A Practical Method for Assessing Urban Fragmentation and City-Center Dominance at the Metropolitan Scale

Cities, particularly at the metropolitan scale, tend to expand outward over time. In the long term, urban sprawl generates a range of environmental, social, and economic challenges. The physical dimension of urban sprawl manifests as urban fragmentation and loss of central strength. Accordingly, developing methods to quantify fragmentation is essential for understanding urban growth trajectories. A city’s fragmentation and outward expansion are often two interrelated phenomena that influence one another, typically accompanied by a decrease in density in the city’s central area. This study selected districts from eight different metropoles from Turkey to propose a grid-based method for creating Urban Fragmentation Index (FRAG) and Central Dominance Index (CDI). The correlation between these two variables was subsequently examined using data from eight case studies. Although the results indicated a moderate positive correlation between the two, the significance level test presented that this relationship was not statistically significant. Therefore, future studies can employ this method—which is easily applicable and repeatable in any city—using larger samples to elucidate the interplay between these two significant factors.