From flood hazard to governable climate risk: An integrated framework for adaptive flood governance and the Flood Resilience and Sustainability Index (FRSI)

Climate change, urban expansion and ecosystem degradation are intensifying flood-risk management challenges worldwide. However, mitigation and recovery approaches remain fragmented across engineering, community adaptation, technology, governance and finance, limiting integrated assessment of resilience and sustainability. This study examines the reported effectiveness and implementation constraints of flood mitigation and recovery strategies, their integration of sustainability principles, and their implications for adaptive governance. A PRISMA-guided systematic review of 62 studies combines thematic synthesis, comparative framework analysis and semi-quantitative evidence mapping. Strategies are compared across cases using reported effectiveness, implementation cost and complexity, scalability, and sustainability contributions. Standardised evidence-mapping scores support contextual interpretation rather than pooled effect estimates or universal rankings. The synthesis identifies three recurring patterns. First, hybrid approaches combine engineered protection, ecological buffering, early warning and community preparedness, with outcomes dependent on local conditions, maintenance and institutional capacity. Second, fragmented responsibilities, weak enforcement, financing constraints and limited community participation impede implementation and recovery. Third, existing assessment frameworks provide incomplete integration of physical, social, ecological, technological, institutional and financial dimensions. These findings inform the proposed Flood Resilience and Sustainability Index (FRSI), a conceptual framework comprising seven domains: hazard and exposure, vulnerability and equity, infrastructure resilience, ecological and nature-based resilience, governance capacity, technological readiness, and recovery-financial capacity. Its contribution lies in organizing these interdependent domains within a common structure for future resilience assessment and policy prioritization; operationalisation and empirical validation remain necessary. The synthesis supports coordinated institutional responsibilities, enforceable risk-sensitive land-use planning, sustained investment in complementary structural and nature-based measures, and equitable access to preparedness and recovery finance. These priorities connect flood-risk reduction with inclusive recovery and long-term adaptation.