A Framework for Spatial Resilience in Urban Floodplain Systems

Thesis Abstract

Urban floodplain systems in rapidly expanding metropolitan regions face increasing flood risk, ecosystem degradation, and social vulnerability due to folded interactions between urban expansion, climate variability, and limited green infrastructure. The study addresses the persistent gap between transfer-oriented flood risk assessments and integrated, spatially explicit resilience planning by proposing a framework that operationalizes spatial resilience for urban floodplains through governance, land-use configurations, and multifunctional infrastructure. The aim is to develop a theory-informed, practically implementable framework that links spatial policy instruments, hazard exposure, and community adaptation to produce resilient urban floodplain outcomes. Specific objectives are to (i) conceptualize spatial resilience in urban floodplain contexts through synthesis of resilience theory, urban geography, and flood risk management; (ii) identify spatial determinants of resilience including land-use zoning, green-blue infrastructure, and informal settlement patterns; (iii) design an integrated framework that combines vulnerability reduction, exposure management, and adaptive capacity enhancing measures; (iv) empirically test the framework using a mixed-methods approach in the Lagos Metropolitan Area, Nigeria, as a representative high-risk tropical delta city; and (v) generate policy-ready guidance for spatial planning, flood risk governance, and community engagement. Methodologically, the study adopts a mixed-methods research design comprising three sequential stages. The population includes urban planning authorities, utility agencies, and residents within flood-prone zones across five high-risk districts. A stratified random sample of 350 households will be surveyed to quantify exposure, sensitivity, adaptive capacity, and perceived resilience, complemented by 40 key informant interviews with policymakers, engineers, and NGO practitioners to capture governance processes and implementation barriers. Data collection instruments include a structured household survey instrument incorporating validated scales for flood risk perception, social-ecological vulnerability, and resilience; semi-structured interview guides for stakeholders; and GIS-derived spatial datasets on land-use, drainage networks, and flood extent historical records. Validity and reliability will be ensured through pilot testing (n=30) and instrument refinement, while triangulation across survey results, interviews, and spatial analysis will enhance credibility. Data analysis employs descriptive statistics and regression analysis to identify spatial determinants of resilience, multilevel modeling to account for nested data structures (households within neighborhoods), and thematic analysis of interview transcripts to extract governance and community adaptation themes. A conceptual model will be specified through structural equation modeling to assess relationships among exposure, vulnerability, adaptive capacity, and resilience outcomes, with model fit assessed via RMSEA, CFI, and TLI. The study will integrate a GIS-based spatial resilience index, constructed from indicators of land-use diversity, green-blue infrastructure coverage, floodplain connectivity, evacuation route redundancy, and social vulnerability indices, to map resilient versus fragile urban pockets. Expected findings indicate that resilience is spatially uneven, with higher resilience in districts featuring integrated green-blue networks, enforceable development controls, and participatory governance, while low-resilience pockets correspond to informal settlements with high exposure and limited access to services. Regression and SEM results are anticipated to reveal that the effectiveness of green-blue infrastructure, coupled with inclusive governance mechanisms, significantly reduces exposure and enhances adaptive capacity, thereby strengthening overall spatial resilience. The study contributes to knowledge by presenting a theory-grounded framework that synthesizes resilience, urban morphology, and flood risk management into a usable spatial planning model; by operationalizing spatial resilience into a measurable index and actionable indicators suitable for city-wide planning; and by offering a transferable approach that can be adapted to similar deltaic urban contexts facing compound flood risk and rapid urbanization. The practical implications include informing zoning reforms, investment in flood-adaptive infrastructure, and the design of participatory planning processes that align with climate adaptation objectives. Policy recommendations emphasize integrating resilience metrics into development approvals, prioritizing nature-based solutions, and expanding community-based early warning and evacuation planning. The main conclusion posits that spatial resilience in urban floodplains emerges from the deliberate coupling of land-use regulation, resilient infrastructure, and inclusive governance, rather than from hazard mitigation alone. Suggestions for further research propose cross-city comparative studies to test the framework in comparable tropical delta regions and the refinement of the spatial resilience index to incorporate dynamic climate projections and post-disaster recovery performance.