spatial-spatial analysis

Green spaces and parks have been considered not only because of their recreational importance but also because of their important role in maintaining and balancing the urban environment and air pollution control (Hosseinzadeh et al., 2017: 62). Therefore; In most countries, open and green spaces are an integral part of land use planning decisions. In the past, due to the limited size and type of function of the city, as well as the ease of access of residents to natural areas, this use was more important for certain social groups such as the wealthy class in terms of hunting and spending leisure time, building facades, creating landscapes, and the like; But today, its development has become an unavoidable biological and social necessity due to reasons such as population increase, rapid physical growth, development of industrial and production activities, increase in motor vehicles, and of course, the growth of various types of environmental pollution, and the occurrence of mental-psychological diseases. (Mohammadzadeh, 2011: 66).
As the capital of Iran, Tehran metropolis has the largest population in the country. District 10 of Tehran is one of the important and old areas of the city, which has a large population. Due to some factors, the creation and development of urban green space has always faced problems and deficiencies. Some of these factors are related to city regulations and laws and the lack of setting a standard green space per capita, which leads to the presentation of statistics from 7 square meters of green space per capita by some institutions to 50 square meters of green space per capita by others, which causes the effect of individual tastes. It is used in urban planning. Currently, the level and per capita of urban green spaces is very low compared to the international standards and the accepted standard of the Ministry of Housing and Urban Development, and in fact it includes the levels and per capita calculated for parks and green spaces, while excluding them the levels and per capita This use will be very low (Alavi et al., 2013: 129)

In this research, based on the descriptive-analytical method, while describing the condition of the parks in the 10th district of Tehran in terms of number and spatial distribution, their condition is also investigated based on the selected indicators. In the following, based on urban planning criteria and standards, the current situation is analyzed and evaluated both in terms of individual indicators and also in terms of the combination of indicators. Based on this, the method of this research is based on the description and analysis of the current state of the parks by collecting data and appropriate descriptive indicators.
The method of data analysis was carried out according to research hypotheses as follows:  1) The first hypothesis: In this hypothesis, judging and testing was done qualitatively-descriptively and based on logical reasoning. In this way, in order to measure and evaluate the appropriateness of the number and spatial distribution of parks to provide optimal access; According to the operational definition, the status of the existing parks in the 10th district of Tehran was investigated based on the indicators of radius of performance, per capita standard and area of green space use, population covered and access, then based on the difference between the existing status in each index and the desired status, about The appropriateness of the number and spatial distribution of parks was judged in order to provide optimal access. To investigate the condition of the parks in terms of the mentioned indicators, the method based on GIS and the functions available in it was used, which includes: accessibility, performance radius, and overlap of information and neighboring uses.
Based on this, the qualitative analysis and judgment is based on the spatial coverage of the existing parks. Thus, if the number and spatial distribution of existing parks is such that all residential areas are located at a suitable distance from them, the research hypothesis will be rejected and otherwise it will be confirmed. That is, when parts of residential areas and the households living in them are located at unfavorable distances from the neighborhood park. This means that adequate spatial coverage is not provided by the existing neighborhood parks (due to the lack of number or their inappropriate spatial distribution).
2) The second hypothesis: in this hypothesis, the method of analysis and test of the hypothesis will be qualitative-descriptive and based on logical reasoning. Thus, after determining the spatial-spatial suitability of the parks in the 10th district of Tehran (according to the method mentioned in the operational definition), more than half of the stations, according to the composite index obtained from the Weighted Overlay function in GIS, are located in very suitable areas. get, the second hypothesis is rejected. But if at least half of the parks have an unfavorable spatial-spatial fit, the research hypothesis will be confirmed.

Table 1 shows the green space per capita in ten districts of Tehran in ten districts of the region. The information about the area of the parks and the population of each neighborhood was obtained from the 10th district municipality of Tehran. Thus, green space per capita in Briyank neighborhood is equal to 3.09, in Haft Chenar neighborhood 2.6, in Soleimani neighborhood 0.41, in Ji neighborhood 0.26 in one region. In these neighborhoods, Haft Chenar and Briyank neighborhoods have a relatively favorable situation, and Ji and Soleimani neighborhoods have an unfavorable situation. that Briyank neighborhood has a better situation and Jay neighborhood has a worse situation than other neighborhoods of the first district. Per capita green space in Imam Khomeini (RA) and Mortazavi neighborhoods is in a very unfavorable situation and Hashemi neighborhood is in an unfavorable situation. Per capita green space in the neighborhoods of 3 districts It is Rah. Salisbil neighborhood is equal to 0.07, Karun is 0.61, Zanjan is equal to 0.35 square meters. Zanjan and Karun neighborhoods are in an unfavorable situation, and Selesbil neighborhood is in a very unfavorable situation. Among the ten neighborhoods, Briyank neighborhood in District 1 has a better situation and Mortazavi neighborhood in District 2 has a worse situation than other neighborhoods in the region.

In this research, neighborhood parks in region 10 were examined and evaluated. The lack of sufficient understanding of the spatial-spatial distribution of neighborhood parks and the quality of access of the citizens of this city to the mentioned use caused this issue to be considered and chosen by the researcher. Tehran has taken place. In this research, the main focus is on neighborhood parks that have the following characteristics: their area is twice the size of a neighborhood park (that is, one hectare) and it is also possible for a 9-year-old child to reach it on foot, and the child during The route should pass through Kendro streets and the local access network. Its compatibility is more with educational use and residential areas.
According to the obtained results, the studied area is in an unfavorable condition in terms of spatial distribution. This situation is observed more in the northern, central and western parts of the region. The southern part of the region is in a favorable condition due to the location of two regional parks. But in the north-west and center of the region, due to the lack of green space and the relatively large amount of this region, it is in an unfavorable condition. The studied region has an extremely dense texture, so one of the priorities of the region is due to the lack of green space per capita. And the existence of the worn and dense texture of the area, the implementation of various plans and programs for the development of green space should be.

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)..