A dual-index decision-support framework for flood resilience in cultural world heritage cities: Integrating traditional ecological knowledge and modern strategies

Cultural World Heritage cities are increasingly vulnerable to flooding under climate change, while adaptation strategies often remain fragmented between Traditional Ecological Knowledge (TEK) and contemporary engineering approaches. This study develops a dual-index decision-support framework integrating the Environmental Impact Index (EII) and Sustainability Index (SI) to evaluate adaptive flood resilience in heritage urban systems. A mixed-method comparative approach was applied across three UNESCO World Heritage cities—Bagerhat, Ayutthaya, and Venice—representing distinct socio-ecological and hydrological contexts. The framework combines expert-based evaluation, Analytic Hierarchy Process (AHP) weighting, and normalized indicator assessment to examine the interaction between traditional and contemporary adaptation strategies within each case context. The findings indicate that TEK-based systems demonstrate strong environmental compatibility and long-term sustainability, whereas engineering-dominant systems provide high institutional reliability but often introduce ecological trade-offs. Hybrid configurations, particularly in Ayutthaya, achieve more balanced outcomes through context-sensitive integration of traditional and modern approaches. The results further demonstrate that adaptive flood resilience is shaped not by the dominance of a single strategy, but by the degree of alignment between ecological processes, governance structures, and cultural practices. The study contributes a transferable and policy-oriented framework for evaluating flood resilience in heritage cities. However, further empirical validation through longitudinal and participatory research is required to strengthen its practical applicability.