نشریه زمین شناسی محیط زیست
پیاپی 31 (تابستان 1394)

In order to study mercury contamination and the factors controlling its distribution in Sefidrud basin, 344 sampels were collected from river sediments, surface and ground waters. Water samples were analyzed for determining Hg concentration and physicochemical parameters such as pH, TDS, temperature, DO, biological oxygen demand (BOD) and chemical oxygen demand (COD). Sediment samples also analyzed for Hg, Al, Fe and Mn concentration. The correlation coefficient showed positive and negative relationships among the parameters. An appreciable significant correlation was found among TDS, pH, DO and the amount of rainfall with mercury in surface water (river), while the most correlated parameters with mercury in groundwater, were rainfall, TDS and temperature. Using distribution map of mercury in sediment and surface waters indicated that Hg trends in sediment and surface waters (except for kiashahr station) are opposite to each other. The results also showed that, Fe, Al and Mn play an important role in reducing the concentration of mercury in water samples, while the behavior of sediments for mercury absorption is strongly depended on the physicochemical properties of water. Therefore, the distribution of mercury in the Sefid rud basin is largely influenced by parameters such as rainfall, sediment composition and physicochemical properties of water (specially TDS, pH and DO).

Robat Karim, is located on southwest of the Tehran province. Most villages in the Robat Karim use underground water resources for potable use. During the period 1393-1392 from 10 deep wells were sampled for drinking water of village and after performing physical and chemical tests, the results of the quality of each variable were determined. Calcium, magnesium, chloride, sulfate, nitrate, hardness, bicarbonate, fluoride, conductivity and total dissolved solids of the tested variables and then used kriging method has the potential to provide maps and software Arc GIS10.2 the pollution was zoning. The results of 30 samples from 10 villages reflect the fact that the quality of groundwater in rural parts of East and Southeast of Ali Abad shows mg / l 64nitrates, in Shahrestanak with mg / l 667sulfate and Hakimabad with the electrical conductivity of 3100 μmho / cm and total dissolved solids mg / l 1918 exceeded the permitted level and is generally lower than other areas.
The causes of pollution in southern and eastern regions can be geological, slope, existing residential and industrial areas, and not respecting the wells Quality Policy.also northern and central parts of the region are in suitable quality level and these areas are appropriate for new wells .

Concentrations of heavy metals in soil depending on the parent material and the pedogenic and geochemical processes affect the distribution. This study aimed to determine the concentration and distribution of some heavy metals in soil geochemical distribution derived from different parent materials in the major geological formations in Zanjan province. For this purpose, number of 67 samples of surface soils from different parent materials, which includes 19 samples igneous parent materials (soils with parent material andesite, basalt, granite, volcanic tuff), 17 soil with sediment parent materials (soil parent material with shale and sandstone) and 31 samples from alluvial deposits were taken. According to the results, the highest mean Cu (38.6), Zn (191.7) and Pb (85.5) in the alluvial parent material, Cr (31.5) and Ni (66) in soils with shale parent material, manganese in soils with granite parent material (674.4) and andesite (673.8) and iron in the soil parent material andesite with (19800) and shale (18600) mg/kg were recorded. The total concentration of cobalt and cadmium in the soil parent material did not show substantial changes. Soil chemical fractionation of various metals was varied. Mobility factor for elements were obtained: Pb(29.8)>Co(25.1)>Ni(18.5)>Cu(6.2)>Zn(5.1). The highest levels of enrichment factor for elements Pb, Zn, Cd and Cu in alluvial parent materials, enrichment factor of nickel, cobalt and manganese in the soil parent material andesite and that for chromium and nickel in soil enriched with shale parent material was obtained. Geo-accumulation indicators showed the similar results.

The global climate is changing, and impacts of climate change are being observed across the world. In recent years, particularly the effects of climate changes on the Earth’s water resources are very considerable. Dararood Basin is one of the subbasin of Aras river catchment. Considering Water supply, Dararood river plays an important role in the study area. Unfortunately, in recent years the amount of water in this area has decreased. Investigating trend in climate and hydrological variables can help to identify the possible climatic changes and fluctuations. In order to identify trend in hydro-meteorological time series data among the nonparametric test, Mann-Kendall was used wildly. The purpose of this study is investigating fluctuations and trends in river flow under potential impact of climate fluctuations using the Mann-Kendall test, during 20 years (1994-2013). For this purpose climate data of four stations including Ahar, Moshiran, Meshginshahr and Parsabad along with 7 hydrometric station data (Cassin, Orang, Oshdalaq, Arbabkandi, Dostbyloo, Boran and mashiran) were used. The results showed that the annual flow of all stations have decreasing trend during the study period. Also the results of this study showed no significant correlation between climatic fluctuations and annual river flow based on the annual average during the study period

Extraction of mineral resources and mining can be lead to soil contamination by heavy metals. To determination of the origin of the metals in the sediments in Forumad chromite mine, the sediment samples were taken and analyzed using the sequential extraction method. Analysis of soil samples showed that the concentration of chromium and nickel in sediment is higher than that of global shale. Chromium and nickel in soil distribution map of the region shows that the highest concentration of chromium and nickel in samples from inside the mine tailings deposits of chromite Forumad been harvested according to the average concentration of chromium and nickel in the global shale, the top the amount of chromium in the sediment was attributable to mining activities. Our study shows that Nickel and Chromium with more than 45% concentration are interchangeable phase, which indicating anthropogenic source. Mining activity plays an important role in increasing the concentration of these elements as interchangeable phase. Cd, Pb, Zn and Fe with more than 30% concentration in residual phase, are related to lithogenic source. The results of the sequential extraction method are compatible with the pollution index in the area.

In arid and semi-arid conditions and water shortage, sensitive to water quality of rivers and factors influencing on them, is necessary. Maroon Watershed in recent decades has been prey extensive land use changes. Drought and misuse of lands were the most important factors in reducing the volume and quality of water resources in the basin. In this study, changes in land use in the watershed Maroon within four ten-year period from 1980 to 2010 using sensors of TM and ETM satellite Landsat and then the changes in water quality over the same period, and even more between 1347 and 1394, were studied over a period of 47 years. Changes in land use in order to increase residential areas and increased agricultural land in the drought occurred during the past 47 years in reducing water quality in the watershed Maroon Ideanak station output is affected. However, due to the drastic changes in land use occurred, increasing the surface of residential and agricultural land feature of lowering the quality of Maroon river water.

Mass movements are a complicated mechanism that many factors and variables can play roles in their occurrence. In this article the frequency and distribution of large landslides in Sufiyan of the E- Azerbaijan province are studied. The main investigation of this study is to investigate that factors influencing the landslides through Analytical Hierarchy Process (AHP) and then hazard zonation map in the studied region. To do this, six landslide factors, including (1) lithology, (2) slope, (3) the distance of fault, (4) elevation, (5) the distance from the spring and (6) land usage, have been detected as important factors affecting the landslides in this area. Each layer is imported as data into GIS, and their weights are illustrated by using hierarchical analysis. Any how by integrating layers in GIS landslide hazards are mapped in 5 levels as very high-risky, high-risky, medium-risky, less-risky and very less-risky. The results show that most parts of the area are in the very less-risky (43%), and the others covered less-risky (22%), medium-risky (17%), high-risky (9%) and very high-risky (9%) parts of the area. From the mention factors in slopes instabilities, lithology, slope and the distance form fault ordinarily have impact on the slope movements of the studied region.