Investigating the Dry–Wet Differentiation of the Yellow River Basin Driven by Climate Change and Anthropogenic Activities

Under the combined effects of climate change and anthropogenic activities, the dry–wet pattern of the Yellow River Basin is undergoing substantial reconfiguration, yet its long-term evolution and driving mechanisms remain unclear. This study constructs a Terrestrial Water Storage Anomaly-based Drought Severity Index (TWSA-DSI) using 1995–2014 as the historical period to characterize spatiotemporal dry–wet heterogeneity. Future changes during 2026–2100 are projected for the near future (2026–2060) and far future (2061–2100) under the SSP126, SSP245, and SSP585 scenarios. A comprehensive driving factor system incorporating vegetation cover, land use, meteorological conditions, and socio-economic factors is established, and dominance analysis is applied to quantify the controlling mechanisms of terrestrial water storage change (TWSC). Results indicate that the basin experienced a historical transition from aridification to humidification. Future dry–wet conditions differ markedly from the historical period, with the basin shifting toward overall humidification as emissions increase. The driving mechanisms of aridification and humidification are significantly different and precipitation is the decisive driving factor influencing the dry–wet evolution of the Yellow River Basin. Especially in the far future under the SSP585 scenario, the proportion of precipitation is as high as 54.9%. These findings provide scientific support for sustainable water-resource management under climate change.