RESULTS AND DISCUSSION
4.1 Sediment budget
4.1.1 Channel erosion and
deposition
The sediments in the LYR are mainly received from the middle reaches,
and long-term deposition in the lower reaches has raised the riverbed
above the surrounding ground, which is called a “suspended river”. The
LYR generally accumulated deposits prior to 2000, with a cumulative
deposition of 83×108 m3 between 1950
and 2000. Since the operation of the XLD reservoir began in 2000, the
LYR has changed gradually from a sedimentation pattern to an erosion
pattern due to the large quantities of sediment trapped by the dam, with
a decrease in the cumulative deposition volume, as shown in Figure 5.