Assessing the effect of land cover composition on land surface temperature.

Abstract

Urban heat island refers to the higher temperature of urban areas compared to the surrounding rural areas. Previous studies on UHI often prove the existence of significant effects of land cover and vegetation density on urban surface temperature. However, there is a need to investigate more information on the relationship between the composition of landscape spatial features and LST. This study assessed the effect of land cover composition on land surface temperature. Land Cover, LST and NDVI were extracted from Landsat 5 TM (2010), Landsat ETM +Landsat 8 OLI/TIRS (2015 &2020) using GIS and remote sensing tools. Remote sensing and GIS techniques were utilized to quantify and map the LU/LC changes and its drawback on LST. Changes in LC, which occurred between 2010 and 2020 in the study area was evaluated and analyzed using geospatial tools and the accuracy assessment was done with the help of google earth software. The result of LU/LC indicated that farmland covered more than 75.87% of the total land cover in 2010 followed by forest land covering more than 11.68%, then built-up covered 7.04% and bare land having 5.41% of the total land cover area. On the other hand, in 2020, built-up areas were noticed to increase by approximately 3% between 2010 -2020. The study also indicated that most areas having lower LST in 2010 were changed to higher LST in 2020.This happened due to the increased in different LC changes especially the decreasing of vegetation cover in the study area. Land surface temperature result showed that the north-eastern, southern parts of the district have relatively low value ranged mean LST. This happened because of high NDVI value. While the Central and northern parts had high LST values. The results and discussions on the influence of land cover effect on land surface temperature were also analysed together with recommendations based on the results of this study.