Preparation of Air Pollution Mapping by Interpolating Kriging Method in GIS, Case Study: Tehran Metropolis

Tehran as the largest city in Iran, is one of the most polluted cities in the world, so necessity of accurate detection of contaminants and identifying contaminated areas for reducing their severity is obvious. The aim of this research was prepared Tehran air pollution map and determining the areas with the highest polluted. Forstudying air pollution situation in Tehran, after gathering concentration of 5 main Atmospheric pollutants (CO, NOx ،SOx ،O3 ،PM25) from 20 air pollutant recorder station, three Interpolation methods in ArcGIS software include: Kriging, radial basis function RBF and inverse distance weighted IWD have been used. In Additon, for comparing methods and selecting the best of them, root- mean-square error RMSE and the correlation coefficient R2 had been used. It determined that in most of parameters IDW had better accuracy for zoning pollution of the area by checking the RMSE values. For achieving results with using mentioned methods, map of air quality limits in the area was ready and by combining five maps and weighing them into each parameter, general pollution map of the area was prepared. Results showed that in Monoxide carbon pollution zoning map, most of the pollution was related to the unhealthy class, in Nitrogen Oxide and Ozone was related to very unhealthy class and in particle matter and sulfur oxide was related to unhealthy class. In final map also most portion was related to unhealthy class. Overlay Masudieh station with 1091 pollution weight had the most pollutants and dangerous weather conditions and Darrus station with 628 pollution weight had better position.