Attribution analysis of runoff evolution in the Yellow River Basin during 1956–2022: A perspective from water discharge into the sea variability

Conducting attribution analysis of runoff changes serves as a critical scientific basis for unraveling the mechanisms of hydrological process variability and supporting water resources management decision-making. Water discharge into the sea serves as an integrated indicator of basin-scale runoff evolution, and its variation process provides critical reference for assessing river health status. Based on the variability characteristics of water discharge from Yellow River into the sea (WYRS) and considering the frequent flow cessation events during 1972–1998, this study divided the research period into the pre-flow cessation period (1956–1971), flow cessation period (1972–1998), and post-flow cessation period (1999–2022).An improved attribution framework was proposed by combining the high-intensity anthropogenic water withdrawal and consumption processes with the Budyko theory. The results show that the WYRS has declined significantly (p < 0.01) over the past 67 years. Anthropogenic water consumption (AWC) was the dominant factor driving the sharp decline in WYRS during flow cessation period, accounting for 44.45 %. In contrast, changes in underlying surface conditions caused by ecological restoration measures became the primary driver (100.74 %) of further WYRS reduction in the postflow cessation period. Overall, unlike traditional studies based on the Budyko framework, the findings reveal that in addition to the impacts of indirect human activities such as underlying surface changes on runoff in the Yellow River Basin (YRB), direct human activities like AWC also constitute a non-negligible driving factor. This study provides a novel analytical framework for attributing runoff changes in highly human-impacted basins, offering scientific support for water resource management and ecological conservation in the YRB.