Polycentric Morphology and Urban Resilience: AI-Based Assessment of Infrastructure Vulnerabilities in Colombo, Sri Lanka

Vollständiger Abstract

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Abstract Polycentric urban development is increasingly promoted as inherently resilient spatial strategy for rapidly urbanising Global South megacities. However, limited empirical evidence demonstrates how distributed morphology actually shapes disaster vulnerability, particularly regarding infrastructure interdependencies within polycentric configurations. This research develops and tests the “Polycentric Vulnerability Paradox” framework, examining how distributed urban form simultaneously creates resilience advantages through redundancy and resilience challenges through coordination complexity and inter-centre dependencies. The study provides first systematic AI-based infrastructure vulnerability assessment of polycentric configuration in South Asian context. An AI-based Urban Morphological Quantification Framework integrating K-nearest neighbour algorithms, neural networks, and XGBoost ensemble methods analyzes Colombo’s 551.52 km² metropolitan area (9,414 grid cells, 400 m resolution) using OpenStreetMap data. Network analysis identifies polycentric centres, inter-centre connectivity patterns, and critical vulnerability nodes. Processing time: 30 min versus 8–10 h for traditional methods. Analysis identified six distinct polycentric centers spanning 18 km, with 847 critical corridor segments (12.3% of road network) whose failure would disrupt inter-centre connectivity. Vulnerability concentrates at inter-centre connection points rather than centre cores, supporting theoretical proposition. Model accuracy: 73% overall, 78% spatial concordance with historical flood events. Population exposure distributes across multiple centres (68% within/adjacent to six centres) creating paradoxical patterns where single-centre disasters impact maximum 18% of population yet city-wide hazards affect majority despite spatial distribution. Polycentric morphology generates neither uniform resilience nor uniform vulnerability but paradoxical patterns where advantages and challenges coexist, with net effects contingent on infrastructure quality and governance capacity. Distributed urban form requires distributed coordination capacity; otherwise morphological complexity amplifies rather than reduces disaster vulnerability.