Application of satellite data and GIS in studying air pollutants in Tehran

Tehran, capital of Iran, is one of the polluted cities in the region. Due to its geographical location, the ensnared condition as surrounded by mountain ranges, and also lack of perennial winds, the smoke and other particulate matters produced from daily life do not go far in the air. Therefore, usually there is a thick layer of aerosols and other particulate matters in the nearby atmosphere. Air pollution and its health consequences has been a major concern for both citizens and urban planners and decision makers of this city. With regard to this fact, our goal in this study is to examine the application of satellite data and spatial analysis to monitor and map air pollution. We have used satellite data and spatial modeling with the help of GIS to study concentrations of different pollutants in the city. Beside its widespread coverage, satellite data are considerably cost effective relative to traditional air pollution data collection methods. We used moderate resolution imaging spectro-radiometer (MODIS) data, together with ground station data to monitor and map air pollutants. Ground pollution survey stations collect daily amounts of pollutants in different parts of the city. However, these ground stations do not have equal distribution across the city and are not sufficient to get a complete figure of sophisticated patterns of pollution in the area. We extracted maps of particulate matters and aerosols from MODIS image, displaying pollution collectively. With the help of GIS, the data of ground stations used to produce maps of amounts of each pollutant separately. Quantitative MODIS aerosol optical thickness (AOT) data compared with these data using a spatial grid. (C) 2007 Elsevier Ltd. All rights reserved.