Equitable accessibility of public open spaces: a comparison of measurement methods in metropolitan area of Izmir, Türkiye

Abstract

The accessibility of public open spaces (POS) is assessed by comparing the characteristics of these spaces with the population characteristics across various urban units. Known as "equity mapping" of POS, this method identifies and addresses spatial inequities and environmental justice issues related to POS accessibility. However, research in this area has advanced further in countries with data availability at small spatial scales (e.g. census tracts), enabling the measurement of accessibility within walking distances. To address the challenges of conducting research in data-limited contexts, this case study in Izmir (T & uuml;rkiye) investigates which spatial analyses can facilitate the development of a comprehensive equity mapping of POS accessibility. T & uuml;rkiye has demographic data available at the neighbourhood level, including age, gender, and education, but lacks data on income, race/ethnicity, and other characteristics commonly used in mainstream research. This paper assumes that children, the elderly, and low-education groups (a proxy for income level) have a greater need for POS. It explores three forms of overlay analyses: feature-based, raster-based, and fishnet-based. Additionally, it examines the metropolitan area and its sub-regions as terrains with different POS accessibility. The results highlight the Centre as having the weakest POS accessibility in neighbourhoods with high child ratios and low education levels. The fishnet-based density analysis offers a finer lens for identifying the locations of priority areas for POS provisioning, even within neighbourhoods. HIGHLIGHTSFor improving public open space (POS) accessibility, GIS-based measurements of physical and social data can determine priority areas in the cityPOS accessibility measurements in mainstream research use certain data and spatial units unavailable in data-limited countriesIn data-limited countries, the grid-based density analysis can provide more accuracy about priority areas for POS planningTaking the city with sub-regions of different POS accessibility helps with determining priority areasIzmir's central city and neighbourhoods with high child ratios and low education levels have the weakest POS accessibility