7632 ‎(2)‎

• UCREFRP Catalog Number: 7632
• Author: Pucherelli, M. J., J. N. Halls and R. C. Clark.
• Title: Green River Channel Mapping Study, 1987.
• USFW Year: 1987.
• USFW - Doc Type: \
• Copyright Material: NO

jJ
,

. ,

M~'!!'84 U 0-85)
Bureau of ReclamatIOn

&i~6L j
~f/ 4ti/
UNITED STATES GOvtRNMENT
memorandum

l..\,'-\

TO

Memorandum ~!
Head. Remote Sensing SectiO~]~

Denver, Colorado
DATE: November 19. 1987

FROM Michael J. Pucherelli. Environmental Biologist
Joanne N. Halls, Advanced Sciences. Inc.
Rich C. Clark, Advanced Sciences, Inc.
SUBJECT: Green Ri ver Channel Mappi ng Study

Applied Sciences Referral Memorandum No. AP-88-4-1

Principal Investigator: Michael J. Pucherelli

1.0 INTRODUCTION

The installation of Flaming Gorge Dam in 1962 has affected the morphology
of the Green River by controlling riverflows. The length of time required
for an impounded river to return to some form of equilibrium may take
a number of years and is dependent on a variety of influences including
sediment dynamics, hydrology, and biotic factors. The influence of
major dams. such as Flaming Gorge, may extend far downstream, as the
reduction of flood volume and duration can produce significant morphologi-
cal impacts (Graf, 1980).

Andrews (1986) reported that the Green River channel width has been
reduced by 60 to 90 feet on three reaches below Flaming Gorge Dam:
downstream from the dam to the Jensen gauge, from the Jensen gauge
to the Ouray gauge, and from the Ouray gauge to the Green River gauge.
This conclusion was based on 56 cross sections over 97 river-miles.
The objective of this remote sensing study was to examine this tech-
nique's ability to adequately quantify channel width changes of the
Green River by mapping the high water embankments from predam and postdam
construction areas.

2.0 METHODS

Aerial photography was obtained by the Bureau of Reclamation for five
dates: 1952, 1963. 1974, 1978. and 1986. The study area includes
approximately 74 river-miles (figure 1). River-mile designations were
taken from the Green River Wilderness Desolation River Guide (Evans
and Belknap. 1974). The 1952 and 1963 photographs represent precon-
struction conditions, while the 1974, 1978, and 1986 photographs repre-
sent postconstruction conditions. The 1952 photography covers only
31.7 river-miles with 24 miles at the north end of the site and
7.7 miles at the south end. The 1963 photography includes photography
from 1964 in order to cover the entire study area. It is not believed