Greenness visibility in urban living environments as pathway to promote health and well-being: Mapping spatial differentiation in Flanders (Belgium) based on viewshed analysis

A substantial body of evidence links green space to positive health outcomes. Beyond the availability of dedicated green spaces such as parks and the overall presence of vegetation and trees, visual exposure to greenery has also been shown to be important for well-being. Enhancing visual access to greenery may thus represent a pathway to promoting health and well-being. However, at regional or national scales, insights into disparities in visual access to greenery remain scarce. Most research and policy efforts rely on two-dimensional (top-down) data, which often fails to accurately capture the amount of greenery visible from individual perspectives, such as from within homes.

This study builds on the work of Labib et al. [20], who developed a high-resolution (5 m grid) Viewshed Greenness Visibility Index (VGVI) for the Greater Manchester area (UK). By introducing technical improvements that significantly increased computational efficiency, we extended this approach to create a comprehensive VGVI map for Flanders, the northern region of Belgium. The resulting map enabled a broad assessment of VGVI disparities across Flanders. Our findings reveal evidence of distributive environmental injustice, as demonstrated by a strong negative correlation (Spearman's Rho = -0.48) between neighbourhood deprivation levels and VGVI scores. In Flanders, residents of more deprived neighbourhoods are exposed to significantly lower levels of visible greenery.

We further explored the differences and similarities between traditional top-down greenness mapping and VGVI, which provides an eye-level perspective. Although a strong positive correlation was observed at the regional scale (Pearson's r = 0.80), this relationship weakens at the local level. Our findings suggest that VGVI analysis is particularly valuable at smaller geographic scales, making it especially relevant for research or spatial policies that address disparities in individual living conditions or target specific locations, such as schools, nurseries, hospitals, retirement homes, and community centres.