent compared to the treatment of FD. Finally, the results showed that the water use productivity in controlled drainage treatments and especially is the CDch treatment was more than free drainage treatment. By implementing controlled drainage system in addition to reducing drainage water, it will be reduced the environmental damage caused by the drainage for downstream farms.

Rivers are one of the most important borrow aggregates and sand and gravel mining in rivers due to the morphological, hydraulic and sediment transport characteristics and methods of extraction creates many negative effects in them. In this research, the influence of distance and shape of consequent bed material mining pits is investigated in order to infilling and rehabilitation and mining management with considering of incoming sediment via an experimental study. The results indicated that, by increasing of the distance between the pits, infilling of upstream pit is constant. But extraction along channel width can increase filled volume of upstream pit up to 10% and can increase migration velocity up to 42%. When the distance between the pits doubles, extraction along channel width can increase filled volume of downstream pit up to 28% compared to the extraction along channel length and reduction of migration velocity is up to 70% in extraction along length and width.