bed form:
A recognizable relief feature on the bed of a channel, such as
a ripple, dune, plane bed, antidune, or bar. Bed forms are a
consequence of the interaction between hydraulic forces
(boundary shear stress) and the bed sediment.
bed layer:
A flow layer, several grain diameters thick (usually two)
immediately above the bed.
bed load:
Sediment that is transported in a stream by rolling, sliding, or
skipping along the bed or very close to it; considered to be
within the bed layer (contact load).
bed load discharge
The quantity of bed load passing a cross section of a stream in
(or bed load):
a unit of time.
bed material:
Material found in and on the bed of a stream (May be
transported as bed load or in suspension).
bedrock:
The solid rock exposed at the surface of the earth or overlain
by soils and unconsolidated material.
bed sediment discharge:
The part of the total sediment discharge that is composed of
grain sizes found in the bed and is equal to the transport
capability of the flow.
bed shear
The force per unit area exerted by a fluid flowing past a
(tractive force):
stationary boundary.
bed slope:
The inclination of the channel bottom.
blanket:
Material covering all or a portion of a streambank to prevent
erosion.
boulder:
A rock fragment whose diameter is greater than 250 mm.
braid:
A subordinate channel of a braided stream.
braided stream:
A stream whose flow is divided at normal stage by small
mid-channel bars or small islands; the individual width of bars
and islands is less than about three times water width; a
braided stream has the aspect of a single large channel within
which are subordinate channels.
bridge opening:
The cross-sectional area beneath a bridge that is available for
conveyance of water.
bridge waterway:
The area of a bridge opening available for flow, as measured
below a specified stage and normal to the principal direction of
flow.
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