Monitoring seasonal land surface temperature and land cover dynamics in West Wollega, Ethiopia, using remote sensing technology

Abstract

This study examines the impacts of land use and land cover (LULC) changes on land surface temperature (LST) over a three-decade period to investigate human influence on regional climate variability. Using Landsat images in 1992, 2002, and 2022, cross-validated with field surveys as well as high-resolution data, we evaluated LULC changes and their thermal effects. Spectral indices such as the Normalized Difference Vegetation Index (NDVI) and the Optimized Soil Adjusted Vegetation Index (OSAVI) were employed to examine long-term LST trends. The results indicate a significant change in the settlement land use type, which increased by 176.36 % in the study area. Meanwhile, forest and grassland areas decreased by 4.3 % and 21.04 %, respectively, whereas bare soil and farmland expanded by 47 % and 21.46 %. NDVI and OSAVI seasonality was striking in the Belg and Kiremt seasons and governed LST variability. There was a steady increase in the average LST every year, with the highest increase in the urban area (4.5 °C by 2022) due to the urban heat island effect, followed by cropland (3.7 °C) due to vegetation loss. Forest cover experienced lower temperature increases, indicating its cooling potential. Urbanization and vegetation degradation increase regional warming, keeping in view the importance of sustainable land-use planning. More greens, climate-resilient urban development, and forest preservation are essential to combat LST exacerbation and trigger resilience to the climate. These observations in such studies emphasize that land management measures have to be complementary to adaptation measures to avoid perturbation of the ecosystem and stop local warming patterns.