The effect of urban green space patterns on the spatial distribution of air pollutants (case study: Tehran)

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.