Monitoring land surface temperature in Bahir Dar city and its surrounding using Landsat images

Abstract

Land surface temperature (LST) is the burning issue in the world since it affects climate and environment at local, regional and global level. Mainly it resulted from urbanization and its associated extreme Land-use and Land-cover (LULC) changes. Therefore, monitoring of LULC alteration is a significant component in examining of LST variation and applying sustainable mitigation measures. The research has the objective to analyze the spatial-temporal patterns of LST and its variation with LULC composition in Bahir Dar city and its surrounding from 1987 to 2017 with fifteen-year intervals using Landsat images. Image preprocessing was done to retrieve NDVI, NDBI, LST and LULC, and urban-rural gradient analysis and LST Intensity (LSTI) were computed. As the result shows that urban areas of Bahir Dar city rapidly expanded since 1987. The mean LST values increased to 34.5 °C in 1987 to 37.57 °C in 2002 and decreased to 34.57 °C in 2017. Paved surface and agricultural land exhibited higher LST values whereas waterbody and vegetation experienced lower LST. The result also shows that LST has a positive relationship with NDBI (1987: R2 = 0.51; 2002: R2 = 0.48; and 2017: R2 = 0.4) and negative relationship with NDVI (1987: R2 = 0.24; 2002: R2 = 0.25; and 2017: R2 = 0.33). The LST increased towards sub-urban areas and LSTI was higher in the distance between 4 and 10 km. The results of this study are significant for urban planners to implement sustainable LST mitigation strategies and create a conducive living environment in Bahir Dar city.

Keywords

• LST
• Urban-rural gradient analysis
• LULC
• Landsat images