Satellite-Based Assessment of Urban Green Infrastructure under Compound Heat Stress in the City of Trnava, Slovakia

Urban areas are increasingly exposed to compound hydrometeorological extremes, particularly combinations of heat waves and moisture anomalies, which strongly affect vegetation vitality and urban microclimate. Urban green infrastructure represents a key adaptation measure; however, its performance under compound stress conditions requires systematic evaluation at the local scale.

This study assesses the response of urban vegetation and surface thermal patterns to compound heat-related stress in selected public spaces within the city of Trnava (Slovakia) using satellite-derived indicators. Multispectral satellite imagery from Sentinel-2 and Landsat missions was used to derive the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST), serving as proxies for vegetation condition and surface heat load. The data were subjected to spatially explicit processing and comparative analysis to identify patterns of vegetation vitality and cooling effects across different urban surface types.

The analysis focuses on periods characterized by elevated temperatures combined with limited moisture availability, representing typical compound stress conditions in urban environments. The results reveal pronounced spatial variability in vegetation resilience and cooling efficiency, highlighting the importance of vegetation structure, coverage, and spatial configuration in mitigating urban heat. The findings demonstrate the applicability of satellite-based approaches for evaluating nature-based solutions and provide practical implications for urban climate adaptation, green infrastructure planning, and the design of climate-resilient public spaces in medium-sized cities.

Acknowledgements

This work was supported by the Slovak Research and Development Agency, under the contract No. APVV-23-0332; VV-MVP-24-0208, and the VEGA grant agency under contract No. VEGA 1/0577/23 and VEGA 2/0115/25 and Programme for Motivation and Support for Increasing the Quality and Efficiency of Scientific Research Activities of Young Scientific Researchers (project name: COMPLANT)