Abstract

Based on data collection and analysis, knickpoints on channel profile and its impacts on low flow water level is studied in the near dam reach downstream the Three Georges Project. The result shows that some pivotal knickpoints with high thalweg elevation and resistant gravel layer play important role in controlling its upstream water level lowering during channel degradation. In future channel incision process, the difference of erosion rate between upstream mixed bed reach and downstream sand bed reach is likely to initiate high gradient on water surface slope.

Keywords: Three Georges Project; channel profile; knickpoint; low flow water level