Integrating Expert Assessments and Spectral Methods to Evaluate Visual Attractiveness and Ecosystem Services of Urban Informal Green Spaces in the Context of Climate Adaptation

This study aimed to develop criteria for the expert assessment of the visual attractiveness of informal urban green spaces and compare these results with indicators derived from spectral indices and geospatial data. The research was conducted in Lublin, Poland, a medium-sized European city. The expert assessment evaluated the overall attractiveness, naturalness, landscape contrast, and uniqueness. The results were juxtaposed with spectral indices, such as the Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), and land surface temperature, which were calculated for the target areas and a 300 m buffer surrounding them. The analyses revealed strong correlations between the expert ratings and spectral indices. For example, overall attractiveness was linked to lower temperatures, while landscape contrast exhibited a relationship with temperature differentials. Moreover, areas with greater landscape contrast showed larger index differences between the site and the buffer. Positive correlations were also observed between attractiveness and land slope. Importantly, the spectral indices highlighted the ecological value of some sites that received lower expert assessments, such as areas dominated by shrubs and bushes. This research introduces the concept of ‘enchanted natural places’ (ENPs) as a framework for identifying and formalizing the protection of visually and ecologically valuable, informal green spaces. The integration of expert evaluations with spectral data provides a novel, robust methodology for assessing urban green spaces, bridging subjective perceptions and objective environmental indicators. This approach underscores the importance of informal green spaces not only for aesthetic and ecological benefits but also for supporting biodiversity and mitigating urban heat islands, contributing to urban resilience in the face of climate change.