8274

• UCREFRP Catalog Number: 8274
• Author: Pitlick, J. and R. Cress.
• Title: Longitudinal Trends in Channel Characteristics of the Colorado River and Implications for Food-Web Dynamics.
• USFW Year: 2000.
• USFW - Doc Type: Recovery Implementation Program Project 48-C,
• Copyright Material: NO

The individual measurements of bankfull width and depth are plotted on mile-by-mile basis in
Figures 20a and 20b (the complete data set, numbering 149 cross section measurements, is given
Table A-4). These data are further subdivided according to whether the cross section is located in
an alluvial or quasi-alluvial reach. In comparing adjacent reaches we note some differences in the
bankfull width and depth, but these differences are generally small and not statistically significant
(Cress, 1997). Note that the y-axes are again scaled in logarithmic units to facilitate comparison
with the previous data on slope and grain size. An exponential fit of the trend in bankfull width
gives a weak straight-line relation (R2 = 0.14) with a slope of 0.0016. A fit of the bankfull depth
data yields a moderately strong exponential relation (RZ = 0.50) with a slope of 0.0030. The
difference in exponents indicates that the bankfull depth increases downstream at about twice the
rate of the bankfull width.
400
E
t 200
100
80
m 60
40
a •
0 0
0
0 0
0 00 00 • 0 • 000 0
m 0• •• • 00 0
0 0 o o 08 • 0 ---- • ?•eo 00
ePQO--.-010.v 0 0 o,
- - 0,0 • • • •0 0
------------- 0 •
•
-$0000 00 0 • ••• a • • 0
00 1- 0c 9 • • 0 •
0 0 0 •
0
0 0 o •• 0 •f•
•
w = 190`e0.0016x
R2 =0.14
350 300 250 200 150 100
10
E
t
a
d
D
Y
C
to
m
1.0
b
•
•
0 00 •• •
• S
0 -
0 0 ••M
0 00 0 0 -- o• "" • ••
0?) o 00
•
a0--. 0 00 •
D 0
0 0 •
0 0
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0 0 0
00 0
0
0
0 00866 •• • 0 00
0 q 6.
oo,__
-, _0
0 CO •! • 0
0 0
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0 mo
0p 0 0 •
00 • 00
0 0
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h = 6.8'e0.0030x
R2 = 0.50
350 300 250 200 150 100
Distance Upstream from Green River Confluence (km)
Figure 20. Trends in (a) bankfull width and (b) depth of the Colorado River. Open circles indicate
cross sections in alluvial reaches; closed circles indicate cross sections in quasi-alluvial reaches.
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