@article { author = {Afarideh, Faezeh and Ramasht, Mohammad Hossein and Mortyn, P. Graham}, title = {Temporal-spatial analysis of air quality index in Tehran during the period of 10 years}, journal = {Physical Geography Research}, volume = {53}, number = {4}, pages = {447-463}, year = {2022}, publisher = {University of Tehran}, issn = {2008-630X}, eissn = {2423-7760}, doi = {10.22059/jphgr.2021.324223.1007620}, abstract = {. Air pollution is measured using the air quality index and by air quality measuring stations. The purpose of this study is to investigate the temporal-spatial changes of air pollution in December and January and during ten years from 1389 to 1398 using the average data of air quality index in Tehran. For this purpose, first air quality data were extracted from 21 air quality control stations in Tehran and then the average air quality data in the two months were calculated and IDW interpolation maps were drawn for both months during the ten years studied. In the drawn interpolation maps, the trend of temporal-spatial changes of air pollution during ten years can be observed, then the percentage of air pollution zones in the city of Tehran for both months during the study period have been calculated. Finally, the maps of December and January of the ten years studied were put together separately and analyzed. Thus, spatial and temporal analysis of air quality was performed in December and January for 10 years. The results show that during December and January of 1389 to 1398, the largest area of Tehran, respectively, in the areas, Relatively healthy (54%), unhealthy for sensitive (23%), healthy (20%) and clean (1.5%) and unhealthy (0.5%) groups. In other words, less than 2% of the city of Tehran is located in a clean area, and even in some years in Tehran, there has been no clean air in these two months. In terms of time, December 2010, January 1991 and January 1995 with more than 70% of unhealthy zones for sensitive groups were among the most infected years. Also, Sharif and Shadabad industrial stations without having a clean zone and with AQI 75 and above have been among the most polluted stations in the ten years studied. Therefore, the problem of air pollution in Tehran, in addition to the spatial dimension (being located in a large area of the city in an unhealthy area), is also a matter of time (high pollution in a long period of time).IntroductionTehran is one of the 8 most polluted cities in the world and although it has only 1.2% of the total area of the country, but 20% of the total population, 40% of industry and 85% of all professionals live and work in it (Ahmadi Moghadam, Mahmoudi. 1390). The importance and necessity of research stems from the fact that the political center of the country with a population of tens of millions of people today has more than 200 days of air pollution (Seidaei et al., 1998). In this study, temporal and spatial changes of air quality index by IDW interpolation method in December and January and during 10 years from 1389 to 1398 are investigated. According to the intensity of this index during these ten years, first two months, December and January, were selected as the most polluted months in this year, and then to continue the work of air quality data, 21 air pollution measuring stations of Tehran Municipality were calculated and produced inside The search took place.MethodologyAccording to the purpose of this study, which is to study the temporal-spatial changes of the average air quality index in Tehran during the ten-year period from 2010 to 2017, the following steps were performed. Air quality data were extracted from 21 air quality control stations affiliated to Tehran Municipality that are scattered throughout Tehran. Then, the average of each month of December and January in each year was calculated. Then, IDW interpolation maps were drawn. Then, from the maps drawn in each year, the percentage of the area of air pollution in the city of Tehran was calculated. Finally, to identify changes and air pollution zones during this ten-year period, ten-year maps were stacked separately and analyzed each month, thus spatial and temporal analysis of air quality in two months. December and January were studied during 10 years.DiscussionAccording to the calculations made during December of the ten years under study, on average, about 3% of the city of Tehran was in the area of clean air. Most of Tehran is located in a relatively healthy area, which during the study period, an average of 58% of Tehran is located in this area. The next area of air pollution in Tehran is a healthy area with an average of 22%, the highest area of this area with an average of 75% is in 1390. Unhealthy zones for sensitive groups with an AQI value above 100, cover an average of 18% of the area of Tehran. In just one year, an unhealthy area with an AQI value above 150 can be seen in Tehran, which in 2010 with an average of 0.5% of the city area.The results of the table and maps show that in January of the ten years under study, on average, only 2% of the area of Tehran was in the clean air zone, and the healthy area, on average, included only 20.5% of the area of Tehran. Becomes. Most of the city of Tehran is located in a relatively healthy area, which during the ten years under study, this amount is 52.5 on average. The unhealthy zone, with about 27% of the city, is in second place.. In the drawn maps, the trend of pollution changes during December can be seen. According to these maps, the highest range of air pollution was recorded in December 2010 and the lowest in December 1990. In the drawn maps related to January, the highest air pollution zone is related to January 2016 and the lowest pollution zone is related to January 2010.The results of the two-month maps of the temporal and spatial analysis of the air quality index are very similar, and there is not much difference between December and January in terms of spatio-temporal distribution of air pollution. The only slight difference is in some stations, such as the Sharif University of Technology station, where more pollution was recorded in December than in January.Conclusion and SuggestionsThe results of the research show that during the months of December and January of 1389 to 1398, the largest area of Tehran in the areas of relatively healthy (54%), unhealthy for sensitive groups (23%), healthy (20%), respectively. ) Are clean (1.5%) and unhealthy (0.5%). In other words, less than 2% of the city of Tehran is located in a clean area, and even in some years in Tehran, there has been no clean air in these two months. In terms of time, December 2010, January 1991 and January 1995 with more than 70% of unhealthy zones for sensitive groups were among the most infected years. Also, Sharif and Shadabad industrial stations without having a clean zone and with AQI 75 and above have been among the most polluted stations in the ten years studied. Therefore, the problem of air pollution in Tehran, in addition to the spatial dimension (being located in a large area of the city in an unhealthy area), is also a matter of time (high pollution in a long period of time)..}, keywords = {Air pollution,Spatial-Spatial Analysis,Air quality index,Tehran}, title_fa = {تحلیل زمانی- مکانی شاخص کیفیت هوای شهر تهران در دورة ده‏ ساله}, abstract_fa = {آلودگی هوا، با توجه به پیامدهای زیان‏بار آن، به یکی از ملموس ‏ترین معضلات زیست‏‏ محیطی تهران تبدیل شده ‏است و بررسی و مطالعه بر روی آلودگی هوای تهران به‏ عنوان مسئلة بسیار مهم در پژوهش‏ های مختلف مدنظر قرار گرفته است. اندازه ‏گیری آلودگی هوا با استفاده از شاخص کیفیت هوا و توسط ایستگاه‏ های سنجش کیفیت هوا انجام می‏ گیرد. هدف از این پژوهش بررسی تغییرات زمانی- مکانی آلودگی هوا در دو ماه آذر و دی در طی ده سال (1389-1398) با استفاده از میانگین داده‏های شاخص کیفیت هوا در سطح شهر تهران است. بدین منظور، داده‏ های کیفیت هوا از 21 ایستگاه کنترل کیفیت هوای شهر تهران استخراج و میانگین داده‏ های کیفیت هوا در دو ماه موردنظر محاسبه شد و نقشه‏ های درون‏یابی به روش IDW در محیط نرم‏افزار ArcGIS ترسیم شد. سپس، درصد وسعت پهنه‏ های آلودگی هوا در سطح شهر تهران محاسبه شد و نقشه‏ ها روی هم انداخته شد و تجزیه و تحلیل گردید. نتایج حاصل از پژوهش نشان می‏دهد در ماه ‏های آذر و دی، طی سال ‏های 1389 تا 1398، بیشترین وسعت شهر تهران به ‏ترتیب در پهنه‏های نسبتاً سالم (54 درصد)، ناسالم برای گروه ‏های حساس (23 درصد)، سالم (20 درصد) و پاک (5/1 درصد)، و ناسالم (5/0 درصد) قرار دارد. به عبارتی، کمتر از 2 درصد وسعت شهر تهران در پهنة پاک قرار گرفته است و حتی در برخی از سال‏ها در شهر تهران هوای پاک در این دو ماه وجود نداشته است. از نظر زمانی، سال 1389، با دارابودن بیش از 70درصد پهنة ناسالم برای گروه‏های حساس، جزو آلوده‏ترین و سال 1393 جز پاک ‏ترین سال‏ های مورد بررسی محسوب می ‏شود. همچنین، ایستگاه صنعتی شریف و شاداباد بدون داشتن پهنة پاک و با داشتن AQI 75 به بالا جزو آلوده‏ترین ایستگاه‏ها در همة سال‏ها بوده‏اند. بنابراین، مسئلة آلودگی هوای شهر تهران، علاوه بر بُعد مکانی (قرارگرفتن وسعت وسیعی از شهر در پهنة ناسالم)، مسئله‏ای زمانی (آلودگی زیاد در دورة زمانی طولانی‏مدت) نیز هست. در پایان دلایل مؤثر بر توزیع زمانی- مکانی اعم از طبیعی و انسانی (حمل و نقل و صنعت) بررسی و در مقیاس ‏های ایستگاهی یا کلی تحلیل شده است.}, keywords_fa = {آلودگی هوا,تحلیل زمانی- مکانی,شاخص کیفیت هوا,شهر تهران}, url = {https://jphgr.ut.ac.ir/article_84664.html}, eprint = {https://jphgr.ut.ac.ir/article_84664_cdded31d99d0e0ab813589fd511aa608.pdf} }