Exploring the relationship between urban form, land surface temperature and vegetation indices in a subtropical megacity

Abstract

Understanding the influence of different urban forms in the local microclimate can inform architects and urban planners towards a climate-sensitive design approach. Land surface temperature (LST) is an important parameter of the microclimate conditions and can be freely and globally accessed through satellite images. This study explores the relationship between daytime and nighttime Aqua/MODIS LST and the urban morphology defined by local climate zones (LCZ) in accordance with the World Urban Database and Access Portal Tool (WUDAPT) methodology. The vegetation cover from each LCZ was analyzed by the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI). Additionally, the geometric and surface properties of LCZs defined by the literature were tested against measured LSTs to explorer if expected correlations between surface properties and surface temperature could be found. The results show a strong negative correlation between LST and both NDVI and EVI. Generally, the LCZ classes with lower vegetation cover presented higher daytime and nighttime LST. Building surface fraction and impervious surfaces presented a positive correlation with nighttime LST and the pervious surface fraction presented a negative correlation with nighttime LST.