Exploring the relationship between thermal environmental factors and land surface temperature of a “furnace city” based on local climate zones

Numerous studies have explored multiple factors that affect the urban thermal environment. Most current studies focus on establishing the holistic quantitative relationships between the characteristics of urban thermal environmental factors and land surface temperature (LST), but less attention has been given to exploring urban subdivisions in detail. The local climate zone (LCZ) system has been proven effective in establishing the quantitative relationships between urban climate and spatial factors, thereby revealing the characteristics of LST spatial variations. This study utilized the random forest regression model to analyze the relative importance and marginal effects of the urban thermal environmental factors on seasonal LSTs based on the whole study area and the LCZ-derived built type area of Fuzhou city, known as a “furnace city” in southeastern China. The results show that: (1) Building morphology and spatial distribution exert a significant impact on LST, with the LST levels of different building forms ranked as open < compact and high-rise < mid-rise < low-rise. (2) Landscape composition exhibits the greatest influence on seasonal LSTs in the whole study city. (3) Building morphology emerges as the most influential category for LST in the LCZ built type area, with the standard deviation of building height having the highest relative importance at approximately 34%. (4) Concentrated compact low-rise self-built houses experience higher temperatures and should be a focus for future urban renewal efforts. We believe that these findings provide quantitative insights for urban heat island analysis and have substantial implications for climate-friendly urban planning.