Evaluating policy effectiveness and equity of access to urban green spaces in Karaj, Iran (2007–2017): a fine-grained G2SFCA analysis

Purpose This study evaluates the effectiveness and equity of urban green space (UGS) accessibility policies implemented in Karaj, Iran, from 2007 to 2017. It investigates whether these policies achieved their intended goals of equitable access to UGSs and identifies areas of success and failure, focusing on spatial and demographic factors influencing inequality. Design/methodology/approach A fine-grained building block scale analysis was conducted using the Gaussian-based Two-Step Floating Catchment Area (G2SFCA) method to assess pedestrian and car accessibility to UGSs. Equity was measured using the Gini coefficient, Palma ratio, Foster–Greer–Thorbecke indices and Bivariate Local Moran's I, enabling the identification of spatial clusters where population growth coincided with declining accessibility. Findings Results reveal a 32% and 39% improvement in pedestrian and car accessibility, respectively, from 2007 to 2017. However, significant inequality persists, with 60% of UGS accessibility concentrated among 20% of the population. Pedestrian accessibility exhibited a more equitable geographic distribution than car accessibility. Key policy goals, including increasing per capita green space and preserving agricultural land, remain unmet due to land speculation, rapid urbanization, and unstable municipal finances. Research limitations/implications The study is limited by the lack of data on demographic variables such as income and ethnicity, and does not assess the qualitative aspects of UGSs. Future research could incorporate these factors for a more comprehensive analysis of UGS accessibility equity. Practical implications Recommendations include adopting sustainable financial models, such as green taxes and public–private partnerships, revising zoning policies to prioritize high-inequality clusters and enhancing the quality of existing UGSs to mitigate spatial and demographic disparities. Social implications Equitable access to UGSs is essential for promoting public health, social cohesion and environmental justice. Addressing inequalities in UGS accessibility can contribute to more livable and inclusive urban environments. Originality/value This study offers a longitudinal evaluation of UGS accessibility policies in a Middle Eastern context, contributing to the underexplored area of UGS equity in developing countries. The findings emphasize the importance of sustainable urban financial systems, equality-focused planning and quality improvement of existing UGSs to address spatial and demographic disparities.