Examining the Role of Local Climate Zones in Urban Heat Island Assessment Using Remotely-Sensed Data

More than half of the world population resides in urban areas where the urban heat island (UHI) effect enhances heat-related hazards. To mitigate the impacts of rising temperatures, it is necessary to develop tools to help public administrators formulate strategies to reduce heat exposure, increase access to cooling, and modify building design. We used Google Earth Engine's Landsat archive to classify local climate zones (LCZ) that consist of ten urban and seven non-urban classifications of land cover. To examine the influence of urban morphology on the surface energy balance (SEB) in high-density, medium-density, and low-density urban regions over one annual cycle, we used Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) and normalized difference vegetation index (NDVI) products. We used the triangle method to examine variability in energy balance partitioning in relation to urban density. As urban density decreases, the variation of evapotranspiration increases. These results indicate that variations in the SEB can be detected using the LCZ classification method. The results from analysis in Fr-LST space of the annual cycles over several years can be used to detect changes in the SEB as urbanization increases.