Toward Holistic Perspective on Dam Efficacy in Transboundary Hydro-Extremes Management

Research on assessing dams preparedness to mitigate hydrological extremes has grown under climate change and water conflicts. However, discerning the success or failure of these strategies remains challenging, especially in Transboundary Rivers. Here, we use a meta-analytic approach to examine 14 moderators of dam efficacy in flood and drought risk management. We synthesize impact assessment datasets from 287 articles for 12 transboundary basins across the globe. Findings show that forest cover and gross domestic product enhance dam efficacy in flood control. In flood hotspots, the synergy of dam management and institutional factors is the paramount determinant of dams performance. Conversely, the efficacy in the drought-prone basins is governed mainly by the interplay of institutional and socioeconomic factors. Climate aridity, precipitation anomalies, and hydropower dams lessens the dams effectiveness in mitigating both hydrological extremes. We argue that endorsing adaptive management through dams in transboundary basins requires a holistic approach. Thus, we emphasize accounting not only for the physical and engineering aspects, but also for the intertwined environmental, socioeconomic, and geopolitical implications.