Application of spatial remote sensing for air quality estimation: the case of the Jorf Lasfar region, Morocco

The Jorf Lasfar region, the subject of this study, is characterized by an establishment near its port, OCP factories, thermal power stations, hydrocarbon storage units, and numerous establishments specific to the chemical agro-food sector likely to emit atmospheric aerosols. To highlight the state of the air, this region is only equipped with approximately ten permanent ground measurement stations. Consequently, air quality monitoring has become necessary for assessing and monitoring the impact of air pollution on the population's health. Unfortunately, insufficient ground-based air pollutant measurement stations have generated accurate microparticle concentration maps at a fine scale. Therefore, to compensate for the lack of measuring stations, we resorted to satellite remote sensing by exploiting the relationship between the air quality measurements provided by existing measuring stations and satellite images. Given the correlation between aerosol rates measured in situ and data extracted from Landsat satellite images, maps derived from atmospheric scattering and surface temperature have enabled the extraction of a certain amount of helpful information better to understand atmospheric pollution in the Jorf Lasfar region. An analysis of these maps showed that the most significant correlation, in particular, was between aerosols in suspension and land surface temperature (LST), as deduced from the thermal infrared band, with a correlation coefficient R of 0.79. Another correlation with atmospheric scattering calculated using the atmospheric correction of the satellite image by the FLAASH algorithm is also noteworthy but is relatively less significant than the first. Therefore, maps of atmospheric diffusion and surface temperature derived from the processing and analysis of Landsat satellite images will be considered a new source of information, allowing for a better understanding of the spatial distribution of aerosols, especially in areas where the number of measuring stations is very limited, such as the Jorf Lasfar region.