Land Surface Temperature Variation in Response to Land-Use and Land-Cover Dynamics: A Case of Didessa River Sub-basin in Western Ethiopia

Land surface temperature (LST) estimation at the River sub-basin level is crucial for developing land-use planning at basin scale and beyond. The present study aims to analyze the LST variations in response to land-use and land-cover (LULC) dynamics in the case of Didessa River Sub-basin, Western Ethiopia using geospatial techniques. We used Landsat 5 Thematic Mapper (1991), Landsat 7 Enhanced Thematic Mapper Plus (2003), Landsat 8 Operational Land Imager (OLI), and Thermal Infrared Sensor (TIRS, 2020). Moreover, meteorological data (1991-2020) of seven stations, namely, Sire, Nekemte, Arjo, Limu Genet, Atnago, Agaro, and Yayu, were obtained from National Meteorological Agency to validate the LST with air temperature. Our results reveal that the cultivated land in the study area increased by 1180 km(2) (22.5%), while grassland and forest cover were declined by 828.7 km(2) (15.8%) and 444.1 km(2) (8.5%), respectively over the past 29 years. These land-cover dynamics contributes for the increasing trend of LST in the study area. The study also analyzed relationship of LST with normalized differences in vegetation index and air temperature. Maximum-likelihood classification methods were used for LULC classification, while the LST data were retrieved from Landsat image. The results indicate that the LST has been increasing since 1991 in reaction to LULC dynamics. Within the sub-basin, high LST values were recorded on bare land and settlement land use followed by cultivated land cover, while forest and water body experienced the lowest LST. This study will contribute in understanding of impact of LULC dynamics on the local climate and would further provide assistance to the policy makers in regard to land-use planning and climate change mitigation strategies.

Automated summary

The present study analyzed the variations in land surface temperature (LST) in the Didessa River Sub-basin, Western Ethiopia in response to land-use and land-cover dynamics. The results showed an increasing trend of LST over the past 29 years, which was influenced by changes in land cover. The study also revealed the relationship between LST, normalized differences in vegetation index, and air temperature.