Geometric and topological analysis of convergence and divergence in urban water pipeline and road networks across regions

Urban morphology strongly shapes infrastructure networks, implying that structural characteristics of water, wastewater, and electricity networks vary across cities and influence service performance. While cities in the Global South exhibit distinct morphological features, it remains unclear whether water pipeline networks in these regions differ systematically from cities in the Global North, particularly in their relationship with roads. This study therefore examines similarities and differences between road and pipeline networks in two Southern cities (Kigali, Rwanda and Kisumu, Kenya) and two Northern cities (La Rochelle, France and Vancouver, Canada). Networks were represented as dual graphs, and network global topological properties and structural similarities were measured. Spatially co-located roads and pipelines were then extracted, and total least squares (TLS) analysis used to test for regional variation in trends in centrality changes and their consistency. Within this exploratory comparative framework, results indicate that pipeline networks exhibit high similarity across both Southern and Northern cases, whereas road networks reflect regional differences. Spatial analysis revealed that in the selected southern case cities, roads and pipelines exhibited lower spatial co-location than in the northern case cities. Moreover, co-located pipeline centrality declined more rapidly from the urban centre towards the periphery in the southern case cities. Furthermore, pipeline structure is influenced by the distribution of urban communities and water facilities, producing heterogeneity that is distinct from road networks and contributes to differences observed between the two regional groups. These findings suggest the importance of accounting for regional and spatial factors when analysing urban water networks and provide a framework for further future context-sensitive infrastructure assessment.