Quantification and delineation of the nonattainment boundary for fine particulate matter: Using geographic information system (GIS), remote sensing data, and in situ monitoring.

摘要

This dissertation describes the work of developing a tool for use in delineating the boundaries of nonattainment areas as defined by the Clean Air Act. The weakness of the ambient monitoring system is discussed, and the need for an advanced method for pollutant assessment is concluded. The task was to utilize the existing particulate matter (PM) data and augment with satellite aerosol optical depth (AOD) to enhance the boundary determination of these nonattainment areas. The integration was accomplished by geostatistical kriging. The PM data were used as the base layer and AOD was used as a covariate to create a map showing the probability of exceeding the current 15 mug/m 3 standard. No study had previously reported results nationwide over a period of three years so this study of satellite and ground monitors offered the opportunity to test the reliability of both the satellite and the ground networks.; In the study area, the correlations between PM and AOD are best in the summer months, and are especially poor in the spring and fall. The annual data correlated well in the northeastern quadrant and typically very poor in the west. Given the variability of the correlations it would be ill-advised to use AOD alone as a predictor of fine particle mass. To improve the geospatial prediction of the extent of aerosol in unmonitored areas, satellite AOD data from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensor may be used to fill in the gaps where emissions may occur without adequate ground monitors. Finally, the estimate of fine particle airsheds by season is enhanced by having an area-wide measure of aerosols to fill in the gaps in rural areas of the country deficient in monitors. The research suggests that the question of locating ground monitors in polluted areas would be aided by using MODIS AOD, as well as the ability to identify sources for pollution enforcement. Monitoring the PM2.5 24-hr standard with daily retrieval from the MODIS sensor could be achieved by monitoring intermittent natural events such as forest fires and transboundary air pollution episodes. Given that U.S. policy toward pollution enforcement is determined by the fixed network of monitors, and health exposure studies depend on a better representation of ambient conditions, the addition of daily tracking of air quality would be welcome in the air pollution policy arena.