Development and Application of a Spatiotemporal Validation Method for CFD-based Analysis of Urban Heat Island and Thermal Comfort

The intensification of urban heat islands (UHIs) has emerged as a critical urban climate issue, as high-density urban development and increased anthropogenic heat emissions lead to rising land surface temperatures. Computational Fluid Dynamics (CFD) models are widely used to analyze urban thermal environments; however, their validation has traditionally relied on point-based meteorological observations, which presents limitations for spatial verification. To address this gap, this study develops a spatiotemporal validation framework that integrates satellite-derived land surface temperature (LST) with CFD simulations. The proposed framework was applied to a 2km × 2km urban area in Gwacheon, Republic of Korea, focusing on Byeoryang-dong and Burim-dong, which are known for exhibiting high-temperature conditions. Landsat 8 LST data acquired on August 29, 2024, were processed at a 30 m grid resolution, and CFD-based roof temperature outputs were downscaled to the same grid for comparison. Spatial thermal patterns were evaluated through grid-level analysis, and model performance was assessed using coefficient of determination. The results indicate a high level of agreement between the CFD simulations and satellite-derived LST across the entire study area (R2 = 0.73, RMSE=1.71°C), demonstrating the model's ability to successfully reproduce city-scale thermal distributions with high predictive precision. Statistically significant correlations were also observed in Burim-dong (R2 = 0.54) and Byeoryang-dong (R2 = 0.42), confirming that the CFD model effectively captures intra-urban temperature variations and replicates observed thermal patterns at the administrative-dong level. The proposed validation methodology enables more reliable urban microclimate assessments and the identification of heat-vulnerable zones. Furthermore, it provides a practical approach for supporting urban planning and climate adaptation strategies by integrating CFD modeling with satellite observations.