Assessment of air pollution at Greater Cairo in relation to the spatial variability of surface urban heat island.

Greater Cairo, Egypt, which lies in the apex of the Nile Delta, is one of the most populated regions in the world. Air pollution is a profound environmental issue prevailing in the urban/rural landscapes of this crowded megacity. The objectives of the present study were to utilize remotely sensed data in order to address the seasonal variations of the nocturnal surface urban heat island intensity (SUHII) as extracted from the American Moderate Resolution Imaging Spectroradiometer (MODIS) satellite and the related seasonal distribution of selected air pollutants, including nitrogen dioxide (NO2), sulphur dioxide (SO2), and carbon monoxide (CO) as extracted from the European TROPOspheric Monitoring Instrument (TROPOMI) for the period from 2018 to 2021. It is observed that there is clear nocturnal urban heat island over Greater Cairo, particularly at the administrative districts dominated by urban land use with high density of population and at the industrial and power generation locations. The highest SUHII is observed during winter. On the other hand, the selected pollutants also represent an urban pollution island (UPI) capping the regions of high SUHII. At the seasonal level, the highest NO2 correlation with the SUHII occurs during spring (R2 = 0.59), while the CO correlates maximum during winter (R2 = 0.51). Nonetheless, the seasonal SO2 distribution is poorly related to the SUHII as this specific pollutant is significantly associated with the industrial land use. Climatic and topographic factors could intensify the distribution of air pollution in the study area. Results of this study demonstrate the significance of geospatial technology tools in the subtle analysis and addressing regional air pollution. The outputs are also of a paramount implication on the management of urban environment and the adaptation of urban air quality.

Oceanographic factors of oil pollution dispersion offshore the Nile Delta (Egypt) using GIS.

Oil pollution is a worldwide concern due to the increasing rate of offshore oil production and transport. As the Nile Delta coast is adjacent to the main route of oil transport through the Suez Canal, accidental oil spills along the offshore region may have a tremendous impact on the coastal waters. If the oil slicks reach the coast, the impact should also be significant. This study aimed to map the oceanographic parameters that may affect oil pollution dispersion along the offshore zone of the Nile Delta using geographic information system (GIS) techniques. Oceanographic data (wave patterns, bathymetry data, sea surface temperature (SST), chlorophyll content, phytoplankton concentration, and organic carbon concentration) were used to analyze the characteristics of water at the onset of oil pollution to interpret the dispersion of the oil slick once discharged into the seawater. The results showed that SSTs and the depth of the coastal zone primarily influence the distribution of the other parameters.