Warming-induced wetting-drying transitions amplify water scarcity risks in China’s Yellow River Basin

The Yellow River Basin (YRB) is located in the eastern part of Asia and originates from the Bayan Karahar Mountains on the Qinghai-Tibet Plateau in China. YRB is one of the important grain-producing areas in China and is highly sensitive to climate warming. However, the region's wetting and drying trends, along with their underlying drivers, remain unclear. Here we use the Lagrangian trajectory model, singular value decomposition technique, and optimal fingerprint analysis to evaluate the wetting and/or drying variations and potential drivers in the YRB. From 1981–2023, we observed a warming and wetting trend across more than half of the upper YRB, and the middle and lower YRB show a warming and drying trend. We calculate contributions of external and internal water vapor sources to precipitation changes as 88.95 % and 11.05 %, respectively. External water vapor mainly originated from Europe (31 %- 50 %) and Asia (31 %-48 %). Atlantic sea surface temperature and anthropogenic factors significantly influence climate change in the YRB. Future (2024–2099) projections suggest that 85.35 % of the YRB will experience pronounced warm-dry condition under a 1.5°C warming scenario. In contrast, the YRB is projected to shift to warm-wet conditions under 2°C and 3°C. However, a return to warm-dry conditions is anticipated under the 4.0°C warming scenario. • Upper Yellow River Basin is warming-wetting, while middle and lower are warming-drying. • External water vapor contributes 88.95 % to Yellow River Basin precipitation changes. • Human factors drive 70 % of precipitation changes, led by aerosols and greenhouse gases. • Yellow River Basin shifts between warm-dry and warm-wet under different warming scenarios.