Human–water adaptation in drylands: Reconciling water use and ecological security in arid inland river basins of China

Dryland regions face intensifying pressure to use scarce water resources without undermining ecological security (ES), yet how human water use adapts within ecological limits remains poorly understood. We develop an integrated human–water adaptation framework to examine the co-evolution of water use efficiency (WUE) and ES across major arid inland river basins in northwestern China from 2006 to 2021. Using a DPSIR-based ES index and ecohydrological and socioeconomic WUE indicators, we track spatio-temporal trajectories, diagnose coupling patterns, and assess whether efficiency gains remain compatible with basin-specific ecological limits. WUE has risen substantially—especially in oasis-dependent basins such as the Heihe, Shiyang and Tarim—while ES diverges: it declines where irrigation expansion intensifies hydrological and land pressures, but stabilizes or improves in basins adopting strict ecological water allocations and restoration measures. Although WUE–ES interactions are shifting from weak or conflicting to more coordinated states, the transition is uneven, with several lower-reach oases showing efficiency improvements alongside ecological degradation, indicating maladaptive development. By operationalising the alignment of WUE with ecological limits, this framework provides a practical basis for adaptive water allocation, ecological protection and integrated governance, supporting resilience of dryland social–ecological systems.