Assessing thermal comfort dynamics through the urban fragmentation approach: a case study of the hot and arid metropolitan of Tabriz

Urban growth modifies both land-use composition and spatial structure, thereby reshaping urban thermal environments and human thermal comfort. However, the influence of spatial configuration and fragmentation on urban thermal responses remains poorly understood. This study investigates how land-use change and urban fragmentation (FI) affect land surface temperature (LST) and discomfort index (DI) across Tabriz between 2000 and 2023. Results indicated that structural consolidation in infill-dominated areas reduced fragmentation, whereas peripheral areas remained highly fragmented. Landscape metrics indicated that greater aggregation of built-up areas was associated to thermal conditions, whereas dispersed development sustained thermal heterogeneity. Positive association was found between thermal stress and subdivision-isolation metrics, whereas negative relationship with aggregation metrics. These findings demonstrate a shift towards configuration-driven urban thermal dynamics, emphasizing that spatial consolidation and reduced fragmentation are critical for mitigating persistent urban heat stress. The results provide actionable insights for climate-responsive urban planning and the design of thermally resilient urban landscapes.