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

E
E
0
N
C
(7
m
ea
CO)
V
m
m
400
100
10
350 300 250 200 150 100
Distance Upstream from Green River Confluence (km)
E
E
d
N
N
i
d
v
3
a
N
100
a
® ® ® ® ® ® •{{pp
® ® ®® ® ® ® ® i
® ®• •• ®e®0 0-®I -ER- - - - - JB - - - -• - - - D8
•
00
00 1, 03 G3
0
g- 00 D5
b •O o' •0 0 0 b • 0 • 0N• 00[le
-? -.0_ - • - - - -E6 Cbo 0 0 •
°?0 --@---0-o------0
0 0 0 0 • 0 "Cbo ? 0 0 0 D,
0
b
1B M
?-_ffl-®--M----
•
10
1
Cl
0
0 0 0
a__ _0_ o
o - -- - -- 0
0 o --------°U -o--- o_
? goo
350 300 250 200 150 100
Distance Upstream from Green River Confluence (km)
Figure 18. Downstream trends in grain size of the Colorado River; (a) percentiles of the surface
sediment size distribution; (b) percentiles of the subsurface sediment size distribution.
Our cross section measurements indicate that the bankfull width and depth of the Colorado River
increase systematically downstream, although not in proportion to each other. The general trends in
cross section morphology (or hydraulic geometry) are illustrated in Figure 19, which shows a series
of main-channel cross sections arrayed from upstream to downstream. These sections are all
located in runs, thus they can be considered representative of individual reaches. Note the average
bankfull depth increases from about 2.5 in at RKM 345 (stratum 11) to about 5 in at RKM 106
(stratum 2), whereas over the same distance, the average bankfull width increases from 114 m to
151 in (see Table 1).
29