Assessment of land-use/land-cover changes impact on Land surface temperature using Geospatial Technology: a case of Addis Ababa including Sheger City, Ethiopia

Abstract

Changes in land-use and land-cover are major environmental issues that significantly impact urbanization and agricultural growth. There has been a notable and consistent rise in LST over the years, posing a significant challenge globally. This study explores how changes in land-use and land-cover affect LST. The study took place in Addis Ababa including Sheger, utilizing Geospatial technologies to extract LU/LC, LST, NDVI, NDBI, NDBaI, and NDWI using images from Landsat TM of 1991 and 2001, and Landsat 8 OLI/TIRS images of 2013 and 2023. These tools proved effective for mapping and quantifying changes in LU/LC and their impact on land surface temperatures. The study area's land surface temperature was determined using a split-window algorithm and utilized zonal statistics in a tabular format to correlate LU/LC classifications with LST. The evaluation and analysis of changes in land use and land cover from 1991 to 2023 were conducted with geospatial tools and corroborated through field data. Findings from the LU/LC analysis revealed that over 56% of the area was occupied by cropland throughout the study period (1991–2023), while built-up areas accounted for over 23%. The research showed that regions which exhibited lower Land Surface Temperatures (LST) in 1991 transitioned to higher LST by the years 2001, 2013, and 2023. This shift was primarily attributed to various changes in LU/LC, notably the expansion of Built-up area and reduction of vegetation covers in the area. The study revealing a strong negative correlation between LST with both NDVI and NDWI. Conversely, LST displayed a strong positive correlation with NDBI and NDBaI. The findings on LST revealed that the northwestern region, including Menagesha Suba and Entoto Park, in addition to the areas around Lake Geferesa and Legedadi, experienced relatively low temperatures ranging from 7ºC to 18ºC, attributed to high NDVI values. Conversely, the southeastern and eastern parts of the city recorded significantly higher LST values, peaking at 42ºC. Thus, a visual analysis of images from 1991, 2001, 2013, and 2023 reveals that the types of land use/land cover, along with the status of NDVI, NDBI, NDBaI, and NDWI, significantly influence the variability of LST values. Finally, this study suggests that geospatial technologies are essential tools for decision-makers, providing a timely and cost-effective approach to analyze and evaluate LST. These technologies also facilitate the study of LST's implications for local environments, such as the prevalence of heat waves and droughts.