Figure 9 Variations in the riverbed
slope (a) and changes in thalweg migration from HYK to GC (b).
4.2.1 Changes in the cross-sectional
form
Changes in both the discharge and the sediment load not only affect the
channel longitudinal profile but also have a strong influence
on the evolution of the
cross-sectional form. The cross-sectional form of the braided reach in
the LYR shows high complexity. Figure 10 shows a set of typical
cross-sectional geometries, represented by the sections at Weicheng (WC)
and Yangxiaozhai (YXZ) in different years. Among them, WL is a
representative section of the suspended river in the HYK-DBT reach, and
YXZ is a typical section of the
secondary suspended river in the
DBT-GC reach.