Spatial analysis of land use and cover changes: Implications of green legacy initiative on climate action in Upper Awash Basin, Ethiopia

Abstract

Analyzing land use land cover change is crucial for understanding the impacts of human activities on the natural environment. The government of Ethiopia has launched the Green Legacy Initiative (GLI) in June 2019 to minimize the impacts of climate change. . This study investigates the relationship between Land Surface Temperature (LST) and land cover indices, Normalized Difference Vegetation Index (NDVI), Normalized Difference Barren Index (NDBaI), and Normalized Difference Water Index (NDWI) using GIS and remote sensing techniques. Landsat imagery from 1993 (TM), 2003 (ETM+), and 2023 (OLI/TIRS) was utilized to calculate LST, NDVI, NDBaI, and NDWI, leveraging both thermal and multispectral data to assess the initiative's effects on temperature regulation. The results reveal substantial land cover changes between 1993 and 2023. Specifically, forest land increased from 492.4 km² (12.5%) to 837.3 km² (21.3 %), while barren land declined from 97.4 km² (2.5 %) to 64.6 km² (1.6 %). These shifts highlight the effectiveness of the GLI in promoting afforestation and curbing land degradation. Furthermore, a significant reduction in LST by 2.3 °C was observed between 2003 and 2023, largely attributed to these large-scale afforestation efforts. Strong negative correlations were found between LST and both the NDVI (R² = 0.98) and the NDWI (R² = 0.97), highlighting that increased vegetation and water bodies are associated with lower temperatures. Conversely, a positive correlation was noted between LST and the NDBaI (R² = 0.91), indicating that barren land is linked to higher temperatures. Therefore, policymakers and environmental analysts should enhance vegetation cover to mitigate the effects of rising temperatures.