Urban Heat Island and Extreme Heat in Portuguese Cities of Tâmega and Sousa: A Comprehensive Study on Climate Change Impacts

This research investigates the increasing frequency of extreme heat events in Continental Portugal, exacerbated by the Urban Heat Island (UHI) effect. UHI, characterized by distinct microclimatic conditions in urban areas compared to rural ones, leads to higher temperatures due to the accumulation of thermal load from buildings, pavements, and asphalt. This exploratory study, focusing on Penafiel and Marco de Canaveses in the NUTS III Tâmega and Sousa, aims to assess the susceptibility to extreme heat since the early 2000s. The objectives include evaluating extreme climate events, analyzing Landsat satellite images from 2000 to 2020, and contextualizing adaptation policies, particularly within the LIFE Climate Action program. Following the problem definition and objectives, the methodology involves a narrative review to gather relevant concepts and a quantitative approach to collect and process climatic-meteorological data from satellite images. Satellite images from Landsat are processed in ArcMap software. The findings indicate that cities like Marco de Canaveses and Penafiel, along with heavily industrialized municipal areas, experience higher temperatures than rural areas, confirming the impact of UHI. These areas coincide with higher exposure to risk due to larger populations and economic activities. Results indicate a significant increase in surface temperatures in both municipalities over the past two decades, with 2020 being particularly noteworthy for moderate to extreme heat levels. The most extreme conditions are observed in urbanized areas with artificialized land use, such as industrial and residential expansions along major communication routes. Extreme heat, a consequence of global warming linked to climate change, poses significant challenges for contemporary societies. Even with various climate models and CO2 emission scenarios, organizations like the IPCC predict more frequent and severe heat events. In response to this scenario, various political levels have developed climate adaptation plans. However, these efforts, especially concerning extreme heat events, lack specificity at the municipal level. The study recommends strengthening these efforts, incorporating Nature-Based Solutions. Strategic actions for mitigation and adaptation are proposed to counter observed trends.