Policy framework and empirical study on adaptive management of river ecological flow based on basin differences

ABSTRACT Amid accelerating climate change, extreme drought events occur frequently, and the conflict between water supply and demand has intensified, exerting severe impacts on domestic water use, productive activities and ecosystem integrity. This paper develops a policy framework for the adaptive management of river ecological flow, specifically designed to align with the unique characteristics of each basin. From the perspective of 'whole-basin governance' and 'adaptive management', we construct a feedback mechanism encompassing 'Problem Diagnosis-Resource Allocation-Regulation Management-Effect Evaluation-Feedback Adjustment'. Through continuous monitoring of drought, the D-A-R (Determination, Assessment and Reduction) approach is employed to dynamically regulate various water use allocations. Empirical research conducted in the Poyang Lake Basin (PY) and the Dongjiang Headwater Watershed (DJ) indicates that by considering hydrological rhythms, water resources carrying capacity, and water resource demands specific to basins, different intervention measures and adjustment scales can be implemented, thereby minimizing the impacts of water resource scarcity. Specifically, introducing the 'hedging rule' cuts the basin's severe-shortage frequency by more than 70%, safeguards ecological flows, and sustains secure water supplies for both households and productive sectors. This paper offers innovative insights and methodological guidance for formulating adaptive policies that simultaneously safeguard riverine ecosystems and foster sustainable socio-economic development within river basins.