Response of summer Land surface temperature of small and medium-sized cities to their neighboring urban spatial morphology

Buildings, hard surfaces, vegetation, and water bodies are the four main urban surface types in the study region that are categorized in this study. It uses summer land surface temperature (LST)1 data obtained with a spatial resolution of 1 x 1 m using thermal imaging mounted on a drone, with a case study centering on a small to medium-sized Chinese town. To assess urban spatial morphology indicators within different ranges around the sample sites, buffer zones at 30 m, 50 m, 100 m, and 150 m were developed. The study determined the effective response range, identified the important urban spatial morphology indicators influencing LST, and examined the link between summer LST and various urban spatial morphologies for the four surface types. The results show that, close to the sample locations, Natural Environment Indicators (NEI) often have a cooling effect whereas Building Indicators (BI) typically have a warming effect. The influence of spatial morphologies on summer LST was primarily centered between 30 m and 50 m from the sample sites. The primary spatial morphological indicators determining LST for various underlying surface types within various spatial ranges are the building structure index (BSI) and water surface rate (WP). The response modes, response ranges, and response intensities of LST, however, varied significantly among various underlying surface types. This work provides new insights into how urban morphological characteristics affect the fine-scale spatial variation of LST within urban heat islands (UHI).