The influence of environmental factors on physiological comfort in urban green areas

Green infrastructure is increasingly recognized as a key factor in mitigating urban heat and enhancing thermal comfort, especially in cities experiencing rising temperatures due to climate change. The thermal conditions in urban parks are shaped by numerous factors, several of which are subject to seasonal fluctuations. Therefore, the study investigates how the heat exchanges between the thermal environment and the human body are influenced by spatial factors and their variation during different phases of the growing season.

The research was carried out based on measurement campaigns of the CLIMPARK project conducted in spring (2023, 2024), summer (2022, 2023) and autumn (2023) in Warsaw in 6 parks of various sizes, spatial development structures and vegetation. Weather conditions were measured at a height of 1.1 meters at 23 different locations, with measurements repeated across different seasons. After calculating the Universal Thermal Climate Index, the study tested which environmental elements had the greatest impact. Spatial indicators were calculated using data from OpenStreetMap, Bing Aerial and the topographic objects database (e.g., Ratio of Biologically Vital Area), hemispherical photos (Sky View Factor), the Tree Crown Map (tree cover), satellite products (e.g., Normalized Difference Vegetation Index, seasonal productivity) and a field inventory (vegetation types). The influence was tested for values measured at the monitoring site and within three buffers: 10, 50 and 100 meters.

The results primarily revealed the impact of direct solar radiation limitations within the park, as well as the heterogeneity of the surfaces on modifying the local bioclimate to varying degrees throughout the day. The study provides insights into the potential of green infrastructure to enhance thermal comfort in urban environments, thereby contributing to more sustainable and resilient urban planning strategies.