Urban Heat Island Dynamics in Bologna: Assessing the Influence of Urban Morphology on Air and Surface Temperatures

This study examines the influence of urban morphological indicators (UMIs) on both air temperature (AT) and land surface temperature (LST) in Bologna, Italy, utilizing a combination of mobile AT data and remotely sensed LST data. Nocturnal temperature 1 2 3 4 data were collected on March 19 and March 24, 2021 for AT and LST data, respectively. 5 UMIs, including building density, mean building height, floor area ratio, and vegetation 6 cover, were calculated to examine their effects on AT and LST, revealing distinct patterns in how structural and vegetative characteristics influence urban thermal conditions. After identifying significant associations between both temperatures and UMIs using Spearman’s 7 8 9 Rank correlation, a supervised linear regression model was applied to examine their 10 interaction effects. With building density emerging as the most influential factor, the model 11 yielded R-squared values of 0.77 and 0.79 for the test data of AT and LST, respectively. The 12 study provides a nuanced understanding of UHI dynamics in Bologna, offering valuable 13 insights for urban planners and policymakers seeking effective strategies to reduce urban 14 temperatures and enhance urban resilience.