Accessibility to Urban Green and Blue Spaces: An Experimental Methodological Approach

To measure access to public Urban Green and Blue Spaces (UGBS) at a high level of spatial detail, this paper develops an integrated methodology combining high-resolution building-level population distribution, network routing models and localized environmental data. Accessibility to UGBS is defined according to the World Health Organization (WHO) indicator, which measures accessibility as the proportion of inhabitants living within 300 metres of a green area of at least 0.5 hectares. The methodology identifies residential buildings and distributes population among them using an area-weighted dasymetric mapping approach. These procedures were performed in a GIS environment and preliminarily applied to the case study of Casalecchio di Reno, Italy. The framework relies on official administrative datasets, complemented by satellite imagery for identifying public UGBS. Implementing the framework within a WebGIS platform could facilitate access, visualisation, and cross-referencing while supporting data sharing and collaboration with local administrations to validate, refine, and update UGBS layers and related access points through editing functionalities. Future developments will focus on improving the accuracy of accessibility and building-level population estimates by refining building and UGBS access information, incorporating building height information and integrating additional spatial indicators such as tree canopy cover.