ABSTRACT
Since the operation of the Three Gorges Project, the Middle Yangtze River (MYR) has been suffering from remarkable channel degradation, along with significant bank erosion in local regions. Therefore, it is necessary to investigate channel adjustments in the MYR. Recent channel adjustments in four subreaches of the MYR were investigated quantitatively. A focus of this study has been especially paid on the variations in bankfull channel geometry and bank erosion intensity. Calculated bankfull channel dimensions in 2002-2015 indicate that: (i) there were significant bank-erosion processes in the Jingjiang Reach, with empirical relations being developed to reproduce the variation in bankfull widths at typical sections; (ii) the reach-scale channel geometry occurred mainly in the component of bankfull depth in each subreach, and generally responded well to the previous five-year average fluvial erosion intensity during flood seasons; and (iii) the longitudinal distribution of bank erosion sites was determined, with the relationship between channel degradation and bank erosion intensity being quantified.
