Exploring the influence of urban morphology on summer daytime and nighttime LST based on SDGSAT-1

Understanding the spatial and temporal variations of land surface temperature (LST) and its influencing factors is crucial for improving the urban thermal environment and promoting sustainable urban development. However, few studies have explored the impact of urban morphology on daytime and nighttime LST. Therefore, this study utilizes SDGSAT-1 data to investigate the influence of multi-dimensional urban morphology on summer daytime and nighttime LST. The results indicate that higher LST during daytime is primarily concentrated in low-rise, high-density urban blocks, whereas higher LST during nighttime is more prominent in high-rise, high-density blocks. Correlation analysis and the importance evaluation of the random forest (RF) regression model reveal that 2D spatial morphology exhibits a stronger correlation with daytime LST (|p| > 0.45), contributing over 50%. In contrast, 3D building morphology shows a higher correlation with nighttime LST (|p| > 0.2), contributing more than 60%. Further analysis using the multi-scale geographic weighting regression (MGWR) model highlights significant spatial heterogeneity in the impact of urban morphology on summer daytime LST, demonstrating that MGWR outperforms global models in capturing spatial variations of LST. These findings provide a scientific foundation for guiding future urban development, particularly in formulating differentiated planning strategies to mitigate urban heat stress.