Spatio-temporal analysis of the relationship between vegetation and air CO concentration in Algeria

Urbanization transforms rural areas into urban spaces, leading to notable social, economic, and environmental changes. This process is often associated with human activity increase, transport, and energy consumption, resulting in higher carbon monoxide (CO) emissions from vehicular traffic and industrial activities. Additionally, urban development often reduces green spaces due to infrastructure and construction projects, aggravating city air pollution. In this context, the work presented in this article conducts a temporal analysis of the relationship between vegetation indices, such as NDVI, SAVI, and MSAVI, with the atmospheric pollutant carbon monoxide (CO), and land occupation across different regions of Algeria. The study is based on five years of data, covering the four seasons of each year, using Sentinel-5P data to assess carbon monoxide emissions and Sentinel-2 data to determine the three vegetation indices NDVI, SAVI and MSAVI. The results of the temporal analysis revealed some interesting elements. Over the first years considered in the study, an inverse correlation is observed between vegetation indices and carbon monoxide, confirming that the presence of vegetation directly influences the concentration of carbon monoxide in the air. However, the latest annual data series show a decrease in the estimated carbon monoxide (CO) concentration, independently of the increase or decrease in vegetation indices. This may be explained by the introduction of new measures to reduce carbon emissions.