Complexity Theory in Sustainable Urban Development: A Systematic Review of Adaptive Governance, Computational Models, and Resilience Frameworks

Background The complexity of cities has been increased by urbanization, which has led to systems that are characterized by emergent behaviors, non-linear interactions, and interrelated socio-economic, environmental, and technical frameworks. These processes are frequently disregarded by conventional linear planning models, which restricts their efficacy in addressing sustainability concerns. Complexity Theory offers a conceptual and analytical framework for the understanding and regulation of urban systems as Complex Adaptive Systems (CASs).Methods In accordance with the PRISMA 2020 principles, this systematic literature review evaluated 91 peer-reviewed articles that were published between 1994 and 2024. The review incorporated qualitative narrative integration, theme synthesis, and bibliometric analysis. The data were obtained from Scopus through a comprehensive Boolean search that encompassed topics related to sustainability, urban development, and complexity science. The research was assessed through a multi-phase procedure, with inclusion criteria emphasizing the explicit application of complexity concepts to sustainable urban design.Results Five thematic domains were identified: (1) conceptualizing urban systems as complex adaptive systems, (2) employing computational methodologies such as fractal analysis and agent-based modeling, (3) establishing adaptive governance frameworks, (4) integrating sustainability across environmental, social, and economic dimensions, and (5) leveraging digital transformation within smart city frameworks. There is evidence to suggest that complexity-informed methodologies improve stakeholder engagement, adaptation, and urban resilience. Nevertheless, issues continue to exist, such as poor evaluation of trade-offs among opposing interests, regional research disparities, data limitations, and inadequate policy integration.Conclusions Complexity Theory provides a strong foundation for resilient, integrative, and adaptable urban design. Longitudinal assessment, equity-centered applications, hybrid approaches that integrate conventional and complexity-oriented methodologies, and improved representation of under-researched areas are all necessary for bridging the divide between theory and practice. This paper offers practical suggestions for policymakers, academics, and practitioners to incorporate complexity thinking into urban sustainability efforts.