Environmental Engineering Reference
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L
m
θ
R
c
A
′
A
m
A
C
′
B
′
Z
B
C
A
A
′
W
i
W
D
m
D
≈
B
B
′
W
p
D
max
C
C
′
W
a
FIGURE 8.31
Meander planform and cross section dimensions for restoration design. (From Soar, P.J.
and Thorne, C.R.,
Channel Restoration Design for Meandering Rivers
, U.S. Army Corps of Engineers
Engineering Research and Development Center, Vicksburg, MS, 2001.)
Note:
Point bars are deined by
shaded regions;
L
m
= meander wavelength,
Z
= meander arc length (rifle spacing);
A
m
= meander belt
width,
R
c
= radius of curvature; θ = meander arc angle;
W
= reach average bank-full width;
D
= depth
of trapezoidal cross section;
D
m
= mean depth (cross-sectional area/
W
);
D
max
= maximum scour depth in
bendway pool;
W
i
= width at meander inlexion point;
W
p
= width at maximum scour location;
W
a
= width
at meander bend apex.
variable as illustrated by Rinaldi and Johnson (1997a,b), who, based on a sample of small Maryland
streams, indicated the measured range of meander wavelengths to be between 2.9 and 7.7 times
the channel width (in meters). They recommended that designers should ensure that the meander
characteristics of the river to be restored be within the range of the data used to develop the regres-
sion equations, and that regional differences and luvial processes be considered when selecting the
meander characteristics.
Generally, the ratio of the radius of curvature to the channel width in well-developed meander
bends is generally in the range of 1.5-4.5, and commonly in the range of 2-3. While the amplitude
of meander systems is variable, the ratio of the amplitude to the wavelength is commonly in the
range of 0.5-1.5 (USACE 1994).
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