Monitoring the dynamics of land use and land cover, and their impact on seasonal land surface temperature in the Upper Awash Basin, Central Ethiopia
Getahun Bekele Debele, Kassahun Ture Beketie
Abstract
Urbanization and agricultural expansion are leading to major alterations in land use/land cover (LU/LC), which profoundly alters the biophysical environment. Monitoring these changes is crucial for managing the environment efficiently. This study examines the effects of LU/LC changes on seasonal land surface temperature (LST) in the Upper Awash Basin (UAB), central Ethiopia, using Landsat 5 TM, Landsat ETM+, and Landsat 8 OLI/TIRS data from 1991, 2006, and 2021. Between 1991 and 2021, built-up areas expanded by 158.1% and agriculture by 50.9%, barren land decreased by 90.4%, shrubland by 76.3%, and forest by 41.0%. These changes led to higher mean seasonal LST, with summer temperatures increasing from 20.1 in 1991 to 26.4 °C in 2021 and winter temperatures from 23.6 to 29.9 °C. In 1991, no areas experienced the highest LST zone (≥ 30 °C) in summer, but by 2021, this rose to 21%. In winter, the percentage increased from 38 in 1991 to 42% in 2021. Built-up areas had the highest mean LST in summer, while barren lands did in winter, showing seasonal variations. Conversely, water bodies and forested lands consistently displayed the lowest LST across all seasons. In summer, LST strongly negatively correlated with NDVI, while in winter, the correlation was moderate, suggesting summer rainfall affects vegetation health. LST has moderate inverse relationships with MNDWI in both seasons, and it shows moderate to strong positive relationships with both NDBI and NDBaI. These findings are valuable for land use planners, environmentalists, and researchers working on effective strategies for regulating LST.