07-17, 14:30–14:35 (Europe/Sarajevo), PA01
Urban Heat Islands (UHI) represent an increasing challenge in cities worldwide, including smaller urban centres such as Varaždin, Croatia. This study analyses UHI dynamics over a Varaždin city during a ten-year period (2014–2024) using exclusively Free and Open-Source Software (FOSS) and publicly available Earth Observation (EO) data. Landsat 8 thermal imagery was used to calculate Land Surface Temperature (LST), and to analyse its relationship with vegetation cover through the Normalized Difference Vegetation Index (NDVI) and the Proportion of Vegetation (PV). Urban expansion was examined using the Normalized Difference Built-up Index (NDBI). All indices were derived from multispectral and thermal bands using QGIS 3.24 and Python 3.12 libraries including GDAL, rasterio, NumPy, and Matplotlib. The results show a measurable increase in surface temperature, with the average LST rising by +4.41 °C, accompanied by a loss of 3,230 pixels in the dense vegetation class (NDVI > 0.4). Simultaneously, NDBI values indicate expansion of built-up areas across the southern and eastern parts of the city. These changes confirm the spatial transformation towards the urbanization and reduced vegetation cover as main cause of local thermal intensification. This study gives a standardized, open-sourced, transparent and reproducible analysis applicable to other medium-sized cities. The study also explores the potential integration of additional EO sources (Sentinel-3, MODIS, VIIRS) and supporting geospatial data (OpenStreetMap) for enhanced spatiotemporal resolution. The findings highlight the value of FOSS tools and open data in supporting evidence-based urban climate planning and advocate for scalable, cost-effective approaches to UHI mitigation through green infrastructure and adaptive design.
Landsat 8 (USGS Earth Explorer) for EO data
QGIS for spatial analysis and visualization
2 - background knowledge helpful
Give indication of resources (video, web pages, papers, etc.) to read in advance, that will help get up to speed on advanced topics. –Weng, Q. (2009). Thermal infrared remote sensing for urban climate and environmental studies: Methods, applications, and trends. ISPRS Journal of Photogrammetry and Remote Sensing, 64(4), 335–344.
Oke, T. R. (1982). The energetic basis of the urban heat island. Quarterly Journal of the Royal Meteorological Society, 108(455), 1–24.
Weier, J., & Herring, D. (2000). Measuring Vegetation (NDVI & EVI).
NASA Earth Observatory. https://earthobservatory.nasa.gov/features/MeasuringVegetation
Roy, D. P., et al. (2014). Landsat-8: Science and product vision for terrestrial global change research.
Remote Sensing of Environment, 145, 154–172.
Kalogeropoulos, K., et al. (2022). Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City. Atmosphere, 13(7), 1102.
Zha, Y., Gao, J., & Ni, S. (2003). Use of normalized difference built-up index in automatically mapping urban areas from TM imagery. International Journal of Remote Sensing, 24(3), 583–594.
Data processing and analysis, Data visualization, FOSS4G for land use planning, land management, monitoring, smart cities, population mapping, FOSS4G and environmental observations
I make my conference contribution available under the CC BY 4.0 license. The conference contribution comprises the abstract, the text contribution for the conference proceedings, the presentation materials as well as the video recording and live transmission of the presentation – yesSanja Šamanović was born on January 30, 1970, in Požega. She graduated from the Faculty of Geodesy, University of Zagreb, in 1997 and defended her doctoral thesis in 2014.
Until 2018, she worked at the Faculty of Geodesy, Department of Photogrammetry and Remote Sensing, where she taught courses related to GIS and Photogrammetry. She participated in all technological and scientific projects of the department during her employment. Throughout her career, in teaching, research, and professional work, her areas of interest have been GIS, remote sensing, and photogrammetry, within which she continuously explores new scientific achievements, following their development and application in science, industry, and everyday life. Since 2021, she has been employed at University North, Department of Geodesy and Geomatics, as an assistant professor.