Journal of Water and Soil Science
Year:2019 | Volume:22 | Issue:4|Papers Count:30

With regard to the crisis of water resources in the country, overdraft of groundwater resources has caused undesirable situation for most of the plains. On the one hand it is necessary for the stability of the resources are constantly using these resources, future generations need to be considered. In this regard, in this study make a cropping pattern with aims to develop a sustainable supply of groundwater resources in the Baghmalek plain has been considered. In this study, time series variables technique are used for predicting future values of variables. Also, the dynamic programming model, is used to determine the cultural pattern. Information needed for this research in two ways questionnaire and the use of statistics resource of agri-jahad and Khuzestan province`s water and power organization in 2013, has been collected. The results show that water input is considering as a limited production factor in the agricultural sector of the region. In addition, using of above pattern, will make fundamental changes in the region`s cropping pattern. The use of modern irrigation methods can increase the agricultural production capacity to double size. The main proposed of study is choosing the patterns that consider intergenerational sustainability about scares inputs such as water.

Evaluating the possible relationships between vegetation and environmental characteristics can assist managers to identify effective factors influencing plants establishment and to characterize various vegetation communities. This study was aimed to evaluate the effects of long term grazing exclusion ( more than 33 years) and the controlled grazing system (resting – rotation grazing system) on the vegetation distribution and some soil properties in the Hamzavi research station in Hanna area-Semirom, Isfahan. Six transects (three parallel transects and three transects perpendicular to the general slope of the area) were established in each area and 10 square plots with the size of 2m2 were placed along each transect; then, the cover percentage, production and list of all plant species were recorded. In each area, eighteen plots were collected randomly and in each plot, five soil samples were collected from 0-30 cm of the soil and then the samples were mixed and one sample of the compound was selected as an evidence plot. Soil properties such as pH, EC, CaCO3, organic carbon, absorbable phosphor, total nitrogen, K, Ca, Mg, soil saturated percentage, cation exchange capacity, soil clay, silt, sand and fine sand contents were measured in the soil laboratory. The independent t test was used to compare the vegetation characteristics in two areas. Cation exchange capacity, CaCO3, gravel percentage, soil phosphor content and grazing management were identified as the most discriminative factors in separating vegetation communities based on Canonical correspondence analysis (CCA) and cluster analysis. Controlled grazing management significantly modified some soil characteristics and increased the production (352 versus 184. 2 kg/ha) and vegetation cover percentage (25. 46 versus 18. 37), as compared to the exclusion area (α = 5%). The vegetation density was increased significantly in the exclusion rather than controlled grazing area (3. 03 versus 2. 02 plant/m2). This study, therefore, revealed that controlled grazing management was more effective on improving some soil quality and vegetation characteristics rather than p long term grazing

The effects of climate change can be released from the surface to the soil depth, thereby affecting soil thermal regime. Thermal energy in the soil plays a very important role in causing climate changes. In this study, for the assessment and detection of the climate changes, soil depths temperature, the measured data related to the daily air temperature at a height of 2 meters (screen) during the years (1951-2014), and the soil depths daily temperature (5-10-20-30-50 to 100 cm), for 3, 9 and 15 hours, were obtained during a period (1992-2014) in Shahrud station. The climate change detection was employed to compare the treatment mean. As well, for detection of trends related to the annual, seasonal and monthly time series and their relation to the soil depths temperature, parametric methods (regression analysis and Pearson) and nonparametric (Mann-Kendall, Spearman) were applied. The results showed that the soil temperature was increased in all months except January, February and March. Also, in the seasonal time series, the soil depths temperature was increased in all seasons except winter. In fact, based on the results, the soil temperature in spring, summer and autumn was increased. Detection trends of the annual soil depths temperature showed that, except for the Pearson correlation coefficient method, soil temperature was increased at all soil depths.

Regionalization is one of the useful tools for carrying out effective analyses in regions lacking data or with having only incomplete data. One of the regionalization methods widely used in the hydrological studies is the clustering approach. Moreover, another effective factor on clustering is the degree of importance and participation level for each of these attributes. In this study, it was tried to use a broad range of attributes to compare their performance in regionalization. Then, according to the importance and role of each attribute in regionalization, the appropriate weight for each of the attributes in each category was determined using the principal component analysis (PCA) method, and the effect of this weighting in forming the homogenous regions was investigated by the Ward's clustering method. In this regard, the maximum 24-hour rainfall data of 63 meteorological stations located in Urmia Lake Basin (ULB) was used in this study during a time period of 30 years (1979-2008). Furthermore, seven categories of attributes were defined in order to regionalize the rainfall. The results showed that by considering different attributes and combining them with each other, a different clustering is obtained in each category in terms of the number of clusters and stations. Among seven categories of attributes, it was found that the geographical and climatic-geographical categories of attributes showed a more appropriate clustering over the ULB. Additionally, the weighting of attributes could have more effect on improving homogeneity and forming the independent clusters in most cases in terms of the scattering of station and how to locate over the basin.

Catchment prioritization in terms of natural disaster intensity as well as prevention and control practices plays a main role in the natural resources and watershed management. In this study, a total of 24 sub-catchments in the Zohreh-Jarrahi basin were prioritized according to their morphometric parameters and using the mixed model of TOPSISMultivariate regression. A total of 12 morphometric parameters including constant component of channel maintenance, drainage density, ruggedness number, infiltration index, stream power index, stream frequency, slope, drainage texture rate, relief rate, form factor, bifurcation ratio and topography wetness index, in addition to rainfall, were studied and scored. Parameters were weighted by using multivariate regression and the spatial distribution of the observed flood events. TOPSIS model was used for the prioritization process. The results obtained from the weighting analysis showed that the ruggedness number, slope and rainfall had the highest effect on flooding in the study area with the score of 0. 068, 0. 024, and 0. 016, respectively. According to the prioritization results, sub-catchments of Seidoon, Emamzadeh Jafar, and Takht Deraz, which had the minimum distance to the positive optimum (0. 0028, 0. 0029, and 0. 0029, respectively) and the maximum distance to the negative optimum (0. 0097, 0. 0098 and 0. 0095, respectively), showed the highest flooding intensity with the score of 0. 7745, 0. 7690 and 0. 7625, respectively. In order to validate the results, prioritization results were compared to the observed flood events. Validation results also indicated the efficiency of the mixed model in delineation of catchments prone to flooding. Three sub-catchments of Seidoon, Emamzadeh Jafar and Takht Deraz were observed to have the highest number of observed flood events, thereby showing the high effectiveness of the model and also, the role of the morphometric parameters in flooding.

The objectives of this study were to estimate the concentration of lead (Pb) and cadmium (Cd) in agricultural products and the health risks of them on the human healths around the Irankooh Mine in Isfahan Province. The soil samples (0-20 cm of surface layer) and crop samples (rice and wheat) were collected using the composite and random sampling method. The total concentrations of Pb and Cd in soil were found to be 71. 18 and 1. 57 mg kg-1. The mean Pb concentrations in rice and wheat were 7. 81 and 2. 31 mg kg-1, respectively. These values for Cd were 0. 15 and 0. 124 mg kg-1, respectively. The mean daily intake of Pb through the consumption of cereals was more than the dietary reference intake (3. 6 μ g kg− 1 day− 1), but the daily intake of Cd was less than the dietary reference intake. The hazard index (HI) mean value for Pb and Cd for children and adults was 4. 60 and 4. 64, respectively. It showed that the consumption of the entire foodstuff could lead to potential health risks for consumers. There is also the cancer risk associated with exposure to lead.

In a pressure flushing method, when the water is discharged from the bottom outlet, after a period of flushing, a flushing cone will be formed at the front of the bottom outlet; the dimension of this cone is affected by several parameters such as outlet discharge flow, water depth of reservoir, and the kind of sediments accumulated in the reservoir. In this study, for the effect of cohesive & non-cohesive sediments, a physical model using specific dimensions was employed in order to develop the sediment evacuation method, and them a Semi-Cylinder structure in front of the lower drain was tested. The experiments were carried out using cohesive & non-cohesive sediments under two conditions: with the semicylinder and without it, at 90 experiments. The results indicated that the with discharge was increased, on i average, under both conditions and the volume of the score cone was increased. With decreasing the water depth, the flow mood was changed to free flushing, increasing the length and volume of the score cone. Semi-Cylinder form, on average, increased the volume of sedimentation and the length of sedimentation; this increase could be due to the formation of a pair of rotating Vortexes inside the Semi-Cylinder structure on both sides of the central axis of the valve.

Groundwater quality evaluation is very necessary to provide drinking water. Groundwater excessive consumption can cause subsidence and penetration of saline groundwater into freshwater aquifers in Ajabshir Plain, on the Urmia lake margin. The main goal of the current project was to evaluate the groundwater quality by employing the qualitative indices of groundwater and GIS. Ten parameters of 15 wells including EC, TDS, total hardness as well as the concentration of Ca++, Na+, Mg++, K+, SO4--, HCO3-and Cl-were analyzed. At first, the maps of parameters concentration were prepared by the kiriging method. Then based on WHO drinking water standards, the maps were standardized and ranked for drawing the maps of quality indices. The results showed that quality index changes were in the range of moderate (61) to acceptable (81). Removing the single map method of sensitivity analysis detected the quality index was more sensitive to the K+ parameter. Finally, the quality index from the eastern north to the western south of Ajabshir Plain and the other areas was ranked in the acceptable and moderate classes, respectively.

In the recent decades, dams have paradoxically been considered as a constraint and or a driving force of surface water conservation. On the other hand, dams have had a number of socio-economic and environmental impacts, the main reason for conducting the current case study on Shah-Qasem Dam in Yasouj, Iran, was to employ the survey field research through a questionnaire to assess the rural peoples’ viewpoint; this was done in four villages of the Southern Sar’ roud County. Based on the (Cochran) formula, 192 individuals were relatively selected from each village. According to the findings, the most important impact of the dam was mainly economical (the average impact was between 2. 37 and 3. 7), whereas the least one was environmental (the average impact was between 1. 81 and 3. 54). Also, the results of the hypotheses’ analyses by means of  2 and Wilcoxon showed the following results: rise of the villages’ income, increase of the cultivated farms, increase in the employed individuals, enhancement of the cultivated crops, the regions production rising, improved tourism, lack of people’ s participation in the decision making process, and reaming of the same plant varieties in the area, as compared with the pre-dam era. It is worth considering, however, that based on the statistical population used, this study was concerned mainly with the short benefits of the dam, rather than its long-term destructive ones.

Preferential flow is of great importance in the environment and the human health. So, rapid water transportation and consequently, pollutants and pesticides leak out and get into the groundwater, making it very difficult to measure and quantify. To quantify and describe the preferential flow, two gravity-driven models were used: 1) kinematic wave model (KW) introduced by Germann in 1985), and 2) kinematic dispersive wave (KDW) model developed by applying a second-order correction to the Germann’ s model by Di Pietro et al. in 2003. So, the experimental data was obtained using the laboratory mini-rainfall-simulator over cylindrical soil samples at the laboratory. Their parameters were obtained using Solver add-ins in the Excel software. Then, the results were compared using the root-mean-square error (RMSE). The results showed that the KDW model could better predict the preferential flow (with lower RMSE). Also, the regression results showed 1) there was no significant relation between the preferential flow and the total porosity, and 2) there is a significant relation between the preferential flow and the macrospores.

The effect of the uplift force in the hydraulics structures is against stability. So, determining and controlling this force can be very important. One of the ways to achieve this purpose is to decrease this force by using the hole drains; in this way, we can build perpendicular pipes with different diameters, leading to the durability of the structure. Therefore, an experimental model of concrete dam was constructed in the hydraulic laboratory. The dam's model was divided into five sections by using 4-hole drains with a thickness equal to the dam's foundation. By running experiments with the maximum water level at the upstream, dam hole drains were opened in their position. Hydraulic potential was estimated by using the Piezometer built in the flume body. Finally, by opening some hole drains, the uplift force was calculated from the equipotential lines. Therefore, the best case (which had the minimum force) was determined, which was a/L=0. 4, to create the most proper hole drain in the dam foundation. (a: distance of drain to heel and L: length of the dam's foundation). To place the hole drain in this position, by applying the zero potential in this position, the up lift force was increased

Modeling of Kaboodval Dam using Plaxis software has been used for the Mouher-Columb behavior model. The effect of two continuities of embankment and watering operations on the meeting was considered. The body structure of the dam was increased from the side of the faces to the middle sections, and the maximum seating was recorded at 25-25 and at about 2200 mm. By examining at different intervals, the largest meeting was in the range of 180 to 185. That is, the level of the embankment was found to be critical in these numbers. Most concerns were regarding the middle of the dam, which had a weaker position. According to the analysis of different parts of Kaboudvall Dam, the materials forming the right wing of the dam in the middle and left wings of the dam were better. In the case of the 19th Module, besides the Mouher-Columb model, the dam could be modeled with hardening and hardening models. Here, the hardening model created a better fit. The hardening model, as it could get more data from the soil, is likely to better model the behavior of the soil dams. Due to the fact that, during the construction, the first sessions usually occur, the hardening model can have a better performance.

This research was carried out to assess the origin and clay minerals characteristics and their relationship with potassium forms in the calcareous soil of this region, with the humid climate conditions. Based on aerial photos and topographic maps, physiographic units were separated and soil sampling was done in each diagnostic horizon. The results showed that smectite was the main and dominant clay mineral in the study area. In well-drained pedons, the convincing process for smectite abundance seemed to be mainly the transformation of palygorskite and mica. According to the results, the exchangeable potassium in the surface horizon was higher than that of the subsurface horizons. The main reason for the higher level of exchangeable K in the soil surface, was more smectite and organic carbon. The results revealed that unlike exchangeable and non-exchangeable K, because of the suitable conditions like temperature and humidity in surface horizons, the relative mean of structural K in the surface soils was less than that in the subsurface. Also, since an increase in calcium carbonate resulted in a decrease in amount of clay and the amount of relative clay minerals (dilution effect), the amounts of exchangeable, non-exchangeable and structural K were decreased.

Channels and surface water are ways for the transfer of pollutants to the environment and human. When any pollutant is spilled into the channel, the pollutant concentrations are decreased after the travel. Reducing the distance is an engineering expedient. To reduce the distance, mixing in water should be increased. Thus, the main goal of the present study was to investigate the effect of the triangular vane on transverse mixing used for control bank erosion. Experiments were carried out in an 80cm width flume. The vane, which was triangular, was made of Plexi-glass with a 30% width of the flume length, 15cm height and 50cm far from the tracer injection. Salt solution was used as the soluble tracer. The experiment was carried out to investigate the effect of the triangular vane for two conditions: with and without vane. The transverse mixing ( ez ) and complete mixing length were estimated for the two conditions of with and without vane. The results showed with installing the triangular vane, the transverse mixing was increased up to 2. 5 and the length of mixing was decreased by 60%, as compared with the tests of no vane.

In order to study the effects of rhizobium bacteria and arbuscular mycorrhizal fungi on water use efficiency and the grain yield of bean, under drought stress conditions, two-year year field experiments were conducted during 2015 and 2016 growing seasons. The experimental design was a split plot arranged in an RCBD with 4 replications. Three irrigations including S1= 95-100% AW (Normal irrigation), S2= 75-80% AW(Moderate drought stress) and S3= 55-60% AW (severe drought stress) were assigned to the main plots and six bio fertilizer treatments including T1=177 rhizobium bacteria strain, T2=160 rhizobium bacteria strain used for seed inoculation, T3= mycorrhizal arboscular fungi used for soil inoculation, T4= T1+T2, T5= T1+T2+T3 and T6= control (no seed and soil inoculation) were randomized to the subplots. Based on the combined analysis of variances for two years, there were significant differences (p 0. 05) in the grain yield, yield components and water use efficiency between the irrigation stress and bio fertilizer treatments. The highest grain yield (2371 kg ha-1) and water use efficiency (522 g m-3) were obtained in the S2T2 treatment. In this treatment, 160 and 177 rhizobium bacteria (T2) in moderate drought stress (S2) were used. These results suggested that inoculation with the rhizobium of seed bean in arid and semi-arid areas could improve yield, water use efficiency and resistance to drought stress by increasing the growth in the root and shoot of the plant.

The effects of dissolved organic matter (DOM), derived from compost, on the sorption of simazine by soils were studied using a batch equilibrium technique. Six soils with different organic carbon contents were investigated in this study. Simazine sorption isotherms on soils were described by the linear equation, and the distribution coefficients without DOM (Kd) or with DOM (Kd*) were obtained. Generally, the values of Kd*/Kd were initially increased and then decreased with raising DOM concentrations of 0-65 mg DOC· L in the soil-solution system form. Critical concentrations of DOM (DOMnp) were obtained, and the value of Kd* was equal to Kd. The presence of DOM with concentrations lower than DOMnp promoted simazine sorption on the soils (Kd* > Kd), whereas the presence of DOM with concentrations higher than DOMnp tended to inhibit the simazine sorption (Kd* < Kd). Interestingly, DOMnp for the tested soils was negatively correlated to the soil organic carbon content, and the maximum of Kd*/Kd (Kmax) was correlated positively with the maximum of DOM sorption on the soil (Xmax). Further investigations also showed that the presence of the hydrophobic fraction of DOM evidently promoted the simazine sorption on soils, whereas the presence of hydrophilic DOM fraction obviously tended to inhibit the simazine sorption.

Flow pattern around the bridge piers includes water surface profile, velocity profile, shear velocity, shear stress distribution, etc. In this research, the effects of the base shape along with scale effects on the flow pattern around the rectangular bridge piers were numerically calculated through "Fluent Software", using Horizontal Velocity Distribution (Vx) and Vertical Velocity Distribution (Vy) criteria. The results showed that in studying the horizontal component of velocity (Vx) for the rectangular bridge piers, the vortices activity radius was 8 times of the length of the pier, and the minimum channel width for vortices activity was 16 times of the length of the Bridge pier; also, the minimum channel length in front of the pier was 4 times of the length of the pier and behind which, it was 25 times more than the bridge pier. Finally, the minimum channel length for the vortexes activity was calculated to be 29 times more than the bridge pier length. Furthermore, for the vertical component of velocity, the flow pattern around the base of the bridge cannot be an appropriate parameter for checking the effects of the length and width of the channel.

Land use/cover maps are the basic inputs for most of the environmental simulation models; hence, the accuracy of the maps derived from the classification of the satellite images reduces the uncertainty in modeling. The aim of this study was to assess the accuracy of the maps produced by machine learning based on classification methods (Random Forest and Support Vector Machine) and to compare them with a common classification method (Maximum Likelihood). For this purpose, the image of the OLI sensor of Landsat 8 for the study area (Sattarkhan Dam’ s basin in the Eastern Azerbaijan) was used after the initial corrections. Five land uses including urban, irrigated and rain-fed agriculture, range and water body were considered. For conducting the supervised classification, ground truth data were used in two sets of educational (70% of the total) and test (30%) data. Accuracy indexes were used and the McNemar test was employed to show the significant statistical difference between the performances of the methods. The results indicates that the overall accuracy of Support Vector Machine, Random Forest, and Maximum Likelihood methods was 96. 6, 90. 8, and 90. 8 %, respectively; also the Kappa coefficient for these methods was 0. 93, 0. 81 and 0. 83, respectively. The existence of a significant statistical difference at the 95% confidence between the performances of the Support Vector Machine algorithm and the other two algorithms was confirmed by the McNemar test.

Zinc is essential micronutrients for plants. This element improves plant growth and yield and plays a role in the metabolism of carbohydrates. Zinc deficiency in soils and Iranian crops is possible due to numerous reasons such as calcareous soils, excessive use of phosphorus fertilizers and unbalanced fertilizer use. The effect of zinc solubilizing bacteria on some wheat properties was considered as a factorial experiment in greenhouse conditions based on a completely randomized design. Treatments consisted of four levels of bacteria comprising B1 (control), B2 (Bacillus megaterium), B3 (Enterobacter cloacae) and B4 (consortium of both bacterium), and ZnSO4 fertilizer at three levels including Zn0 (control), Zn20 (20 Kg/ha) and Zn40 (40 kg/ha). During the experiment, some parameters such as plant height and chlorophyll index were measured. At the end of the cultivation period, soil available zinc, dry weight of root and aerial part, and the zinc concentration of the root, shoot and grain were determined. Grain yield and zinc uptake in the grain were also calculated. The results indicated soil exchangeable zinc content was increased significantly (P<0. 05) in all bacterial treatments, as compared to the control treatment. The maximum amount of soil exchangeable zinc, grain yield, zinc concentration and uptake in grain were observed in the treatment containing bacteria consortium with the application of 40 kg/ha of zinc sulfate fertilizer, which was followed by the treatment containing Enterobacter cloacae with the application of 40 kg/ha of the zinc sulfate fertilizer. The maximum amount of all measured properties in the treatment containing Enterobacter cloacae and Bacillus megaterium indicated the possibility of applying those bacteria for zinc enrichment in wheat, crop optimal production, and the sustainable agriculture.

Because of the undesirable effects of lead on soil properties and human health, evaluation of its remediation methods seems to be essential. In order to evaluate the effect of humic acid (HA) on the decontamination of lead (Pb) spikedsoils in the presence of wormwood plant (Artemicia absantium), an experiment was carried out in a completely randomized block design with three replications. Experiment factors including different concentrations of Pb (Pb(NO3)2 in the solid form) (0, 250, 500 and 1000 mg kg-1) and levels of HA (0, 100 and 200 mg kg-1) were considered. At the end of the growing period of plants, some soil and plant properties were measured. According to the results, BR, MBC, root and shoot dry weights, RWC and Fe and Zn concentrations in the shoot were decreased by increasing the soil Pb concentration. So, the mean values of BR and MBC in Pb1000 treatment was 60 and 51. 1 percent lower than those of Pb0, respectively. Pb accumulation in the root and shoot was enhanced as a result of the increase in the soil Pb concentration. The maximum Pb concentration of shoot (37. 10 mg kg-1) and root (38. 1 mg kg-1) was seen in the Pb1000 treatment. Also, the results suggested that humic acid had a positive effect on the shoot of Fe, Zn and Pb concentrations. So, the concentration of these elements in HA200 treatment showed an increase 1. 25, 1. 64 and 1. 66 times more than that of HA0, respectively. Leaf proline amount was increased significantly by elevating the soil Pb concentration; however, application of 200 mg kg-1 humic acid decreased leaf proline by 54. 5 percent, as compared to the control (HA0). Therefore, humic acid effect on increasing the plant Pb uptake, improving soil biological properties, and increasing availability and dissolution of Pb showed its ability in promoting the phytoremediation efficiency. According to the obtained results of this study, woodwarm plant (Artemicia absantium) is a non-accumulator that could not be used for phytoremediation purposes.

A labyrinth weir is a nonlinear weir folded in the plan-view which increases the crest length and the flow rate for a given channel width and an upstream flow depth. Nowadays, a labyrinth weir is an attractive alternative for those weirs that have a problem in passing the probable maximum flood. The three-dimensional flow pattern and unlimited geometric parameters provide a major challenge to the designers of these weirs. The present study aimed at determining discharge coefficients of sharp-crested triangular labyrinth weirs using the support vector machine (SVM). The results were compared with the experimental data. For this purpose, 123 laboratory test data including geometric and hydraulic parameters such as vertex angle (θ ), magnification ratio (L/B), head water ratio (h/w), Froude number (Fr), Weber Number (We) and Reynolds number (Re) were used. The results showed that the SVM-based model produced the most accurate results when only three geometric parameters, e. g. (h/w, θ , L/B), were introduced as the input parameters (R2 = 0. 974, Root mean square error [RMSE] = 0. 0118, mean absolute error [MAE] =0. 0112 and mean normal error [MNE] =0. 017 for the test stage). Also, for these weirs, polynomials linear and nonlinear regression equations were presented. Finally, the discharge coefficient of sharp-crested triangular labyrinth weirs based on the Rehbock equation was evaluated and compared with the SVM using nonlinear and linear regression methods

Since 2001, water main drainage of sugarcane farms located in the east side of Karoon River has been deviated to Shadegan lagoon. The average discharge and salinity of the drain water in spring and summer were 20 and 20. 5 m3 sec-1 and 17. 1 and 13. 3 dS m-1, respectively. Therefore, there have been considerable changes in the lagoon water quality when compared to the time before entering the drain water. Therefore, an experiment was performed to investigate the effects of sugarcane waste water on the quality of Lagoon’ s water. The results showed that the average salinity was increased significantly before and after the entrance of the drainage into different points. The average salinity in the sample point No. 2 (along the entrance of the drainage) in summer was changed from 17. 7 to 51. 5 dS m-1. The results, therefore, revealed that after the entrance of drainage water to Lagoon, during summer time, water salinity and mineral concentrations were increased for all locations except the points of 1 (on the northern margin of Lagoon) and 3 (influenced by Jarahi River). Phosphate ion concentration was increased at all investigated locations, but the highest phosphate concentrations were observed at the location points of 1 and 2 in summer. Given the important role of this lagoon in the protection of animal and plant spices, it is essentially important for sugarcane production companies to adopt a special measure for the protection of Lagoon from any source of pollution.

Subsurface drip irrigation systems, compared to other irrigation systems (basin and furrow), enhance the delivery of water and nutrients directly into the root zone. The purposes of this study were to determine wetting front advancement in a subsurface drip irrigation and to compare the results with the HYDRUS 2D model simulation. In this study, the irrigation using T-Tape was carried out on a sandy-loam soil by two emitters at different irrigation times. The Wet moisture meter device was used to determine the soil water content. Evaluation of the simulated and measured soil water content was performed by using the adjusted determination coefficient (R2), relative error (RE), and the normalized root mean square error (NRMSE). Based on the results, the NRMSE of soil water content prediction for the emitters at the depths of 20 and 40 cm was calculated to be in the range of 10 to 19 and 10 to 13 percent, respectively. Also, RE for the emitters at depths of 20 and 40 cm was in the range of-16 to-5 and 8 to 11 percent, respectively. The average R2 for the emitters at depths of 20 and 40 cm was calculated to be 0. 87 and 0. 98, respectively. Also, five scenarios (F1, F2, T1, T2 and S1) were evaluated to assess the amount of water stored in the soil profile and water mass balance. The results indicated that the model could be used to predict the soil water content subsurface drip irrigation.

Evaporation is one of the important components in water body’ s management, leading to changes in the water level and water balance. Also, its accurate estimation is faced with certain difficulties and complexities. Because of the limitations of physical and empirical methods based on the meteorological data, remote sensing technology can be widely used for evaporation calculation due to its capabilities for spatial data estimation and minimization of the meteorological data application. Many models have been developed to estimate evapotranspiration using remote sensing technology. Regarding the use of these algorithms for estimating evaporation from water surface, a few studies have been done; however, there is yet no comparison between them to estimate evaporation from the water surface. For this purpose, in this study, the output from two models estimating spatially distributed evaporation of water surfaces from remotely sensed imagery is compared. In order to implement these models, Terra/MODIS Images for four months including June, July, August and September in of 2006, 2007, 2008 and 2009 were prepared. Comparisons were made using pan data from Urmia synoptic station. In general, there was a reasonable agreement between the evaporation outputs from both models versus a pan data observation. The statistical analysis also showed that the SEBS algorithm (by applying the salinity factor), despite being simple in its implementation, has higher accuracy than the SEBAL algorithm.

The present study was conducted to evaluate zinc availability and forms, as well as their relationships with soil properties in some soil samples of Kermanshah and Ilam provinces. Sequential extraction included Mg(NO3)2 (soluble + exchangeable), NaOAc pH = 5 (carbonatic fraction), Na-hypochlorite at pH = 8. 5 (organic fraction), hydroxylamine hydrochloride at pH 2 (Mn oxides associated Zn), hydroxylamine hydrochloride (amorphous Fe oxides associated Zn), ammonium oxalate (crystalline Fe oxides associated Zn), and HNO3 (the residual Zn). DTPA-Zn was in the range of 0. 34-3. 7 mg/kg. The results showed that soluble+ exchangeable, Mn oxides and crystalline Fe oxides associated Zn were not detectable by atomic absorption. Distribution of Zn fractions was in the order of Organic-Zn < Car-Zn < amorphous Fe oxides-Zn < Res-Zn. Organic matter bound Zn and amorphous Fe oxides associated Zn and the residual fractions showed a significant negative correlation with the calcium carbonate equivalent. It seemed s that calcium carbonates were the major factor in controlling the Zn content in the studied soils.

and the optimum application. Field measurement of infiltration is very expensive, time-consuming and laborious. Soil structure also important effects on water infiltration in the soil. The objectives of this study were to determine the spatial variability of water infiltration, to select the most appropriate infiltration model, to calculate the parameters of relevant models, and to quantify the soil structure by using the fractal geometry. Infiltration parameters were estimated by using some physical soil properties, as well as fractal parameters, in this research. To achieve these purposes, 161 sites were selected and their infiltration was measured by using the constant head double-ring infiltrometers method in a systematic array of 500*500 m. The observed infiltration data from all examined sites were fitted to three selected infiltration models. Soil bulk density (BD), soil water content, soil particle size distribution, soil aggregate size distribution (ASD), organic carbon content (OC), saturation percentage (SP), soil pH and electrical conductivity (EC) were also measured in all 161 sites. For the quantitative assessment of soil structure, the aggregate size distribution, fractal parameters of the Rieu and Sposito model as well as the mean weight diameters (MWD) and geometric mean diameter (GMD) were also obtained. The obtained results indicated that the infiltration rates of the studied areas had generally low basic infiltration rates (1. 1-31. 1 cm hr-1) for most sites with the average of 6. 69 cm hr-1. According to all obtained results and based on the least-square method, the Philip model was selected as the best performing model to account for infiltration. The aggregate size distribution demonstrated a fractal behavior, and the infiltration parameters could be significantly correlated with the fractal parameters and other soil physical properties.

In recent years, with the excessive use of underground water resources in the Malayer Plain, the water level has dropped sharply and underground water resources, which serve as the main source of water supply for the agricultural sector and drinking, the city is facing a serious risk. Because of the relevance of each of the fields with other agricultural fields around, this study was done to show the potential effect of this problem on the welfare. So, in this study, the special econometric method was employed. The purpose of this study was to analyze the welfare of farmers and how it is affected by the exploitation of underground water resources. For this purpose, by using social welfare function, the effect of change in the value of groundwater level of social welfare producers was addressed. The necessary information was collected from 119 questionnaires carried out in 2015. Moran's I statistics showed that the results of special regression method were better than those of Ols. The results of this study indicates a decline in the welfare loss of groundwater level and the continuation of the harvest of underground water resources would lead to a reduction in access to water and reduced production. The rate of change in return for the welfare of the reduction of every meter of underground water level to cultivate wheat and potatoes was 6983 and 7634 million Rials, respectively

Regional flood frequency studies are initialized by the delineation of the homogeneous catchments. This study was based on "Region of Influence" concept, aiming to find the similar catchments in the south of Caspian Sea. The methodology utilized the Particle Swarm Optimization Algorithm, PSO, to optimize the fuzzy system over a dataset of catchment properties. The main catchment variables in relation to flood were determined by the principle component analysis method and employed as the inputs in the fuzzy system. Catchments grouping was performed over these fuzzy input variables by the iterative process. The optimum similar groups were obtained by PSO, and the heterogeneous Lmoment index was used as the termination criterion for the optimization process. A total of 61 hydrometric stations located in the study area were selected and their relevant catchments' physical, climatic and hydrologic properties in relation to flood were studied. Principle Component Analysis by Variomax Rotation Factor over the catchments datasets tended to four out of 16 physical variables, including area, mean elevation, Gravelious Factor and Form Factor, as the main parameters in terms of homogeneity with 84 percent of accumulative variance. These variables, as well as mean annual rainfall, were used as the input data to define the fuzzy system. PSO algorithm was then employed to optimize the developed fuzzy system. The developed algorithm tended to yield the best result in the 9th iteration with 26 and 22 for the minimum average and the optimum values of cost function, respectively. The topology of the resulting algorithm included inertia weight, local and acceleration rates, the number of generations and population size, with the values of 0. 7298, 1. 4962, 1. 4962, 10 and 5, respectively. This study tended to a total of 61 regions of influence, proportional to the relevant 61 sites. According to the geographical location of the catchments in the region, it could be concluded that the geographical proximity doesn't necessarily involve homogeneity. The obtained results indicated the efficient potential of PSO-FES in the delineation of the homogenous catchments in the study area.

Alginate biopolymer, due to possessing a high capacity and affinity for heavy metals, is a suitable material for the removal of metals from polluted waters; however, the weak structural consistency of alginate hydogels limits the practical application of this natural polymer in water purification practices. In this study, sepiolite clay mineral was used as a solidifier of alginate hydrogel to produce hybrid materials with different clay: alginate ratios (1: 2, 1: 4 and 1: 8). Subsequently, the sorption of Pb by the prepared hybrid materials was studied in different Pb concentrations (25 to 2000 mg/L) and temperatures (15, 25, 35 and 45 ° C). The results showed that the Langmuir and freundlich equations could significantly describe Pb sorption data on the sorbents. Based on the Langmuir model estimation, alginate showed and sepiolite showed the highest and lowest capacities for Pb sorption, respectively; also, the hybrids were intermediates in this respect. The capacity and affinity of all sorbents were enhanced with increasing the temperature from 15 to 45 ° C. Standard enthalpy changes (Δ H° ) were found to be positive, confirming that the process of Pb sorption on the sorbents was endothermic. Positive values were also obtained for the standard entropy changes (Δ S° ), suggesting increased randomness at the solid-solution interface during the sorption of Pb ions on the sorbents. The values of the standard free energy change (Δ G° ) were negative for all different temperatures, thereby indicating that sorption on the sorbents was spontaneous and favorable. Overall, it could be concluded that modification of alginate with sepiolite might cause the decreased sorption capacity of alginate; however, the hybrid materials are good candidates for the Pb removal from aqueous solutions because of their high sorption capacities.

One of the factors leading to the contamination of water resources is human activity, producing waste materials. In this paper, the effects of contamination on the water quality of Taleghan River, was simulated using of Qual2k model and the seasonal changes were evaluated. The qualified data collected during two months, August (as the dry season) and February (as the wet season), were used in the modelling. The results showed that the dissolved oxygen change was in the range of 4. 5-6. 52 mg/L in August. However, it changed between 4. 8-5. 3 mg/l in February and this reduction in the wet season was due to the run off deposition and the seepages of farmland near the river. Furthermore, BOD in the wet season and the dry season changed by 6-31 and 10-26 mg/l, respectively. These changes were due to the sewage dilution in flow during the wet season. Evaluation of the pH values in wet and dry seasons also showed that water of the river was more alkaline in the wet season, which is due to the effect of non-point resources or the fertilizer entrance after farm land bleaching by rain. Evaluation of Taleghan river EC variation also showed these changes were not significant during the wet and dry seasons. Water temperature was altered by 3-100C and 19-250C, respectively, in February and August.