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 ...
Read More
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.
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 ...
Read More
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.
Hadi Zahedi; Yousef Rashidi; Seyed Hossein Hashemi
Abstract
Introduction: Today, noise pollution is recognized as serious health and environmental problem. With the spread of urbanization and migration and the construction of roads, rails, and air transport networks, as well as the rapid development of the industry over time, the issue of noise pollution is ...
Read More
Introduction: Today, noise pollution is recognized as serious health and environmental problem. With the spread of urbanization and migration and the construction of roads, rails, and air transport networks, as well as the rapid development of the industry over time, the issue of noise pollution is considered a serious issue that prompted urban planning officials to provide a suitable solution for it. The use of sound barriers is one of the methods that is used in reducing and controlling the sound propagation path and is effective in reducing the traffic noise due to the movement of tires on the road, air passing rapidly over the vehicle, vehicle traffic, and some intentional anomalies (such as raising the volume of internal speakers, tampering with car exhaust, etc.). Currently, 20 highways in Tehran have noise pollution, and in some cases, sound barriers have been installed. The Sayyad Shirazi Highway is also equipped with three sound walls. The purpose of this study was to investigate the performance of the sound barriers located in the Sayyad Shirazi Highway. Material and methods: In this study, a three-section noise barrier was installed in Sayyad Shirazi Highway using a B&K2236 sound level meter according to the standard of the US-EPA in terms of sound level (at a height of 1.5 meters from the ground) in different positions relative to the wall. The sound level was measured at a distance of 5 and 20 meters behind the wall and then two factors of sound level reduction and the amount of sound loss were evaluated. Also, by measuring the sound level at houses (with a stone facade and double glazing) and in the living room of different floors, the equivalent sound level was compared with the sound standard in houses compiled by the US-EPA. Results and discussion: The equivalent sound level inside the highway varied between 70 to 80 dBs, and at a close distance (5 meters) behind the barrier, a decrease of about 15 dBs, and at a distance of 20 meters, a decrease of about 12 dBs was observed. Although in the barrier of Zanbagh Alley, due to the short length of the barrier and not properly designed barrier, the sound barrier (lack of proper installaion angle) was lower. Nevertheless of the reduction of about 12 dB, the equivalent sound level does not comply with standard limit (55 dB). It is difficult to meet the national standard due to the short distance between the highway and residential houses., Inside the houses behind barriers, measurements also indicated a relative non-fulfillment of standards. Although it seemed that with increasing altitude, the effect of sound barriers in reducing the equivalent level of sound would be less, this was not observed until the third floor, and sometimes even due to the loud noise of the utility room, the noise level in the first floor, was higher than the second and third floors. Due to the 6 meters height of the wall, with increasing height and in the fourth and fifth floors of houses behind the noise barrier, the effect was less, however, buildings with more than three floors were less observed near the barrier and the highway. Conclusion: The performance of the noise barrier was generally positive in reducing the equivalent sound level. The sound barriers of Bustan Vahed between Farvardin and Abuzar and the noise barrier of Zanbagh Alley were able to significantly reduce the noise level caused by traffic to a lesser extent. According to this study, none of the locations complied with the national standard limit (55 dB) of noise pollution.
Parya Broomandi; Yousef Rashidi
Volume 16, Issue 2 , July 2018, , Pages 49-64
Abstract
Introduction: Airborne particles are considered to be an important indicator of air quality and high concentrations of these particles cause many health problems. Around the world, it is impossible to avoid contact with bio-aerosol contamination in urban life. The presence of pathogenic microorganisms ...
Read More
Introduction: Airborne particles are considered to be an important indicator of air quality and high concentrations of these particles cause many health problems. Around the world, it is impossible to avoid contact with bio-aerosol contamination in urban life. The presence of pathogenic microorganisms in dust storms can cause diseases such as pneumonia, asthma, and other respiratory infections. The aim of this study was to investigate the relationship between airborne particles with airborne microorganisms in normal and dusty days. Materials and methods: The sampling method was quick take 30 equipped with a single-stage sampler at the elevation of 1.5 to 2 meters above the ground. Air flow was 14.3 L/min and its duration was 5 min. The original samples were diluted several times (10-5 - 10-4) to reduce the microbial population sufficiently to obtain separate colonies upon plating. All cultures were incubated at environmental temperature (25 ± 2 °C) for 3 to 5 days and repeated twice. Any increase in PM10 concentrations were in agreement with an increase of bacterial and fungal concentrations during dusty days in Ahvaz city during the warm period (April to September) in 2011. Results and discussion: The concentration of particles in June, July and August was greater than the standard value. The results of the present study illustrated that the average number of bacteria and fungi, respectively, in dusty days was 5 and 1.7 times that of normal days. Also, the predominant species of bacteria and fungi during the occurrence of dust storms were Bacillus sp. (45% of total bacteria) and Aspergillus sp. (44% of total fungi), respectively. Therefore, any increase in the number of airborne microorganisms (bacteria and fungi) during dust storms can cause biologically harmful effects on human health. Conclusion: Based on the annual and seasonal changes in meteorological parameters and HYSPLIT, it can be seen that the probable origin of airborne particles are neighbouring countries to southwestern Iran, especially the northwestern parts of Iraq and the eastern parts of Syria.
Hossein Shahbazi; Vahid Hosseini; Yousef Rashidi
Volume 12, Issue 3 , October 2014
Abstract
In this study, the performance of WRF/CAMx modeling system in predicting primary and secondary gasephase pollutants is evaluated. The main goal of this research was investigating the impact of initial and boundary concentrations, used to feed the CAMx model, on the accuracy of the model and the level ...
Read More
In this study, the performance of WRF/CAMx modeling system in predicting primary and secondary gasephase pollutants is evaluated. The main goal of this research was investigating the impact of initial and boundary concentrations, used to feed the CAMx model, on the accuracy of the model and the level of pollutants over Tehran modeling domain. For this purpose, CAMx model was ran in two cases with different initial and boundary concentration. The model performance in two cases compared against observations measured at air quality monitoring stations. Results showed significant impact of initial and boundary concentrations on model accuracy and level of pollutant concentrations over the city. When using constant zero initial and boundary concentrations model showed poor performance in predicting level of pollutants and daily maximum concentrations, especially for NO2and O3concentrations which mostly produce during chemical reactions in the atmosphere. But using MOZART data to prepare initial and boundary concentrations lead to improve in model accuracy and predicting daily maximum concentrations.
