Modeling the Expansion of Urban Green Infrastructure: A GIS-Based Approach to Park Accessibility in Niš

<p>Provision of equitable access to available urban green spaces is one of the key elements for promoting environmental justice as well as well-being among the population in urban areas. This research introduces a spatial model for park-network extension in Niš, based on an analysis of accessibility focused on network-based methodologies and GIS-based spatial decision support. The paper considers three scenarios of service area estimation for: 1) existing parks, 2) parks defined by General Urban Plan 2010-2025 (GUP), and 3) identified free parcels that could become grounds for developing new parks. Accessibility analysis is conducted for two cases: 1) considering built-up areas, and 2) population distribution. An 800-meter walking distance is accepted as a threshold boundary, the standard threshold measure for park accessibility considering maximization of environmental and socio-cultural ecosystem services. The findings indicate that existing and GUP-planned parks offer considerable potential for the improvement of urban life since almost 60% of the built-up area in the study area contains a park in proximity of 800 m, however, even though physical coverage reveals considerable beneficial change, the accessibility analysis about population points to social inequality in the planned spatial distribution of parks, where a significant share of the population remains without a park >1.5ha within 10 minutes' proximity. The outcome is a replicable model of analysis for park accessibility and expansion, which offers a systematic framework to urbanists for strategic augmentation of their green infrastructure systems. </p>