Maryam Charmzan; Reza Esmaili; Mitra Mohammadi; Vahid Moradnezadhesare
Abstract
AbstractBackground and Aim:Air pollution is one of the most important environmental problems in the last century that threatens human health and particulate matter is one of the deadliest types of air pollution.This study was done to choose the best interpolation algorithm in the spatial distribution ...
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AbstractBackground and Aim:Air pollution is one of the most important environmental problems in the last century that threatens human health and particulate matter is one of the deadliest types of air pollution.This study was done to choose the best interpolation algorithm in the spatial distribution of PM2.5 suspended particles in Mashhad in 1395by different spatial models.Material and Methods: PM2.5 particulate concentrations was collected from 21 active air quality measuring stations in different parts of Mashhad and IDW, Ordinary Kriging (OK) and Universal Kriging (UK) interpolation models were evaluated to spatially investigate the air pollution situation in Mashhad. The root mean square error (RMSE) was used to compare the models and select the best model, and the Standardized RMSE was used to choose the most optimal conditions for running the OK and UK models.Results: The results showed that the highest seasonal average of PM2.5 pollutants in 1395 was related to autumn (40.84 µg/m3) and the lowest was related to spring (27.78 µg/m3). Also, the east to north area of Mashhad is in a more unfavorable situation in pollution concentration than the western areas of the city. Comparison of models using RMSE index also showed that OK model due to having the lowest amount of RMSE for seasonal average and annual concentration of suspended particles PM2.5 has a lower error in the predicted values than the measurement, so it has better conditions for intermediation.Conclusion: This research eventually led to the production of maps of PM2.5 Pollutants situation in the whole city of Mashhad, which is very useful in order to identify high-risk areas in the city and use useful measures to reduce air pollution in those areas.
Sara GHolamhosein Ghoochani; Shabnam Hoshdar Tehrani; Reza Esmaili
Abstract
Background & objeftive: 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 ...
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Background & objeftive: 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. Materials & Methods: 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. Results: 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. Conclusion: 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.