Identifying Barriers and Enablers for Climate-Adaptive Floodwall Design: A Cross-Country Fuzzy Synthetic Evaluation of Australia and Vietnam

<p dir="ltr">Climate-Adaptive Floodwall Design (CAFD) is critical for mitigating climate-related flood risks, yet cross-country evidence on stakeholder priorities remains limited. This study applies Fuzzy Synthetic Evaluation (FSE) to analyse perceptions from 92 flood management professionals in Australia and Vietnam regarding 15 barriers and 15 enablers, grouped into five themes: governance, financial feasibility, technical capacity, stakeholder engagement, and site-specific hydro-physical conditions. Descriptive statistics show shared recognition of hydro-physical constraints and the value of cost–benefit analysis, forecasting, and risk mapping. Notably, Nature-based solutions (NbS) ranked highest in Vietnam but lowest in Australia, highlighting divergent adaptation preferences. Independent samples t-tests further reveal significant differences in technical capacity, financial feasibility, and stakeholder engagement, with Vietnamese respondents more concerned about technical limitations, particularly restricted data access, while Australians emphasised funding constraints despite their advanced economy. Policy implications include expanding the role of NbS in Australia while addressing funding constraints in resilient flood defences, and, in Vietnam, enhancing technical capacity by ensuring equitable access to data across all stakeholder groups, without favouritism toward those with higher authority. Study limitations include sample size, equal weighting assumptions, and FSE’s inability to assess trade-offs; which urge the next research phase to address these through the Analytic Hierarchy Process (AHP).</p>