4247

• UCREFRP Catalog Number: 4247
• Author: Pucherelli, M. J. and R. C. Clark.
• Title: Comprehensive Report ‎(1986-1988)‎ on the Effects of Green River Flows on Backwater Habitat Availability as Determined by Remote Sensing Techniques ‎(Remote Sensing)‎.
• USFW Year: 1989.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

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riverine habitats be monitored annually for the survival and preservation of
the endemic fishes.

1988 Study

The 1988 data indicated that considerable variation in backwater area and
number may occur between years at anyone site. It is obvious that
backwaters are much more numerous and substantially larger above Desolation
than below it. If there is a direct correlation between backwater area and
Colorado squawfish young-of-the-year, researchers may use this information
in the design of future monitoring studies of the Green River.

Control of Green River flows seems an essential element in backwater
availability. High, fluctuating flows during the summer season are
detrimental to the survivability of Colorado squawfish. In contrast
however, high flow conditions before young-of-the-year squawfish enter the
system may be necessary to maximize backwater habitat by scouring out Green
River sediments. Durin the summer of 1989 the remote sensin section i
study how fluctuatlng flows an~ winte flow conditions alter bac water
~itat availability.

Videography Discussion

Thevideography study was preliminary in nature; however, we believe that
the data sufficiently indicate that airborne videography/MIPS may be used in
similar applications as aerial photography/GIS for backwater mapping and
river monitoring. Airborne videography has been employed in a number of
previous studies including forestry surveys (Harne and Markku 1988),
detection of saline soils (Everitt et al. 1988), rangeland ground conditions
(Everitt and Nixon 1985) and plant community studies (Nixon et al. 1985).

Meisner and Lindstrom (1985) summarized the negative and positive aspects of
aerial photography and airborne videography. The principal disadvantage of
videography is low resolution. That is, the number of lines across a video
format field are considerably less than that on an aerial photograph format
field Although the resolution of videography was cause for some error in the
videography results, it did not have a major effect on the quality of
backwater mapping on the Green River. In some instances wet sand was
mistaken for water, as well as the reverse situation. We believe this
confusion was caused by three primary factors: (1) the quality of the
Panasonic video was inferior (in comparison to the Ikigami video), producing
excessive blue tone and lacking in red tones. Further investigation of the
optimum video camera, including infrared video, is required. (2) The video
film used for this study was duplicated onto 1/2-inch tape from the original
3/4-inch tape. This resulted in lower resolution than is possible with an
original tape, and future studies will be conducted with the original 3/4-
inch tape. (3) The video interpreter had less experience identifying and
delineating backwaters than did the aerial photography interpreter. This
situation could easily be rectified through practice of interpretation
techniques. To minimize error, consistency should be maintained for any
river monitoring efforts by utilizing only one or two interpreters
throughout the course of the program which are familiar with backwater