Journal of Water and Soil Conservation
Year:2020 | Volume:27 | Issue:1|Papers Count:14

Background and Objectives: During the recent decades dust storms have become serious natural hazards in the world. Although dust storms have been investigated in various aspects, variation in wind speed and visibility and the frequency of dust storms require more investigation. In this study, diurnal, monthly and yearly variation of parameters including wind speed, visibility and PM10 (particulate matter 10 micrometers or less in diameter) and frequency of dust storms was studied in the Sistan region for the twenty seven-year period. Materials and Methods: Sistan in the southeast part of Iran is considered as the study area. Sistan has an arid and semi-arid climate with very low precipitation (59 mm) and humidity and high evaporation (nearly 4820 mm) and annual temperature (22 ° C). To analysis the diurnal, monthly and yearly variations of wind speed and visibility, the collected data at the Zabol meteorological station were obtained from the Iran Meteorological Organization for the study period. DDI (Dusty Days Index; the days with wind speed more than 15 m/s and visibility less than 1000 m) and DSI (Dusty Index) were applied in this study to analysis the monthly and yearly frequency of dust storms during 1991-2018. Furthermore, the hourly concentration of PM10 was received from the meteorological and environmental stations of the respective centers during 2013-2018. Results: The results show that the diurnal variation of wind speed, visibility and PM10 was similar in all months during the study period. The highest PM10 concentration and lowest visibility were observed at 10: 30 am in accords with highest wind speed. The highest visibility occurred at 7: 30 pm when PM10 and wind speed were lowest. The highest DDI, DSI and PM10 values-8 days, 15 days and 662 𝜇 𝑔 𝑚 − 3 respectively, were observed in June. The highest DDI and dust storm duration-74 days and 3186 minutes (531 hours) were observed in 2001. The period of 1999-2004 is dustier than the periods of 1990-1999 and 2005-2018. DSI were 174, 14 and 66 days in these periods, respectively. Strong correlations were observed between wind speed and visibility, wind speed and PM10 and, visibility and PM10. These correlations show that PM10 and visibility are dependent on wind speed. Furthermore, positive correlations were observed between PM10 and wind speed, DSI and wind speed and DDI and wind speed. These correlations indicate that variations of PM10, DSI and DDI are highly dependent on wind speed. Conclusion: In the study period of 27 years, the Sistan region is dustier than other parts of Iran due to higher intensity and frequency of dust storms in this region. Dustiness in the Sistan region is highly dependent on the situation of Hamoun Lake and thus the recovery of the lake is the best controlling approach to reduce the intensity and frequency of dust storms.

Background and Objectives: Groundwater recharge is one of the most important factors in sustainable development and management of groundwater resources. Obviously, other hydrological, social and economic factors should also be considered. Estimation of recharge is a complex and challenging process. This is due to the fact that recharge is dependent on variables such as land use, topography, soil, climatic conditions, as well as other hydrological factors. In this research, the monthly water balance components were estimated using the distributed WetSpass model. Materials and Methods: In this research, water balance components including evapotranspiration, interception, runoff, and groundwater recharge for the Arazkouse Watershed during the years 2001-2015 on a monthly basis at spatial resolution of 100×100 m were simulated using the WetSpass model and rainfall, temperature, evaporation, wind velocity, groundwater depth data and soil texture, topography and land use maps of the area. Results: The findings in this research are based on evaluation criteria used in calibration and validation periods of flow hydrograph components including direct runoff, base flow, and total flow simulated by WetSpass model and hydrographs separated by WHAT software. The WetSpass model had a relatively satisfactory performance for simulating groundwater recharge and other hydrologic components of the Arazakouse watershed. It should be noted that the Nash-Sutcliffe coefficient values for the calibration and validation periods as standard criteria of evaluation in the hydrological simulations for direct runoff are 0. 6 and 0. 51, respectively. In addition, considering the base flow, the Nash-Sutcliffe criteria for the calibration and validation periods were 0. 55 and 0. 50, respectively. The values for total runoff for calibration and validation periods were 0. 63 and 0. 53, respectively. After investigating the efficiency of the model, the temporal-spatial distribution of water balance components for different land use types and slope classes was investigated. The analysis shows that the variability of the hydrologic components is significantly affected by climate and its seasonal changes, and also by characteristics of physiography, vegetation and land use. The annual volume of recharge and runoff in the forest areas are 23115791m3 and 1776217m3 respectively. The highest proportion of groundwater recharge in forest lands belongs to slopes above 0-10%. The highest proportion of runoff in this land use belongs to slopes above 30%. The highest volume of annual runoff in the Arazkouse watershed is in the residential areas in medium and high slopes with 156300m3. Conclusion: According to the research, it can be stated that the amount of water balance components, especially the amount of recharge as an important factor in the investigation of surface and groundwater interaction are influenced by climatic, physiographic and land use/land cover factors. Therefore proper estimation of water balance components can play an important role in sustainable management and development of surface and groundwater resources.

Background and Objectives: The unceasing growth in demand for water in the industrial sector, drinking water and reduction in the amount of water available for agricultural sector has led to a reduction of water usage in rice, which threatens its production. Crops simulation models can be used to carry out various studies such as selection of suitable cultivar and plant, determining the best agricultural management and production capacity of the area. The purpose of this study was to investigate the ORYZA2000 accuracy in simulating grain and biomass yields, and studying water balance and productivity of rice affected by irrigation and planting dates. Materials and Methods: In order to evaluate the ORYZA2000 model and investigate the productivity of rice production under irrigation management and planting date, a split plot experiment based on a complete randomized block design with three replications was carried out on a local (Hashemi) cultivar in the years of 2016 and 2017 in the Rice Research Institute of Iran, Rasht. Irrigation interval was considered as the main factor at 4 levels including full flooding, 5, 10 and 15 days irrigation intervals and transplanting date was assigned to subplot at three levels (April 21th, May 11th and May 31th). Evaluation of simulated and observed values of grain yield and biological yield was conducted based on coefficient of determination, T-test, root mean square error (RMSE) and normalized root mean square error (RMSEn). In this research, the water balance equation throughout the growing season was considered which its components included irrigation, rainfall, actual evaporation, actual transpiration, leakage and deep penetration and changes in the water stored in the root development zone. Water productivity was investigated based on the grain yield of rice for transpiration, evapotranspiration, irrigation and total precipitation and irrigation. Results: The results of this study revealed that normalized root means square error of the grain yield and biological yield were determined 8% and 6%, respectively. Also, the results showed that among water managements, flooding irrigation and 15-day irrigation interval had the highest water productivity regarding transpiration and evapotranspiration and the amount of input water and irrigation, respectively. Among the planting dates, the planting date of May, 11th had the highest water productivity based on transpiration, evapotranspiration and planting date of April, 21th, had the highest water productivity based on irrigation and irrigation and rainfall. In these conditions, the planting date of April, 11th and May, 21th, with an average of 136 and 116 millimeters, had the highest and lowest water reserves, respectively. The highest amount of water saving during the two years of experiment was observed in irrigation intervals of 10 and 15 days (145 and 143 mm, respectively) and the lowest was recorded in the flood treatment (92 mm). Conclusion: Considering paddy and biomass yield of rice, water productivity and water consumption, five days irrigation treatment had the best paddy and biomass yield in April 21st planting date. This treatment was the best treatment in terms of productivity and rice production, with 9% reduction in water use and 6% reduction in paddy yield of rice. According to the present study, the ORYZA2000 model can be used to support the results of experiments under irrigation management conditions and planting dates.

Background and Objectives: Bio-fertilizers can affect soil structure by affecting soil porosity and aggregate stability. In fact, the activity of soil microorganisms, in addition to their effects on plant roots, has significant effects on organic compounds and, in most cases, soil structure. Therefore, the aim of this study was to investigate the effect of bio-fertilizers namely mycorrhiza fungi (Glomus mosseae) and rhizobium (Mesorhizobium caesar) separately and together on some physical (bulk density and soil porosity) and chemical (Soil reaction, electrical conductivity and cation exchange capacity) properties of soil under greenhouse and field conditions, which has been less studied, so far. Because the application of bio-fertilizers in the soil can be one of the best ways to maintain and improve the physical and chemical quality of the soil. Materials and Methods: In order to investigate the effect of Mycorrhiza fungi and Rhizobium on some chemical and physical properties of soil, an experiment was conducted in both field and greenhouse conditions in a completely randomized-block design with three replications. Mycorrhizal fungi specie Glomus mosseae, rhizobium (Mesorhizobium), mycorrhiza-rhizobium and control (no bio-fertilizer) were the treatments at the field condition. Sterilized mycorrhiza background material and non-plant (non-bio-fertilizer) were the two additional treatments in the greenhouse condition. The plant cultivated in this experiment was chickpea. At the end of the growing season, disturbed and undisturbed soil samples were taken from different depths and physical and chemical soil properties, mentioned above, were measured. Results: In the field and greenhouse conditions, mycorrhiza treatment reduced soil pH. Different treatments had no significant effect on cation exchange capacity under greenhouse and field conditions. Probably because, the cation exchange capacity associated with the soil specific surface area. In the greenhouse condition, the lowest bulk density at the first depth 0-5 cm (P<0. 05) was observed in pots containing mycorrhiza-rhizobium treatments (1. 30 g cm-3) and mycorrhiza (1. 36 g cm-3) and the highest bulk density was observed in the control treatment without plant and without inoculation (1. 49 g cm-3). Also, treatments containing bio-fertilizer significantly increased soil porosity compared to the control without plant. So that, in the first depth (0-5 cm), the mycorrhiza × rhizobium bacteria treatment (0. 50 cm3cm-3), in the second depth (5-10 cm), the mycorrhiza treatment (0. 49 cm3cm-3) and in the third depth (10-15 cm), all three bio-fertilizer treatments, had the highest porosity. The field conditions reduced the effects of the treatments on the soil physical properties, which may be due to the less impact of the treatments applied due to the large extent of the area and the uncontrolled environmental conditions. Conclusion: Since different bio-fertilizer treatments had different effects on rooting depth and plant yield, the effect of the different treatments on soil structure improvement was different at different depths. In general, treatments containing bio-fertilizers improved the soil physical parameters and structure by affecting plant and root yield.

Background and Objectives: Understanding the ecological and geomorphological processes of the spatial distribution of loess deposits helps us to find their interactions in the arid and semi-arid regions. The Iranian loess plateau with a unique landscape and complex topography also located in steppe vegetation with semi-arid climate. The aims of present study are point pattern analysis of hillside, stream and their interactions using different summary statistics in the particular part of Iranian loess plateau. As there is a small distance between hillslope and complex topography in the study area, unmanned aerial vehicle (UAV) imagery used to prepare precise colored aerial photos for statistical analyses. Further, regarding to the mentioned purposes, this research has enough novelty compare with previous studies, and thus, it is a new step in studying the spatial pattern of loess facies; In other words, this study attempts to find the effective relationship between the hillside and streams in terms of the expansion of channel erosion in the study region. Materials and Methods: The study area has dry Xeric soil moisture and Thermic soil temperature regimes. The UAV technique used to prepare the precise colorful images with highly spatial/temporal resolution to model the spatial patterns of hillside and streams density. The topographic attributes (primary and secondary) obtained from digital elevation model (DEM) applied with a spatial resolution of 20×20 cm. The univariate and bivariate point analyses (modelling) used for variable analyses in Spatstat package in R and Progammita software. Finally, Mark correlation function (MCF) used to investigate the question of reducing the size of density dependent. Results: The results of univariate g(r) and O-ring (r) showed that different hillside facing i. e. flat, north, south, east, and west have the aggregated pattern in all distances in the study area. These implied that the same directions are distributed more closely next to each other and their arrangements follow the special pattern. In addition, the interaction between streams and north-face using the bivariate g12(r) and O12(r) confirmed the positive interaction between streams and north-face in all distances in the study area. The MCF analysis also showed that the slope as the effective factor has positive interaction with streams, and steep slopes are more aggregated compare with the low slopes. This suggests that the steeper slopes are more likely to form streams than flat lands. Conclusion: Generally, the streams probability form in the steep slopes more than flat areas due to their shear energy, which leads to more soil losses. Further, the soil loss on the steep slopes is more than flat terrain. Finally, UAV technologies are recommended in the study of spatial pattern of deposits for detailed observations, highly accurate data, and deciding natural resource managers to reduce soil erosion.

Background and Objectives: Nowadays, due to the impact of contaminants on the general health of living organisms and humans, it is essential to identify toxic pollutants removal from water sources. At present, using low-cost locally-available wastes such as biochar has become commonplace as a cost-effective alternative to costly methods to remove heavy metals from the water environment. The main objectives of this study were to assess the Pb sorption from water solutions by the biochar derived from olive kernel, the effect of contact time, solution reaction, the initial solution concentration, the sorbent levels, the isotherms and the kinetic of Pb removal process. Materials and methods: The biochar was produced from olive kernel produced by injecting nitrogen gas at a temperature of 600 ° C for one hour under oxygen-free conditions. The biochar properties were determined using Scanning Electron Microscope (SEM), Fourier Transform Infra-Red Spectrometer Spectrum. The carbon, nitrogen and hydrogen contents and specific area were determined using CHN Elemental Analyzer and Methylene-blue, respectively. The effects of contact time (from 0. 5 to 16 hours), solution pH (from 2 to 8), sorbent contents (from 0. 2 to 10 g. lit-1) and Pb concentration (from 25 to 2500 mg. lit-1) on Pb removal from water solution were studied. The sorption isotherms was studied using Langmuir and Freundlich isotherms. Results: Based on results, cation exchange capacity of olive kernel biochar and olive biomass were 57. 42 and 8. 12 Cmol kg-1, respectively. Specific surface for olive kernel biochar and olive kernel biomass were 13. 2 and 3. 92 m2 g-1, respectively. The results obtained from SEM confirmed that the produced biochar had more pores than olive kernel biomass. Carbon percentage in the produced biochar was 1. 5 times higher than that of olive core biomass. It was observed that 31 to 71% of total Pb was removed from water solution by amended biochar during the time. The maximum sorption was observed after 8 hours. The amount of lead adsorption increased by increasing the pH of the solution to about five and then decreased. The optimum sorbent content for used biochar was 4 g lit-1. The results showed that biochar adsorption of lead ions follows Langmuir isothermal model. The results of kinetic models showed that, the adsorption of lead corresponded to the kinetic model of the pseudo-second-order equation (R² = 0. 99). Conclusion: Considering Considering the economic aspects of olive kernel biochar production, it is recommended as a suitable, efficient and inexpensive adsorbent for lead removal. These findings can provide useful information for environmental management with respect to Pb removal, especially around Pb-processing factories and polluted areas of Zanjan province.

Background and Objectives: Although evidences suggest an increase in salinity and depletion of water and soil resources, the growing demand for food has made the use of unsuitable and unusable water quality unavoidable due to severe population growth and lack of quality water resources. Salinity affects the germination and seedling growth of plants through the toxicity of the elements, disruption of the absorption of the elements and the reduction of water potential. The establishment and germination stages are the most sensitive stages of plant growth to salinity and there are several methods to reduce the negative effects of soil and water salinity and increase the uniformity of emergence and ultimately yield of plants. Application of electric shock and hydropriming, respectively, are new and practical methods to increase salinity. Although, there is limited scientific information regarding the effects of electric shock on seed germination, seed priming is one of the most commonly used methods to reduce the negative effects of salinity. These methods induce initial resistance to salt stress. For this purpose, an experiment was conducted to investigate the effect of priming and electric shocks on germination and some of the initial vegetative traits of wheat. Materials and Methods: The experiment was carried out in a factorial experiment with three replications in two separate experiments in the year of 2017 at the research site of Medicinal plants of Faculty of Agriculture, Torbat-e-Heydarieh University. Factors include seed primer at two levels (non-primer and primer with distilled water for 48 hours), electric shock at two levels (non-shock and electric shock with a voltage of 20 kW) and salinity with sodium chloride at three levels (zero, 200 and 400 mM). The field test was performed as a split factor in the form of a randomized complete block design in the 2016-2017 crop year at the Medicinal Plants Research Institute of the Faculty of Agriculture, Torbat-Heydariyeh University. Salinity stress treatments were applied as the main plot and shock levels and pre-treatment as a factor in the sub-plot. The treatments were similar to the germination test. Due to the fact that the water used to irrigate the saline farm was about two decimetres per meter, it was considered as a control treatment. Results: The results of analysis of variance showed that the effect of seed primer, induction of electric shock and salinity and their interaction at 1% level in all studied traits had a significant effect. The results of simple effects of three independent factors showed that the primitives of the seeds before cultivation increased all studied germination traits (other than germination speed). Field results indicated that traits were affected by different treatments of primer, shock and salinity. Seeds and application of electric shock caused a significant increase in the number of spikes per square meter, number of seeds per spike, 1000 seed weight, chlorophyll A, plant height, grain yield and biological yield, as well as harvest index of wheat and increasing salinity levels significantly reduced these traits. The decrease in traits was higher due to increased salinity levels in non-primer-non-shock conditions compared to primer-induced shock conditions. Conclusion: The application of electric shock and hydropriming significantly increase the seed germination and primary growth of wheat and so increase the competition power with weeds on lab. and in addition in farm conditions, electric shock and seed priming enhanced yield and its components, especially in salinity stress conditions.

Background and Objectives: Water resource management is often associated with conflicts such as the lack of satisfaction of water users with the amount of water allocated to them. Different stakeholders are involved in water resources allocation and the water allocation to each of them affects the type of their strategic behavior. The game theory is a method for studying the strategic behavior of decision makers in water resource issues with the goal of developing appropriate strategies and can be used in modeling water allocation. In this paper, the non-cooperative game theory by application of stability definitions is considered for the modeling of the bilateral agreement by the industry and agriculture sector in unequal conditions. Materials and Methods: In this study, the water allocation issue between industry and agriculture sectors has been investigated by various stability definitions. Each of two industry and agriculture sectors needs to increase the amount of water to expand their activities. The agricultural sector is able to share its water to the industrial sector in exchange for the cost, while the industry can provide agricultural machinery and equipment in return for payment. The agricultural sector has two strategies, water sharing and no water sharing. While the industry sector also has two payment and no payment strategies that can take each one. In order to solve the problem, linking this game and another game in which the industry sector has advantages than the agricultural sector can be proposed. In this case, the exclusive privilege of each sector are considered, in which case each of the two agricultural and industrial sectors will benefit from the cooperative game and will less willingness to engage in non-cooperative behavior. Results: In this study the industry and agriculture sectors can play in the game in three ways: 1-They have both cooperative behavior. 2-Both non-cooperative behaviors. 3-One side has cooperative behavior and the other has non-cooperative behavior. Although both industry and agriculture sectors may have payments to each other, but the outcome with payment, according to the Nash and Limited-Move and Non-Myopic stabilities, is not stable. The results show that financial payments in this interconnected game are not perfect solution. When the payment is considered impractical, all related strategies can be eliminated. Therefore, the interconnected game becomes smaller. Each of the two sectors of agriculture and industry does not have the desire to change the cooperative behavior due to possible threats from the other part. In other words, if the agricultural sector decides to change its behavior to increase its outcome, the industry sector has changed its decision. Therefore, the agricultural sector will not shift its strategy from cooperative to non-cooperative behavior. This is precisely the behavior that is consistent with the GMR, SMR, SEQ, Limited-Move and Non-Myopic stabilities. Conclusion: In this research, the non-cooperative game theory and stability definitions have been used to model water allocation and bilateral agreement by the industry and agriculture sectors. The concept of Nash stability in finding the ultimate solution to water resource problems, which is often not a single-player game with dynamic nature, may fail. Non-Myopic stability simulates a player's behavior by understanding the interactions among decision-makers, which may be inappropriate for water resource issues, because players cannot take more than a few moves and react in the future in the real-world. Other stability definitions can better predict the possibility of solving the water conflict. The application of these stability concepts can improve the efficiency of conflict resolution models. When there is uncertainty about the behavior of players, the application of different stability concepts is useful and can provide a suitable solution for better decision making in management problems.

Background and Objectives: Considering the growing demand for water in different sectors in one hand and reducing precipitation and its spatial and temporal imbalances, on the other hand, the water scarcity is one of the main problems of farmers in different regions. Excessive harvesting of groundwater resources also significantly reduces the groundwater level in aquifers. Planning for optimal utilization of existing water resources by introducing suitable cropping pattern with maximum benefit and minimum water consumption is necessary. Therefore, in this study, along with comparing two methods of conventional linear programming and goal programming, optimal cropping pattern and optimum harvesting rate of groundwater resources in Gorgan and Kordkoy cities in Golestan province (most of them located in the Gharehsou-Sou basin) is presented. Materials and Methods: The Ghareh-Sou watershed in Golestan province is considered a study area because it has an important part of province’ s agricultural land and it is an agricultural hub. After providing information about the area of cultivation, the cost of production and the price of sales of major agricultural products were estimated. Also, net irrigation demand was calculated considering irrigation efficiency using NETWAT software. Using information on the potential of groundwater harvesting, the optimal cropping pattern and groundwater harvesting rate, considering market constraints and the goals of increasing profits and reducing water use, is determined in both linear and goal programming and then the results were compared. Results: The results showed that considering the optimal pattern resulted in conventional linear programming, water consumption in Gorgan and Kordkuy could be reduced by 19. 6 and 8. 8 percent, respectively and the profit from agricultural production in Gorgan and Kordkuy cities will experience increase an equal to 12. 6 and 10. 4 percent. The conventional linear planning suggests the products such as wheat, rice, potatoes and forage corn in Gorgan city and wheat, rice, rainfed spring soybean and summer cotton in Kordkuy while the goal programming suggests the optimized cropping pattern with an increase of 5 percent in profit and with a 45 percent reduction in water consumption. The results of goal programming showed that the most cropping in Gorgan city should be wheat, rice, tomato, and rapeseed while it should be wheat, rice, and rainfed spring soybean in Kordkuy. Conclusion: The outcomes of conventional linear and goal programming for determination of optimal cropping pattern in Gorgan and Kordkuy cities showed there is no optimal cropping pattern in the current condition. Using the results of the study can reduce water consumption in two cities of Gorgan and Kordkuy and this decrease in water consumption will not only decrease profits but also increase profits in both cities.

Background and Objectives: Increasing population along with the global crisis of fresh water resources necessitate the use of unconventional water resources in agriculture as the largest consumer of fresh water, especially in arid and semi-arid regions. Since one of the important goals in sustainable agriculture due to the water resources crisis is to increase water use efficiency, therefore, it is necessary to use techniques to achieve this goal. Due to the scarcity of high-quality water, the use of unconventional water (municipal wastewater) is increasingly under consideration. Materials and Methods: An investigation was done to evaluate effects of different regimes of urban wastewater on performance and yield components of Quinoa plant (cv. Titicaca), at Research Greenhouse of Ferdowsi University of Mashhad, during 2017-2018. The research was based on completely randomized design with 3 replications in greenhouse conditions and in pots. Five applied treatments were urban fresh water, urban wastewater, alternate wastewater and fresh water, mixture of 50-50 wastewater and freshwater and subterranean irrigation with urban wastewater. Physical and chemical properties of irrigation water and of soil were determined before experiment. The obtained data analyzed using statistical software of SAS (Ver. 9. 0) and the means were compared using LSD test at 5% percent levels. Results: The results showed that the treatments were effective on number of leaves, shoot fresh weight, plant height, SPAD index and leaf area at 1% significance level (P<0. 01), but on number of branches, shoot dry weight and stem diameter at 5% significance level (P<0. 05). According to the results of the study, the use of urban refined wastewater increased all the traits. The results showed that the highest and lowest of shoot fresh weights (13. 9 and 7. 2 g), shoot dry weights (0. 98 and 0. 46 g), leaf number (86. 3 and 51. 3), branches number (10 and 6), height (49. 7 and 25. 9 cm), leaf area (218. 8 and 135. 8 cm2) and grain yield (24. 23 and 17. 8 g) in subterranean irrigation and control treatment, respectively. Conclusion: The urban wastewater, alternate, mixture of 50-50 and subterranean irrigation treatments resulted in an increase of 62. 5%, 37. 5%, 58. 3% and 93. 1% of total yield, respectively. Furthermore, the results of the experiment showed that the use of refined sewage water for irrigation of Quinoa crop can increase the yield of Quinoa, decrease the cost of supplying and using fertilizers.

Background and Objectives: The soil moisture characteristic curve (SMCC) is a key concept in the modeling process of physical and hydrological studies of soil that plays a critical role in soil and water management. At the same time, the accuracy of the models used to describe the SMCC is affected by the trend of its parameters changes. The uncertainty analysis of hydraulic parameters of SMCC plays an important role in the modeling process, determining the model input parameters and evaluating the performance of the models. Therefore, the objective of this study was to evaluate the application of the GLUE simulation method, which is based on Monte Carlo simulation method, to estimate the uncertainty of alpha and n variables with constant assumption of other SMCC parameters, in three models of vanGenuchten, vanGenuchten-Mualem and vanGenuchten-Burden. Materials and Methods: Initially, two soil samples were taken from Shahid Bahonar University of Kerman field and the SMCC for both soil samples (sandy loam and silty clay loam textures) was plotted on the basis of all three models using the Pressure Plate data and RETC Software and their moisture curve parameters were derived. Then, using the GLUE method, the uncertainty of alpha and n parameters in all three models were investigated. In addition, based on GLUE performance, the intrinsic uncertainty of each of the three models was evaluated for each of the tissue classes studied. Results: The posterior distribution for each of the studied hydraulic parameters were obtained for three models in each textural class. The 95% confidence interval of SMCC simulations was obtained for all three models in two texture classes as the main output of this study. To quantify the uncertainty of the models, four uncertainty assessment indices were calculated and evaluated. Based on the evaluation indices, the best models for silty clay loam and loamy sand were the vanGenuchten-Mualem model (PCI=85. 71, d-factor 0. 2013, S=0. 079, T=0. 4642) and the vanGenuchten model, (PCI=28. 75, d-factor=0. 0766, S=0. 6453, T=1. 1034), respectively. Conclusion: The results of the posterior distributions diagrams showed that the alpha and n hydraulic variables were less identifiable in the calibration process and could not determine the optimal range for them, therefore, these two variables play a major role in the uncertainty of soil moisture curve. Also, the uncertainty analysis of all three models showed that GLUE method was able to estimate soil moisture curve points so that the moisture curve obtained by RETC software for all three models was within 95% confidence level. The presence of about 85% of the soil moisture curve points for silty clay loam texture within the 95% confidence interval indicates the high capability of the GLUE method.

Background and Objectives: Lead (Pb) is a toxic heavy metal and is a ubiquitous contaminant in terrestrial and aquatic environments. The major inputs of Pb in aquatic systems come from drainage and surface runoffs effluent discharges from industries. Lead could be removed effectively by adsorption on a range of natural adsorbents. Biochar is a relatively novel sorbent produced by the pyrolysis of a feedstock under oxygen-limited or anaerobic conditions and usually has adsorption ability for heavy metals due to its higher surface area and cation exchange capacity. Agricultural residues, especially grape pruning residues, being produced in large quantities in the vineyards, are inexpensive and efficient biosorbents for Pb removal, hence, this study aimed to examine the potential mechanisms of Pb removal from aqueous solution by grape pruning residues and its biochars. Materials and Methods: In order to study the lead (Pb) adsorption behavior by grape pruning residue and its biochar, batch experiments carried out with different initial concentration of Pb (0 to 200 mg/L) with 0. 03 M NaNO3 as a background solution. The effect of pH (4, 5, 6), ionic strengths (0. 01, 0. 03, 0. 1 M) and temperature (10, 20, 30, 40 oC) were investigated. Results: The results showed that the adsorption capacity of adsorbents increased with increasing initial concentration, pH and decreasing ionic strengths. The adsorption data were well fitted with Langmuir and Dubinin-Radushkevich models compared to Freundlich and Temkin models. Sorption capacity factors (qmax, KF, B, qD) and sorption energy factors (n, KL, KT) of gape pruning residue biochar was more than grap pruning residue. Temperature of background solution significantly affected Pb adsorption and the highest adsorption capacity was obtained at 40 oC. The sorption energy parameter (E) of Dubinin-Radushkevich isotherm (3. 6 to 7. 6 kJ mol-1) and negative Gibbs free energy (Δ G) values (-16 to-21 kJ mol-1) revealed the physical adsorption and spontaneous of Pb adsorption on the grape pruning residue and its biochar, respectively. The entropy (Δ S) and change in enthalpy (Δ H) were found to be 0. 002 J mol-1 K-1 and 0. 31 kJ mol-1 for grape pruning residue and 0. 002 J mol-1 K-1 and 0. 40 kJ mol-1 for grape pruning residue biochar, reflecting an affinity of Pb on the bioadsorbents and endothermic nature of Pb adsorption reaction. Conclusion: This study revealed that the optimized pH and ionic strengths to reach the maximum sorption could be obtained based on the isotherm experiments, while the thermodynamic investigations could be of help to find the optimum temperature to achieve the most effective sorption by given adsorbent. Results from this study suggested that grape pruning residue and its biochar are effective adsorbent for the removal of Pb from wastewater, since it is a low-cost, abundant and locally available.

Background and Objectives: The estimation of sediment load is vital for designing the crossing structure and rehabilitation of rivers. Bed load transport in alluvial channels has been extensively studied and different equations have been presented based on laboratory or field data. The estimation of bed load transport rates using different equations gives different results. Due to the complexity of the interaction between sediment transport and flow behavior, there is still a high level of discrepancy ratio between the estimated and the measured values. Therefore, in each river, according to its hydraulic and geometrical conditions, it is necessary to choose the best equation that has a higher accuracy to estimate bed load in that river. In order to achieve an equation that gives a better estimation, the conditions of the study area must be carefully compared with the conditions and assumptions in which each equation is formed, so that a more appropriate and logical answer can be found which is closer to reality. Therefore, it is very important to achieve new and innovative methods that can improve accuracy in calculation of the different estimation methods for sediment loads in rivers. According to different methods of estimating sediment load in the rivers and their high computing volume the need for a comprehensive computational software is vital to increase accuracy, as well as to compare the different results obtained from these methods in this field. Materials and Methods: Considering that there is still no software that can use most of the existing equations to calculate sediment load in the rivers and provide the best equation among them, in this research by developing a user-friendly software named “ Sediment Transport Estimator (STE)” , which is designed in the VB. NET programming language in the Windows environment, the ability of available equations of estimating bed load in Babolrood River of Mazandaran province has been evaluated in 3 reaches with the names of Anarestan, Daronkola and Kelarikola; in 13 sections which bed load is measuring. Results: The results showed that by using the developed software the best method for estimating bed load in the studied river is Toffaleti method with an abundance of discrepancy ratio between 0. 5 to 2, 69. 2%. In this case, the abundance of discrepancy ratio between 0. 5 to 2 for the reach of Anarestan, Daronkola and Kelarikola are 66. 7, 100 and 50 percent, respectively. Conclusion: The Toffaleti, Yang, Yalin, Einstein-Brown and Ackers-White equations, respectively, offer better results than other equations, and the equation Toffaleti, in which 69. 2% of the data are calculating in discrepancy ratio range of 0. 5 to 2, is giving the best results in the studied river.

Background and Objectives: Potassium is one of the constituent elements of soil and plant. some plants are able to absorb about eight percent of there dry weight. Low grain size and high specific surface area (double diffusion layer) prevent potassium from spreading rapidly to the root of the plant. The purpose of this study was to investigate the effect of superabsorbent polymer A 200 and potassium and rainfed wheat loess soil. Materials and Methods: In this investigation, the effects of superabsorbent polymer on soil humidity absorption were assessed. The study used a split-plot design format. Main plots were potassium sulfate fertilizer at 2 levels (200 Kg per hectare and no potassium sulfate) and sub plots were superabsorbent at 4 levels (0, 500, 1000, 2000 kg/ha) with 4 repetitions. The research was carried out in Gorgan University of Agriculture Sciences and Natural Resources Research Farm located at SeyedMiran during 2014-2015 growing season. Row spacing was 20 cm, used 268. 5 kg ha-1 (seeds were drilled manually). Fertilizer rates were based on soil test results and which were added to soil surface before planting and incorporated. Data analysis include the analysis of variance and mean comparisons using LSD and correlation which carried out using SAS software. Results: Results showed that increasing potassium intake, stem length, straw and grain yield, number of tillers and panicles per square meter was significantly increased. As well as traits such as yield. The use of superabsorbent grain weight, tiller number, number of heads per square meter, number of grains per spike, stem length and panicle length increased. The use of superabsorbent 200A of 2000 kg per hectare yield by an average of 4489. 74 kg per hectare The highest grain yield with potassium levels of performance compared to the plots without K, the interaction between potassium. Integrated use of super absorbent polymer and potassium fertilizer is not significant and improves some characteristics and finally potassium fertilizer and super absorbent polymer yield and the most effective in increasing yield and yield components of wheat, respectively. By increasing potassium uptake, nitrogen uptake and its consumption efficiency increase The correlation between potassium and grains harvesting with grain and straw yield was also high. Correlation between grain yield and straw yield was respectively. 83. 0 and 73. 0. Conclusion: Soil moisture enhances the diffusion of potassium into root. In addition Increase soil moisture may induce increased microbial activity and decomposition of organic matter increased the concentrations of potassium and nitrogen in the soil. In the study, soil moisture with absorbent enhance the absorption of nitrogen and potassium and increase yield.