Author(s): Meilan Qi; Xiaofeng Liu; Marcelo H. Garcia; Peifu Jiang
Linked Author(s): Marcelo García
Keywords: Sediment reduction; Three Gorges Dam: riverbed; Degradation; Fielddat
Abstract: Sediment supply in the Yangtze River downstream of the Three Gorges Dam (TGD) has been reduced to less than 40% of its pre-dam value since October2003 when the TGD reservoir started operation. The resulted channel degradation has been observed. Herein, the hydrological and morphological data collected over the past five years is analyzed. Observed bed elevation data indicates that degradation rate is the highest near the TGD site and it propagates downstream. Evidence also supports that the degradation rate decreases in time. A one-dimensional sediment transport numerical model was used for a 60-km reach immediately downstream of the TGD. The model, which simulates the transport of both suspended load and bedload, was calibrated with the observed field data. It was then used to predict future channel evolutions which will be valuable for the engineering management.
Year: 2009