Dr. Niannian Fan
Dr. Niannian Fan
Sichuan University, China
Title: Abrupt drainage basin reorganization following a Pleistocene river capture in the Yimeng Mountains, China
River capture is a dramatic and abrupt natural process of internal competition through which mountainous landscapes evolve 1 and respond to perturbations in tectonics and climate. River capture may occur during the dynamic reorganization of drainage networks where one catchment grows on the expanse of another, resulting in a victor that steals the neighboring headwaters 1-3.  While river capture occurs regularly in numerical landscape evolution models 2-6, field observations of captures are rare. Here, we document a late Pleistocene river capture in the Yimeng Mountains, China, that abruptly shifted 25 km2 of drainage area from one catchment to another.  River terraces and imbricated cobbles indicate that the main channel incised 27 m into granitic bedrock within 80 kyr, following the capture event, and upstream propagating waterfalls reversed the flow direction of a major river. Topographic analysis shows that the capture shifted the river basins far from topographic equilibrium, and active divide migration is propagating the effects of the capture throughout the landscape.