Characteristics of Channel Incision Induced by Human Activity in a Wandering Reach in 20 Years

The wandering reach of the lower Yellow River has undergone significant channel degradation since Xiaolangdi Reservoir operation, with a cumulative scour volume 14.1 × 108 m3 in 1999–2018, and severe resulted rapid incision this reach. annual river bed downcutting depths at section- reach-scales water stages low high flows were calculated to investigate characteristics quantitatively. results show that sedimentation sections varied significantly, magnitude varying between 1.1 m 4.2 m. reach-scale depth reached up 2.9 decreased by more than 3.3 hydrometric stations. previous 6-year average fluvial erosion intensity is major influencing factor controlling incision, empirical functions established three sub-reaches. data using proposed equations agreed well observed depths, so these can be used calculate processes recent 20 years