Adel Khazaei; Majid Abaspour; Sasan Babaei Kafaky; Lobat Taghavi; Yousef rashidi
Abstract
Introduction: The metropolis of Tehran as the largest capital of the Middle East is faced with phenomena such as environmental degradation, land use change and high concentration of agricultural and industrial disasters. Knowing the changes of land use in the past and predicting its future status is ...
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Introduction: The metropolis of Tehran as the largest capital of the Middle East is faced with phenomena such as environmental degradation, land use change and high concentration of agricultural and industrial disasters. Knowing the changes of land use in the past and predicting its future status is necessary in order to carry out a principled, dynamic planning. In this study, the spatio-temporal dynamics of land use changes in the Tehran in a 20-year period and the prediction of future changes in these land uses in the next 40-year were selected as the general objectives of this study.Material and Methods: After forming a database of Landsat 5 and 8 satellite images for three times of 2001, 2011 and 2021, the land use map of this times were prepared. For the validation of the maps Google Earth images, ground points and accuracy and Kappa coefficients were used. The time period from 2021 to 2061 was considered to predict future changes. In order to zoning and predict the future of land use changes, 6 land use change transfer sub-models with artificial neural network, Markov chain, and LCM model were used. Evaluation of the accuracy of the model was obtained from the comparison of the ground map of 2021, the future map of 2061, and the values of Null success, success, Miss and False Alarm were obtained.Results and Discussion: The results showed that the period from 2001 to 2021 was associated with the expansion of residential areas, the growth of urban areas and the reduction of green spaces including gardens and parks. The expansion of residential areas has been primarily in poor and barren soils and then in gardens and green spaces. This urban growth was clearly in region 5, 21, 22 and its physical development process was linear. The decrease in the level of gardens and green space is very catastrophic and this decrease is especially evident in the central areas of the city due to the high density of buildings. Urban parks are clearly in a complicated condition in the eastern areas of Tehran. The area of rain fed agriculture has increased and the area of barren soils and poor lands has decreased. Most of the changes in land use related to low capacity lands and agricultural lands have occurred. Studying the maps of the future of land cover showed the continuation of the same trend of the past 20 years. Although the growth of residential areas will be slower than the previous period, but the capacity and dimensions of the city will continue to increase, especially in the western, southern and southwestern regions. The decreasing trend of gardens, parks and urban green space is still observed. This process is more intense in the case of parks and they will be destroyed more quickly. The reason for this is besides drought and withering of trees due to climate change, pollution, and conversion of these green land uses to rain fed agriculture, parks, poor rangelands and urban areas. As for the urban green spaces, the 16 and 4 regions have the worst positions, and the 17, 19. 2, 5 and 22 regions will not be safe from this damage either. The decrease in the area of rangelands and cities moved to new areas will increase; the cycle of destruction of vegetation will increase from the outskirts of Tehran.Conclusion: Construction was more in the south of Tehran and the decreasing trend of urban green space will continue to be observed. The central areas of Tehran will be completely devoid of trees due to the predominance of the urban areas, and the point to consider is the destruction of the green belt in the north of Tehran in the future.
Hashem Sadeghzadeh; Bijan Yeganeh
Abstract
Introduction: The study aims to select the optimal model to estimate the emissions from vehicles withcompressed natural gas (CNG) powertrain systems in Tehran to identify, evaluate and plan for controllingemissions through CNG vehicles, and determining the pollution level of passenger cars produced by ...
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Introduction: The study aims to select the optimal model to estimate the emissions from vehicles withcompressed natural gas (CNG) powertrain systems in Tehran to identify, evaluate and plan for controllingemissions through CNG vehicles, and determining the pollution level of passenger cars produced by the Iranianautomotive industries and compare it with pollution standards.Material and methods: In this study, locally-produced CNG vehicles' information was used to estimate thepollutants emitted from domestic CNG vehicles using IVE and COPERT modeling software. Finally, themodeling outputs were compared with the results of the ISQI emission test.Result and discussion: Results showed that contrary to the initial assumption, supposing IVE software wassuitable for advancing the research objectives, the performance of IVE software was not reliable for CNGvehicles, and the outputs of COPERT software were much closer to the values measured in the ISQI emissiontest. The COPERT estimated values were more accurate by 65 and 78 percent for carbon monoxide and NOX,respectively, but 13% worse for carbon dioxide.Conclusion: Based on the findings, the COPERT model is more accurate than IVE for modeling CNG vehicles'emissions, especially for CO and NOX. According to the findings, it is necessary to reconsider the superiorityand application of IVE software for determining the emission inventory and estimating the air pollutantsemitted from the CNG fleet in the country.
Maryam Chehrehei; Seyed Alireza Mirza Hosseini; Nabiollah Mansouri; Youssef Rashidi; Mohammad Hassan Behzadi
Abstract
Introduction: Volatile organic compounds such as gasoline vapors have adverse effects on the environment. In the metropolis of Tehran, gasoline is considered a toxic and dangerous pollutant. One of the most important sources of gasoline vapor emissions in the environment is storage tanks for petroleum ...
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Introduction: Volatile organic compounds such as gasoline vapors have adverse effects on the environment. In the metropolis of Tehran, gasoline is considered a toxic and dangerous pollutant. One of the most important sources of gasoline vapor emissions in the environment is storage tanks for petroleum products, operational processes, and the number of emptying and loading of storage tanks and gasoline sales activities at gas stations.Material and methods: To calculate the emission of gasoline vapors from storage tanks of petroleum products in gasoline supply channels, the TANKS 4.09 software was used. Data such as physical characteristics of the reservoir (dimensions), number of loading times of reservoirs, spatial characteristics of reservoirs (climatic parameters), specifications of petroleum products stored in the reservoir, etc. were entered into the software for 22 districts of Tehran.
Results and discussion: According to the outputs, the emission of gasoline vapors from 412 tanks installed in 148 gas stations located in 22 districts of Tehran was about 7702356 liters per year. About 56.78% of it is released in the warmer 6 months and about 43.21% in the colder 6 months of the year. In the spring, summer, autumn, and winter seasons, about 27.06%, 29.56%, 22.63%, and 20.73% gasoline vapors are released into the environment. Emissions occurred more in 6 months of the year, with most of the emissions of gasoline vapors being from mid-May to mid-November. By comparing the percentage of vapor emission with the percentage of the number of loading times, percentage of operating capacity, number of tanks, and percentage of gas stations in Tehran, it can be concluded that effective factors in increasing gasoline vapor emission are a high number of loading times, high maximum operating capacity, number of tanks, and low number of gas stations. The highest emissions are related to regions 4, 2, and 15, respectively, which have the highest statistics in these cases according to surveys and classification based on maximum gasoline sales, number of loading times, maximum operating capacity, and number of tanks.Conclusion: Considering the number of gasoline sales (about 4219217500 liters) and the amount of waste and emissions of gasoline vapors (7702356 liters per year), it can be concluded that the number of gasoline products consumed in 1397 in Tehran was about 4226919856 liters.
Mahmoud Ahmadi; Zahra Alibakhshi; Manouchehr Farajzade Asl
Abstract
Introduction: Change detection is a process to find the paradoxical regions in different temporal imageries of a similar area. Vegetation is very effective at the absorption of grime and lead, prevention of the spread of contaminations in urban environments, clearing the air, and reduction of heat islands. ...
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Introduction: Change detection is a process to find the paradoxical regions in different temporal imageries of a similar area. Vegetation is very effective at the absorption of grime and lead, prevention of the spread of contaminations in urban environments, clearing the air, and reduction of heat islands. The need to investigate the decrease or increase in vegetation is extremely important in Tehran as a metropolis, as well as its satellite counties because of the increase in population and construction. The purpose of this research was to investigate the spatiotemporal changes in the vegetation of Tehran and its satellite cities in association with temperature during different temporal periods. The results of this research can be useful in studies concerning urban viability, reducing the effects of urban heat islands, and environmental sciences. Material and methods: Initially, the extraction and preparation of data were carried out using the ETM+ sensor of Landsat 7 satellite from 2001 to 2015, with June being selected as the hottest month of the study area. Then, the selection of days to be studied and correcting imagery, preparing LULC maps and plotting the area percentage was done. The computation of vegetation indices and built-up areas and the calculation of land surface temperature along with the assessment of the accuracy of surface temperature data were other stages of the research methodology. Finally, the area percentage of each index, as well as the scatter plot and Gaussian function chart were produced and the spatial variation of vegetation was studied. Results and discussion: According to the land use and land cover map (LULC) in 2001, 2005, 2010, and 2015, the vegetation significantly increased in 2015 compared to previous courses. The development of the residential area in the west region was higher than in other regions. In the charts of the area percentage for each land use class and its change over the four selected years, the vegetation percentage has been decreased since 2001, which continued in 2010 and 2015. In this study, the relationships between surface temperature and NDVI and SAVI indices were not linear, which showed that there is another controlling factor. In the normal density function chart, which is usually described by mean and standard deviation, variations of NDVI and SAVI indices were similar in the second and third periods, and the mean increased in these two periods compared to the first period, and the height of curve increased due to the reduction of variance. In this study, the results showed a decrease in the value of LST in the second and third periods from 2006 to 2015. On the other hand, the vegetation area was increasing in the region. From a spatial point of view, Tehran has the highest percentage of class one of NDVI that have no vegetation surfaces. Conclusion: Regarding the study of NDVI, SAVI and NDBI indices, the overall trend of vegetation cover in the study area was increasing. Considering the values of 15R2"> , the vegetation in Ray County was defunct. In the cities of Robat Karim and Tehran, vegetation cover was increasing. The high growth of satellite towns in the surroundings of Tehran has led to the allocation of land and fields and vegetation to residential areas, which exacerbate the heat islands and the unfavorable conditions of life.
Abutaleb Sabr; Mazaher Moeinaddini; Hossein Azarnivand
Volume 16, Issue 3 , October 2018, , Pages 79-100
Abstract
Introduction: In recent decades, air quality change and its risks are correlated with the expansion of urban and industrial areas and other land-use changes. One of the important effects of land use/cover changes (LUCC) is wind erosion and as a result, an increase in particulate matter (PM) concentration ...
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Introduction: In recent decades, air quality change and its risks are correlated with the expansion of urban and industrial areas and other land-use changes. One of the important effects of land use/cover changes (LUCC) is wind erosion and as a result, an increase in particulate matter (PM) concentration in residential areas. For this reason, the effects of LUCC on PM concentration in Tehran’s airshed was studied. Material and methods: Data on LUCC and landscape metrics were studied in the years 1985, 2000 and 2014. Then, the relationship between LUCC and PM concentration in Tehran was investigated by trend analysis methods. To find the most important wind directions with strong effects on Tehran’s air quality, conditional probability function (CPF) and directional relative strength (DRS) were used. Results and discussion: LUCC results showed that the area of agricultural land-use has been expanded from 1985 to 2000, yet decreased from 2000 to 2014. The trend was vice versa for barren lands during the mentioned time periods. In addition, the urban area has increased in the whole period. The landscape metric results showed that landscape patches became smaller and the landscape has been fragmented. The results of the PM10 concentration trend analysis revealed that it has been increased dramatically since 2007. Comparison of the average concentration of PM10 before and after 2007 showed a significant difference. The results of CPF and DRS illustrated that no specific wind direction was detected before 2007, but afterwards both increased in specific directions (south to west), which is compatible with most LUCC and fragmented areas in these directions. Conclusion: Our results showed that specific wind directions may lead to an increase in the PM10 concentration which is compatible with LUCC directions. Therefore, LUCC could be a significant reason for the increase in PM10 concentration in Tehran.
Masoud Ganji; Akbar Abravesh
Volume 16, Issue 2 , July 2018, , Pages 101-110
Abstract
Introduction:
Air pollution in the metropolis of Tehran is a serious environmental issue. Assigning an optimal budget to deal with air pollution problems in the East (no.4) and West (no.22) regions of Tehran, determining the optimal proportion of green spaces and determining the ratio of applying optimal ...
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Introduction:
Air pollution in the metropolis of Tehran is a serious environmental issue. Assigning an optimal budget to deal with air pollution problems in the East (no.4) and West (no.22) regions of Tehran, determining the optimal proportion of green spaces and determining the ratio of applying optimal traffic constraints in these two regions, and addressing similar problems, are all necessary and require a statistical optimization scale for resolving them. Unfortunately, so far, no study has been done in this regard, and research on this issue is needed. The main purpose of this research is to investigate the difference between the air pollution in East and West of Tehran and provide a benchmark for responding to the above issues.
Materials and methods:
A new statistical approach has been proposed in this study for comparing air pollution in the East and West of Tehran, which eliminates the problems associated with conventional methods such as the t-test and nonparametric tests. In this method, the air pollution index values of the two regions have been modelled using a suitable statistical distribution and, then, the probability that air pollution in the East of Tehran would be more than in the western part of it would be reached through a Bayesian method. The value of this probability, called R, has been used as an optimal scale for allocating air pollution-related assets between the two regions.
Results and discussion:
Air pollution data was collected in the east and west of Tehran in the winter of 2016 in terms of air quality index (AQI) and was modelled using distributions with a power hazard function. The mean and standard deviations for air pollution data in the East of Tehran have been obtained as 76.70 and 37.074, respectively, and the corresponding statistics for the West of Tehran were 72.14 and 34.166, respectively. Although, the sample mean of AQI in the East of Tehran is a little greater than in the West, the nonparametric Mann-Whitney test shows that there is no significant difference between air quality of these two regions. The 95% Bayesian confidence interval of R has been obtained (0.594 and 0.436) and a Bayes estimate of R has been obtained at 0.519. According to the results, although there is no significant difference (at a confidence level of 95%) between the air pollution in the eastern and the western parts of the city, with a probability 0.519, the air in the East of Tehran was more polluted than the West. Also, this probability value is an optimal scale which can be applied to the appropriate allocation of facilities related to air pollution between the two regions. That is, 51.9% of facilities related to air pollution should be allocated to the East of Tehran and 48.1% should be allocated to its western part.
Conclusion:
It seems that the proper allocation of funds from different regions of Tehran to control Tehran's air pollution can be a step towards solving this problem. The statistical method presented in this study provides an optimal amount for allocating funds to the East and West of Tehran. Officials can use the optimal amount based on this method to create appropriate policies for the proper distribution of funds and facilities in East and West Tehran. For example, to maximize the effectiveness of tree-planting in air purification, with this proportion it is better to plant trees in the eastern part of the city more than in the western part. Also, it is suggested that traffic constraints in eastern Tehran should be greater than in the western part of it.
Mahmoud Ahmadi; Prastoo Azimi
Volume 11, Issue 1 , April 2013
Abstract
During last decades the environmental and economic effects of climate changes have been very important for environmental scientists. According to temperature fluctuation studies, the minimum, maximum, and average temperatures are to be increased. So, the objective of this study is the investigation of ...
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During last decades the environmental and economic effects of climate changes have been very important for environmental scientists. According to temperature fluctuation studies, the minimum, maximum, and average temperatures are to be increased. So, the objective of this study is the investigation of variations of the number of freezing days during a 57 years data set and modeling the data by multivariable statistics methods. The applied models were ARIMA time-series, Regressions, and Correlation coefficient. The results showed that the variations of temperature were very disorder from 1951 to 1975 and they were not following a specific model. However, it showed the decreasing in freezing days during 1976-2007 which could be due to urban warming and crating island effect in this duration.
Reza Cyrus Sabri; Roya Azadeh Sabri
Volume 8, Issue 2 , January 2011
Abstract
The fast pace of development of Tehran (a capital city with a population of 12 million and grandiose ideas) over the last 30 years is the major cause of the deterioration of the natural environment and watershed. Stream corridors in the northern part of the city are the major areas for most of the wildlife ...
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The fast pace of development of Tehran (a capital city with a population of 12 million and grandiose ideas) over the last 30 years is the major cause of the deterioration of the natural environment and watershed. Stream corridors in the northern part of the city are the major areas for most of the wildlife diversity in Tehran and are easily affected by human intervention. The two major elements of the stream corridors are soil and water. If either of these is affected by human activities the ecosystem will become unhealthy and its natural balance will be unsettled. Therefore special consideration to environmental capacities is essential. This study was conceived on the basis of a phenomenological approach; an extensive literature review on the subject and the case study were also conducted. The research attempts to consider the Evin-Darakeh stream corridor as a green infrastructure by describing the benefits of green infrastructures. In order to reach this goal, planning principles for this stream corridor and the related strategies are explained.
Mojtaba Rafieian; Esmaile Shieh; Ayoobb Sharifi
Volume 7, Issue 3 , April 2010
Abstract
Cities are complex and dynamic entities which are the main habitat of mankind. Nowadays cities are facing various challenges that threaten their quality and consequently that of urban residential areas. Developing relevant indicators is a vital step toward assessing these environments’ quality ...
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Cities are complex and dynamic entities which are the main habitat of mankind. Nowadays cities are facing various challenges that threaten their quality and consequently that of urban residential areas. Developing relevant indicators is a vital step toward assessing these environments’ quality and can led to better decision making. The aim of this paper is to develop a tool comprising relevant indicators and to assess their relative importance for measuring the environmental quality of dwellings and urban neighborhoods. Impetus for the research was a need to inform planning and policy decisions in the Tehran metropolitan area. Residents of two Tehran neighborhoods participated in this study. During interviews, respondents were presented with five tasks: an inventory task, an importance selection task, a grouping task, a ranking and rating task for groups of attributes, and finally, a ranking and rating task for attributes within each group. After acquiring the needed data, attribute weights were calculated using four weight estimation methods. Next, the effects of neighborhood, sex, and age on the observed differences in attribute weights were examined, and a Comparison between the methods of attributes weight calculation was conducted. Based on two cluster solution methods, attributes were assigned to different clusters. These resulting clusters were then used to design the empirical model of urban environmental quality. In the end, after comparing the results of current study with those of previous studies, some amendments are suggested to be incorporated in revision of Iranian urban planning process, and some implications are presented for urban development policy.
Niloofar Farighi; Houman Liaghati; Mahmoud Shariat; Seyyed Masoud Monavari
Volume 6, Issue 3 , April 2009
Abstract
Today Solid Waste like Air and Water can ́t across the city and state and become as a social problem. Of cource unsuitable management in solid waste can polluted the air by burning materials or by running the Slug and penetrationto water resources, and can Cause Pollution. In general Solid Waste Management ...
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Today Solid Waste like Air and Water can ́t across the city and state and become as a social problem. Of cource unsuitable management in solid waste can polluted the air by burning materials or by running the Slug and penetrationto water resources, and can Cause Pollution. In general Solid Waste Management Means to Collect and decrease Solid Waste generation by Correct Consuption Pattern, solid waste separation in origin by education and .... Problems of collecting and landfill of Tehran solid waste has been appeared by increasing the population and their activity. The Method has been carry out Research is questionnaire. Questionnaire is seperated in two groups, like people and Staff. In each questionnaire asked some questions and analysed by Excel. The other method has been based on observation. It means we separated Zone 3 in 4 groups, Vanak, Jordan, Mirdamad and .... Then we have been made tables and 8 questions for each box. Then these question has been analysis by Excel. Approximatelly, the situation of half of the boxes to the houses was good and half was bad. The situation of 70% of the boxes to the commercial area was good, and 30% was average whieh means boxes were collected better in commercial areas. Appearance situation was 96% average. Waste near the boxes during the day was 99% good but at night was 63% bad, and 37% average. Volume of boxes in comparison with waste during the day was 99% good but at night was 62% bad and 38% average. With a view all 400 boxes whieh was bad need washing. Settlement of boxes in legs area in all 400 boxes was good. The situation of boxes in comparision with generator population in all 400 boxes was average. These resoults has been that the physical area of the boxes are good the volume and the way of collection of solid waste specially at night are bad
Nadia Abbas Zade Tehrani
Volume 6, Issue 2 , January 2009
Abstract
This research is an attempt to develop a new method for studying the Urban Environmental Carrying Capacity with the aim of considering the process of monitoring and controlling of ecosystem health in the urban planning and management strategies.A new method was developed to address the waste production's ...
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This research is an attempt to develop a new method for studying the Urban Environmental Carrying Capacity with the aim of considering the process of monitoring and controlling of ecosystem health in the urban planning and management strategies.A new method was developed to address the waste production's spatial indicators to determine Degree of Carrying Capacity (DCC) in metropolitan Areas. The method was then examined in Tehran zones (Districts) for the year (2003).The results show that in 35 Districts (30%), The final Degree of Carrying Capacity of waste production's indicators is Critical (DCC=5) , in 23 Districts (20%) is very high to Critical (DCC=4-5), ,in 48 Districts (42%) it is from medium to high(DCC=2-4) and in 9 Districts (8%) it is from low to medium (DCC=1-2) .None of the Districts has optimal Degree of Carrying Capacity.
Mohammad Reza Bemanian
Volume 5, Issue 4 , July 2008
Abstract
Cities ever-increasing development that has been achieved without getting advantage from natural environment will bring about imbalance condition between urban and natural spaces. River valleys as cities’ ecological elements have always had effective role in creating mutual relation between man-made ...
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Cities ever-increasing development that has been achieved without getting advantage from natural environment will bring about imbalance condition between urban and natural spaces. River valleys as cities’ ecological elements have always had effective role in creating mutual relation between man-made city spaces and nature. Tehran has special geographical situation as located at the foot of Alborz Mountain. Tehran river valleys originated from Alborz foot in north and continues till south of the city. These river valleys could play important role in paving the way for providing fresh water resources, natural corridor of climate flowing, green open spaces, parks, recreational areas, as well as places for public services activities. While investigating the current situation indicates that Tehranوs River valleys not only do not increase the quality of Environment, but also play a negative role in the context. The present article is going to introduce as environmental revitalization plan for the above mentioned river valleys. Velenjak River Valley as the case study, was case studied through field work research and SWOT analyzing approach. Results of the study indicate that ; Determining district for river valley , preventing polluted water (waste water) to be mixed with the river valleyوs conservation and expansion of green areas, protecting the open views and perspectives, numerous landscape making, and make it a proper place for various customs, etc...,can play a pivotal role in revitalization of Velenjak River Valley as a vital Environmental, Enter raining, and service corridor in prospering the life quality in Tehran City as one of the most polluted ones in the world.
