sadat feiznia

subsidence in urban areas poses significant risks to infrastructure, including buildings, roads, railways, pipelines, sewage systems, and wells. Therefore, assessing its potential is crucial. This study models the subsidence risk in Karaj city using Geographic Information Systems (GIS) and the Weight of Evidence (WoE) model. To achieve this, we created maps of factors influencing subsidence, such as slope, alluvial thickness, groundwater fluctuations, aquifer layering, particle size, and permeability. These maps were then compared with recorded subsidence data to determine the weight of each factor's influence. By integrating the effects of these factors, a Subsidence Index (SI) map was generated and categorized using the Success Rate Curve (SRC), identifying five sensitivity zones from very sensitive to very low sensitivity. The effectiveness of the WoE model was evaluated, revealing that the subsidence sensitivity prediction map covers 93.64% of actual occurrences. Results indicated that aquifer layering positively influences subsidence development, with the highest impact arising from alluvial deposits with good permeability and fine particles. This factor, with a weight of 3.72, demonstrates significant influence among all evaluated parameters. In terms of thickness, the most significant subsidence occurred in alluvial deposits exceeding 200 meters. Areas experiencing groundwater level declines of over half a meter annually markedly contributed to subsidence. Additionally, slopes of less than two degrees were identified as the most susceptible to subsidence. Thus, while many areas in Karaj are relatively safe, the threat is notably higher in the southern and southwestern parts, requiring special attention in urban management.

Water and soil play an important role in all human environmental activities and controling physical, chemical and biological processes in the environment. The existence of limitations of water resources, especially the fresh water of rivers and dams, makes it necessary to pay more attention to them against pollution. Contamination of water and soil with heavy metals are serious environmental pollutants that enter the environment in many different ways with natural and human origin and cause serious damage. Karaj Dam is one of the most vital sources of drinking water supply in the metropolis of Tehran, which faces a serious risk of pollution due to the development of human activities. This study investigated the concentrations of heavy metals (Zn, V, Ti, Pb, Ni, Mn, Cu, Cr, and As) in 40 soil samples and sediments, as well as five suspended sediment samples, in the river of the Laniz watershed in Karaj, Iran. Due to the construction activities in the watershed including the construction of the Tehran-North Freeway, the natural condition has been affected over the past decade and therefore need to use and new inventory method to separate the effects of natural geochemical from humane effects. The single-element indices of contamination factor (CF), geoaccumulation index (Igeo), normalized enrichment factor (EF), and ecological risk potential factor (ER), as well as two multi-element indices of pollution load index (PLI) and ecological risk index (RI), were employed. At first the elements and samples were grouped by principal component analysis (PCA) and cluster analysis. FA distinguished two groups of elements; called natural and human-natural origins. The cluster analysis divided 50% of the freeway-affected samples into two distinct clusters. Based on the CF index, the As contamination was extreme in the suspended sediment samples and soil samples related to the Freeway while the Pb and Mn carried out the next rank. Also, the single Igeo index revealed the high As contamination. Moreover, based on the Igeo, most suspended sediment samples related to the Freeway put in the extreme contamination class for all of the elements. However, the Mn-modified enrichment factor showed only one freeway-affected and two freeway-unaffected samples exhibited extreme enrichment, and the enrichment of other samples was low or moderate. Unlike the single-element indices, PLI and RI showed that the suspended sediment and soil samples related to the freeway had low pollution load and ecological risk. Compare of single and multiple contamination indices revealed an inconsistency of pollution risk that can be addressed into the background value (in single indices) and the toxicity response factor of the metals (in multiple indices). Results indicated that due to spatial-temporal changes of human effects, it would be better to use different values for both background and elements toxicity response. Therefore, to reach a reality image of contamination risk, more researches are needed to elucidate the mentioned standard value based on the regional variations.

Investigating the spatial variability of runoff and its influencing factors to provide solutions to reduce it is very important. In recent years, many theoretical and field studies have evaluated the spatial production of runoff as heterogeneous.

In this study, to investigate the affecting factors in runoff production of the slope main aspects (northern, southern, eastern, and western) of the Gachsaran and Aghajari formations were selected a part of the Gach Kuhe and Margha watershed in Izeh city. For this purpose, a rain simulator was used in both formations at 16 points with 3 replications at rainfall intensities in 1 and 1.25 mm/min. Also, soil factors of Gachsaran and Aghajari formations such as percentages of gravel, sand, silt and clay, pH, soil salinity, moisture, calcium carbonate, organic matter, and sodium content were investigated. SPSS 17 and EXCEL 2007 software were used for statistical analysis.

The most important factors affecting runoff production were identified using multivariate regression. The results showed that runoff production in Aghajari Formation is more dependent on soil chemical properties, but runoff production in Gachsaran Formation is more dependent on soil physical properties.

Haji-Arab River is a seasonal river in the south of Qazvin province. Quaternary alluvial deposits in Qazvin province spread on wide range. Since many coherent studies in terms of geology, sedimentary environment, mineralogy and climatic conditions have not been done in the mentioned sediments, so this study has been done to study the sediments of this river and determine its sedimentary facies. Therefore, the results of this study can provide a more precise understanding of the sedimentology status and sedimentary environment of this area.

This study was conducted to investigate the sediments of this river and to determine its sedimentary facies. Sampling was done from 4 boreholes and trenches around the ancient Qara Tappeh hill. Sediment granulation has been done by dry sieving, wet sieving and laser shaker sieving. Sedimentological studies show that the occurrence of frequent floods in the region has changed the texture of channel sediments and changed various parameters of particle size. Haji-Arab River, flows from south to north direction. This river originates from the central mountains and extends to Sagz-Abad. Sampling has been done around the ancient hill of Sagz-Abad (Qara-Tappeh) with an altitude of 1274.9m above sea level. This hill is located 52 km south of Qazvin (7 km north of Sagz-abad of environs Buin-Zahra city) and 132 km west of Tehran. Sampling were done in September 2016. The boreholes and trenches were excavated by Department of Archaeology, University of Tehran. From 4 boreholes with a maximum depth of 8.3 meters, 57 samples have been taken from around the ancient hill of Qara-Tappeh. Collected samples were dried due to humidity outdoors. 15% of the samples were granulated in two forms: dry and wet. Since the result difference was more than 10% due to grains adhesion, other samples were sieved by wet method. Particles smaller than 4µm were granulated by laser shaker sieving. Statistical parameters such as kurtosis, sorting, skewness and mean were calculated using Gradistat software. Also In this study, sedimentary facies were studied using field and laboratory methods. Sediment type was named based on Folk (1974) classification and facies classification based on Miall classification (1996, 2006). Finally, by combining all the data, a sedimentary model for Haji-Arab River was offered.

The study of sediments in this river led to the identification of three categories of sedimentary facies, which are: mud facies (Fl, Fm, Fr), sandy facies (Sm, Sp, Sl, Sh) and gravel (Gh, Gcm, Gms, Gci, Gmg, Gmm), which have settled in different parts of the river environment. Based on the identified facies, structural elements Floodplain Fines (FF), Sandy Bedforms (SB), gravelly Bars and Bedforms (GB), Sediment Gravity flow deposits (SG) and channels (CH) have been formed in this sedimentary basin. Sedimentary models of this river include Fine-Grained Meandering River, Sand-Bed Meandering River, Gravel-Bed Braided River and Shallow-Gravel-Bed Braided River.

Generally, coarse-grained, sandy and fine-grained sediments, poorly to very poorly sorting, absence of fossils, light color of sediments, the presence of plant traces indicate that the Quaternary sediments of the study area form in river system which include sub-environments such as, Channel, off-channel and floodplain deposits. Examination of sediment sequence in the study area shows the transition from a humid and low-energy environment to a dry and high-energy environment during the Quaternary. According to field studies and studies of sedimentary facies of Haji-Arab River, silt sediments are the most widespread in Haji-Arab catchment. Gravel with lower percentage are observed in limited parts of the basin and in the upper parts of the studied sequences. Therefore, based on the above evidence and the characteristics of facies in the Miall (1996) classification, fine-grained sediments have been deposited in the meandering River and coarse-grained sediments of this region have been deposited in a braided river. According to the studies, the architectural elements of FF, CH and SB and to a lesser extent GB and SG can be considered for this basin. Based on this, Can be considered 4 river models including fine-grained meandering rivers, Sandy meandering river, gravel wandering river and shallow gravel bed braided can be used for Haji-Arab River in the study area.

Recently, aerosols as one of the air pollutants (with natural or anthropogenic sources) have received increasing attention. In this study, the purpose is investigation of soil potential in production of dust (aerosol) storms using wind rose and storm rose.

Meteorological data and WRPLOT view software were used to draw the wind rose and hurricanes. Also, in order to study the wind direction on dusty days, the data of the Meteorological Organization and also to investigate the effect of meteorological parameters such as gentle wind percentage and prevailing wind percentage, statistical methods such as regression relationship, Pearson coefficient have been used. Also, the trend of annual and seasonal changes in the concentration of suspended particles (dust) has been studied in order to determine the seasons with the highest frequency of dust occurrence.

The results indicated that winds blow from northwestern and west in all seasons. The highest frequency of winds is western. The wind roses of spring and summer indicated that the most frequent direction of prevailing winds are western to northwestern. Southeastern direction comes in next level. These storms are more frequent in winter and autumn seasons. Also, investigation of storm roses demonstrated that dominant winds have speed of less than 4.5 meter per second (80%). This research shows that in study area, winds cannot erode the soil and product the aerosols.

Therefore, the main source of recent dust must be searched in the neighboring countries.

Soils are severely damaged by acid rain; acid rain also leads to excessive dissolving of minerals and valuable nutrients in the soil, which weakens vegetation. In this study, in order to determine the interaction effect between the slope aspect and precipitation intensity relative to acid rainfall in the Aghajari and Gachsaran formations, a part of Margha and Kuhe Gach watersheds of Izeh city with an area of 1609 and 1202 hectares were selected. A sampling of runoff and sediment was done in 16 points with three replicates in northern, southern, eastern, and western aspects of Aghajari and Gachsaran formations at different rainfall intensity of 1 and 1.25 mm/min and in distilled water, acidity 4 and 5 using Kamphorst rain simulator. The results showed that in both Gachsaran and Aghajari formations, rainfall intensity has the highest effect on runoff and sediment production in three concentrations of precipitation and also The interaction effect between precipitation intensity and slope aspect plays the least effect on in runoff and sediment production, and in Gachsaran and Aghajari formations, a runoff was much more sensitive to sediment production than the interaction effect between slope aspect and precipitation intensity.

Acidic rainfall is one of the complications of industry life that a point of view geographically in recent years spread widely and the attention of many researchers has been found. These rains have significant effects on the different ecosystems of earth. In this study, in order to investigate the sensitivity of erosion and sediment yield of Gachsaran Formation to acidic rainfall and its density change, parts of the Kuhe Gach watershed area in Izeh Township are selected with the area of 1202 hectares. This investigation in order to determine productivity runoff and sediment in 8 points and with 3 replicates in Gachsaran formation in different intensities 1, 1/25 mm in min and in the intensities of distilled water and 4, 5 acidic water in four aspects of northern, southern, eastern, western with using kamphorst rain simulator was done. In order to analyze statistical was used SPSS and EXCEL packages. The highest of runoff and sediment rates in Gachsaran formation in 1, 1/25 mm in min are related to 4 acidic rainfalls. The rainfall of 5 acidic also runoff and sediment are more than the rain of distilled water. The infiltration rates in rainfall different intensities also showed a significant difference.

The erodibility of watershed area is a function of several factor, one of these factors is topography. Including main topography features is slope aspect of which directly or with the effect on other environmental factors is caused changes in soil hydrological processes particularly the potential for runoff and sediment production. Soil erosion is the most important environmental factor in the world that adversely affects all-natural ecosystems as well as those under human management. Although soil erosion has existed throughout history, it has been intensified in recent years due to improper land use. Environmental factors, such as climate situation, topography, soil, and land use affect sediment formation in watershed areas. Aghajari formation is among the most erodible in Iran. Aghajari formation, covered with Bakhtiari conglomerate, is located on Mishan marl formation. This marl formation was formed between Pliocene and Miocene. Aghajari formation consists of gray and brown calcareous sandstone, gypsum red marl, and siltstone. Its main section spreads from Omidiyeh to the Aghajari oil field and it has a thickness of 2965 meters. The presence of gypsum marls has made Aghajari formation apt to erosions of different kinds, especially surface erosion, rill erosion, badland, and mass movement. One of the most eridibility of Iran is the Gahsaran formation. Gahsaran formation has oil industries that yearly thousands of tons of sulfur and carbon dioxide interpolate into the air. And it can be caused by acidic rainfall. Thus investigating the role of acidic rainfall on soil erosion and sediment production in these areas is necessary. Gahsaran formation has a thickness of about 1600 meters. A viewpoint of lithology is consisting of salt, anhydrite, colorful lime, and some shale. Gahsaran formation age is lower Miocene.

In this investigation in order to investigate sensitivity to the erosion and sediment yield the main aspect of slope of Aghajari and Gachsaran formation deposits, part of margha and kuhe gach watershed areas in Izeh Township respectively with the area of 1202 and 1609 hectares was elected. In this investigation in order to determine productivity runoff and sediment in 8 points and with 3 replicates in Gachsaran formation and in 8 points and with 3 replicates in Aghajari replicates in rainfall intensities 1 and 1/25 mm in min in 4 slope aspect; northern, southern, eastern and western with using of kamphorst rain simulator was done. In order to analyze statistical from SPSS and EXCELL was used. The study utilized the Kamphorst rainfall simulator. This fully standardized, easily portable rainfall simulator was designed to cover a plot area of 625 cm2. The rainfall simulator is used to determine the characteristics of soil, erosion, water infiltration, and is also suitable for soil research. It is a standard method to use it to determine the erodibility of surface deposits. The experimental plot area of 625 cm2 with a smooth gradient was selected, which was the representative of the main slope aspects. Meanwhile, the Kamphorst rainfall simulator was installed at the height of 200 cm to reach to raindrop boundary velocity.

The highest of sediment rate in both Gachsaran and aghajari formations in rainfall intensities 1, 1/25 mm in min is belonged to eastern slope aspects. The highest of runoff rate in aghajari formation is belonged to northern slope aspect and in Gachsaran formation is belonged to southern slope aspect. There was a significant difference in the south-east, south-west slopes in comparison of the amount of sediment produced in different aspects of the slope in the Aghajari Formation at the intensity of 1 mm/min. But, there was a significant difference in the amount of runoff produced and permeability of north-west slopes. And at 1.25 mm/min intensity, sediment production in south-east and south-west slopes showed a significant difference. But runoff was significantly different in north-south, north-east and north-west slopes. In terms of sediment production in Gachsaran and Aghajari formations, the total rate was highest at two intensities of 1 and 1.25 mm/min in the eastern slope. But, in terms of runoff in Aghajari Formation, the northern slopes have the highest runoff and in Gachsaran Formation, the southern slopes have the highest runoff. And, in terms of permeability in Aghajari Formation, the southern slopes and in the Gachsaran Formation, the western slopes have the highest penetration rate in the two intensities.

The rate of productivity sediment also in Aghajari formation in both mentioned intensities is more than Gachsaran formation. But the rate of productivity runoff in mentioned intensities in Gachsaran formation is more than Aghajari formation. The rate of changes in productivity sediment and runoff in various slope aspects in both formations also significance difference showed.Key words: Soil erosion, Sediment production, Aghajari formation, Rain simulator, Gachsaran formation

The Earthchr('39')s environment and ecosystem is an extensive and complex set of different components and factors that have been formed as a result of the gradual evolution of living organisms and the components of the Earthchr('39')s surface. This collection includes nature and all living things. As one of these beings and a part of the environment, man is affected by nature and is also affected by it. This effect, which manifests itself in various forms, is mainly due to the various activities. From the past until now, nature has been used and exploited in multiple ways. As a result of this impact on the environment, it has mainly manifested itself in the form of degradation and has increased in recent decades for various reasons. This issue means that the increasing trend of exploitation of nature, due to the intensity and nature, causes various concerns that manifest themselves in the form of ambiguities and essential questions. In the general case (exploitation of nature), the general and key questions are what mechanism follows this growing process of exploitation of nature, to what extent it is correct and logical, and the primary purpose of this exploitation?One of the forms (types) of use and exploitation of nature globally and in Iran is mining activity. Naturally, the general and key questions raised above, both in general and in the discussion of specific uses (here mining activity) can be examined and explored. However, in recent years, this activity can be examined in various situations (in terms of exploitation intensity and increasing mining trend. But it seems that a general explanation and the nature of the action and activity, not based on the intensity of activity, also has sufficient credibility and an excellent position. Is. However, as stated, the purpose is to investigate basically and in general the relationship between nature exploitation in Iran in the form of mining activities with nature? Basically, in this regard, the only and always the aforementioned goal in such industrial (economic) activities, or does nature itself have a place and importance in this? This study aims to provide an appropriate answer to the key question that to what extent economic activities and exploitation of nature, mining here, are in line with naturechr('39')s capacity and follow the principles of sustainable development? In summary, the present study seeks to properly assess the environmental sustainability or instability of mining activities and, in this regard, the degree of proportionality between the positive (mainly economic) and negative (mainly environmental) effects on the environment of residents in affected areas. To become clear.

 In summary, the recent research was carried out in several stages as follows: In the first stage, based on the nature of the issue and attention to factors such as the proximity of the mine to residential areas and people, as well as the importance of different factors affecting the mine and Bastak area and In particular, Paytaveh gypsum mine was designated for research. In the next step, general and specialized questionnaires were designed by considering different aspects of my impact. A general questionnaire for surveying the general public and, in fact, residents of areas adjacent to the mine, and a specialized questionnaire for obtaining more technical and comprehensive data and information from relevant experts (environment, natural resources, industry, and mining), environmental activists and villagers and responsible people in that village. Paytaveh village) was designed and used for use in the final tables of the evaluation method (RIAM method). In the last step, these data and scores, and status classes were used to determine the environmental stability or instability of the mine in a method called the Phillips method.

Results :

As mentioned in the research method, the raw information and data extracted from the opinions of different people were used to score and determine the status of various factors. The results showed that among the 15 factors studied in this study, 7 factors have a negative effect, 5 factors have a neutral effect (ineffective), and 3 factors (all in the category of economic factors) have a positive effect. Meanwhile, socio-cultural factors did not affect, and all four factors in this category were completely neutral and ineffective. By placing the numbers in the said formulas, the final number S in the Phillips formula was determined to be zero. Therefore, according to the classification, the resulting number, zero, is in the instability range. In simpler terms, the calculations show that the mining project is considered unstable and has led to environmental instability.

 The Phillips method was used to investigate and determine the environmental stability or instability due to mining activity in the Paytaveh Bastak area based on information obtained from the RIAM method. The results showed that this project has different effects in the study area. ‌‌‌But in general, the result of the effects indicates the dominance of negative effects over positive effects, and as a result, the environment caused by these effects is unstable. Finally, there is a key issue to consider: the balance between the benefits of mining and its environmental impact is essential to achieving sustainable exploitation of mineral resources. Although the results showed that in the study area, there is no balance between the positive and negative effects of mining activity, but the evaluation and analysis of the views of residents show that the efforts of miners to increase the weight of positive effects (mainly economic: employment of villagers in mining and cooperation with villagers in to carry out the necessary construction and infrastructure activities of the residents) will help increase the satisfaction of the residents and at least in the short term the continuation of the project will be acceptable from the residentschr('39') point of view and will lead to relative relative positive effects in the short term (employment and income for residents). Development and essential infrastructure of residents) will help increase residentschr('39') satisfaction, and at least in the short term, the continuation of the project will be acceptable to residents. It will lead to the relative maintenance of tangible positive effects in the short term (employment and income for residents. However, the use of the word sustainability and especially sustainable development for this activity in general and in this region will not have a proper scientific and logical aspect. In short, mining, as one of the main pillars in many developed and developing countries has always faced many economic, social, and environmental challenges concerning its stakeholders. This has led mining companies to pay more attention to better interact with their stakeholders in recent decades. Therefore, achieving sustainable development has become one of the industrychr('39')s priorities. This key issue will be achieved only if the exploiters try to increase the positive effects, reduce the negative effects of mining and generally pay attention to the demands of the residents of the adjacent areas of the mine, as the main stakeholders, to improve their quality of life and environmental concerns. Perhaps only then will it be appropriate and effective to talk about the environmental sustainability of mining activities in such areas.

Submarine Groundwater Discharge (SGD), any flow or all water flows on the continental banks of the sea bed, is defined regardless of the liquid composition and the driving force of its agent (Barnett et al., 2003). This occurs in a calm and continuous flow of SGD wherever its table has a positive relative hydraulic gradient with the sea level, which is attached to the surface runoff. The outflow of the flow into the sea will cause a temperature anomaly on the surface. The depletion of the underground submarine currents plays a remarkable role in the water cycle, which can be considered as an important part of water balance. Therefore, it is important to identify the range of anomalies caused by the probable depletion of SGD into the sea.

Remote sensing systems are used to determine the site of SGD depletion into the sea or lake, including aerial images with high resolution (Lewandowski et al., 2013). The aerial manual infrared imaging (Duarte et al., 2006) or ground thermal imaging (Schuetz and Weiler, 2011) are highly expensive and are certainly not suitable to assess the regional scale or continuous monitoring of SGD depletion in large blue bodies (Wilson and Rocha, 2016). Hence, free data and images of the Landset 8 satellite for 2017 and 2018 were used to determine sea surface temperature maps. For this purpose, corrections were first applied to thermal bands in the ENVI 5.3 software environment. Then, to investigate the existence of geometrical and non-geometrical errors, the quality of the data was examined on satellite images. Analyses and extraction of sea surface temperature maps were carried out using GIS 10.3.1 software. After preparing a suitable temperature map, the least surface roughness level was determined by applying different classifications in the GIS environment. Then, the distribution of each anomaly was finally prepared to prepare the distribution map of thermal anomalies. In this study, a digital elevation model (DEM) was used in GIS software to provide geomorphometryindices and maps related to environmental variables (slope, Topographic Position Index, profile curvature, general curvature, plan curvature, and height) and statistical modeling. Finally, the layers were prepared and the required adjustments were made in the software settings. Maxent Version 3.3.3 software was then used to perform statistical modeling.

Some anomalies were observed by examining the rainfall of existing pluviometry stations (n = 14) in the study area and investigating the rainfall amount (the same month, the month before, six months before, the same year, and the preceding year). The regression relationship between levels of anomalies and rainfall values determined at different times revealed a strong relationship between the anomaly levels and the amount of rainfall in the previous month. Finally, the seasons studied in 2017 and 2018, the results obtained from the study of SST, STA, and the least common level defined, along with rainfall investigations, all indicated that that the highest temperature anomalies with iterations in two different histories belonged to January 2017 and 2018, which were used for subsequent analyses. The depth studies in the range of anomalies included in January 2017 and 2018, as well as the common level of anomalies from the two dates, show that anomalies obtained in the deep-sea regions are not located and the depth of these anomalies is low within the range, which increases the probable presence of the underground spring. It can be stated that the results obtained are related to the depth of temperature anomalies because they are in the shallow depth of the sea and less than 30 meters, which is the reason to increase the likelihood of the presence of the submarine springs in these areas. According to McBride and Pfannkuch et al. (1975), Shaban et al. (2005), Thomas et al. (2002), Lewandowski et al. (2013), Wilson and Rocha (2016), and Farzin et al. (2017), SGD presence rate decreases with the distance from the shore, and the presence of submarine springs would be expected at a water level close to the shore in the disorders created at the surface of the sea, which corresponds to our results. All temperature anomalies, particularly the repeated anomalies in January 2017 and 2018 are located 3 km away from the coast, which increases the probable presence of SGD. According to the results of the jackknife test, the most important indices are in the presence of temperature anomalies and the presence of SGD (depth) and slope, which indicates that the presence of SGD spring is up to a depth of 4 meters and the appropriate slope for the presence of SGD depletion region is 5%.Figure (1): The classification map of the presence of SGD based on temperature level anomalies and environmental variables.Figure (2): The Jackknife test for model sensitivity analysis

The environmental factors play a role in the creation of temporal and spatial changes of SST and STA. Based on the results obtained from geomorphometrystudies and inequalities, as well as those of maxent modeling based on the common level of temperature anomalies in January 2017 and 2018, it can be concluded that anomalies occurred in the Bandar Magham, Bandar Nakhiloo, and coasts of  Bandar Divan, Bandar Shenas, Bandar lengeh, and Bandar kong indicate that these areas have a very high probability of underground aquifers. These submarine currents seem to have a substantial amount of evacuation that could have significant effects on the coastal ecosystem and the regional water balance. If the quality of the evacuated water is not intrinsically salty and is desirable to be used, it can be utilized as a water supply source in the area.

Due to physical and chemical composition and lack of vegetation cover and therefore less organic matter, Marlons formations are the most sensitive formations to erosion, so that by removing the particles of the soil and transporting their to the lower regions, cause different forms of erosions. Due to the physical and chemical properties of marls, the study area has caused various types of erosion in the basin and downstream urban areas has been affected followed by mudflows resulting from their erosion and sedimentation. In this research, 35 soil samples were taken from the different work units to determine the physical and chemical characteristics and also to study the soil losses using a rain simulator. Along to this, 5 samples from particular marl units of the area was taken and transferred to the laboratory for mineralogical experiments. The K method in the global erosion equation was used to evaluate the degradability of detached materials that according to this method, the highest value of k is related to forms with a coefficient of 70%, and the least of which is the surface and rainfall erosion form with a coefficient of 25%. Also, due to the fact that there were 4 units of work with attached materials, the stripy method was used to evaluate their erodibility.

Sediment and erosion are two natural phenomena in watersheds. Due to irregular recording and sampling difficulties, daily data are not available for sediment records. Therefore, decision makers and researchers have to apply interpolating methods to estimated sediment yields. In this study, 30 watershed characteristics including physiography, geomorphology, vegetation, climate conditions in 69 watersheds located in the Karoon and Karkheh basins were used to statistical analysis. Based on the principle component analysis, eight characteristics including area, perimeter, river length, relief, mean of elevation at 85% upstream and 15% point of longest flow path and the number of landslide events were selected. Then using Cluster Analysis, six homogenous regions were identified and multiple regression models were applied. Due to constriction of large dames on the studied watersheds, access to the reliable data is a challenges for sediment yield analysis. Based on the sediment-precipitation double-mass curves 29 out of 35 stations were influenced by upstream dam. Results indicated that the effects of large reservoir dams can influence the downstream sediment yield along 98 Km of river length. The results show that in each group a particular combination of variables influence the sediment yields of the watersheds. According to the validation indices (NS and R2) the obtained models have the high performance (R2 = 0.71 and NS=0.72). In general, the physiographic characteristics of the watershed such as length, area, main flow path and relief are more important than other climatic, vegetation and geological factors. The total explain variance by the mentioned variables is 87.3%.

Atmospheric dust particles play a significant role in the transfer of chemical elements released from industrial and urban sources. So that the contaminants attached to these particles, can be transported over long distances and are as a function of meteorological conditions, the physical and chemical properties and nature of surface. The aim of this study was to evaluate the metal richness and degree of heavy metal contamination in atmospheric deposited dust in Tehran.

Atmospheric dust samples were collected from eight locations in Tehran in 2018. Heavy metals (Pb, Zn, Cu, Ni, Cr, Mn and Al) were analyzed in dust using ICP-MS. Metal richness and degree of contamination were determined using Enrichment Factor (EF), Geoaccumulation Index (Igeo), degree of Contamination (Cd) and modified degree of contamination (mCd). Paired t-test, Pearson correlation and Hierarchical cluster analysis (HCA) were also used for analysis.

The mean concentration trend of elements in the warm and cold seasons was similar as Al>Zn>Mn>Pb>Cu>Cr>Ni. Results of enrichment factor index in atmospheric deposited dust showed that Pb and Zn in warm season and Pb and Cu in cold season were highly enriched. Paired t-test results showed a significant difference between Cu and Cr between seasons. Cluster analysis also showed Al of natural origin and other elements of anthropogenic origin.

The results of this study showed that atmospheric deposited dust particles of Tehran have high levels of contamination especially in cold season. Therefore, it is necessary to formulate more effective and practical policies to improve Tehran’s air quality.

The purpose of this research is investigation of the heavy metals pollution in PM10 aerosols in atmosphere in city of Kermanshah. The concentrations of thirteen elements consisting of Cu, Ni, Pb, Cd, Se, Zn, Fe, Cr, Co, As, Mo, V were analyzed by ICP for 55 soil samples (in various point of the height of 600-1600m) and 41 aerosols samples. The heavy metals pollution have been investigated using geo- accumulation index, contamination factor, enrichment factor, factor analysis. The results obtained from this studying, showed that elements of Cu, Ni, Pb, Cd, Se, Co, As, V have low pollution, elements of Fe, Cr have medium pollution, element of Zn has high pollution, element of Mo has very high pollution. Based on results of enrichment factor, Zn is the most enriched element. Mo have located after Zn. These elements have high EF-values. This indicates that they are probably dependent on non-soil sources such as vehicle exhaust. Enrichment Factor for Cu, Pb, Ca, Ni, V and Cr are in the range of 1 to 10. This implies that these elements were influenced not only by crust, but also by other pollution sources. Enrichment Factor of other elements (selenium, arsenic, cobalt) are less than 0.1. This indicates that these elements have originated from the crust. Based on results of enrichment factor and factor analysis, these elements have anthropogenic source that emissions of vehicle and industry-oil burning emissions have the main role in emission to atmosphere.

One of atmospheric phenomena of dry and semi-dry areas and areas adjacent to these areas is the phenomenon of dust and production of particulate matter (PM10) that have many environmental hazards. The purpose of this research is determination of chemical composition and source identification of elements in aerosols in city of Kermanshah. Enrichment factor are used to identify natural and anthropogenic sources of these elements in aerosols. Tracing of sreams is performed using contour line in level of 500hpa . Samples of aerosols is analyzed for 20 elements by ICP-OES. According to this study, The elements such as iron, potassium, calcium, selenium, arsenic, cobalt, phosphorus, magnesium and sodium have low EF- values, this indicates that these elements have originated from the crust. These elements account for 84% of the total concentration of elements. This shows that crustal elements are the main contributor to the elements in PM10 in the Kermanshah atmosphere. The results of this research show that the most frequent pass of streams to west Iran; west to east of Iraq is in the first rank, then, westnorth to eastnorth of Jordan, east to westsouth of Syria and east to west of Mediterranean. Therefore, it can be stated that Iraq and its neighboring regions have important role in production of aerosols.

Street dust is an environmental medium with complex composition in urban environment. Heavy metals remain in urban dust for a long time and re-suspended in the atmosphere. This study aimed to evaluate the metal richness and degree of contamination in Tehran street dust. 

Dust samples were collected from nine locations in Tehran in 2018. Heavy metals (Cd, Cr, Pb, Zn, Fe, and Al) were analyzed in street dust using ICP-MS. Metal richness and degree of contamination were determined using Enrichment Factor (EF), Geoaccumulation Index (Igeo), degree of Contamination (Cd) and modified degree of contamination (mCd). Pearson correlation (PC) and Hierarchical cluster analysis (HCA) were also used for analysis.

The mean concentration trend of elements was as Al (53486.54)> Fe (46535.07)> Zn (638.14)> Pb (200.33)> Cr (111.94), Cd (0.49) mg/kg. The highest metal enrichment was due to Pb and Zn. The geoaccumulation index also showed that Cd and Pb had the highest values. Degree of contamination indices also showed high levels of contamination in street dust. Significant correlation was observed between Zn-Cr-Pb and Pb-Cd. Significant negative correlation was also observed between relative humidity-Pb-Zn. Elemental clustering also showed that Pb, Zn, Cr, and Cd had anthropogenic sources and Fe and Al had natural sources of diffusion.    

The results of this study showed that the street dust of Tehran is highly polluted. Therefore, this environmental medium can have significant negative effects. Therefore, continuous monitoring of street dust is essential.