Identifying Global Flood Protection Potential and Archetypes of Dam Regulation by Quantitative Modeling

Flood regulation measures (primarily through dams), combined with a range of non-regulative measures, sit at the heart of modern flood management aiming to mitigate flood impacts. However, the undertaken flood protection measure for a particular region is often selected based on how flood risk evolves under historical and future climate scenarios, whereas relatively less attention has been paid to assess the effectiveness and burden of different measures in face of varying flood magnitudes (constrained by hydroclimatic conditions) and protection targets (constrained by human settlements in floodplains). As a result, it remains unclear whether existing dams can realistically meet evolving protection demands, or whether they are already operating under disproportionately increasing pressure.

To address this, we introduce a quantitative framework (FRAMES, Zheng & Lin, 2025) to evaluate the applicability and adaptivity of regulative measures. We focus on how systems bear the Operational Load (OL)—defined as the storage demand placed on infrastructure across varying flood magnitudes (Return Periods) and protection targets (Exposure Levels). By analyzing 4,732 global settlements paired with 5,963 dams, we quantify the response patterns of OL across diverse geographic and developmental settings globally. These settlements are further categorized into distinct archetypes based on the marginal effectiveness of their regulative systems. Preliminary findings indicate that 57.5% of global settlement show diminishing returns of applying dams for flood protection. Such results indicate in these regions, management should prioritize land-use controls, zoning, and local resilience measures to alleviate disproportionate infrastructure pressure. Conversely, in regions where regulative potential remains high, emphasis should be placed on maintaining system redundancy and avoiding infrastructure lock-in. This study provides the first global quantitative baseline of flood protection potentials and adaptivity, offering a new foundation for evidence-based decision-making in flood management.