جستجوی مقالات مرتبط با کلیدواژه « urmia plain » در نشریات گروه « آب و خاک »

In the past years, by increasing population and water consumption, as well as the high cost of developing surface water resources, the exploitation of groundwater resources has increased significantly. In the current situation, a significant part of the country's water consumption in all sectors of consumption is provided by groundwater sources. On the other hand, the development of industry and the entry of pollutants, including heavy metals, into the groundwater endanger the health of humans. The present research has investigated the non-cancerous risk caused by heavy metals in the groundwater of Urmia plain for both children and adults. This research is based on a descriptive-analytical method based on the available data, in which the concentration of polluting metals obtained from the studies conducted in the fall and winter of 2016 from the number of 12 wells supplying rural drinking water in the Urmia plain has been analyzed. Also, human health risk assessment was measured using the United States Environmental Protection Agency index. The results showed that there are six heavy metals including cadmium, copper, iron, manganese, nickel, and lead in the region's groundwater, among which two of the wells have cadmium and lead values higher than national and international standards. Also, the total non-cancer risk index through ingestion and skin absorption for both children and adults groups was found to be 0.23 and 0.096, respectively, which is less than one, and this indicates that the water quality of the region is suitable for drinking.

Agricultural activities have grown more due to population growth and increasing demand for more products in the Urmia plain in recent years and have mainly been expanded with groundwater withdrawal, and because of the limited availability of surface water resources, this issue has led to a sharp drop in groundwater resources in the area. In this research, the groundwater footprint indicator was used to study the agricultural products’ effect on groundwater stresses. For this purpose, eight crops were selected, and the indices of water footprints, groundwater footprints, groundwater stresses, water use intensity, and efficiency were calculated. The results showed that the groundwater footprint indicator and the stress on groundwater resources for all studied products in Urmia plain were respectively 464.5 km2 and 5.97 units. Among the studied crops, wheat and alfalfa put the most stress on the groundwater of the region with 1.78 and 2.8 units, respectively. By increasing the irrigation efficiency to 25%, the stress index applied to groundwater for wheat yield became less than 1 unit. The study results on the water use intensity and products’ efficiency also showed that water consumption decreases with increasing efficiency, and products’ efficiency increases. However, increasing irrigation efficiency alone will not eliminate the entire stresses on the agricultural sector, the environment, and in particular, groundwater resources, and it is only an additional factor along with other factors.

The aim of this study was to study the effect of landform and geological formations on some physico-chemical properties of soils in order to better identify the soil in order to optimize land management and promote the sustainable agriculture of the southern part of Orumieh Plain with an area of 35000 (ha) in West Azarbaijan province, Iran. In this research, satellite images, aerial photographs, topographic and geology maps were used to identify and distinguish different forms of land. Separation of soil series were carried out based on geomorphologic and geophysical methods. 40 soil profiles were drilled and described in standard dimensions. Five soil profiles were sampled every genetic horizon and transferred to the laboratory. The moisture and temprature regime of the soils were determined as Xeric and Mesic. Soils of the studied area were classified as  Inceptisols and grate subgroups of Fluventic. The most dominant formations in the Barandoz and Ghasemlou river catchment were limestone, and lime is one of the determinant factors in the formation of rocks at different soils in the study area. On the other hand, physiography and topography have also played a significant role, so that the upper terraces have more developed soils and some sloping regions had young and less evolved soils. With decreasing height and proximity to Lake Urmia, the effect of groundwater level and its salinity on the profiles is evident. In the meantime, the margin of the rivers due to the sediments of the present age have young and uncoated soils.

The present study was conducted to evaluate the ecological risk indices of Zn, Cu, Cd, Pb and Ni in the soils from Urmia region (Ghahramanloo village), as irrigated with treated wastewater. Accordingly, six different soil sites (five soil sites under wastewater irrigation and one soil site under well water irrigation as the control) were selected and sampled (AP horizon, 0-30 cm depth). Soil samples were air dried, passed through a 2-mm sieve, and analysed to determine the chemical properties and the studied heavy metals. The results showed that irrigation with the treated wastewater significantly increased the total elements in the order of Cd (228%)> Zn (118.5%)> Ni (81.5%)> Pb (54.2%)> Cu (23.5%). Nevertheless, with the exception of cadmium, other elements were within the admissible range based on the national and international standards. Ecological risk index (min = 125, max = 152, mean = 140) showed a considerable risk in all studied soils and Cd could be regarded as the major metal affecting the index yield.

Over the past decades, due to climate change and water scarcity, the recovery and use of urban wastewater, especially in arid and semi-arid climates, has increased. But since wastewater is considered as an unconventional source of water, its use in agriculture requires special management which, while benefiting from it, does not have environmental and health hazards in soil, plant and surface water and underground water resources. On the other hand, sewage systems often have significant amounts of heavy and toxic metals, the type and amount of which varies from place to place, and even in the specific location, over time. The soil also has a limited capacity to absorb and maintain these elements, and if their concentration exceeds the permitted range, they can cause pollution of the water, soil, plant and human cycle. Therefore, the present study was conducted to investigate the effect of irrigation with treated wastewater in Urmia city on concentrations, distribution and contamination of Zn, Cu, Cd, Pb and Ni elements.

In field work, 6 soil profiles (5 profiles from the wastewater-irrigated soils and a profile from the well-irrigated soil as control soil) were dug, described, and sampled. At around each profile, composite soil samples were also obtained in the root depth of the area (Ap horizon, the depth of 30 cm). Soil samples were first air-dried and passed through a 2-mm sieve and then analyzed for the determination of heavy metals. The available and total fraction of zinc (Zn), copper (Cu), cadmium (Cd), leads (Pb), and nickel (Ni) were extracted by DTPA method and concentrated acid (HNO3) procedure, respectively. The content of Zn, Cu, Cd, Pb and Ni were determined by an atomic absorption spectrophotometer (Shimadzu AA-6300). Descriptive statistics were conducted using SPSS 16 for Windows. In order to study the effect of irrigation with treated wastewater on the extent of contamination of heavy metals, the AP (availability percentage), PI (Single-factor pollution index), NPI (Nemerows pollution index), and PLI (Pollution load index) in the affected soils with this wastewater was calculated. Also, all soil and water experiments were performed in 3 replicates and then, using the excel data software category, tables and charts were plotted.

The soils were alkaline and calcareous as characterized by high pH, ranging from 7.6 to 8, and calcium carbonate equivalent, ranging from 30 to 42%. On average, the value of the available fraction of the examined metals in the wastewater-irrigated soils ranged from 1.9 to 3.5 mg kg-1for Zn, 2.5- to 3.5 mg kg-1for Cu, 0.4 to 0.62 mg kg-1for Cd, 2 to 2.9 mg kg-1for Pb, and 1.34 to 1.75 mg kg-1for Ni. Comparing to the control, irrigation with wastewater resulted in a considerable build-up in the available fraction of the metals in the rank of Ni (79-142%)> Cd (54-125%)> Zn (35-73%)> Cu (13-87%)>Pb (6-32%). These patterns can be due to the quality and quantity of the used wastewater and impact of the used wastewater with its receiving soils. Similar to the available fraction, there was an increasing trend in the total fraction of metals in the order of Cd> Zn>Pb> Ni> Cu following wastewater irrigation. In this context, the mean content of total Zn, Cu, Cd, Pb, and Ni in wastewater-irrigated soils was as 51-157%, 10-32%, 243-310, 11-203%, and 13-126% higher than those of control soil, respectively. In spite of such enrichment, only the Cd values exceeded the maximum acceptable limits. The AP index is an appropriate index to compare the mobility potential and the toxicity of heavy metals in soil. In this study, the highest rate of this index among the heavy metals was related to Cd and its lowest level was related to Pb, which showed more toxicity and more mobility of Cd compared with other elements. The average of single-factor pollution index of five elements was observed in sequence Cd> Zn> Ni>Pb> Cu that the element of Cd had the highest class of PI (class 4). The highest and lowest of NPI values of five elements were observed in profiles 4 and 2, respectively. Also, the greatest effect of the five elements of this study is on the elements of Cd and Zn in the generation of this level of contamination. The pollution index of the five studied elements in irrigated soils with treated wastewater was similar to the NPI, its maximum was observed in profile 4 and Cd showed the highest effect on increasing the value of this index.

The results of this study showed that irrigation with sewage significantly increased the available fraction of the metals in the order of Ni (78.9-141.8%)> Cd (54.4-125%)> Zn (35.7-73.3%>Cu (13-87%)>Pb (6-32.3%) compared to the control. However, with the exception of cadmium, the available fraction of other elements was within the permissible limit. Compared to the control, in the majority of studied soils, the total fraction of the metals (with the exception of copper) was significantly increased and the lowest and highest increase associated with Cu (10-32%) and Cd (2 - 3 times). Also, the results of pollutant indices showed that the majority of the studied soils were in the low to high contamination and Cd was known as the major metal affecting the indices yield.

Groundwater is the most important resource of providing sanitary water for potable and household consumption. So continuous monitoring of groundwater level will play an important role in water resource management. But because of the large amount of information, evaluation of water table is a costly and time consuming process. Therefore, in many studies, the data and information aren’t suitable and useful and so, must be neglected. The PCA technique is an optimized mathematical method that reserve data with the highest share in affirming variance with recognizing less important data and limits the original variables into to a few components. In this technique, variation factors called principle components are identified with considering data structures. Thus, variables those have the highest correlation coefficient with principal components are extracted as a result of identifying the components that create the greatest variance.
The study region has an area of approximately 962 Km2 and area located between 37º 21´ N to 37º 49´ N and 44º 57´ E to 45º 16´ E in West Azerbaijan province of Iran. This area placed along the mountainous north-west of the country, which ends with the plane Urmia Lake and has vast groundwater resources. However, recently the water table has been reduced considerably because of the exceeded exploitation as a result of urbanization and increased agricultural and horticultural land uses. In the present study, the annual water table datasets in 51wells monitored by Ministry of Energy during statistical periods of 2002-2011 were used to data analysis. In order to identify the effective wells in determination of groundwater level, the PCA technique was used. In this research to compute the relative importance of each well, 10 wells were identified with the nearest neighbor for each one. The number of wells (p) as a general rule must be less or equal to the maximum number of observations (n), here it is the number of years. So, for each well there are a 10 * 10 matrix. It should be noted in monitoring adjacent wells to a specific well, its dataset is not used. To quantify the effect of each well according to the number of its participation in the analysis and frequency of its effectiveness, each well is ranked. In the next step, the ineffective wells were recognized and eliminated using both the variation coefficient and Error criteria. Following, the procedure will be discussed.
Results In this study, at first step using PCA technique wells were identified with a more than 0.9 correlation coefficient. Then each well ranked based on the relative importance and according to the specified thresholds, the variation coefficient and error of monitoring was estimated. The wells remain in threshold 1 led to the lowest variation coefficient, considered as effective wells in the evaluation of aquifer parameters. By eliminating ineffective wells at each threshold, the variation coefficient is reduced because of the elimination of wells with a greater difference in water depth compared to the average of whole wells. To check the certainty of obtained results, the error criteria were calculated for each threshold. According to the results, both variation coefficient and standard error of monitoring in threshold 1 come to be at least. Thus, 12 wells remain in the threshold 1 are considered as the important wells in monitoring the water table of plain Urmia. Monitoring error for these 12 wells is equal to 5.1 % which is negligible and can be introduced as index wells in sampling and estimation of groundwater table in plain Urmia. Using this method, instead measurements of water table in 51 wells it can be performed exclusively in the 12 wells.
Due to reduction of precipitation and unauthorized uses of groundwater resources, water table monitoring is very important in the accurate management of these resources. Because of extensive aquifers and large number of wells, water sampling and data collection is very time consuming and costly process, that leads to no economic justification in the lot of proceedings. Principal component analysis technique is suitable method to reduce sampling points and summarize information. In this study, at first step using PCA technique wells were identified with a more than 0.9 correlation coefficient. Then each well ranked based on the relative importance and according to the specified thresholds, the variation coefficient and error of monitoring was estimated. The results showed that the 12 wells remain in threshold 1. In this way, the cost, time and manpower required to measurements and analysis process cut into quarters.

Multiple biological and physiological processes in the plant, including carbohydrates and proteins formation, activation of 50 enzymes for energy transmission as well as reducing water losses from leaf pores, are mostly affected by the presence of potassium in the plant. In order to test this hypothesis, five soil subgroups (TypicCalcixerepts, FluventicHaploxerepts, TypicEndoaquepts, TypicHalaquepts and VerticEndoaquepts) belonging 15 series of gardened and adjoining virgin soils were described and sampled. The studied soils had been influenced under horticultural practices for over five decades.
The soil samples were analyzed for different K forms, K adsorption and physico- chemical properties after air drying and grinding to pass through a 2 mm-sieve. The particle-size distribution was determined by the hydrometer method (Bouyoucos, 1962). The total carbonate in the soil expressed as the calcium carbonate equivalent (CCE) was determined by a rapid titration method (Nelson, 1982). Organic matter (OM) was measuredby the Walkley and Black (1934) dichromate oxidation method. The pH of the soil was analyzed in 2:1 CaCl2/soil suspension using glass electrode pH meter (Crockford and Norwell, 1956) and EC was detected in a saturated extract. The cation exchange capacity (CEC) was measured using sodium acetate (1 M NaOAc) at pH 8.2 (Chapman, 1965). Water soluble K was extracted with deionized water (1: 5 w/v) after shaking for 30 minutes on a mechanical shaker and later contents were centrifuged to separate clear extract (Jackson 1973). Exchangeable K was determined by extracting the soil with neutral normal ammonium acetate, Non-exchangeable K was estimated as the difference between boiling 1N HNO3 –K and neutral normal ammonium acetate K (Thomas 1982).
The result showed that for most of the studied soils, long-terms horticultural practices decreased the amount of different K forms as a result of changes in soils types, agricultural practices and soil properties. In Comparing to the virgin soils, long-term horticultural and irrigation activities caused a decrease?? in soluble K from 0.05 (a drop of 15% with depletion factor of 0.85) to 1.48 mmol l-1(a drop of 95% with depletion factor of 0.05), potassium absorption ratio (PAR) from 0.08 (a drop of 31% with depletion factor of 0.69) to 1.17 mmol l-1(a drop of 97% with depletion factor of 0.03), exchangeable K from 12.01 (a drop of 3% with depletion factor of 0.97) to 285.98 mg kg-1 (a drop of 97% with depletion factor of 0.43),exchangeable potassium percentage(EPP) from 0.49 (a drop of 12% with depletion factor of 0.88) to 3.47% (a drop of 59% with depletion factor of 0.41), available K from10.42 (a drop of 3% with depletion factor of 0.97) to 180.65 mg kg-1(a drop of 53% with depletion factor of 0.47) and non-exchangeable potassium from 43.05 (a drop of 8% with depletion factor of 0.92) to 114.65 mg kg-1 (a drop of 19% with depletion factor of 0.81). Isotherm studies showed that the uptake of potassium in gardened series were more than virgin soils. The highest adsorption values were observed in VerticEndoaquepts (gottape) subgroup.In this series of soil, amount of available k (potassium soluble exchangeable K) and expandable clay increased by long-term horticultural practices which can be effective in increasing K buffering capacity.
long-term horticultural practices decreased K in soil solution and potassium adsorption ratio. The main reasons for the decline of soluble K can be explained by possible movement of K into the depths, dense cultivation and harvesting crops as well as high levels of calcium and magnesium in irrigation water of study area.In comparison with adjoining virgin soils, horticultural practices caused significant decrease in the amount of exchangeable K, exchangeable K percentage (EPP) and available K. The most important cause of reduced exchangeable potassium may be related toK uptake by apple trees (The study area is generally under the apple orchard user) which had the great need for K. Consequently, due to lack of fertilizers application and agricultural practices,the amount of available K declined in soils about 80percent. On the other hand, In the Non-exchangeable K amount with long-term horticultural practices non- significant reduction occurred. Since the amount of exchangeable and available k in these soils is high, it seems to be enough to satisfy the needs of the regional products.

Quaternary sediments have occupied most of the agricultural and natural resources of urmia region. Recognition of physicochemical and mineralogical properties of these soils is essential to optimum and stable use of these lands. In this study, eight soils profiles excavated on Quaternary sediments of Urmia region were investigated. The results showed that little thickness and evolution of studied soil was possibly due to the sequential soil erosion and sedimentation processes.Consecutive erosion-deposition processes at different periods led to the formation of calcic horizons and sedimentary layers in lower depths indicating climatic fluctuation, along with dissolution and translocation of carbonate in wetter periods as well as its deposition and accumulation in drier periodsClay mineralogical results revealed smectite, kaolinite, illite, chlorite and vermiculite as dominant clay minerals in the study area. Illite, cholorite and kaolinite mainly considered as inheritance fromthe parent materials while pedogenic formation explain the presence of vermiculite. Moreover, smectites was found to have three origins of inheritance, neoformation and transformation and its abundance was increased with depth. The origin of smectite in the buried horizons was attributed to the illite transformation. According to the heavy moisture demand on illite weathering, the occurrence of this process can be associated with more humid condition during the past climate. So the achieved results of present study can be a clue to recognize the climatic changes in the study area.

In recent years, decrease in depth of Uromia Lake, has resulted in higher increase of salinity threat in agricultural lands around the Lake. The aims of this study were 1- Investigation of the spatial changes in soil salinity using the Bayesian Maximum Entropy method (BME); 2- prediction of the boundary between saline and agricultural lands; and 3- Assessment of the uncertainty involved with salinity boundary prediction in South Uromia Plane, North West of Iran. ME and MSE criteria were used for comparison of the results. Prediction error variance resulted from BME equations, was used for assessing the uncertainty of the soil salinity boundary prediction. Cross-validation results showed that BME method with ME and MSE equal to 0.42 and 0.33 for autumn 2009, and 0.2 and 0.64 for spring 2010 respectively, had a high accuracy in spatial prediction of soil salinity, considering that only probabilistic type soft data was used. A sharp boundary was detected between salty and non-salty lands in the area and the BME method had a high ability in predicting the uncertainty involved with boundary predictions. Monitoring soil property variation such as salinity is sometimes limited because it is costly and requires time to gather necessary the hard data. BME method has shown potential for using soft data in cases that hard data are not readily available.

In the world, groundwater resources are counted the second freshwater resources after polar glaciers. Investigating changes in groundwater levels in any region has an important role in planning and sustainable water resources management. Continuous decline of groundwater level has been observed in many places of the world in the past half-century. It has indicated the depletion of groundwater reserve in large scale. This reserve depletion has been caused either by over-exploitation or reduction of groundwater recharge. In the recent years, groundwater use has continuously increased to meet demand for expanding industrial, agricultural and urban water supply. Meteorological parameters changes exert extra pressure on further reduction of groundwater level. Since, until now, the comprehensive studies about trend changes of ground water level have not accomplished in Urmia region therefore the main goal of the present research is to investigate the changed trend of Urmia ground water level using Mann-Kendal non-parametric method.
The study area has located at 55° 10´ 26" longitude and 37° 4´ 12" latitude in northwest of Iran. For studied region, the mean annual precipitation is 304 mm and its climate is dry and cold. This plain located in west part of Urmia lake in west Azarbayjan. In the present research, trend analysis was conducted on groundwater level of 31 piezometeric stations in the monthly and annually scales in the period of 2002-2011 using Mann-Kendall non-parametric test. Data Analyze was carried out using the boxplot software in SPSS. Trend line slope was estimated by using Sen’s estimator for each time series. Homogeneity of trend was tested using the Van Belle and Hughes method.
The results showed that the trend of groundwater level for all stations was negative and the negative trend in 1% probability level was significant for 56 percent of the stations. The investigation of trend line slopes revealed that in average, the groundwater level of Urmia plain has been decreased about 19.9 cm/year. Also, the results of homogeneity test of trend in 5% probability level showed that the trend was non-homogeneous for different months and heterogeneous for various stations.
According to the obtained results from the present research, the changes trend of the region ground water level is negative. If the exploitation from ground water resources continues in the present form, social and economic crisis can be formed. According to the results of this research, it is necessary to control the ground water exploitation and ground water level will be increased by increasing agricultural water efficiency and artificial recharge.

Increasing population and demand for water resources caused to evaluation water quality and manage water resources unavoidable. In Urmia plain water quality and quantity is confronted with critical condition. The purpose of this research is to zone the groundwater quality in Urmia plain for potation consumptions by AHP model and GIS technique. To achieve these purposes, the data of 128 deep wells from 2011 to 2012 was used. In the beginning, raster maps of studied region were provided with different methods of interpolation. In attention to wells distribution in the plain the Kriging method was used to zone maps of Sodium, Chlorine, Sulfate, Total dissolved solids, total hardness and electrical conductivity. Based on Schuler diagram and using analytical hierarchy process, the most efficient weights for each hydro-chemical variables were selected. Finally with overlapping hydro-chemical layers and exerting definitive weights in geographic information system, groundwater qualitative potential map in the studied region for determining the suitable places for drinkingwater was provided. The results showed that among five defined potential region, 78.4% of studied region is in good up to acceptable range, 7.7% is in inappropriate range, 12.9% is in bad range and 1% is in potable in necessary times. Entirely, central, south, northeast and northwest parts of studied region have best quality of groundwater for drinking consumptions.

The groundwater resources of the Urmia plain have been under intensive tension for the last recent years. This has caused the production and observation wells to become dry and in some local places well deepening to take place. In some other locations، the groundwater level is high and there is a danger of local water logging condition along with its associated drainage work. For the settlement of welfare groundwater resources، the modeling practice was used for the depiction of Urmia plain groundwater resources system reactions against different imposed management and executive scenarios. By the present work، the modeling with 28 observation wells took place for the year of 2008-2009. The comparison of calculated hydraulic head contour lines with that of the observed hydraulic head in nature showed a sound performance of the model. This made to impose and apply different scenarios in the model. To go forward، the decrement of 25 percent and the cease of pumping rate at western part of the plain caused average groundwater level rise of 0. 5 to 4 meters in eastern part of the plain. This led to have an average groundwater level fall of 1 to 3. 5 meters، respectively.