نشریه پژوهش های حفاظت آب و خاک
سال بیست و سوم شماره 1 (فروردین و اردیبهشت 1395)

Soil pollution by heavy metals is environmental problem which can affect human and animal health, environmental and agricultural productions. Phyto-extraction is the technology of using plants for cleaning polluted soils which is an effective, Cheap and environmental friendly method. Phytoremediation is a method in which clating agents and mineral acids are used to enhance uptake of heavy metal by plants. The aim of this study were: (a) to determine the potential of radish for extracting Zn from polluted soils and (b) to assess the effects of different additive (EDTA and H2SO4) in enhancing plant uptake of heavy metal and (c) to assess the effects of different levels of soil Zn on radish growth and Zn concentrations of above and below ground parts of this plant.
A Factorial experiment were conducted in Soil Science Department, using a completely randomized design and three replications. The experimental factors were type and rate of soil additive (10 and 20 mg/kg of EDTA and 0, 750 and 1500 mg/kg H2SO4) and Zn levels of polluted soils (0, 200, 400, 600, 800, 1000 and 1200 mg/kg).
The results showed that The Application of soil additives increasd the concentration and absoption of Zn in above and below ground part of radish and decreasd the dry weight of those. Application of 20 mg EDTA per kg of soil cause the highest concentration of Zn in the above and below ground part of radish, so that increased it respectively 304 and 182 mg.kg-1 compared to control. Rate of 20 mg EDTA/kg soil increasd absorption of Zn by plant 28.7 percent. After treatment with 20 mg EDTA /kg soil, treatment with 10 mg EDTA /kg soil, 1500 mg H2SO4 /kg soil and 750 mg H2SO4 /kg soil were better treatments respectively. Zinc concentrations of aerial parts were higher than those of below ground parts and the highest concentration of zinc in these parts were 810 and 425 mg/kg respectively. The dry weight of above and below ground part of radish decreasd but its concentration for Zn increasd as the Zn levels of polluted soils increasd. An antagonistic effect between p, K, Fe and Zn uptake was also observed.
In general the result showed that the radish plant was a Zn hyperaccumulator plant with translocation factor of greater than 1 and it can be used for phytoremediation of Zn polluted soil. The application rate of soil amendments had significant effects on their performance and unappropriate application rate of them had negative effects on phytoremediation. Based on the results obtained in this experiment application of 20 mg EDTA/kg soil is recommend for Zn phytoremediation.

Digital soil maps with fine resolution are one of the basic needs of users and decision-makers in agriculture, natural resource and environment. However, in our country, there is scarcity of this kind of data and producing fine resolution soil data is very costly. Therefore, downscaling digital soil maps arises as a suitable option in order to produce fine resolution soil data. Objectives of this study were to examine and evaluate downscaling digital maps of some soil surface properties from block supports 50,100 and 250 m to block support 10 m using direct approach across Merek sub catchment in Kermanshah province with an area of 24000 ha.
Material and The first spatial structure information of soil surface properties including %sand, % silt, %clay, %organic carbon, % equivalent calcium carbonate and %gravel determined using legacy data(320 randomized point samples) and variography. Then, block kriging maps were produced with block support 50,100 and 250m. Terrain attributes, Landsat images, geology map, geomorphology and land use maps were used in this study as auxiliary variable. Correlation coefficient between auxiliary variables and target variables is calculated and auxiliary variables were significant at the 0.01 level selected as model inputs. Afterward, downscaling direct approach is used. In this approach, relationship between the soil properties and auxiliary variables with coarse resolution identified using generalized linear models (GLMs) and regression tree. Next, calibrated parameters and fine resolution covariates are applied to prediction soil properties in fine resolution. Models are trained on 75% of the block support data accordance with original data and evaluated on the remaining 25%, using k-fold validation (k=4) procedure.
The results showed that amount of sand and gravel had minimum and maximum correlations with covariates, respectively. Considering all the pixel sizes, the highest correlation obtained among soil properties and elevation, direct duration, convexity, slope, topographic wetness index and mrvbf. Downscaling gravel map from block support 50m to 10m by GLMs showed best performance (RMSE=5.57%). Downscaling sand, clay, equivalent calcium carbonate and organic carbon from 250m block support and silt from of 50 m to 10 m block support using regression tree lead to estimate the lowest root mean square error (3.9%, 3%, 4.39%, 0.21% and 2.31% respectively). Besides, regression trees showed the best performance in downscaling of soil properties with different pixel size.
it seems that direct approach would be able to downscale digital maps of soil variables (such as silt, calcium carbonate equivalent, sand and organic carbon content) with acceptable accuracy and efficiency. Obviously, GLMs and regression tree can lead to strong results if the correlation between soil properties and auxiliary variables is high. It can be concluded that various auxiliary variables at diverse pixel sizes have different relationships with the target variable which affect the performance of the downscaling.

Natural rivers are one of the main sources of water and energy. Design and management of natural rivers needs a complete understanding of mechanics of flow pattern and sediment transport. The complex three-dimensional flow characteristics in river bends necessitates the use of a three-dimensional numerical model. The purpose of this study is predict the flow pattern and location of erosion and depositional in Sine-Generated channels, Also, the effect of Froude number and the ratio of width to depth on flow and bed shear stress considered.
The numerical model used in the present study is called SSIIM, an acronym for sediment simulation in intakes with multi block option. In this study is predict the flow pattern and location of erosion and depositional in Sine-Generated channel having 50 0 with rigid bed. The k and SST k models were used to predict the turbulence in this simulation. For verification of the results of the numerical model the experimental data (da Silva and Tape) was used.
By changing the Froude number from 0.15 to 0.41, flow pattern and velocity distribution did not change but increased erosion. Also by decrease width to depth ratio form 12.5 to 4 the number of rotary cells in Section increased from 2 to 3 number and it was found in wider rivers, power of secondary flow decrease but the downside and the upside of it is the same deep rives.
The result of simulation shows that SST kmodel has better accordance with experimental data than kmodel. Distribution of bed shear stress depends on Froude number although secondary flow is independent. Furthermore, distribution of bed shear stress and secondary flow is dependent on the width to depth ratio, so that the for b/h

In order to study the effects of Urmia Lake on physicochemical and mineralogical properties of soils in Dizadj Dol region, 24 soil profiles in two soil sequences with the similar parent material, topography and climate were investigated. One of these sequences is affected by Urmia Lake and the other one is not affected. According to the results, all of the profiles which have been affected by the Lake have nitric horizons. Natric horizons in these soils have been formed due to high amounts of sodium ions resulted from UrmiaLake. Varivace analysis of physico-chemical properties of these soils showed that the values of soil organic carbon, CEC, EC, exchangeable Na, ESP and pH of the two sequences were significantly different (P≤ 0.01), but soil depth, clay content and calcium carbonate equivalent were not significantly different. Analysis of clay mineralogy showed that the clay mineral composition in these sequences were mostly smectite, illite, kaolinite, chlorite and vermiculite. Smectites and vermiculites in these soils are mainly of pedogenic origin and have been formed via transformation of illite. In the soils which have been affected by Urmia Lake, the main origin of smectites was neoformation process from soil solution. Illites, chlorites and kaolinite are inherited from parent material. Comparision of results of soils in these two sequences showed that the upraise of Urmia Lake has lead low amount of organic carbon and to high amounts of EC, exchangable sodium, ESP, CEC, pH and higher amounts of smectite in the soils affected by Urmia Lake.

The calibration of hydrologic models is a worldwide challenge due to the uncertainty involved in the large number of parameters and the inability to reliably measure the distributed physical characteristics of a catchment results in significant uncertainty in the parameterization of physically based, semi-distributed models. The difficulty even increases in a region with high seasonal variation of precipitation. Therefore, a successful application of a hydrologic model in applied water research strongly depends on calibration and uncertainty analysis of model output (). Shen and et al. () quantify the parameter uncertainty of the stream flow and sediment simulation by SWAT model in the part of China. The research indicated that only a few parameters affected the final simulation output significantly. Shape and et al. () assessed the capability of the Soil and Water Assessment Tool (SWAT) model to capture event-based and long-term monsoonal rainfall–runoff processes in complex mountainous terrain and found that high elevation steep sloping regions were generally base flow dominated while lower elevation locations were predominately influenced by surface runoff. In this paper, the Generalized Likelihood Uncertainty Estimation (GLUE) method was combined with the Soil and Water Assessment Tool (SWAT) to quantify the monthly stream flow in the eastern Gorganrood river basin.
The Golestan Regional Water Company (GRWC) monitoring site at Gazaghly was chosen as the outlet for the entire watershed since it is the lowest monitoring station on the river not subject to dam influence. Annual precipitation decreases in the west to east direction, low (200 mm) to high (880 mm) and from south to north direction. Model has been calibrated and validated using monthly runoff flow data of ten years 1984 and 1993. Data pertaining to year 1984-1990 has been used for calibration and 1991-1993 for validation.
In semi-distributed models such as SWAT, it is necessary to identify the most sensitive parameters to obtain a better understanding of the overall hydrologic processes before calibration. Based on this study, only a few parameters affected the final simulation output significantly. The parameters such as CN2 (curve number), GWQMN (threshold in the shallow aquifer), RCHRG_ DP (deep aquifer percolation fraction), ALPHA_ BNK (base flow alpha factor for bank storage), ESCO (soil evaporation compensation factor) and SOL_ K were found to be the most sensitive parameters. According to results, the parameter CN2, was the most effective parameter on the output discharge of the studied area and CN2, was identified as a main source of uncertainty in results. Statistical model performance measures, coefficient of determination (R2) of 0.80, the Nash-Sutcliffe simulation efficiency (ENS) of 0.72, for calibration and 0.83, and 0.80, respectively for validation, indicated good performance for runoff estimating on monthly time step in the outlets of the Gazaghly gauging station. 69–74% of the observed runoff data fall inside the 95% simulation confidence intervals in the calibration and validation periods. The evaluation statistics for the daily runoff simulation showed that the model results were acceptable, but the model underestimated the runoff for high-flow events.
SWAT was applied to simulate monthly runoff in part of the Gorganrood river basin. Results of uncertainty analysis indicated that SWAT model had large uncertainties for calibration period, although the simulation of monthly runoff for the Gazaghly station was satisfactory during the calibration period and in the model calibration stage 69 of runoff observations were within the corresponding 95% confidence interval. This study would provide useful information for hydrology modeling related to policy development in the Gorganrood river basin and other similar areas.

Snow water equivalent (SWE) is a key parameter in hydrological cycle. In Iran, measurement of snow depth and its water equivalent is usually is limited due to lack of automated snow measuring instruments. According to research conducted in the field of snow water equivalent, wind speed, temperature, precipitation and elevation are the factors affecting the amount of snow water equivalent. Because values for wind speed, temperature and precipitation can affect the long-term snow water equivalent, Therefore the aim of this study using of meteorological and geographical parameters to estimate snow water equivalent of snow stations in the study area.
In the current study, based on meteorological data and interpolation method snow water equivalent was estimated. To this regard, first, average amounts of precipitation, air temperature and wind speed were computed during periods of 10, 20, 30, 40 and 50 days. Then, binary correlations between snow water equivalent and the parameters were estimated. Parameters that had the highest correlation were selected. Then in SPSS software between these parameters and the elevation of the stations, the snow water equivalent to a multiple regression obtained. The regression equation were validated with snow water equivalent data measurement in snow stations.
Based on these results, the average precipitation, temperature 40-day, and wind speed of 30-day, showed the highest correlation with snow water equivalent, respectively. The best snow water equivalent equation obtained using the relevant parameters. Estimated data was also compared with the observed data, based on the Nash- Sutcliffe criteria (NS= 0.83) and regression coefficient (r= 0.91). The results showed an acceptable accuracy of the equation on snow water equivalent estimation.
In this study, due to the lack of meteorological measuring in snow stations, the interpolation methods for estimating the amount of precipitation, wind speed and temperature parameters the location station was used. The results indicated that of the interpolation methods, radial basis functions with model a Inverse Multiquadric for average wind speed of 10 to 50 days, Completely Regularized Spline model to estimate the average temperature of 10 to 50 days and kriging method with Gaussian model for estimating the average precipitation 10 to 50 days, of the high accuracy in the snow stations. Using the parameters that were most correlated with snow water equivalent, a regression equation to estimate snow water equivalent obtained. Evaluation showed regression equation can be used to estimate snow water equivalent in the respective stations.

Using computer models as a cheap, fast and at the same time accurate method in studying and simulating the flow in a porous media has attracted the attention of many researchers and experts. The aim of this research is to investigate the effects of constructing Roudab dam on Sabzevar Roudab aquifer, which is located dam downstream.
Sabzevar Roudab catchment basin, with an area about 1828 km2, is located in northeast of Iran in west of Khorasan Razavi province. To manage the surface waters and to supply part of water demand in Roudab plain area, a dam is under constructing on Roudab's river. In order to study the water flow system of Roudab plain aquifer groundwater in Sabzevar and the effect of constructing Roudab dam on it, groundwater model of Sabzevar Roudab aquifer has been simulated using MODFLOW code in GMS software with conditions of existing and not existing of Roudab dam. The aquifer model in steady state condition has been calibrated for the year of 2010 and in unsteady state condition has been verified for 12 month period in year 2011.
The hydraulic conductivity from the calibration of aquifer model in steady state condition is between 4 to 14.7 meter per day and specific yield changes in unsteady state condition calibration is optimal and has been estimated to be between 0.06 to 0.22. The aquifer model studied here has the most sensitivity to the hydraulic conductivity and to the discharge of the extraction wells. The reason is that the major portion of the aquifer depletion is done by the extraction wells and natural discharge has a smaller share in the aquifer depletion. Due to the excessive exploitation of Sabzevar Rudab aquifer, water table has dropped in this plain. The severity of the decline in several areas depends on the amount of recharge and discharge of an aquifer. In other words, the general trend of the plain hydrograph is descending and its water balance is negative.
The model results show that the water table curves presented by the aquifer model, before and after constructing the Roudab dam do not show any significant changes, because the groundwater water balance before and after constructing the dam is not significantly different and also because it is almost unaffected by the surface recharge. It is worth mentioning that constructing Sabzevar Rudab dam would lead to further decline of the water table elevation of the aquifer. Has been predicted average decline of the water table in Roudab aquifer in years of 2014, 2015 and 2016 will increase about 0.17, 0.2 and 0.23 meters, respectively.

Accuracy of spatial estimation of soil properties such as clay, organic matter and calcium carbonate equivalent is very important in plant nutrition and environmental planning. The most important step before statistical analysis and using geostatistical estimators is data check. In addition to investigation of outlier data and data distribution, another important action in geostatistical studies is trend surface analysis. Analyzing trend surface can evaluate the role of factors such as stone kin, climate, topography and generally regional anomalies. The objective of this study was trend-surface analysis and its effects on variogram modeling and mapping of clay, organic matter and calcium carbonate equivalent.
For this purpose, 100 surface soil samples in 0-15 cm depth were selected randomly based on different classes area slope from 41353 ha area in Selin plain farmland located in Kaleibar region, East-Azerbaijan. Soil properties such as clay, calcium carbonate equivalent and organic matter were measured by hydrometer, return titration and wet oxidation method, respectively. For analyzing trend surface used multiple regression models which its independent variables was geographical coordinate and dependent variable was a soil properties. For zoning clay, organic matter and calcium carbonate equivalent and residuals of removing trend used ordinary kriging. The effect of removing trend surface in variogram modeling and kriging estimating were evaluated by cross-validation method with indexes mean error (ME), root mean square error (RMSE) and determination coefficient (R2).
Trend surface analysis showed that the best regression models for trend determination of clay, calcium carbonate equivalent and organic matter were first order, first order and quadratic, respectively. Removing the detected trend led to decrease in sill but the nugget effect did not changed. However, no significant difference was observed between accuracy of kriging estimator in presence and remove of trend. This can be attributed to the fact that both abnormal manner of environment and activations of human. So that, the regression models of the trends were 35, 18 and 21% of clay, organic matter and calcium carbonate equivalent variations, respectively. However, removing the detected trend led to increase 9.1, 2.7 and 6.6% of R2 for clay, organic matter and calcium carbonate equivalent, respectively.
generally, investigation of trend surface recommended in soil studies that is more deals to spatial data. Because the trend depends on the location and conditions of the study area as well, the source of the creating trend trend trend trend trend.

Iran as an arid and semiarid country has been faced with low precipitation and water shortage. In this regard, the application of suitable management practices using plant residues is one of the most important strategies resulting in the improvement of organic matter content as well as water retention of soils. Therefore, in many soils of arid and semiarid regions, organic matter is as the best amendment to increase water content and improve physical properties of the soil (23, 40). Plant residue can increase soil moisture content through the improvement of soil organic carbon content and the reduction of runoff and evaporation (9, 25). Application of plant residue is one of the common methods for improving soil properties. However in some areas, plant residues are removed from the filed or burned by the farmers. This study was performed to investigate the effect of different types of plant residues and their management on soil moisture content as well as aeration properties under field conditions.
The experiment was conducted under field conditions as factorial statistical design based on RCBD consisting three replicates. The first factor was residue type including barely straw and alfalfa residue and the second factor was different managements of the residues including 1) incorporating one percent of the plant residues with the soil, 2) incorporating 0.5 percent of the plant residues with the soil, 3) surface retention of plant residues, 4) burning of plant residues and 5) control. After nine months, the final soil moisture content at seven suctions including 0, 30, 50, 100, 500, 1000 and 1500 kPa was measured. In addition, the available water content and aeration porosity were calculated.
The result showed that among the experimental treatments, the incorporation and also surface retention of plant residues increased soil moisture compared to control, whereas, burning the plant residues reduced the moisture content. In comparison to the control, the incorporation of one percent barely straw to the soil led to the highest increases in the moisture content at PWP (70%) and the available water (12.5%). Reversely, burning of barely straw showed the highest reduction in the moisture content at PWP (34.5%) compared to control. In addition, the surface retention of plant residues resulted in the highest increase (48%) in aeration porosity compared to control.
The findings of this study showed the favorite efficiency of incorporating and surface application of organic sources in improving soil moisture and aeration porosity.

Dust deposition causes great difficulties for humans in urban regions. The objective of this research was to assess the temporal and spatial distribution of magnetic susceptibility (MS) of atmospheric dust deposited in Kerman. Samples were collected monthly from 35 different locations distributed over the urban area of Kerman for 7 months. Total concentrations of major heavy metals including Cu, Pb, Zn, Ni and Mn as well as the magnetic susceptibility of the samples were measured. The results showed that atmospheric deposits had the highest MS in November and the lowest one in July and August following the same trend as that of heavy metals Cu, Pb and Zn. The results also showed that the highest MS values were obtained for the dust samples from the west of Kerman where the concentration of Cu, Pb and Zn in dust was also high. Considering the role of human activities in increasing pollutants concentration in Kerman, proper management practices should be exercised to reduce air pollution resulting from various industries.

Several investigations have been carried out in order to remote sensing of soil texture using radar data. Whereas there is no report on application of using passive and free satellites data including ETM and MODIS for this aspect. The remote sensing of soil texture also is limited by the existence of vegetation on soil surface. So the current research was aimed to evaluate ETM data applicability for remote sensing of the soil texture as well as assessment of the vegetation effects on the accuracy of the predictions. In this regard, soil separates were measured at 225 different points of study area on Northern slopes of Mount Sahand and available ETM data were downloaded. Several methods including empirical, statistical, and black box (artificial neuron network, ANN) using Excel, SPSS, and Matlab software’s were applied to create different functions for remote sensing of soil separates. Results showed that vegetation existence led to lower accuracy of the prediction. Results showed that although empirical and statistical approaches showed low accuracy (with R2 lower than 0.3) for remote sensing of the soil separates, black box model using ANN algorithm was accurate enough (with R2 higher than 0.5).

Quantitative prediction of river discharge one of the most important elements in the management of surface water resources, especially take suitable decisions in occurrence of floods and drought events. Various approaches introduced in hydrology to predict river discharge which conceptual models as well as data-driven models are the most important ones.In this study, long term recorded data sets in Araz-Kouseh watershed with 1678 km2 area located in northern Iran (Golestan province) were used to investigate the precision of different river discharge prediction models. The IHACRES model as a conceptual hydrological model and KNN and M5 as data mining models selected for modeling of monthly river discharge and the results were compared to examine the accuracy of studied models. In some studies, the expressed models used for daily river discharge prediction but the main objectives of this study are application of these models to predict monthly discharge for a watershed.
Material and The 29 years (1985-2013) daily rainfall and discharge data belonging to Araz-Kouseh hydrometry and meteorological stations used to extract monthly time series for modeling. The required quantity and quality conditions of datasets for modeling confirmed using different statistical tests. Recorded datasets divided to two subseries, first one used for calibration period and second one used for validation of investigated models. The results of models in calibration and validation period analyzed considering model efficiency goodness of fit criteria.
The results of IHACRES conceptual hydrological model for both calibration and validation periods (correlation coefficients equal to 0.81 and 0.79 for calibration and validation periods respectively) show suitable ability of this model to predict monthly river discharge. Moreover investigation of results of both M5 and KNN data mining models (correlation coefficient equal to 0.94 and 0.89 for calibration and validation periods respectively for KNN model and equal to 0.92 and 0.88 for calibration and validation periods respectively for M5 model) reveals that application of these models led to significant increase in prediction precision in comparison with IHACRES model.
The results of this study indicate the data mining models, i.e. M5 and KNN, outperform conceptual hydrological model, i.e. IHACRES, for prediction of monthly river discharge considering different goodness of fit criteria. It is clear that the accuracy of the prediction of data mining models are very close to each other but the M5 model is selected as best model in this study because of its explicit equations for prediction. Furthermore, investigation of time series of predicted river discharge show data maining models had better prediction for low discharges in comparison high discharges.

Mulching is one of the most common ways to soil stabilization, prevent wind erosion and control dusts. Some types of mulches is not economically practical choices, thus use of inexpensive and safe industrial wastes in the mulch compositions have both economically and environmentally importance(waste recycling). Therefore, a key objective of this research is use two types of industrial waste for preparation of mulch. Since Proctor method has been considered to test and compare the strength of mulches, so another purpose of this research is simplification of Proctor method to estimate the strength of soil stabilizer mulches under the influence of wind erosion.
Based on the results of previous studies and pre-treatments, some mulches were tested. These mulches were non-living composed of different percentages of stone powder, converter sludge, clay soil, and sandy soil. Instron device was used to measure the compressive strength of the mulch. Considering applying of the Proctor method for working with Instron device, simplification of the procedure was also performed. These two methods were called as “Proctor” and “simplified Proctor” methods, whose results were compared as the criterion for utilizing the simplified method. The treatments included five types of mulch in three replications, where their compressive strength was measured by the two methods of “Proctor” and “simplified Proctor” and were compared by the random factorial designs.
Reducing the clay percentage from 80 to 50 and increasing the percentage of sand from 20 to 50 in the treatments containing clay and sand in both methods resulted in compressive strength reduction of mulches. Increasing the percentage of the stone powder from 5 to 25 and simultaneous reduction of clay percentage from 85 to 65 together with constant percentage of converter sludge led to decreased compressive strength through the simplified Proctor method. The differences between the results of the two Proctor and simplified Proctor methods were not significant, but the simplified Proctor method had specific order in the results.
Compressive strength reduction with reduced clay percentage and increased stone powder percentage was showed in the comparison of the treatments containing clay and stone powder through the simplified Proctor method. However, the results of the Proctor method lacked a logical order. The comparison of the treatments containing clay and sand indicated that in both methods, as the clay decreases and the sand increases, compressive strength reduced. Compressive strength test results using Instron device was compared in both simplified Proctor and Proctor methods, therefore it was showed that these two methods do not have a significant statistic difference, although orderly changes of the simplified Proctor method results was found. Considering the simplicity and time reduction in the simplified Proctor method, this method is recommended for mulch comparisons in wind erosion.

Emitters discharge influenced by various factors such as pressure, manufacturing coefficient of variation, clogging or irrigation water temperature changes. Emitting pipes according to the hydraulic and technical specifications, the use of them in the trickle irrigation systems are increasing.Therefore investigation of the relationship between discharge – pressure and discharge- temperature is required in these pipes in order to improve the efficiency of trickle irrigation systems. Maroufpoor and Parvini(2012) fund with investigation of the relationship between discharge – pressure and discharge- temperature.That in all emitter and tested temperatures power of the discharge - pressure equation was less than 0.2 and all of were emitters pressure compensating. The effect of temperature on the discharge 3 emitter at 95 percent significant and was non-significant other emitters.
In order to evaluate the effect of temperature and pressure on emitters discharge, 8 emitting pipe, 6 type of non-compensating and 2 compensating was tested on the constructed physical model of drip irrigation in the water laboratory of University of Kurdistan. In each experiment, according to the standard on every model from the emitting pipes slices, 25 slices were selected randomly. Each slices was consists of 5 units emitters. Slices length varied proportional to the distance of unit’s emitters in the range of 2 to 5 m. The effects of four different water temperatures (13, 23, 33 and 43°C) with different pressure ranges (between zero and 1.2 times more than the maximum pressure) on the emitters were evaluated. The thermostat and element were used to supply water temperatures of 23, 33 and 43 ° C. To supply water temperatures 13 ° C was used of the ice pieces. Generally in the every temperature, discharge of compensating emitting pipes was measured at 10 pressures and in the non-compensating emitting pipes was measured at 7 pressures. Data analysis was performed in a randomized complete block design using SAS software.
According to the results obtained from the experiments of discharge- pressure at all temperatures, in the both C1 and C4 emitting pipes, power of the discharge - pressure equation was less than 0.2,therefore, as compensating are acceptable and were good degree of them flexibility. As well as in the rest of the emitting pipes power of equation was variable between 0.2 and 1 and as non-compensating and them flexibility was the high degree of flexibility. According to the results obtained from the experiments discharge – temperature, in the all emitting pipes of non-compensating, the effect of temperature on discharge at 95 percent was significant, that generally discharge had increased with increasing temperature. In the compensating emitting pipes with increasing temperature from 13 °C to 23 °C, flow rate has increased at 95 percent significantly, but from temperature of 23 °C to temperature 43 °C there was no significant difference between emitters discharge.
In general it can be concluded that the relationship discharge – pressure in the external and internal emitting pipes of common market is acceptable and desirable. Also is suggested that, in the design of trickle irrigation systems that is used emitting pipes, was ensured the effect of temperature on the discharge of emitting pipes units and the necessary correction coefficients is applied emitter nominal flow rate.

The effect of mineral clogging by soil particles is one of the main factors affecting the performance of drainage systems. Many drainage systems designs do not pay attention to laboratory and local studies on certain important parameters and some of them use to be specific for a given conditions. Several studies carried out in The Netherlands have shown that nearly 80% of drainage projects’ failure happens as a result of inappropriate performance of drain filters. Since field studies in order to evaluate drain envelopes is not economical from viewpoint of time and cost. Therefore laboratory evaluation is proper for envelopes. The main goal of this study was obtaining a set of empirical equations in order to estimate hydraulic and clogging parameters using hydraulic head and discharge through drains which are easy to measure. Removing the effect of piezometers installed the Permeameter was another goal.
To conduct this research, The Permeameter which designed and was made according to ASTM-5101 standard, was used PP-450 and gravel envelope were evaluated according to USBR standard. Required soil for this experiment was collected from a drainage project in the north of Khorramshahr at 1.65 m depth. The test was conducted in laboratory using Permeameter by producing 4 different hydraulic pressure head (25, 50, 75, 100 cm). In this study, special parameters (envelope hydraulic conductivity, soil hydraulic conductivity, soil-envelope hydraulic conductivity, gradient ratio) were calculated by measurement of outflow changes in soil envelope system and hydraulic pressure head of manometer.
After the tests were completed, the values of hydraulic conductivity for soil-envelope system, soil and geotextile envelope were estimated as functions of hydraulic head and outflow values. Furthermore, other relations were proposed for gradient ratio. The relations between different parameters were analyzed by Sigma Plot software and proper relations were proposed. The errors of the fitting equations and the difference between measured and estimated values were analyzed using the statistic indices. Results showed that these models are accuracy estimation of assessed parameters.
Correlation coefficient of these equations for pp450 envelope for soil-envelope hydraulic conductivity, soil hydraulic conductivity, envelope hydraulic conductivity and gradient ratio are 0.96, 0.96, 0.62 and 0.96 respectively and for gravel envelope for soil-envelope hydraulic conductivity, soil hydraulic conductivity, and envelope hydraulic conductivity are 0.98, 0.98, and 0.63 respectively. Low correlation coefficient for estimation of envelope hydraulic conductivity is related to envelope clogging during experiment time. Using of proposed equations can be estimate clogging and hydraulic performance of drainage envelopes in different conditions.

Some of heavy metals such as copper (Cu) and manganese (Mn) are toxic and represent as hazardous pollutants due to their persistence in the environment. Heavy metals can be introduced into soils and aqueous environment by natural processes or anthropogenic activities. They are non-degradable in nature and highly toxic to plants, animals and human beings. Various methods exist for the removal of heavy metal ions from solution, such as filtration, chemical precipitation, ion exchange and sorption by activated carbon and others. Discarded tires are an interesting and inexpensive medium for the sorption of heavy metals. There has been little research on heavy metal sorption into tire rubber in competitive systems. Therefore the present study was conducted to assess the sorption behavior of Cu and Mn on different size of tire rubber in a competitive system.
The finely ground discarded tire rubber with three sizes including 0.088-0.125, 0.177-0.250 and 0.353-0.500 mm were prepared from Yazd Tire Company in Iran. A batch experiment was conducted by adding of 200 mg of ground tire to 10 ml of Cu aqueous solution of the desired concentration (10 to 50 mg L-1). After 24h, supernatant was separated by filtration and analyzed for remaining Cu and Mn by atomic absorption spectroscopy technique.
Sorption of Cu and Mn on tire rubber increased with increasing of metal concentration from 0 to 50 mg L-1. The greatest sorption of Cu (1088.9 mg Kg-1) was found at the smallest tire rubber size (0.088-0.125 mm) and decreased by 35% when the largest size (0.353-0.500 mm) was used. At the highest concentration, sorption of Cu was restricted by Mn competition. In the whole range of studied metal concentrations, Mn occupied the least sorption sites of tire rubber. The sorption of Mn was not affected by tire rubber size and was restricted by Cu competition. Based on average, the experimental data were fitted in Langmuire (R2=0.94) better than Freundlich one (R2=0.87), showing monolayer sorption of Cu and Mn on discarded tire rubber. The values of maximum sorption capacities calculated from the fitted Langmuir equation showed that Cu sorption was higher than Mn. There was an increase in the qm values of Mn when the tire rubber diameter decreased. In this study, separation factor (RL) was used to predict if an adsorption system is favorable or unfavorable. In all cases, the values of RL were between 0 and 1, pointing to the favorable sorption of Cu and Mn on three size of rubber.
Results clearly showed that ground discarded tire rubber (especially, the smallest size) are an effective adsorbent for the removal of Cu and Mn in competitive system. The equilibrium sorption isotherm of Cu and Mn onto discarded tire rubber is well described by the Langmuir and Freundlich models, but the Langmuir model fits the experimental data better than the Freundlich model.

Changes in the pattern of land use through the process of industrialization, infrastructure development and agricultural development is causing environmental issues such as soil pollution. The soil contamination with heavy metals is a serious and expanding problem. Heavy metals entering the food chain, threaten ecosystem and human health. This study aimed to assess and monitor soil contaminants including heavy metals and total petroleum hydrocarbons (TPHs) in soils of five oil refineries.
In the current study oil- contaminated soils from five refineries including Abadan, Isfahan, Tabriz, Tehran and Shiraz were collected and physical, chemical and biological characteristics of soils examined. Total petroleum hydrocarbons (TPHs) and heavy metals (cadmium, chromium, lead and nickel) in soil samples were measured and the data was ststistically analysed.
TPH levels in contaminated soils of Abadan, Isfahan, Tabriz, Tehran and Shiraz were 6.4 , 13.8 , 11.5 , 2.1 and 15.4 percent respectively and positively correlated with organic carbon of soil amples. The values obtained here were higher than the national and international standards. The highest concentration of chromium (mg/kg) was recorded in Abadan (83.3), Tehran (212) and Shiraz (61.1) refineries. The highest concentrations of nickel (mg/kg) were obtained from Tabriz (76.3) and Isfahan (122.1) respectively. The amount of cadmium and nickel in soil was higher than the standards of Europe and the world. A significant negative correlation was observed between heavy metal and hydrocarbon concentrations and microbial respiration, suggesting negative effects of pollutants on soil microorganisms which may also affect plants and other organisms.
In terms of heavy metals and petroleum hydrocarbon contamination, Tehran Refinery is in a better situation compared to other refineries, and this might be due to an environmental action plan running in this refinery. Given the contamination of refineries` soil, it is recommended that environmental monitoring and industrial cleaning is taken into consideration . It is also recommended to use filtering programs, including bioremediation of soil in these areas.

The flood is second destructive incident in Iran. Greater understanding of different points of view Hydro meteo logy and watershed systems and analysis modeling of rainfall, runoff, determination of flood zone reference the hydrological and hydraulic conditions in the watershed, not only in terms of financial and legal, but also to predict and help flood warning systems are helpful ways. The purpose of this research provide the perfect solution to establish flood warning system using hydrological models and hydraulic models in the basin upstream is of the Germichai dam. In hydrological studies after restructuring the data, flood frequency analysis has been done up to a day at the station. To choose distribution for all stations using the Best-fit test based on L- moments of stations, three parameters were normally distributed. Applying the ratio of the maximum one-day flood into flood peak moment values for different return period flood peak moment of the river at the dam site Germichai was calculated. River flooding, especially in the current conditions of relatively high recurrence caused flooding along the river due to the steep terrain of the river is low. By examining the persistence of storms and their levels, early warning alarms were calculated for each of the stations. After the set time alarm events based on the frequency of Miane station, Flood warning system for flood areas within the flood level is designed to suit the threshold.

Nowadays the importance of reservoirs management makes the use of gates on the spillways crucial .This causes the change in hydraulic flow over the spillway and the aim of this study is to explore some of these hydraulic changes. In this research by using Flow-3D and volume of fluid (VOF method) and k-ε (RNG) turbulence model , chute spillway with ogee crest and flip bucket has been simulated. Additionally investigation on the effects of 4 openings 15%, 30%, 45% and 100% which is done by radial gates. has shown that the increscent of openings causes increscent velocity, depth and cavitation potential on spillways. Also in some openings with low discharge, due to the formation of low discharge which is lower than sweep discharge, formation of flow aggregated on the spillway is possible and the hydraulic effects of this phenomena should be should be taking into consideration. Also by simulation of jet trajectory from the flip bucket, Results showed low error in length and maximum height of the trajectory. In conclusion, using Flow-3D for prediction of tail water preservation is highly recommended. Eventually, two correlation for the dependency of length of the trajectory, maximum height, flow discharge and opening gate ratio were presented.

Evaluation of frequency distributions for rainfall erosivity factor analysis has been less considered. Thus, the present study aimed to identify and evaluate different frequency distributions fitted to the amount of rainfall erosivity factor in monthly, seasonal and annual scales in Iran. For this attempt, entire available rainfall events reported for 20 years in 70 stations were analyzed based on the Wischmeier and Smith equation. The different frequency distributions were then fitted to data in each of the time scale and station using EasyFit software with the help of chi-square test. According to results maximum Gumble distribution was selected as the best fitted distribution in most of months and seasons and also, 3-parameter lognormal, gamma and 2-parameter lognormal frequency distributions stood in the first rank among fitted frequency distributions. Also, stations with more stable rainfall regime and influenced by similar rainfall regimes had less variability in the type of fitted distributions in different time scales.

Erosion rate in the Golestan province has a high rate due to geographical location, climatic and resource degradation. Determining a suitable method for measuring soil erodibility is one of the priorities in the prevention of destructive erosion. Wishmeyer and Smith equation (1978) is one of the important methods for calculating soil erosion, that is known the Universal Soil Loss Equation. In this equation, cover management (C) is one of the six factors affecting soil water-erosion that it`s measuring is not simply possible. One of the widely used methods for estimating this factor is using satellite imagery. Researcher provided many ways to evaluate vegetation management factor using NDVI to assess soil losses with USLE method (Lin et al., 1999; DeJong, 2002). These methods use regression model to analyze the correlation between the amount of measured C factor at the farm.
So, in this research scrambled to derive relevant indicators from satellite images of different in the Golestan province agronomic main crop growth and obtain their relations between them with real erosion in the farm.
Evaluation C factor was measured by using simulated rainfall with 2 intensity of 32 and 105 mm/h in duration 20 minute in 6 consecutive times. Cover management factor also was measured using CERL method, and vegetation indices (SAVI & NDVI) were computed from of Landsat 8 images in 6 consecutive times using ERDAS IMAGIN 2011. Then, the relations between CSERL factor and vegetation indices (SAVI & NDVI) were obtained using Excel software and Adjusted coefficient of determination, Regression coefficient and Correlation were obtained using SAS software were used as evaluation indices.
According to the results, ) in order to predict CSERL factor using satellite images NDVI index (R2 = 0.76 is more suitable comparing SAVI index (R2 = 0.54). The vegetation indices derived from satellite images have higher relation with C factor derived from higher rain intensity. By examining trends of CSERL changes in 6 consecutive time on the rainfall intensity with 105mm at duration of 20 minutes per hour rainfall was also found that this factor was 0.16 and 0.03 in December and June respectively.
In this survey, observed that there is significantly relation between C factor and NDVI index (R2 = 0.76 at 99% probability level. According to the results, NDVI index had a best estimation with CSERL in higher intensity (R2 = 0.76) and so this index is offered as a method with proper accuracy.