Onačillová et al. (2026) Local climate zones and diurnal surface heating in a Central European city: A comparison of Landsat, ECOSTRESS, and ENVI-met with in situ measurements in Košice (Slovakia)

Identification

• Journal: Remote Sensing Applications Society and Environment
• Year: 2026
• Date: 2026-01-01
• Authors: Katarína Onačillová, Tomáš Fedor, Michal Gallay, Ján Šašak, Jozef Bogľarský, Ján Kaňuk, Nikola Salajová
• DOI: 10.1016/j.rsase.2026.101933

Research Groups

• Institute of Geography, Faculty of Science, Pavol Jozef Šafárik University in Košice, Slovakia
• PHOTOMAP, s.r.o., Košice, Slovakia
• Stengl a.s., Bratislava, Slovakia

Short Summary

This study investigated how Local Climate Zones (LCZ) modulate land surface temperature (LST) and the surface urban heat island (SUHI) in Košice, Slovakia, using a multi-sensor and multi-scale framework. It found that compact and impervious urban zones exhibit the highest LST and SUHI intensities, up to 15 °C warmer than vegetated areas, providing a transferable workflow for assessing SUHI dynamics and informing targeted cooling measures in Central European cities.

Objective

• To produce a 10 m Local Climate Zone (LCZ) map for Košice using a hybrid Geographic Information System (GIS) and remote sensing (RS) workflow.
• To quantify LCZ-specific Land Surface Temperature (LST) and Surface Urban Heat Island (SUHI) by leveraging Landsat for intra-urban spatial heterogeneity and ECOSTRESS for diurnal dynamics during summer 2022, distinguishing heat-wave and non–heat-wave periods.
• To diagnose microclimate mechanisms, including air temperature (T-air) profiles and ventilation, using ENVI-met simulations, linking responses to LCZ morphology.
• To compare satellite-derived and modelled thermal signals (LST and T-air) with data from in situ loggers and meteorological stations to evaluate consistency, identify biases, and highlight limitations.

Study Configuration

• Spatial Scale: Košice, Slovakia (approximately 242 km²), with a 10 m LCZ map, 70 m ECOSTRESS LST, and 30 m Landsat LST (thermal bands 100 m resampled to 30 m).
• Temporal Scale: Summer 2022 (June–August), focusing on heat-wave (26 June–1 July, 3–5 July, 20–23 July, 16–19 August) and non–heat-wave conditions.

Methodology and Data

• Models used: ENVI-met microclimate model.
• Data sources:
  • Satellite: Landsat-7 Enhanced Thematic Mapper Plus (ETM+), Landsat-8/-9 Thermal Infrared Sensor (TIRS) (Collection-2 Level-2 Surface Temperature products), ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) (Level-2 Land Surface Temperature and Emissivity products).
  • Observation: In situ surface temperature measurements from Comet Pt1000TG7 sensors at six sites, and official surface synoptic meteorological observations (SYNOP) from Košice Airport.
  • GIS/Ancillary: 10 m Local Climate Zone (LCZ) map generated using a hybrid GIS–RS workflow, ESA WorldCover 2021, airborne LiDAR-based building-height layer, digital elevation products (Digital Surface Model (DSM) and Digital Terrain Model (DTM)), orthophoto imagery, and Urban Atlas 2018.

Main Results

• The LCZ classification map for Košice achieved an overall accuracy of 89.07% and a Kappa coefficient of 0.88.
• Compact and impervious LCZs, such as industrial zones (LCZ 10), large low-rise (LCZ 8), and compact mid-rise (LCZ 2), consistently showed the highest LST and SUHI intensities, reaching up to 15 °C warmer than vegetated classes.
• Tree-dominated LCZs (LCZ A) and water bodies (LCZ E) consistently exhibited the lowest LST values, acting as significant cooling elements.
• The average SUHI intensity across all LCZ types increased from approximately 2.88 °C during the pre–heat-wave period (22–25 June) to 3.57 °C during the heat-wave days (26 June–1 July), indicating an amplification effect of extreme heat.
• Satellite-derived LST patterns showed broad spatial consistency between ECOSTRESS and Landsat, although ECOSTRESS tended to underestimate extreme surface temperatures and smooth fine-scale heterogeneity.
• Comparison with in situ measurements yielded Root Mean Square Error (RMSE) values between 8 °C and 15 °C and mean bias error (MBE) between -3 °C and -9 °C, with moderate positive but non-significant correlations (e.g., ECOSTRESS r = 0.47, R² = 0.22, p = 0.34; Landsat-8 r = 0.34, R² = 0.12, p = 0.51).
• ENVI-met simulations revealed persistent early-morning thermal stability and weak ventilation in compact historical and mid-rise districts, consistent with elevated nocturnal heat retention and strong vertical temperature gradients.

Contributions

• This study provides one of the first diurnally resolved, multi-source assessments of SUHI in a Central European mid-size city, integrating satellite observations, microclimate simulations, and in situ measurements.
• It offers a transferable workflow for assessing SUHI dynamics in mid-sized Central European cities, bridging a regional gap in fine-scale, diurnally resolved SUHI analysis.
• The research provides evidence for targeting cooling measures in compact, highly impervious LCZs and supports heat-aware urban planning by linking urban morphology and land cover to surface thermal behavior.
• The study's strengths include the integration of Landsat's spatial detail with ECOSTRESS's sub-daily sampling, the use of a high-resolution (10 m) LCZ framework, independent in situ thermal observations, and ENVI-met simulations for microclimatic interpretation.

Funding

• Slovak Research and Development Agency (APVV) under contract No. APVV-23-0210: Urban Overheating: Consequences, Mitigation and Perception.
• Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, the Slovak Academy of Sciences (VEGA) under contract No. 1/0780/24.
• Cultural and Educational Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic (KEGA) under contract No. KEGA 023UPJŠ-4/2025: Remote Sensing Education with a Focus on Satellite and Unmanned Aerial Platforms – Development of a Textbook and Online Educational Resources.

Citation

@article{Onačillová2026Local,
  author = {Onačillová, Katarína and Fedor, Tomáš and Gallay, Michal and Šašak, Ján and Bogľarský, Jozef and Kaňuk, Ján and Salajová, Nikola},
  title = {Local climate zones and diurnal surface heating in a Central European city: A comparison of Landsat, ECOSTRESS, and ENVI-met with in situ measurements in Košice (Slovakia)},
  journal = {Remote Sensing Applications Society and Environment},
  year = {2026},
  doi = {10.1016/j.rsase.2026.101933},
  url = {https://doi.org/10.1016/j.rsase.2026.101933}
}