9455

• UCREFRP Catalog Number: 9455
• Author: Lyons, J. K., M. J. Pucherelli and R. C. Clark.
• Title: Sediment Transport and Channel Characteristics of a Sand-Bed portion of the Green River Below Flaming Gorge Dam, Utah, U.S.A.
• USFW Year: 1992.
• USFW - Doc Type: R-92-08,
• Copyright Material: NO

Table 3. - Green River reach 1 channel morphology
comparisons for predam (1964),and po stdam (1974, 1978,
and 1986) periods at alluvial and confined sites.
Site 1964 1974 1978 1986
161 km -193 km
(alluvial)
area (ha) 680.31 659.28 665.30 676.33
width (m) 211 205 207 210
193 km - 238 km
(confined)
area 981.59 913.90 921.51 939.01
width 222 207 209 213
238 km - 256 km
(alluvial)
area 382.36 336.35 334.95 351.28
width 215 189 189 198
260 km - 279 km
(alluvial)
area 367.99 358.27 350.99 354.76
width 212 207 203 205
Total alluvial
area 1430.66 1353.90 1351.24 1382.37
width 213 201 201 206
Totalreach
area 2412.25 2267.80 2272.75 2321.38
width 217 204 204 208
Note: Site descriptions are distances downstream from
Flaming Gorge Dam.
Channel surface area was stable from 1974 to 1978, ranging from a small decrease of 2 percent
for the alluvial segment between 200 kilometers and 279 kilometers below Flaming Gorge Dam
to a slight increase of 0.9 percent for the 32-kilometer alluvial reach starting 161 kilometers
downstream from the dam. Channel surface area for reach 1 increased by only 0.2 percent from
approximately 2268 hectares in 1974 to 2273 hectares in 1978.
Channel surface area and width increased somewhat at all sites between 1978 and 1986,
ranging from 1.1 percent for a reach located between 160 kilometers and 279 kilometers below
Flaming Gorge Dam to 4.9 percent for the reach between 138 kilometers and 156 kilometers
below the dam (alluvial). Channel surface area for reach 1 increased by about 49 hectares or
only 2.1 percent over this time span.
Reach 2 experienced less channel narrowing at a later time than reach 1. Little or no change in
channel surface area and width took place in reach 2 between 1952 and 1974, 12 years after
dam completion (table 4). The major reduction in channel surface area in reach 2 occurred
between 1974 and 1981, when channel surface area decreased from about 631 hectares to
approximately 602 hectares, or 4.6 percent. Channel surface area in reach 2 increased only 1.4
percent between 1981 and 1987.
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