Enhancing Robustness and Addressing Inequities through Operational Flexibility in Cooperative River Basin Management

Effective transboundary river management requires systematic, collaborative efforts among nations sharing a river basin to ensure sustainable and equitable water resource allocation, support energy generation and food security, mitigate environmental impacts, and preserve the ecological integrity of river systems. This study introduces a novel framework for incorporating equity into the systemwide optimization of transboundary river operations, explicitly addressing the asymmetrical distribution of energy and water supply risks among riparian nations. Unlike traditional approaches based on game theory and hydro-economic modeling, which focus on static compensatory schemes for cooperative management, our framework leverages dynamic operational flexibility to achieve equitable and robust water resource allocation within the existing and planned infrastructure. The framework employs multi-objective robust optimization at the basin scale to generate adaptive operational strategies that incrementally integrate inequality aversion in hydropower benefits among nations, as quantified by the Atkinson inequality index. Through fully coordinated reservoir operations, the approach adaptively allocates water flow and storage in response to changing hydrological conditions, ensuring a fair distribution of benefits and trade-offs across riparian states. We demonstrate this methodology using the Zambezi River basin, where planned dams in the upper (Zambia and Zimbabwe) and lower reaches (Mozambique) are projected to double hydropower capacity. Results highlight that incorporating equity considerations yields hydrologically robust strategies that balance trade-offs between hydropower production, irrigation demands, and environmental flow requirements at the national level. These findings underscore the transformative potential of adopting dynamic, equity-focused approaches to transboundary water resource management in the face of escalating climate variability and uncertainty.