جستجوی مقالات مرتبط با کلیدواژه « pollutant » در نشریات گروه « جغرافیا »

The intensification of air pollution under the influence of various factors, including population growth and urbanization, is the concern of activists in this field. It is necessary to check the pollutants carefully using precise techniques. In this study, elements of NO2, CO, and Particulate Matter effective in air pollution were analyzed spatially and temporally (monthly, annually) using the TROPOMI instrument of Sentinel 5 sensor in East Azerbaijan province. Investigations showed that in the cold season, more areas of the region experience the presence of CO and NO2 pollutants, which are mainly caused by fossil fuels, industries, and residential areas. But their concentration is high in the hot and cold seasons respectively. Evidence shows that in densely populated areas, we are facing high concentrations and the presence of NO2. A high concentration of suspended particles is also seen in the summer season. According to the findings, all three elements have a high distribution in the cold season; on the other hand, the concentration and spatial distribution of pollutants is influenced by factors such as weather, topographical conditions, and industrial centers.

Air pollution is a common problem in Iran especially Tehran metropolis. Urban green spaces have significant effects in controlling the improvement of air in cities. Environmental functions in reducing urban air pollution is an important aspect of green space, in fact, green spaces are the breathing lungs of cities.

This research was conducted with the aim of investigating the effect of green space patterns on the air pollution index in Tehran metropolis in 2014.

This research is a descriptive analytical study that investigated the subject by using spatial models. By obtaining air pollution concentration data and then applying corrections, monthly seasonal data have been prepared. Considering that the data are points in the first step with interpolation methods, the areas of each pollutant were determined separately by season. The fuzzy method was used to compare pollutants with the same unit after normalization and eliminating the uncertainty. Relation between the pollutants and the green spaces was determined by the NDVI layer extracted from the Landsat images in the spring and autumn seasons. The regression between the pollutant by season and type of pollutant was prepared with NDVI, which has a significant correlation. Also, due to the significant correlation between the congestion pattern of Tehran's urban roads with all pollutants, the current urban road pattern was considered as a model for the development of green spaces. Pollutant PM2.5 was examined as a case study and its outputs were prepared and examined.

Geographical Context: 

The geographical area of the current research is Tehran metropolis.

Because of the correlation of the city's green spaces and air pollutants, as well as the coefficients between the pollutants and the density of urban roads, the results show that the pattern of city roads can be as a model for the development of green spaces. This development will lead to a reduction in the amount of air pollution pollutants and also its results show a high improvement in the level of pollutant levels in Tehran metropolis.

The pollution measurement stations in Tehran city are not suitable in terms of number and location. Also, many of them show a failure for several months. In order to carry out more detailed studies in the future, it is necessary to increase the number of pollution measurement stations in the city, and find the effective location for them.

One of the most tremendous environmental crisis is the pollution of the cities that it's main cause is the human activities besides environmental factors. Modern thought toward urban development is that cities must be compatible with natural environment as far as possible and takes the step toward sustainability. Thus for access to a sustainable development in the cities, the deduction and control of air pollution can be of high importance important . So in the present research, the potential grading of air pollutant density in Tabriz by using ELECTRE method has been evaluated. The general framework of this research is based on gathering different informative layers (wind , crowd , land use, topography , queen space deficit , noise and vibration ,temperature ,inversion, connecting roads , volume of travels origin and destination) has been utilized as criterion and limitation factor.
Their valuing and weighing in the form of ELECTRE model as one of multi criteria analysis tactics in a functional contexts of the research subject was examined and used for the 10 districts of Tabriz.
Moreover for measuring the air pollutant's condensation, the data concerning to pollution monitoring stations of this city (Abrsan, Bagh shomal , Behdasht , hakim Nezami , Rah Ahan, Raste kauche station) have been used. Comparing the findings of the model and the data relevant with the stations indicate that the pollutant of PM10, SO2, Co are in critical and unhealthy condition in most of the stations especially in Raste Kauche, in which the crowd density and improper distribution of usages have more effect on the pollutants of this area, so that the most service and commercial uses which attract the population and vehicles during the day, ate located in district No.8 i.e. the central texture of the city. While the said district among the other districts has the most communication uses and the least green space, that such factors has caused the environmental instability and increase of pollutant's condensation. Based on the findings of this research, use of multi criteria analysis technique, in addition of increasing the accuracy and increase of the work speed, will increase the variety and causes the better quality of the results.

The Caspian Sea is the largest water basin that enclosed by land within Eurasia continent. This sea that referred to Caspian in the global map, has strategic importance because oil and gas storage and caviar fish. The most important problem that originated in bio geographical parameters is the lack of a determinate legal regime. According to the 1982 convention, only the littoral states are responsible for establishing of the closed sea Legal regime. The lack of consensus on which delimitation is suitable, Caspian has turned into one of the critical areas. One of these crises is the environmental problems. Economic problems of the newly established countries, cause the excessive use of marine resources, particularly oil and gas. Poor technology and lack of independent environmental monitoring of regional and global organizations, failure to comply with the standards required for the exploitation and transportation of oil and gas resources. In addition, various contaminants is severely threatened the Caspian Sea life.For this reason in this paper, by the librarian research, the role of bio geographical factors in the setting the regime right in the Caspian sea from the perspective of the political geography of the sea was investigated.Factors that threaten the Caspian Sea bio geographical plays an important role in determining the legal regime and include oil pollution, ship and floating population (urban, rural), industrial facilities, artificial islands, environmental contaminants and rivers and in accordance with the 1982 Convention and also due to the geographical conditions of the Caspian Sea, were evaluated. The results show that the countries of Azerbaijan, Russia, Kazakhstan and Turkmenistan to produce more oil pollution and setting the regime right in the Caspian sea that's likely to oppose their activities. However, after Russia and Kazakhstan, Iran has most polluted rivers, but due to the beaches damage caused by oil pollution is agree to determining of the pollution deterrent legal regime of the sea.

1. During the past decade, many efforts for investigating the relationship among air pollution and meteorological factors have been undertaken and some statistical methods have been proposed. Population increase and technological advancement were among the factors affecting creation and extension of air pollution in big cities, forcing large cities all over the world to contemplate measures to curb and prevent the spread of pollutants. Air pollution is emblematic of a wide range of impacts on biological, physical and economic systems. In recent years, air quality has been debated as a pivotal factor in materialization of the quality of life in urban areas, specifically in densely populated and industrial areas. In the present research, in order to evaluate air pollution in the city of Mashhad, eleven air-monitoring stations were used and several parameters for air pollution were studied. The main purpose of the research is to use a model which can establish a link between weather and pollutant factors as well as to identify climate factors affecting air pollution in the city of Mashhad and predict the density of pollutant gases using neural network and linear regression.
2. Study Area: Mashhad Metropolis, the capital of Khorasan Razavi province spanning over a land area of 204 square kilometers, located in northeast of Iran at a longitude of 59 degrees and 15 minutes and a latitude of 35 degrees and 43 minutes up to 38 degrees and 8 minutes in the vicinity of Abrood, Kashafrood, is flanked by Hezarmasjed and Binalood mountains. It has a cold and arid climate and has its own specific climate and regional specifications. The preponderance of the city has a cold and air climate, with some cold and semi-arid regions and a small cold and wet section situated in the loftiest heights of Hezarmasjed and Binalood mountains. Overall, the city of Mashhad has a changing climate, inclining towards cold and arid.
3. Material and Data and information regarding pollutants in the city of Mashhad for a one-year period was obtained from Khorasan Razavi’s environment organization. The data is collected from eleven air-monitoring stations on an hourly basis. The average for each day has been used as the data for that day. Then meteorological data, including wind speed; wind direction; rain; air pressure; relative humidity; average temperature and maximum and minimum temperature were obtained from meteorological organization. After collecting the required data and information, first the average for the data concerning air pollutants, gathered on an hourly basis, was calculated. Then using ArcGis, climate parameters and pollution information were merged, using merge button, to form a coherent daily output. The next step involved using inverse distance weighting interpolation, which is one of the methods used in meteorological and geographical studies. In this method, for the purpose of prediction in locations where data is not collected, the data gathered in the vicinity of the intended location is used. In the next stage, the correlation among meteorological data and air pollutants was calculated. Finally, Neuorosolutions was used in order to predict non-linear factors and teach the neural network.
4. The findings of the study reveal that the potential neural network, compared to regression and multilayer perceptron, was able to establish a link between meteorological parameters and the density of pollutants (NO-O3-CO-SO2) in the city of Mashhad. The aim of the present study is to use a model which can establish a link between climate factors and air pollutants and identify the climate factors which affect air pollution. The result of sensitivity analysis graph indicates that among the climate factors affecting the pollutant of CO, relative humidity at the hour (12:30) and the direction of wind are the most influential. It was also revealed that relative humidity at the hour (6:30) and maximum absolute temperature are the climate factors affecting the density of sulphur dioxide. As for the graphs depicted in the study, it was revealed that the potential neural network, compared to the other two models, was able to establish a more logical relation among air pollutants and climate factors. In the potential neural network for carbon monoxide, the Mean Square Error (MSE) was calculated to be 66.61 and in regression model it was 76.92. Similarly, the Mean Absolute Error (MAE) was 3.005 and 3.12 respectively. In the neural network model for sulphur dioxide, MSE was calculated to be 14.12 and MAE was 2.15; while in the regression model these measurements were 14.003, -0.18 and 2.13 respectively.

In this paper using descriptive and inferential statistics we tried to analyze and assess the impact of climate elements and air pollutants in Sanandaj. on the input rate of asthma and mortality we. Studied populations as the number of people admitted to the hospitals in 8-year period (2001-2008) for asthma and the number of deaths during the five-year period (2004-2008) for heart failure disease in the city of Sanandaj. Data on pollutants were supplied from the Environment Department (2008) and data on climateelements (2001-2008) were collected from the Meteorological organization of Sanandaj city. The results show that considering the weather elements in the model، each unit increase in average of minimum temperature of the elements، the average maximum relative humidity and prevailing wind speed woud cause increase in heart failure deaths، respectively، at 0. 16 and 0. 06. With of each unit increase in mean minimum temperature and maximum wind speed، 0. 211 death units were increased while 0. 360 units were decreased. So despite the pollutants per unit of temperature in the region 0. 051 units regardless of the model were more or less the impact of mortality. Without entering pollutants in the model، the effectof average minimum relative humidity، average relative humidity، average wind speed and prevailing wind speed has respectively 0. 160، -0. 141، -0. 632 and 0. 198 values on the asthma admissions. By entering pollutants had climatic elements of the combined model، none of the elements and pollutants impacted on hospital admissions for asthma. MI mortality was significant in both sexes. The relationship between both sexes and admissions and ages was 0-20 and 21-40 and significant. In other words، unlike heart failure disease، the rate of asthma at the ages of less than 40 years was seen. In general، heart failure and asthma were respectively not dependent on gender and age.

The expansion of urbanization and urban development, along with the acceleration of the population growth and the development of industrial activities that consume fossil fuels, has greatly increased the air pollution, with its consequences primarily as a variety of respiratory, cardiovascular, pulmonary, Skin and ... diseases threatening the inhabitants of the cities.
On the other hand, climatic parameters such as humidity, sunshine clock, temperature, air pressure and radiation levels of the sun increase the amount of pollutants in the atmosphere and increase their impact on humans and natural ecosystems. Therefore, by altering the composition of effective gases in the life of the earth's organisms and disturbing their balance, human beings have harmed themselves and the environment, causing extensive changes in the climatic patterns and, on the other hand, have exposed their lives and health to risk. In this paper, the relationship between climatic elements such as temperature, pressure, humidity and atmospheric pollutants such as carbon monoxide (CO), nitrous oxide (NO2), sulfur dioxide (SO2), hydrocarbon (HC) and particulate matter (PM10) with the prevalence of various diseases in Isfahan province have been investigated. For this purpose, after the data collection, statistical calculations were performed and the results were presented as tables and charts and the relationship between each variable and patients suffering diseases was investigated.
The results show that there is a significant correlation between climatic elements such as temperature, pressure and humidity with the prevalence of cardiovascular, pulmonary, ocular and skin cancer.

Civic areas are the major living field for the ever –increasing largest part of the world's population .population growth, development of city-settling and a change in the ways and attitudes of people's lives have created significant problems in big cities. Nowadays, big cities encounter such problems as air pollution, lack of sufficient green space, irregular increase of vehicles and population, etc. Tehran is considered as one of main demographic, political, economic, commercial and industrial regions in the country and occurrence of any climatic changes leads to irreparable losses such as shortage of water resources, severe floods, soil erosion, etc while this matter can be a factor to cause environmental problems systematically. Considering the fact that Tehran is Located in Alborz mountain foot and its many north –west to south-east Branches produces several effects on the city and because of its location in the mountain slope, its general level has a steady height above the sea level. Hence, its amount of rainfall undergoes severe changes. In fact, the amount received by the heights is rather much more than that of the lower points annually (Zargham, 1377, p.53). In this research, the trend of precipitation has been measured and examined by the use of data from 5 selected synoptic and 3 pluviometer stations of Tehran city during the statistical period of 20 years (1364-1384) and the degree of its correlation with the amount of pollutants in Tehran city has been measured using the data from Pollution polls stations which have been located according to synoptic stations, and SCHEFE and square Omega (w2) models.