A novel approach for disentangling the contributions of different soil and water conservation measures to streamflow reduction on the Loess Plateau, China

Study region: The Yanhe River Basin (YHRB) in the middle reaches of the Yellow River typifies the loess hill and gully region of the Loess Plateau, characterized by severe soil erosion and the extensive implementation of soil and water conservation measures (SWCMs). Study focus: Climate change and anthropogenic activities, particularly SWCMs, are major drivers of hydrological variability in the Loess Plateau. However, the individual effects of different measures on streamflow remain poorly disentangled. To address this issue, we developed a new attribution framework that integrates dynamic SWCM data on vegetation restoration, terraces, and check dams into the traditional Budyko framework. Using long-term hydrometeorological and SWCMs implementation data from 1976 to 2015 in the YHRB, we quantitatively assessed the contributions of specific SWCMs to streamflow reduction. New hydrological insights for the region: SWCMs (i.e., the non-climate component in our Budyko attribution) dominated streamflow reduction in the YHRB, accounting 12.5% (1976–1985) and 34.6% (2006–2015) of natural streamflow, with a strengthening influence over time. Contribution patterns also shifted: check dams dominated in earlier decades, vegetation restoration prevailed in later years, and terraces showed steadily increasing effect. These results reveal changing roles of different measures under policy and ecological restoration. The proposed method also offers practical guidance for optimizing conservation strategies, such as adaptive vegetation management and upgrading aging check dams, to balance soil conservation with sustainable water resources.