Assessment of air quality and damage caused after an anthropogenic disaster in the city of Beirut

Abstract

Air pollution is an important cause of concern and has a significant impact on health as well as the environment. Air pollutants are released into the atmosphere by various sources, and the concentration in cities is mainly due to anthropogenic sources like emissions from industries, factories, vehicles, fossil fuel combustion, waste production, etc. But certain high episodes of air pollution can be witnessed in cities which can cause serious threats to human beings and the environment. Remote sensing is one of the sustainable measures, which allows the integration and presentation of useful information at various temporal and spatial scales. This tool can be helpful in understanding and managing natural disasters and man-made risks contributing to air pollution. Analyzing the cause of such high pollution episodes can help to take necessary steps to reduce the emissions, and damage or to take precautions to avoid man-made disasters. One such incident of an explosion of ammonium nitrate in a port had a long-lasting impact on the air quality in Beirut where the average concentration of air pollution already exceeds WHO threshold limits. This paper explores the concentration of aerosols and NO2, before and after the incident of an explosion that took place in Beirut. Assessment of the damage near the port caused by the explosion in Beirut was done using a change detection technique for which an algorithm was developed. Due to the non-availability of field data for the study area of Beirut, the algorithm was developed and validated for Chennai city and extended to Beirut. The aerosol and NO2 concentration data were extracted from sentinel-5p/TROPOMOI and validated with ground data through regression analysis. The results obtained from this study can be used as an early warning system and decision support system for mitigating loss due to the explosion.