Abstract Drainage reorganization is a fundamental process shaping landscapes and redistributing continental water resources. On the eastern Tibetan Plateau, geomorphic evidence indicates that the drainage divide between China's two longest rivers, the Yangtze and Yellow Rivers, is migrating northwestward, implying that the Yangtze is capturing the Yellow River's headwaters. We test this hypothesis through integrated analysis of topography, drainage network morphology, channel steepness, and knickpoint dating using a calibrated stream‐power model. Results demonstrate that a series of river capture events between ∼1.7 and 0.8 Ma systematically transferred at least ∼30,000 km 2 of drainage area from the headwaters of the Yellow River to the Yangtze River. We attribute this reorganization to Quaternary climate change, which amplified the erosional advantage of the steeper, high‐relief Yangtze basin, triggering headward erosion. This ongoing process has reduced the long‐term average runoff of the upper Yellow River by ∼5 billion m 3 /yr, a volume that exceeds the designed annual diversion capacity of the first phase of the nearby South‐to‐North Water Diversion Project. Our findings underscore that landscape evolution exerts a first‐order, geological‐timescale control over water resource distribution, providing an important framework for assessing large‐scale water management strategies.
Li et al. (Fri,) studied this question.