Cooling potential of green infrastructure: the case of the municipality of Póvoa de Varzim (Portugal)

Urban environments are increasingly affected by microclimatic changes driven by land-use transformations and climate change, particularly through the intensification of extreme heat events. This study investigates the microclimatic impacts of urban development in Póvoa de Varzim, Portugal, focusing on the influence of land use on Land Surface Temperature (LST) and the cooling potential of Green Infrastructure (GI), assessed through the Normalized Difference Vegetation Index (NDVI). The analysis was conducted in July 2022, during one of the most severe drought periods recorded by the Portuguese Institute for Sea and Atmosphere (IPMA). Results show that green areas reduced LST by up to 7ºC compared with built-up and bare soil areas. Green Space Density was the most influential predictor (21%) in the Random Forest model, which achieved a validation R² of 0.82. A strong inverse relationship between NDVI and LST was also confirmed, with 51.3% of spatial units showing significant negative linear correlations. Green spaces promote local cooling through shading, evapotranspiration, and reduced heat absorption by impervious surfaces. These findings reinforce the need to integrate GI and Nature-based Solutions (NbS) into urban planning in coastal municipalities, helping to reduce thermal stress during extreme heat events, strengthen climate resilience, and support Sustainable Development Goal 11.