Predictive assessment of urban comfort and cumulative heat exposure for climate-resilient district regeneration

Urban overheating increasingly threatens quality of life, demanding predictive tools for climate-resilient planning. This study presents an assessment framework, validated against in-situ temperature measurements, integrating remote sensing, GIS urban modelling, and CFD microclimate simulation to evaluate neighbourhood-scale heat mitigation interventions before implementation. The workflow is sequential: diverse-sources open datasets are processed in GIS to derive urban morphology and properties, translated into a three-dimensional CFD domain, and returned to GIS as hourly rasters for spatial and statistical analysis. The approach introduces cumulative thermal stress metrics, quantifying total daily hours exceeding severe heat thresholds, computed as the hourly count of UTCI values above 32 °C, advancing beyond conventional snapshot-based evaluations. Applied to a thermally vulnerable neighbourhood in Seville, Spain, three scenarios were comparatively assessed: baseline conditions, reflective materials intervention (higher albedo), and combined reflective materials with urban greening. High-resolution spatiotemporal analysis reveals that reflective materials alone reduce air temperature (~ 1.25 °C peak reduction) but worsen daytime outdoor comfort through increased radiant heat. Combined interventions prove essential, achieving localised UTCI reductions exceeding 7 °C, improving daytime comfort over 86% of the district with respect to reflective materials alone, and cumulative reductions of 2–4 h in daily severe thermal stress exposure. By translating microclimate simulation into exposure metrics that municipalities can act upon, this predictive framework supports the prioritisation of interventions in vulnerable districts of Mediterranean and similar climates, where reducing heat exposure advances inclusive and resilient cities (SDG 11), urban climate action (SDG 13) and the reduction of inequalities (SDG 10) through the same measure.