Analyzing causes of urban hotspots in Wrocław: Implications for climate-responsive cities

Urban hotspots are the points with elevated surface temperatures compared to their surroundings and are a critical component of the Urban Heat Island (UHI) effect and localized climate change. Over the past 25 years, Wrocław has experienced rapid urban development, which is one of the specific causes of hotspot formation and it is not still well explored. This study investigates the spatiotemporal dynamics of hotspots in different functional urban zones. It considers the land cover, urban form, and human activities. Landsat images from 1999 to 2023 were used to estimate Land Surface Temperature (LST) and Land Use/Land Cover (LULC) maps were created using an Artificial Neural Network (ANN). Hotspots were identified and linked to zones including urban expansion areas, commercial districts, residential zones, and transport infrastructure. Findings show that approximately 60% of hotspots are linked to the urban expansion and 20% to the commercial development. Loss of vegetation and increased built-up density were found to be the primary reasons of elevated surface temperatures. This research shows the importance of urban planning, including strategies such as expanding green spaces, implementing green roofs, and using reflective and permeable materials.