Journal of Water and Soil Conservation
Year:2019 | Volume:25 | Issue:5 |Papers Count:22

Background and Objectives: Agriculture is considered as one of the main sources of wealth in the economy. Because of its significant role in providing food, social welfare and economic growth, developing countries should keep it at the forefront of their economic plans to overcome the economic crisis. Management and planning of agricultural water resources are strategically vital. In this research, both cropping and import aspects of the products have been considered. The aim of this research is to study of land capability and existed resources for agriculture production so that it improves the economic and social conditions of the farmers in country. Materials and Methods: In this study, the data are collected from documented reports of the ministry of agricultural Jihad and the Iranian National Irrigation and Drainage Committee. A comprehensive mathematical model is presented that it aims to reduce the amount of water consumed, increase the production of strategic products and consider the social factors such as the employment of local laborers. In fact, it is possible to determine how much water can be allocated and which product should be cropped so that both water resource management and profitability is being guaranteed for farmers. Generally speaking, the nature of decision-making in the real world is uncertain and finding a solution without consideration of this issue will make the decision unrealistic. Fuzzy decision approach can be applied to tackle uncertainty in many problems, but this approach has its practical limitations and in some circumstances, it may not be able to model the uncertainty accurately. Accordingly, we use a new concept of uncertainty which is called as the Z-number. To optimize multiple objectives, an interactive approach has been applied. The proposed mathematical model is linear and is solved by Cplex software. Results: In the country, there are no agricultural cropping patterns based on regional needs, the status of water resources and exports. This matter not only leads to the loss of water resources, but also have a significant impact on farmers' productivity losses and without a specific program, there may be a sharp price fluctuation of agricultural products in markets. Considering the strategic aspects of some agricultural products such as wheat, alfalfa and barley in the presented study, the production rate of these products is higher than other ones. Results showed that the products will not be planted in 22% area of the land and this is because the limitation of resources for planting or the import may be cost-effectiveness rather than planting. Conclusion: The results show that in the proposed model, the strategic importance of agricultural products directly affects the amount of production. According to the statistics of the Ministry of Agriculture in 2014, 61. 18% of the total agricultural products are covered in this research. The obtained results show that decision making based on the Z-number approach provides a conservatism solution rather than fuzzy and deterministic approaches.

Background and Objectives: Fire is a major threat for natural resources in the world and is an important factor in changing physical and chemical properties of soil. Knowledge of the positive or negative effects of fire on soil properties can be a great importance for the management of natural resources. The aim of this study was to investigate the effect of fire on physical and chemical properties of soil in rangelands of Badreh area in Ilam province its comparison with non-fire areas (control). Materials and Methods: After field studies in Badreh area in the eastern of Ilam province, soil samples were taken from 0-5 and 5-20 cm depths and collected randomly and transferred to the laboratory. Physical (soil texture, mean weight aggregate diameter, saturation moisture and bulk density) and chemical (organic matter, total nitrogen, phosphorus available, potassium available, calcium and magnesium exchangeable, cation exchange capacity) analysis were carried out on soil samples. Results: The highest amount of sand (46. 4%) and soil silt (24. 4%) were found in burned pasture and the highest clay content (39%) was found in control rangelands. Fire significantly (α =0. 05) decreased the stability of aggregates and soil porosity in burned rangelands compared to unprocessed rangelands (14. 28 and 8. 68%). The bulk density of the burned pasture was 9. 1% higher than that of the control pasture. In the soil surface layer, the soil moisture content increased 16. 98% compared to the control treatment. The fire decreased the amount of soil organic matter from 2. 66% in control pasture to 2. 19% in burned pasture (α =0. 05). Soil acidity significantly increased in burned pasture (pH=7. 45) compared to control pasture (pH=7. 07). The highest cation exchange capacity (24. 82 cmol kg-1) and the lowest (18. 98 cmol kg-1) were obtained in control and burned rangelands, respectively. Also, with an increase in soil depth, the cation exchange capacity of soil decreased to 14. 10%. The most available phosphorus, magnesium and calcium were obtained in burned pasture at the soil surface. Fire had no significant effect in the subsoil layer, on the amount of soil phosphorus, magnesium and calcium exchangeable. Conclusion: In general, the results indicate that fire in rangelands of Badreh area in Ilam province affected physical and chemical properties of soil. In most cases, soil quality is decreased chemically (decreasing organic matter, nitrogen, cation exchange capacity) and physically (soil texture changing, soil aggregate stability, porosity and bulk density), and in some cases, fire caused to release the nutrient elements such as phosphorus, calcium and magnesium in the soil and improved the nutrient cycling nutrients in the soil.

Background and Objectives: During the past decades, landslides have been a significant subject of research as a consequence of their devastated nature. Landslides are common geomorphic processes in mountain areas and are responsible for mass movements involving rock materials, regolith and/or soil debris. For manufacture roads, railways, water pipe line and electric line, the preparation of landslide distribution map is very much significant. Determining the occurrence of future landslides depend on the geological, geomorphological and hydrological processes that led to instability in the past and also at present. To assessment terrain susceptibility to landslides, a number of various techniques are used, ranging from qualitative assessments based on expert judgment, which are intrinsically subjective to quantitative assessments based on advanced statistical techniques or mathematical models. The purpose of this research is landslide susceptibility mapping in Fereydoun Shahr watershed using a combination of data-driven and knowledge-based methods. Materials and Methods: The steps of methodologies that were applied in the current study, including six steps. Step1. data sources that are used in the current study including data related to field surveys, historical reports, topographic maps of 1: 50, 000-scale, meteorological data, geological map of 1: 100, 000-scale, A digital elevation model (DEM) with the resolution of 30 m × 30 m was extracted from the ASTER GDEM data, The Landsat 8 OLI images with the resolution of 30 m × 30 m. Step2. Preparing the inventory map. In this study, a landslide inventory map with a total of 80 landslide events was provided by the extensive field survey, Interpretation of aerial photos of 1995 with a scale of 1: 40000 by stereoscopy as well as satellite images of Google Earth. Step3. Landslide-conditioning factors. Step4. Multicolinearity analysis of landslide conditioning factors. In the current study, 12 factors were used as conditioning factors. These include elevation, slope, plan curvature, stream length, distance from streams, topography wetness index, surface area ratio, distance from roads, lithology, distance from faults, rainfall and land use. Step5. Combination of EBF data driven and AHP knowledge driven models according to the relation between the landslides location and the different datasets. Step5. Validation of models using AUC and SCAI indicators. Results: The results of the multicollinearity test among the parameters using Tolerance and variance inflation factor indicators showed that among the 26 initial conditioning factors, 14 factors have multicollinearity, As a result, this factors were eliminated from the modeling process and modeling was performed using 12 parameters. Results of the spatial relationship between landslide and conditioning factors using the EBF (belief, disbelief, uncertainty and plausibility) model revealed that high potential of landslide occurrence was for the areas with high degrees of belief and low degrees of disbelief. Weighting of conditioning factors by AHP showed that parameters of lithology, elevation and distance to road, slope and rainfall are the most effective prediction factors in landslide occurrence. The consistency ratio shows 0. 034 value, which is reasonably good accuracy value, which reflect the high accuracy of ranking consistency between the factors. Conclusion: Due to some shortening of the AHP knowledge driven and EBF data driven models when applied individually in landslide susceptibility mapping, it can be overcome by using ensemble techniques. The AUC results showed that the success rate and prediction rate for ensemble model are 0. 872 (78. 3%), 0. 903, respectively. results of SCAI values of the ensemble model is desirable, in the high and very high susceptibility classes. The resultant landslide susceptibility map show that the high susceptibility areas are mainly distributed along the northwest to west direction in the study area. This map can provide very useful information for planners, decision makers and engineers in slope management and land use planning in landslide areas.

Background and Objectives: The implementation of different irrigation methods in different areas is influenced by factors such as climatic conditions, water quality, topography, soil characteristics, product type and socio-economic factors, some limitations in each of the above factors In the studied area, changes in the proposed irrigation system. Issues and topics related to the choice of proposed irrigation method, can be investigated by quantitative and qualitative indicators, the possibility of using these two simultaneously in the method of hierarchical analysis process, it has turned it into a powerful tool for analyzing issues in this section. Considering the above and the power of the hierarchical analysis process to decide on the appropriate method for irrigation for the region and its strength in combination with GIS and less use of these two with each other in studies in recent years, in different parts of the country, As well as the northern Khorasan province and the city of Esfarayn, It was studied. Materials and Methods: This research was carried out in Esfarayne County, North of Khorasan province and between 57 degrees and 30 minutes east longitude and 37 degrees and 4 minutes north latitude and total area of 5192 square kilometers. In this study, a method was developed and presented for grading the factors influencing the selection of new irrigation systems. The effects of different factors using the correct digits (+3) to (3) investments are rated at seven points. In order to influence more important factors or preventing the same effect of factors with a different degree of importance, the coefficient is considered as the weight of each factor. This index is based on project conditions are determined using analytic hierarchy process. By combining analytic hierarchy process and geographical information system (GIS), multiplied by the weight of the layers entered. The final score, obtained of algebraic summation scores of each factor for each region. This rating is in fact the potential use of each new irrigation systems. Data related to this study, has been prepared the irrigation database under management of Jihad Agriculture in Esfarayen city. Results: In this research locating new methods of irrigation for 77, 075 hectares of irrigated lands (agriculture and gardens) Esfarā yen city of North Khorasan province is performed and results are shown as maps with scores of each region of plan area for each new irrigation systems. The results of this research show that: Out of 77, 075 hectares of land in the study area is intended, in accordance 58835 hectares (76. 5%) were recognized fit to Low Pressure Irrigation, 17105 hectares (22%) suitable for Local Irrigation Systems and 1135 hectares (1. 5%) suitable for Sprinkler Irrigation Systems. Conclusion: Low pressure irrigation system in the majority of regions except the northern areas because of unsuitable topography, has achieved the highest score. Therefore, Low Pressure Irrigation for raising irrigation efficiency suggested to the majority of area and in other areas (North), Localized irrigation system has been selected as the best new irrigation systems.

Background and Objectives: Increasing water demands and limited water resources in arid and semiarid regions has made management and planning necessary for the optimal use of water resources. On the other hand, the surface water resources providing a major portion of water supply for drinking, agriculture and industrial sectors. In this regards, managers need to adopt optimal policies for planning water resources use, especially dams reservoirs. Therefore, many attempts have been made to develop computer models to perform such simulations. One of the most effective methods to evaluate complex systems is system dynamics. This approach is a feedback-based and object-oriented approach. Any dynamic system is characterized by interdependence, mutual interaction, information feedback and circular causality. However, VENSIM is a visual modeling tool that allows models of dynamic systems to be conceptualized, simulated, analyzed and optimized. VENSIM model provides a simple and flexible way of building simulation models from causal loop or stock and flow diagrams. So, in this research, system dynamics and particle swarm optimization algorithm were used to optimize the rule curve of Choghakhor Dam. Finally, the accuracy of the methods was evaluated. Materials and Methods: The study area is located near Borujen city. Choghakhor dam is a earth fill dam and its water is mainly supplied through precipitation and springs. In this study, the results are compared with monthly data collected over ten years period (2004-2014) in the Choghakhor Dam. The relations between the inflow, the volume of reservoir storage and the rate of release of each period were determined and they were defined by using system dynamics approach in VENSIM model and using pso algorithm in MATLAB model. The objective function and all of the limitations are the same for both of the models. Results: The results showed that the coefficient of determination (r2) which is a measure of the degree of correlation between the system dynamics simulation and the observation data was 0. 995 for the reservoir volume and 0. 991 for the release rate. After optimization, the difference between the requirements and the release rates decreased and reduced the waste of water. The difference was 11. 78 MCM for system dynamics approach and 18. 82 MCM for PSO algorithm. While in observation, the difference was 25. 68 MCM. Conclusion: In general, the results showed that the system dynamics model is more accurate than the PSO algorithm in optimization of the reservoir operation by rule curve adjust in Choghakhor dam. Also, the results showed that combining simulation and optimization in VENSIM environment can increase the accuracy of optimization to acceptable levels. In this way, in optimizing the curve of the Choghakhor dam, this method is more accurate than the PSO algorithm. Therefore, the system dynamics model can be a useful and practical way in reservoir water resource management.

Background and Objectives: Spillways are one of the most important and most sensitive parts of the dams structures, which are responsible for the drainage of the dam in emergencies and floods. Although many studies have been conducted to identify flow characteristics over the spillways, but little information is available on the effect of the convergence of spillway walls on the hydraulic characteristics of the supercritical flow downstream of the chute and the potential for cavitation occurrence. To reduce the costs of relatively long spillways and also consideration of topographic factors, spillway walls especially in chutes constructed convergently. Due to the convergence of the walls and the interaction of the flow of spillway with these walls, the supercritical stream is formed, which the result of this interaction is the formation of waves at the downstream of the spillway and on the walls of the chute. This phenomenon affects the downstream flow and causes uneven hydraulic conditions on the spillway; therefore, the height of the waves on the wall affects the design of the walls of the chute and in this regard, the profile of the waves on the wall is also important. Materials and Methods: In this study, using Flow-3D software, RNGk   turbulence and finite volume method, flow over convergent spillway of Gavshan dam simulated and then, the effect of convergence of the spillway walls of Gavshan dam under different angles of convergence including 0, 1, 2, 2. 5 and 3 degrees of convergence on hydraulic characteristics of the flow, such as the average velocity distribution, medium pressure and mean depth of flow, as well as the probability of occurrence of cavitation were investigated. To verify the numerical result, experimental data of hydraulic model was used. Results: The results showed that with increasing in convergence of spillway side walls, the average speed and depth of flow increased. Location of minimum depth of flow on spillways with increasing convergence on the side walls becomes closer to the spillway crest. Convergence of the side walls creates two sets of secondary wave in axes and corner of spillways, which leads to an increase in the height of the side walls. Conclusion: With the increasing convergence angle, Froude number decreases along the flow path. Also, through exploring the pressure values, it was relieved that due to the rise of the flow depth along the walls, the pressure increases near the chute walls accordingly. Furthermore, by calculating the cavitation number at different sections of each numerical model, it was determined that as the convergence angle of the model narrows, the cavitation index increases and consequently, the highest cavitation risk will be spotted for the least convergent model.

Background and Objectives: Reservoirs operation problems have various and diverse objectives that rarely lead to an optimized solution and usually contain a set of optimal solutions (Pareto Front). Solving these problems in the past has been possible only with the use of simpler methods, including the use of weight coefficients for various purposes and the conversion of them into a just one objective function. However in recent years, with the development of multi-objective methods, there is a good way to solve them. In this regard, the purpose of the present study was to investigate the efficiency of multi-objective optimization algorithms MOPSO, SPEA-II and NSGA-II in the reservoir operation problem using LDR, N-LDR operation models to generate the optimal Pareto front in order to sustainable development. Materials and Methods: In order to obtain the mentioned purpose, first, the NSGA-II, MOPSO and SPEA-II optimization methods were evaluated using some benchmark problems such as standard ZDT family functions with identical conditions (equal population number and number of runs). After evaluating multi-objective optimization methods using standard ZDT family functions, NLDR, LDR and SOP operation models were coded in MATLAB programming environment and linked with multi-objective optimization methods. For each of the two optimization-simulation models (LDR and NLDR), the two objective functions were defined as follows: the first objective function was to minimize the sum of the MSI and the second objective function was the reliability maximization that the maximum of which is usually obtained under the SOP operation conditions. Reservoir operation models for a 37-year period from 1356 to 1392 were executed to find the coefficients in both linear and nonlinear models in the same conditions for each multi-objective optimization algorithm with 5000 itrations. The optimal Pareto front was obtained. Results: The results of this study showed that the SPEA-II optimization method in NLDR operation model, has reached to the best optimal Pareto front among others. So, from its three answers were selected (by using various criteria) as sample and then sustainability indices such as reliability, resilience, vulnerability and MSI were computed for those three answers. By comparing the values of objective functions and other sustainable development criteria in SOP conditions and the NLDR-C response, it can be observed that using the multi-objective optimization model, we can by less shortages (less MSI 21, 76 compared to 55), reach to approximately maximum reliability (reliability in SOP conditions). However, in NLDR-A solution, the least shortage (MSI equal to 13. 02) can be observed compared to other sample solutions and SOP policy. Conclusion: According to the research findings, it was observed the SPEA-II optimization method in all of the standard ZDT family functions has reached to a more optimal Pareto front than other optimization methods. Also, compared to other optimization methods, this method has a more complete front of Pareto's solutions, which indicates the efficiency of this optimization method in multi-objective optimization problems. In the case of LDR and NLDR models with the same number of iterations, also it was observed that the NLDR model has shown better results, which can be due to the higher degree of freedom of nonlinear relationship in determining the operation policy of the reservoir releasing. In this research, a series of optimal (Pareto optimal) solutions was presented to meet the stated objectives. However, selection of the best solution as the optimal policy of operation is the responsibility of the relevant authorities and decision makers, so by taking into account the economic, social and environmental consequences, the best optimal solution can be chosen among others and the operation policy corresponding to the selected solution, can be determined.

Background and Objectives: In order to optimize the management of soil and water resources, it is necessary to pay attention to the physical properties of soil, especially the soil structure. The soil physical property improve by adding some mineral and organic matter. The addition of some organic materials always increases the efficiency of the absorption of elements and improves the physical properties of the soil, but the effect of some minerals such as zeolite, despite the positive effects on the physical and chemical properties of the soil, can have a negative effect that needs more investigations. Therefore, this research was carried out with the aim of effecting the application of zeolite and cow manure on some physical parameters of soil. Materials and Methods: In order to study the effect of zeolite and cow manure on some soil physical parameters a factorial experiment was conducted based on completely randomized design with three replications under greenhouse conditions. The experimental factors consisted of natural zeolite at three levels (0, 6, 12%) and cow manure at three levels (0, 0. 5, 1%). The soil was sampled at a depth of 0-30 cm from Mashhad Water and Soil Research Center. Primary soil characteristics, cow manure and zeolite were measured according to standard methods. Soil of each pot was planted with experimental treatments with mixed ratios and corn seeds. All the pots watered with distilled water at field capacity based on weight before maize flowering plants for 75 days. At the end of the growth period, the plant was separated from the crown and the soil was dried. Physical parameters including bulk density, saturation moisture content, water dispersible clay and mean weight diameter of aggregates were measured according to standard methods. Results: The results showed that the increase of zeolite levels increased the saturated moisture content (total soil porosity), the water dispersible clay and decreased the bulk density and the mean weight diameter of aggregates (dry sieve). The cow manure had no significant effect on bulk density, total porosity and increase saturated moisture content. However, the water dispersible clay and the mean weight diameter of aggregates (wet sieve) were significantly decreased by adding organic matter. In spite of the positive effect of zeolite on bulk density and saturated moisture content, there was a negative effect on the water dispersible clay and the mean weight diameter of aggregates (wet sieve). Conclusions: Zeolite, like any other compound, may have positive and negative effects. In spite of the positive effect of zeolite on some characteristics, it had negative effects on the water dispersible clay and the mean weight diameter of aggregates. Considering the improving influence of organic matter on water dispersible clay and the mean weight diameter of aggregates, combining cow manure with zeolite to modify the negative effect of zeolite can be recommended.

Background and Objectives: Soil saturated hydraulic conductivity is one of the most important physical characteristics of soils which affects water movement in soil. Knowledge of this parameter can help to understand and solve environmental problems. However, measurement of this parameter by direct laboratory and field methods is hard, time consuming and expensive. Thus, there is need to use alternative methods based on conveniently available soil properties to estimate it with less effort, time and cost. Nonparametric methods are new indirect methods to estimate hydraulic properties of soil, including soil saturated hydraulic conductivity (ks). The aim of this study was to use two methods such as M5P decision tree and an IBk instance-based learning method, which is a classifier with k nearest neighbors to estimate ks from conveniently available properties of soil. Materials and Methods: In this study a dataset of 151 soil samples which was collected from a site in Bojnord province was used. Conveniently available soil properties includig sand, silt and clay percentage, bulk density, particle density, EC, OC, TNV, saturated moisture and pH. Saturated hydraulic conductivity was measured with the Guelph permeameter. The Gamma test was used to determine important parameters for predicting and the modeling procedure of ks. Then, various combinations of parameters of the data set were compared to each other based on their Gamma value, to determine the optimum combination of parameters for modeling ks. Using the optimum combination which had the least Gamma value, the M5P decision tree and the IBk instance-based learning methods were performed. To improve the IBk, two different distance weighting systems were used. Finally, evaluation statistics of each model including R2, RMSE, MAE and MAPE were calculated. Results: The optimum combination determined by the Gamma test which was then used for modeling, included sand, silt and clay percent, TNV percent, EC and bulk density. The tree selected bulk density as the most important discriminative parameter and constructed 3 linear equations for predicting ks, based on the bulk density value. Evaluation criteria calculated for this model with RMSE= 23. 89 cm/d and MAPE= 20. 50% didn’ t predict ks accurately. Different weighting systems didn’ t improve IBk performance. Also, the IBk model with RMSE=31. 23 cm/d and MAPE=23. 24% didn't estimate ks accurately. Conclusion: The decision tree model performed better than the instance-based learning model to estimate ks. Also, the tree showed some information about the structure of the studied soil.

Background and Objectives: Unconventional operational conditions within main irrigation canals, due to intensifying following drought conditions, has resulted to poor performances of the irrigation districts in water distribution between the water holders from the equity perspectives. Accordingly, have convinced the managers to employ the modern operational strategies. However, hiring these smart operational strategies need automatic control systems and getting the advantages of the approach is quite impossible by using the conventional operational methods. Materials and Methods: An automatic control system, using Model Predictive Control, is designed and tested in the present study. Also, simulation of the hydraulic conditions of the irrigation canal is accomplished by a simplified mathematical model of Integrator-Delay (ID) model in Matlab. Moreover, the operational strategy of different error gets employed by the MPC controller by defining a new state variable of the “ Difference Error” . The Roodasht main irrigation canal is selected as the case study of the research, due to special hydraulic conditions of this canal, including consequent water shortages periods as well as inflow fluctuation at the canal head-gate. Accordingly, a wide range of operational scenarios is chosen based on the practical operational information. Then, the performance of the designed MPC controller with and without employing the operational strategy is evaluated by the equity indicator within the operational conditions. Results: The obtained results indicate that execution of the MPC controller is reasonable enough to handle both of the regular and severe inflow fluctuations. The equity performance indicator shows that MPC controller distributes irrigation water almost equitably under the frequent and severe inflow fluctuations so that the corresponding values obtained 1. 21 and 4. 33 percent respectively. However, the results reveal that equitable water distribution has not achieved when water shortages scenario has appeared. During the water shortages, MPC could not be able to meet the equity objective. So, the water level difference operational strategy is required to be employed by the MPC controller. According to the results, significant improvement equal to 13 and 17 percent has been achieved in equity index after upgrading the MPC controller with the strategy. Conclusion: This study reveals the necessity of employing the operational strategy to improve the performance of the controller within the severe operational conditions. The main advantages upon upgrading the control systems with the operational policy, including the procedure used in this study, has not imposed and extra charges to the control system. Therefore, getting the advantages of the strategies is highly suggested to implement reasonable performances of the system. The developed plan for this study is recommended for the operation of those irrigation districts suffering from water scarcity. The strategy is capable of reasonably water distribution in a systematic manner between the off-takes locating along the canal.

Background and Objectives: Heavy metals are one of the most important soil pollutants. The increased level of them in the environment with respect to their stability has led to researchers attraction in recent decades. Soil contamination produced by heavy metals released from vehicles is a serious environmental problem. Considering the importance of soil contamination, evaluation of soil contamination by various industries seems to be necessary. Characteristics of the spatial distribution of pollutants in contaminated soils are important factors to identify and eliminate pollution. This study aimed to investigate the spatial distribution of heavy metals such as Ni, Zn and Cu at the roadside soils of Zabol-Zahedan route. Materials and Methods: 252 soil samples were collected from a depth of 0-20 cm, using a regular systematic sampling process. In addition to the total concentration of the metals in the soil, the soil’ s properties including its pH, EC, organic matter, lime percentage and soil texture were measured. The contamination assessment of soil was done by using the enrichment factor and biological accumulation indicator. The copper and zinc concentration zonation map was prepared using conventional and exponential Kriging method and for Ni using conventional Kriging method and Gaussian model. The accuracies of the method were compared by using mean absolute error (MAE) and root mean square error (RMSE) and the method with the highest accuracy was used to prepare the heavy metal maps. Results: As the distance from the road increased, the concentration of heavy metals decreased. To prepare the map of nickel Gaussian model and for the zinc and copper Exponential model has the highest precision. The average Zn, Cu and Ni concentration at 0, 50 and 100 meters intervals were 54. 33, 52. 75, 51. 56, 9. 67, 9. 49, 9. 03 and 10. 26, 10. 02, 9. 76 mg kg-1. Zn, Cu and Ni concentrations in roadside roads in the study area were less than the WHO limit. The results of this study showed that the relationship between zinc, copper and nickel is positive and meaningful. In fact, the existence of correlations between different metals represents their common source. Conclusion: The results of spatial distribution of metals showed that these soils are uncontaminated to Zn, Cu and Ni. The concentration and distribution of these elements in the region are of geological and human origin. Zn, Cu and Ni are naturally occurring in the soil, but human activities, such as agricultural activities and the combustion of fossil fuels, have led to the accumulation of these metals in parts of the study area.

Background and Objectives: There are rare and contrary reports about the effects of microbial biofilms formation on the physical, chemical and biological properties of soil. There is no possibility of direct study of microbial biofilms in the soil due to limited scientific techniques; therefore, other similar materials are used as analogue for biofilm. Arabic gum is one of the analogues of biofilm, which is also discussed in some case studies. However, so far no report on its effect on different soil texture classes has been presented. Therefore, in order to evaluate the effects of Arabic gum on several soil characteristics of two different soil texture classes, the present study was designed and conducted. Materials and Methods: To do this study, two different soil types including clay loam and loam texture classes and different amounts of Arabic gum (0, 5 and 10 g per kg of soil) with three replications were investigated in a factorial experiment in a completely randomized design (CRD). Arabic gum was mixed with soil and after one-month incubation time, the disturbed and undisturbed samples were taken from the soils and different soil characteristics including bulk density (Db), soil moisture content (θ s), saturated hydraulic conductivity (Ks), saturated water content, soil aggregate stability (WAS), mean weight diameter of aggregate (MWD), mass fractal (Dm) of aggregates, soil acidity (pH), organic carbon (OC) content, cation exchange capacity (CEC) and microbial respiration (Rs) were measured. Results: The results showed that the effect of applied amounts of Arabic gum on θ s, soil Db, Ks and Rs in loam soil was lower than that of clay loam, whereas the application of 10 g Arabic gum per kg soil in clay loam soil caused an increase by approximately 12, 18 and 317 percent, respectively, in the volumetric and gravimetric θ s and the Ks; while these effects were not seen in loam soils. Usage of 10 g Arabic gum per kg soil also reduced the Db of clay loam soil up to 5%, while no changes were found in the Db of loam soils. Also, in treated soils, both applied amounts of Arabic gum (5 and 10 g per kg soil) showed positive changes in soil OC and the WAS, MWD and Dm of aggregates, being independent from soil type. According to the results, the amount of 5 g Arabic gum per kg soil can be recommended to improve the characteristics of the clay loam soils. Conclusion: The use of Arabic gum can improve the physical, chemical and biological properties of soil. In fine-textures soils with higher contents of clay, much less amount of it is needed, while in coarse-textured soils, more amount of this polymer are needed; in the other words, the effect of microbial biofilm formation is more pronounced in fine-textured soils.

Background and Objectives: The availability of clean and healthy water is one of the most important issues facing humankind and as water consumption levels increase further, pollutants also contaminate water resources in different ways and this will become even more critical in the future. Environmental pollution, especially water, which is an important factor in limiting human progress, has become so important that the fight against it has been the subject of global and regional seminars. Pollution of groundwater and surface water into nitrate in many parts of the world is a serious problem. Different physical, chemical and biological methods exist for nitrate removal, including reverse osmosis, ion exchange, decomposition of chlorination, electrodialysis and chemical denitrification. In recent years, much attention has been paid to low-cost materials such as bark, plant nanoadsorbents and other waste materials. The aim of this study was to investigate the possibility of using oak leaf absorbent as an inexpensive and cost effective absorbent for removing nitrate from aqueous solutions. Materials and Methods: In order to carry out absorption tests, the first pace is to prepare the absorbent. To do this and in order to achieve the desired result, oak leaf absorbent was used as the best option to obtain the best in terms of absorption. After preparation of absorbent, characterization experiments were carried out, including particle size and a absorbent special surface by methylene blue absorption. Then, discontinuous tests were performed and the data analysis method was mentioned. The present study was conducted in a laboratory scale and was performed in a discontinuous. In this study, oak leaf absorbent was first crushed against a relatively dry sunshine by household grinder and then passed through the sieve No. 200 to prepare absorbent nanomaterials. After being washed with distilled water in an oven at 70 ° C for 24 hours. In this study, the effects of factors such as pH, adsorbent mass, contact time and initial concentration of nitrate were tested. Experiments were performed in a discontinuous system with three replications. Data analysis and drawing of charts were done by Exel software. The kinetic models of Lagergrne and Ho were used to examine the adsorption process, Also using equilibrium absorption data was analyzed using Freundlich and Langmuir isotherm models. Results: The results showed that for the absorbent, the equilibrium time after 120 min and the maximum nitrate absorption at pH=5 were obtained. By increasing the absorbent mass from 0. 3 to 0. 7 g, the removal efficiency ranged from 88. 93 to 93. 82 percent, However, with increasing adsorbent content from 0. 7 to 1. 6 g, the absorption efficiency reduced. By increasing the concentration of dissolved nitrate (5-120 mg/l), the removal efficiency decreased from 94. 41 to 89. 35%. Conclusion: Based on the results, the absorption process was followed by the Ho et al model and the absorption data was more consistent with the Freundlich isotherm. Therefore, it can be stated that oak leaf can be used as a suitable and cost effective absorbent with the least technology in nitrate removal.

Background and Objectives: The type of landuse greatly affects soil properties. Assessing the effects of landuse on soil quality properties, helps to identify sustainable management practices and to prevent soil degradation. The landuse change, such as cutting forest trees and the grasslands conversion to agricultural lands destroys natural ecosystems, also causes current or future production capacity reduction and these will have harmful effects on the soil physics characteristics. Considering the wide variation of land use in Iran and the fact that the values of soil quality properties are not the same in different regional conditions, this study was conducted to study the soil quality properties, especially physical soil properties, in different landuses in a part of Shahrekord. Materials and Methods: This research is located in a part of the Bardeh catchment area with an area of 80 km2 in 40 km northwest of Shahrekord (the center of Chaharmahal and Bakhtiari province). The main landuse in this area is natural pasture and dryland farming. 85 soil samples were randomly obtained (0-20 cm) and compound sample were taken at intervals of 1 km and from depth (0-20) cm, so according to the land use map of the area, 58, 17 and 10 top soil samples were collected respectively from pasture, dryland and irrigated farming. In addition, at each sampling site, undisturbed soil samples were obtained to determine soil bulk density and saturated hydraulic conductivity and some physical characteristics such as soil particle size, bulk density, total porosity, stability of soil structure indicators and saturated hydraulic conductivity were measured in samples. Statistical analysis was performed on the basis of statistical methods and using statistical software Statistica Ver. 8. Analysis of variance (ANOVA) and mean comparison (Duncan method at 5% level) were used to study the soil quality characteristics in different landuses. Results: The results showed that bulk density, Silt percentage, stability of soil structure by dry and wet method in agricultural lands (dryland and irrigated farming) was more than pasture land that did not show a significant difference. While the total soil porosity and percentage of sand in the pasture landuse was higher than those of dryland and irrigated farming. Also, in agriculture, especially dryland farming, the percentage of clay was more than the pasture landuse, but the saturated hydraulic conductivity was less which was not statistically significant. The results of analysis of variance and the mean comparison of studied characteristics did not show a significant difference between pasture, dryland and irrigated farming. Conclusion: To prevent land degradation and soil quality reduction, a long-term solution is reduction the tillage operations and the addition of organic matter. In pasture lands, the grazing must be prevented prior to pasture preparation.

Background and Objectives: In calcareous soils of Iran, due to high pH, nutrients are slightly soluble and their absorption by plants is difficult. In order to solve these problems and to achieve optimal yield in such soils, the use of sulfur as a correction agent is necessary to reduce the local pH of the soil and increase the solubility of nutrients. The aim of this study was to evaluate the sulfur effect inoculated with Thiobacillus bacteria on some chemical properties of soil (pH, electrical conductivity, phosphorous, sulfate iron and available zinc) and nutrients concentration in wheat grain in four areas of Kermanshah province with different available sulfur. Materials and Methods: An experiment was carried out in four sites (Chogha Narges, Mahidasht, Najaf Abad and Ghomsheh) with different levels of available sulfur (7, 13, 18, 27 mg kg-1soil) in Kermanshah Province. Sulfur was applied at 0, 250, 500 and 1000 kg ha-1 as Pastille Sulfur (PS), using complete randomized blocks design with three replications in a during cropping season 2015-2016. Seeds of wheat were planted in plots. Before cultivation, the phytochemical properties of soils were analyzed using standard laboratory methods. Soil samples at tillering, stem elongation and post harvesting stage was collected for determination of pH, electrical conductivity (EC), phosphorous (P), sulfate (S-SO4), iron (Fe) and available zinc (Zn). Finally, grain yield and concentration of nutrients were determined using routine methods. Results: The result showed that PS significantly decreased the soil pH and adversely, increased EC, P, S-SO4, soil DTPA-extractable Fe and Zn in the Chogha Narges, Mahidasht (P<0. 01) and in Najaf Abad and Ghomsheh (P<0. 05) at tillering, stem elongation and post harvesting stage compared with the control. The lowest pH and highest EC, P, S-SO4, Fe and Zn value were observed with 1000 kg ha-1 So at stem elongation. After harvesting due to the reduction of sulfur oxidation and buffering capacity of soils, pH and nutrients gradually reduced in comparison to the stem elongation stage. Also, nutrients concentration (P, S, Fe and Zn) in wheat grain was significantly increased by the application of PS compared to control. The highest nutrients concentration was observed with application of 1000 kg So ha-1. Conclusion: The effect of simultaneous application of sulfur and Thiobacillus bacteria on the chemical properties of the soil and nutrients concentration in wheat grain was promising, which indicates its good potential for use in agriculture. Each calcareous soil, has a specific potential for sulfur oxidation which depends on its characteristics and the only amount of calcium carbonate is not a suitable measure for the application of sulfur to increase the solubility of nutrients.

Background and Objectives: One of the major applications of hydraulic jump is controlling of channel scour downstream from high-velocity conveyance systems such as chutes and spillways by dissipating a large portion of the kinetic energy in a hydraulic jump stilling basin. Hydraulic jump stilling basin are usually made of smooth and impenetrable concrete, which causes environmental problems as well as cost and construction problems. It is becoming more common to use hydraulic jump stilling basins in natural rip-rap lined or bound rock channels. These basins are inherently rougher and permeable compared to traditional basins. At present the influence of channel permeability on the hydraulic jump characteristics such as sequent depth and jump length is unknown. In this research hydraulic jump characteristics in a stilling basin with porous permeable bed as an alternative to concrete basins is studied. Materials and Methods: To conduct the experiments a laboratory flume of 6 meters long and 80 centimeters wide with glass walls, equipped with a head tank up to 3 meters high was designed and built at Ferdowsi University’ s hydraulic laboratory. The flow rate required for the experiments was supplied by a centrifuge pump with a capacity of 100 liters per second. Two slice gates were used at the beginning and at the end of the flume to develop super-critical flow and adjust the downstream depth and fix the jump position. Three different types of wellgranulated gravel in the range of 9. 8 to 38 millimeters with different lengths and thicknesses were used to create the permeable bed. The experiments were carried out for five different Froude numbers within the range of 5. 3 to 7. 4. Primary, secondary and jump lengths were measured for each experiment and compared with the results of a non-permeable smooth bed. Results: The results showed that parameters like average diameters of the grains, thickness and length of the bed and the Froude number affects the ump dimensions and the energy loss caused by it. Greater granulation as well as the thickness or the length of the bed increases the penetration of the flow into the bed, weakens the jump and increases the energy loss. So the ratio of the conjugate depths and the length of the jump decreases. Conclusion: Permeability of the bed reduces the hydraulic jump dimensions so that the sequent depth ratio is reduced by an average of 15. 8 percent compared to smooth bed and also the jump length is reduced by about 25 percent.

Background and Objectives: Aqua solutions containing nitrogen as nitrate are considered to be one of the most important pollutants of surface water and underground water. Denitrification bioreactors provide a carbon sourced environment. Passing drainage water through such bioreactors results in an increase in denitrification level and nitrate elimination. In this study, biochar is used as carbon wall in bioreactors. At first, nitrate and ammonium elimination performance of biochar-filled bioreactors and wheat straw-filled bioreactors were compared. Then, the effect of height of bioreactor on concentration of output nitrate and ammonium is taken under study. Also, performance of bioreactors in nitrate and ammonium elimination is investigated in a four month time period. Materials and Methods: In order to perform this research, poly-ethylene bioreactors with height of 125 centimeters were used. Height factor is taken under study in four levels; H1=32. 5 cm, H2=62. 5 cm, H3=92. 5 cm and H4=125 cm. Control bioreactors (B0) were filled with 30% wheat straw and sample bioreactors (B1) were filled with 30% Biochar of wheat straw. Results: The results showed that output nitrate concentration of denitrification bioreactors significantly depends on biochar type. Output concentration of biochar-filled bioreactors (B1) is 18. 16 mg/liter while the output nitrate concentration of wheat-straw filled bioreactors (B0) is 49. 01 mg/liter. Also, it has been shown that increasing bioreactor’ s height would reduce output nitrate concentration in both bioreactors. After four month of sampling, output nitrate concentration from 160 mg/liter was reduced in different treatments; 20. 91 mg/liter in H1B1, 12. 85 in H1B2, 8. 05 mg/liter in H3B1 and 5. 23 in H4B1. However, in control treatments nitrate concentration was reduced to 42. 17 mg/liter in H1B0, 36. 36 mg/liter in H2B0, 28. 99 mg/liter in H3B0 and 19. 65 mg/liter in H4B0. Time also has a significant effect on nitrate elimination (P<0. 01). After four month of experiment, average concentration of output nitrate in sample bioreactors reached the minimum 21. 77 mg/liter, while it was measured 59. 21 mg/liter on the first day of experiment. Concentration of output ammonium in both biochar-filled and wheat straw-filled bioreactors was increased comparing to concentration of input ammonium. It can be explained as some of the nitrate is dissimulate to ammonium by anaerobic bacteria. However, this increase was less than 0. 5 mg/liter and negligible. Conclusion: The performance of nitrate elimination in biochar-filled bioreactors is more than wheat-straw bioreactors. Also, height increase in bioreactors would result in more nitrate elimination.

Background and Objectives: When the water supply system faces serious problems and crises, it is necessary to identify the root causes and the history of the problems, in order to provide an effective solution. Measures can be effective when they occur on time, otherwise they will have a high cost and less impact. In this paper, the history of salt water influx into the water resources system of Azarshahr plain was identified using the statistical analysis and GIS and the reason for the ineffectiveness of the actions has been discussed and ultimately its effects on supply the demand of the next 20 years evaluated in WEAP software. Materials and Methods: Changes in systems are usually gradual until these small effects accumulate and rise above the threshold of tolerance. In this study, using groundwater quality data, groundwater level and Lake Urmia level, the date of the influx of saline water into aquifer was identified in late 2000 after five years of drought. Using the neural network, resource changes for the next 20 years are anticipated and according to the demands, the effects of change in supply the demand of the next 20 years in the WEAP software was assess based on the water year scenario. Results: As a result of five consecutive droughts, the extraction of the aquifer have increased rapidly and since no significant structural measure and in particular, non-structural measures such as transparency (full access to data) and the participation of all stakeholders in solving the problem and eventually lack of adequate responsibility for non-effective measures exist, the cumulative effects of these 5 drought years have brought about a big change in the system. Due to this change, the system's capacity was severely affected and the possibility of supply the future demands in the plain would not be possible, which seriously threatened the economic and social sustainability of the region. Conclusion: A large change occurred on the Azarshahr water supply system after five consecutive drought years at the end of 2000 with a large influx of saline water from the Islamic island to the aquifer. The structural measures undertaken were so small that failed to neutralize the effect of this large change. In practice, salinity of groundwater has expanded by the year 2014. If it wants keep the crop of 2015-2016 in the next 20 years, there will be a deficit of 16 to 18 million cubic meters in supply of agricultural demands. With management of agricultural water demand, with the implementation of drip irrigation system in the form of stepping up (every 5 years 5%) will reduce this deficiency to 13 million cubic meters at the end of the 20-year period, with an annual decline of 1% of arable crops along with management agriculture demand will reduced this deficit to 10 million cubic meters at the end of the 20-year period.

Background and Objectives: The bed forms or in the other word, bed irregularities are structures that form due to stream flow and they have direct impact on roughness and flow resistance in sand bed rivers. Bed forms have different shapes and forms in sand bed rivers. Since river discharge and flow velocity are totally affected by roughness, accurate prediction of the shape of the bed is of great importance. Due to the influence of different parameters in the formation of the river bed form, it is difficult to determine the governing equations and the mathematical models with sufficient precise. Today, the use of artificial intelligence systems has expanded as a new way of analyzing water resources issues. The objective of this research is to introduce a method that can be used to predict the shape of the river bed with high precision. Materials and Methods: In the present study, in order to obtain better results and to reduce the dispersion of data, the data were randomly divided into two parts of the training (70%) including 1647 laboratory data and test (30%) containing 560 laboratory data. The decision trees were coded on the data of the test section in the WEKA programming environment and finally calibration was performed on the data by using Random Forest and Random Tree algorithms. Then, the experimental methods of Van Rijn, Engelund and Hansen and Simons and Richardson were implemented on test data. Results: Evaluation of the results were done using root mean square error (RMSE), Correctly Classified Instances and Roc area under curve. The results showed that the best performance reached by Random Forest algorithm for experimental data with statistical criteria of CCI=85 (%), RMSE=0. 17, ROC=0. 97. On the other hand, by examining the results of empirical methods, it was determined that for laboratory data, van Rijn method has better performance with the results of CCI=64 (%), RMSE=1. 07. Among different environmental variables of discharge, width, depth, slope of the channel, average diameter of sediment particles and temperature for laboratory data were the most important parameters in predicting bed forms. Conclusion: In this research, the superiority of soft computing models was evident compared to the empirical methods in modeling and prediction of the bed form and the models performed in the VKA environment were better. Basically, because of the formation of the river bed form is depended on several factors and also because of its complex nature, the prediction of this phenomenon is very difficult and sometimes with high errors. Since artificial intelligence methods are used to analyze issues that do not explicitly describe the nature of the problem, so many of the issues of bed form can be solved with these methods.