Mapping Social Vulnerability Through Accessibility Patterns: The Istanbul Case

Abstract. Cities are essential for economic, social, and cultural life, driving innovation but also creating inequalities. Challenges like rapid growth and inadequate infrastructure lead to vulnerabilities in urban areas. This phenomenon of social vulnerability extends beyond individual sociodemographic characteristics; it is also closely tied to the quality of services provided by the living environment, spatial organization, and accessibility. Within this framework, the phenomenon of social vulnerability is not limited to the sociodemographic characteristics of individuals; it is also directly related to the services offered by the living environment, spatial arrangements, and, in particular, accessibility. This study explores social vulnerability through the lens of accessibility and socioeconomic status, using the 15-Minute City model. The Mean Shift clustering algorithm was utilized to cluster buildings and a new classification of points of interest (POIs) with 12 categories was proposed. A theoretical accessibility analysis for these POIs were conducted for each building cluster, and an accessibility index was computed. Additionally, land cover analysis was performed for each neighborhood, followed by correlation analyses between the accessibility index, land cover, and socioeconomic scores. The findings show no significant link between land cover and accessibility, but there is a strong correlation with 0.57 between access to sports facilities and socioeconomic status. Lower socioeconomic groups have limited access to fragmented areas, while higher groups reside in well-planned regions with more services. The study shows that spatial inequalities are tied to income, living standards, density, and transportation, emphasising the need for future research on social dimensions.