Generalization of GIS data as a tool supporting the understanding of the urban heat island effect. Case study of the city of Wrocław based on design experience

The article presents how various urban factors influence the urban heat island (UHI) effect and explores the correlations between these factors. The authors attempts to verify the potential of using data in Geographic Information System (GIS) analyses to study the urban heat island effect, and in further research to analyze the assess to nighttime cooling potential in the city, using Wrocław as a case study. The study utilized Landsat 8 satellite imagery and spatial data on greenery and built-up areas to analyze their impact on radiative temperature. The proposed method simplifies and calibrates data, enabling comparison of different areas. It also allows for the analysis of relationships between the values of various factors within a single grid cell or study area. This approach helps identify areas across the entire city with similar factor combinations and compare their temperature distributions. GIS analyses enable examination of neighboring areas and identification of other factors influencing variations in radiative temperature. The research presents how individual factors affect ambient temperature. Building density and height significantly increase radiative temperature, whereas the presence of water and greenery, especially in large amounts, has a cooling effect. To assess temperature distribution differences in urban spaces, four locations in Wrocław were compared based on building intensity and greenery levels: Przedmieście Oławskie, Przedmieście Świdnickie, Plac Grunwaldzki, and Olimpia Port. Results indicate that despite the presence of a river, Przedmieście Oławskie has the highest radiative temperaturę due to dense building and low greenery. In contrast, Olimpia Port, with the lowest building density and highest greenery, is the coolest area. The aim of the research is to indicate the representative areas in urban tissue, where further research measuring the local air temperature can be implemented. Future stages of the project plan to include additional factors such as air flow, impermeable surface area, and building materials to further investigate the impact of urban planning on ambient temperature.