Evaluating the effectiveness of impact-based severe weather Early Warning Systems for Flood Risk Management in South Africa: A conceptual review

Flooding remains one of the most frequent and destructive hydro-meteorological hazards in South Africa, causing substantial socio-economic losses, infrastructure damage, and threats to human life. In response to increasing flood risks associated with climate variability and extreme weather events, the South African Weather Service has increasingly adopted impact-based severe weather early warning systems designed to communicate not only meteorological hazards but also their likely consequences for communities, infrastructure, and livelihoods. This conceptual review examined the effectiveness of these systems in strengthening flood risk management in South Africa. The paper synthesised theoretical and policy perspectives on impact-based early warning systems and critically reviewed institutional, socio-economic, and communication factors that shape their effectiveness. The findings indicate that while South Africa has made significant progress in transitioning from hazard-based to impact-based warning systems, challenges related to institutional coordination, dissemination gaps, community risk perception, and socio-economic vulnerabilities continue to undermine their effectiveness. The paper further identifies emerging opportunities linked to technological innovation, participatory governance, and community resilience. The study concludes by highlighting the need for context-specific empirical research in vulnerable flood-prone communities such as Port St Johns. This study contributes to disaster risk reduction and climate adaptation scholarship by synthesising theoretical, policy, and institutional perspectives on impact-based flood early warning systems in South Africa. It identifies key institutional, socio-economic, and communication factors that affect system effectiveness, highlights research gaps, and provides a conceptual foundation for future research and evidence-based flood risk management.