Three-Dimensional and Immersive Visualisation for Flood Risk Communication: A Critical Review of Mechanisms, Evidence and Evaluation

Flood risk visualisation has advanced rapidly over approximately the past decade, but technological sophistication has not always been matched by evidence of communication effectiveness or operational readiness. This critical review examines when, why, and under what conditions 3D and immersive visualisation supports flood risk communication. Following a PRISMA-guided process a final analytical corpus comprised 42 studies. The findings reveal a shift from static and technically oriented flood representation toward situated experience, public communication, evacuation training, collaborative interpretation, and decision support. GIS, BIM, and web-based 3D systems continue to provide the analytical foundation of the field, while virtual, augmented, and mixed-reality tools increasingly translate flood information into place-based and experiential forms. The most consistently reported benefits relate to spatial understanding, engagement, perceived realism, risk awareness, and decision support. However, these benefits are highly dependent on audience expertise, communication purpose, representational complexity, and the task being supported. Evidence quality remains uneven, with many studies relying on prototypes, small samples, expert feedback, or short-term usability assessments, and relatively few progressing to comparative, longitudinal, or operational validation. The review challenges the assumption that more immersive visualisation is necessarily more effective. Instead, effectiveness depends on alignment among audience, communication mechanism, flood-management stage, evaluation maturity, and implementation conditions. To support this alignment, the review proposes the Audience, Mechanism, Stage, Evaluation, Implementation framework, which links design choices, evidence strength, and implementation requirements. The central question is whether a particular visualisation approach provides a credible, accessible, and decision-relevant improvement for a defined audience and context.