levee:

An embankment, generally landward of top bank, that confines

flow during high-water periods, thus preventing overflow into

lowlands.

live-bed scour:

Scour at a pier or abutment (or contraction scour) when the

bed material in the channel upstream of the bridge is moving at

the flow causing bridge scour.

load (or sediment load):

Amount of sediment being moved by a stream.

local scour:

Removal of material from around piers, abutments, spurs, and

embankments caused by an acceleration of flow and resulting

vortices induced by obstructions to the flow.

longitudinal profile:

The profile of a stream or channel drawn along the length of its

centerline. In drawing the profile, elevations of the water

surface or the thalweg are plotted against distance as

measured from the mouth or from an arbitrary initial point.

lower bank:

That portion of a streambank having an elevation less than the

mean water level of the stream.

mathematical model:

A numerical representation of a flow situation using

mathematical equations (also computer model).

mattress:

A blanket or revetment of materials interwoven or otherwise

lashed together and placed to cover an area subject to scour.

meander or full

A meander in a river consists of two consecutive loops, one

meander:

flowing clockwise and the other counter-clockwise.

meander amplitude:

The distance between points of maximum curvature of

successive meanders of opposite phase in a direction normal

to the general course of the meander belt, measured between

center lines of channels.

meander belt:

The distance between lines drawn tangent to the extreme limits

of successive fully developed meanders.

meander length:

The distance along a stream between corresponding points of

successive meanders.

meander loop:

An individual loop of a meandering or sinuous stream lying

between inflection points with adjoining loops.

meander ratio:

The ratio of meander width to meander length.

meander radius

The radius of a circle inscribed on the centerline of a meander

of curvature:

loop.

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