Spatiotemporal Assessment of the Correlation Between Rainfall and Aerosol Optical Depth Using GIS and Google Earth Engine in Iraq

Abstract Dust storms, intensified by climate change, pose a significant environmental challenge in Iraq and the Middle East. This study evaluates remote sensing-derived Aerosol Optical Depth (AOD) data and investigates its correlation with rainfall to explore the spatiotemporal co-variation between the two variables. The analysis covers the period 2000-2021, with high-spatial-resolution long-term Google Earth Engine (GEE) data to investigate AOD over Iraq and rainfall data from IMOS to study the association of aerosol with rainfall over 38 stations covering all of Iraq. Time series components have been decomposed into (trend, seasonal, and random) of the monthly mean rainfall and AID index using R Studio. The results demonstrate that rainfall and aerosol index AOD distributions vary significantly monthly and seasonally between Iraq’s northern and southern regions. There is no rainfall during the summer; even so, AOD data show the highest values in the summer and minimum values in the coldest winter months across the study locations. Maximum AOD levels occur over the southern area with less rainfall, progressively decreasing towards the north, while rainfall values are at their highest. Temporal and regional examination of AOD changes in Iraq reveals notable variances, with high dust levels having the most significant impact between 2008 and 2012 and a relative decrease after 2013. Dust concentrations in the southern and central regions are higher than in the north, particularly during the summer and spring. The study found a good inverse correlation (r = −0.7) between AOD levels and rainfall. The results demonstrate that rainfall reduces aerosol concentrations, especially in arid areas, whereas other regions are affected by different factors that require more examination. These findings underscore the critical role of rainfall in mitigating dust levels and emphasize the urgent need for sustainable environmental management to combat increasing desertification under ongoing climate change.