Quantifying anthropogenic impacts on water conservation and exploring enhancement pathways within a coupled nature-society framework

The Yellow River Water Conservation Area (YRWCA), an ecologically functional water source area of the Yellow River Basin, China. This study developed a novel assessment framework based on the dualistic natural-societal water cycle paradigm to quantify the Water Conservation Function (WCF) via an ecologically based method, evaluate the impacts of key anthropogenic drivers, and identify effective pathways for WCF enhancement. The multi-year average water conservation across the YRWCA was 140.00 mm, with significant spatiotemporal variability. While the upstream Lanzhou region (LYR) showed a slight increase (+0.99 mm/decade), the Nanshan tributary (NWR) and Yiluo River basin (YR) experienced clear declines (–3.84 and –4.25 mm/decade, respectively). Scenario analysis revealed that industrial and domestic water uses exerted suppressive effects on WCF, whereas agricultural irrigation, terracing, and check dam construction contributed positively to its enhancement. Notably, optimizing vegetation structure emerged as the most effective enhancement strategy (+17.08%). However, its efficacy was region-dependent: low-canopy vegetation was most suitable for the LYR, while tree-grass intercropping performed best in the NWR and YR. This study provides a scientific basis and actionable strategies for ecological restoration and water resources management in the Yellow River Basin. • Incorporates vegetation’s ecological functions for assessing water conservation. • Industrial & domestic water use reduces water conservation by 0.01–0.06 m³ per m³ . • Terracing and dams add 12.2–40.7 and 0.19–1.04 × 10 ³ m³ /km² to water conservation. • Optimization of vegetation planting structures raised water conservation by 17.08%.