Abstract
Continuous channel
degradation has occurred
recently in the Lower Yellow River (LYR) due to water impoundment of the Xiaolangdi Reservoir. In this paper, observed hydrological data from 1999 to 2005
were used to analyze the processes and characteristics of recent channel adjustment
in the LYR. Main research results can be described as follows. The scour amount in the braided reach
made up 77% of the total one in the LYR, and the scour magnitude per unit
channel length in the braided
reach upstream of Gaocun was relatively large, while
the value in the
reach between Gaocun and Sunkou
was lowest among all the
lower reaches. Cross-sectional profiles adjustment in the lower reaches was
characterized by channel narrowing. The longitudinal main-channel profiles in the LYR during different periods were
concave-shape curves, and concavity
values of these
profiles increased slightly
with the recent channel
degradation. Bankfull
discharges in the lower reaches increased due to the scouring in the main
channel. Migration amplitude of the thalweg in the braided reach was greater than that in the
meandering reach.
Keywords:
The Xiaolangdi
Reservoir, the