Coupled effects of land use, spatial configuration, and energy fluxes on thermal resilience in mild-climate cities
摘要
With extreme climate events becoming more frequent, strengthening thermal resilience in urban outdoor spaces has emerged as a priority for the built environment and spatial planning. Using Kunming (a temperate-climate city) as a case study, we first track the co-evolution of temperature and humidity along micro-scale transects. In 2024, disturbance-prone segments exhibited concurrent amplification of thermal and humidity variability (ΔT ≈ 1 °C; ΔRH = 3.59%), indicating that thermal response can serve as a practical proxy for coupled thermal–humidity fluctuations. We then investigate how land-cover composition and spatial configuration regulate surface energy exchange and, in turn, microclimate resilience. Results show that resilience depends less on land-cover shares per se than on the partitioning and spatial coupling of latent (LE) and sensible (H) heat. Higher-resilience segments show lower TSI values (0.131–0.149), stronger radiative cooling potential (ε/α > 5), and limited subsurface energy loss (Gratio ≈ 0.04), consistent with enhanced diurnal buffering; in the most buffered segment, ΔT remained below 0.32 °C. By contrast, fragmented green–blue patches and their proximity to high-sensible-heat surfaces (bare ground and built-up areas) erode cooling performance during heatwaves and sharpen intra-segment thermal contrasts. Landscape metrics further suggest that compact, regularly shaped, and evenly distributed patches support resilience, whereas fragmented, aggregated, and irregular configurations increase vulnerability under extreme heat.