7762

• UCREFRP Catalog Number: 7762
• Author: Valdez, R. A. and B. R. Cowdell.
• Title: Annual Summary Report-1994, Effects of Flow Regulation and Ice Formation on Overwinter Nursery Habitat of Age-0 Colorado Squawfish in the Green River Below Flaming Gorge Dam.
• USFW Year: 1994.
• USFW - Doc Type: \
• Copyright Material: NO

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Backwater

GLOSSARY

A body of water with no measurable velocity, created by a drop in water level which cuts off
flow through a secondary channel or a portion of the main river channel. Access to the main
river channel is not blocked. Backwaters ice over early and are one of the first habitats to
form solid ice cover.

cfs Cubic feet per second; 35.31 cfs = 1 ems

Free Water Depth

Frazil Ice

Depth of water above substrate and below ice cover (includes both surface ice and
frazil ice). Does not include water between ice layers.

Form of ice found on frozen rivers, caused by supercooled water in motion and formed as
variable size crystals; forms solid surface ice at low velocities or anchor ice at high velocities.

Freezing Point Depression ('d') Measure of the solute content of a solution, and hence its water diffusion
pressure through tissue membranes. Most freshwater teleosts (modem bony
fishes) have a 'd' for blood and plasma of about -O.570C.

Ice Lenses

Jam Ice

Surface Ice

Type of surface ice formed under fluctuating flow conditions. Typically an ice lens is formed
during high flow, then breaks from shore and collapses as the free water drops out beneath
it Ice lenses can form daily with daily fluctuating flows, forming and collapsing on top of
each other, creating a thick ice layer formed of many different lenses.

Form of ice mass found on frozen rivers, characterized by broken and dislodged blocks of ice
mixed with frazi1 ice.

Form of ice found on the surface of rivers and streams; formed by frazi1 ice crystals in areas
with current

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