Spatial Analysis of Carbon Monoxide Pollutant in Mashhad by Interpolation Method and Using Geographic Information System (GIS) during 2017-2018

Carbon monoxide is a toxic gas and since it is colorless, odorless and tasteless, it often has no warning signs for people who are at risk of this pollutant. This study focused on the spatial distribution of carbon monoxide on a monthly basis with the interpolation method in Mashhad city. In this study, data were collected from 19 metropolitan stations in the city. Then the inverse weighing intervals, ordinary kriging, and universal kriging methods were used. To determine the best spetial distribution, the root mean square error were applied .finally, the best interpolation methods was selected.with the help of geostatistical map in Arc GIS, monthly zoning map have prepared during 2017-2018. The results showed that ordinary kriging is a best method rather than universal kriging and inverse weighteing due to the lees error. By providing monthly zoning map in 2017-2018, it was cleared that in the months of April, May and June, the middle belt of the city was more polluted from northwest to southeast. The estern part of city in July, August and September have been more contaminated rather than other area. The months of October, November and December wre more polluted in central part of the urban area and from the western to southwestern of the city, in December, February and March, were indicated more pollution. A mong the metropolitan stations for measuring air pollution, southern part of Khayam and sadaf had a highest levels of carbon monoxide and Khaghani and Elahie were lowest rate. Also, monthly zoning maps indicated that the highest pollution rate in hot season was in the eastern and in cold season was in the western part of the city. However, the amount of carbon monoxide was less than standard level during 2017-2018.