Andenet Ashagrie (PhD)Melkamu Tarekegn2024-10-282024-10-282024-06https://etd.aau.edu.et/handle/123456789/3509Urban green space (UGS) is crucial for maintaining ecological balance in rapidly urbanizing areas. This study aimed to estimate UGS and quantify oxygen production in Addis Ababa, Ethiopia, for the years 2017 and 2024 using Geographic Information System (GIS) and Remote Sensing (RS) technologies. Sentinel-2A satellite imagery was employed to analyze the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI), assessing changes in vegetation cover and built-up areas. UGS was categorized into dense vegetation, sparse vegetation, and shrub and grassland to estimate oxygen production. The results revealed a significant decline in green spaces and an expansion of built-up areas from 2017 to 2024, indicating rapid urbanization. In 2017, UGS covered 18,818.33 hectares, producing an estimated 33,872.994 tons of oxygen per year. Detailed oxygen production for 2017 included dense vegetation (2,663.39 tons/year), sparse vegetation (2,613.72 tons/year), and shrub and grassland (3,299.22 tons/year). By 2024, UGS reduced to 16,842.17 hectares, with an estimated oxygen production of 30,315.906 tons/year, including dense vegetation (2,862.129 tons/year), sparse vegetation (3,017.96 tons/year), and shrub and grassland (2,402.379 tons/year). Accuracy assessments using Google satellite imagery and ground-collected GPS data validated the classification results. These findings highlight the ecological impact of diminishing green spaces due to urbanization. This research underscores the urgent need for sustainable urban planning and the preservation of green spaces in Addis Ababa to mitigate adverse environmental effects and maintain ecological balanceen-USUrban green spaceoxygen releaseGIS and Remote Sensingsentinel 2A imageThesis