Erosion and aggradation processes and calculation method for the Qingshuigou channel on the Yellow River Delta

The spatial and temporal evolution characteristics of the Qingshuigou channel during 1976-2015 were comprehensively analyzed to investigate the long-term evolution process of the channel. A calculation method for the erosion and aggradation volumes at the Qingshuigou channel was proposed on the basis of Delayed Response Model and by considering the effects of water and sediment conditions and channel extension and retreat. Results showed that the channel reaches at the upstream of the avulsion point were eroded and then aggraded during 1976-1980. Meanwhile, the sediment deposited at the downstream channel reaches and the deposition volume increased in the downstream direction as the channel and floodplain widened. The evolution of the upstream and downstream channel reaches became in-phase after 1980. Influenced by the water and sediment conditions and other factors, the channel was eroded during 1980-1986 and aggraded during 1986-1995. Erosion occurred again due to the artificial water diversion in 1996 and the implementation of water and sediment regulation scheme. The erosion rates decayed exponentially with time after 2002. The proposed method could accurately calculate the erosion/aggradation volume of the channel for a long time period, and it might be used to predict channel evolution in the near future.