Simulating land surface temperature using biophysical variables related to building density and height in Dar Es Salaam, Tanzania

Abstract

Land use and land cover dynamics are pivotal to communicating land surface temperature (LST) scenarios. This study characterises the influence of biophysical variables on LSTs in the Dar es Salaam Metropolitan City (DMC). Landsat images were analysed using geographically weighted regression (GWR) and ordinary least square (OLS) models to determine biophysical variables (soil adjusted vegetation index, normalized difference built-up index, and normalised difference bareness index) and LST relationships. The GWR analysis resultsrevealed that LST had a weak to strong negative correlation with the soil adjusted vegetation index, a moderate positive correlation with normalized difference built-up index, and a low positive correlation with the normalised difference bareness index. GWR predicted LST better than OLS, with coefficient of determination -R2 values of 55%, 80%, and 62% for 1995, 2009, and 2017, respectively. In addition, higher model residuals values were observed in high building density compared to low building density areas. This study provides a broad understanding of the biophysical variables’ impact on LST in DMC and provides reference for site-specific urban land-use planning and designing strategies for LST mitigation.