meander scrolls:
Low, concentric ridges and swales on a floodplain, marking the
successive positions of former meander loops.
meander width:
The amplitude of a fully developed meander measured from
midstream to midstream.
meandering stream:
A stream having a sinuosity greater than some arbitrary value.
The term also implies a moderate degree of pattern symmetry,
imparted by regularity of size and repetition of meander loops.
The channel generally exhibits a characteristic process of bank
erosion and point bar deposition associated with systematically
shifting meanders.
median diameter:
The particle diameter of the 50th percentile point on a size
distribution curve such that half of the particles (by weight,
number, or volume) are larger and half are smaller (D50.)
mid-channel bar:
A bar lacking permanent vegetal cover that divides the flow in a
channel at normal stage.
middle bank:
The portion of a streambank having an elevation approximately
the same as that of the mean water level of the stream.
migration:
Change in position of a channel by lateral erosion of one bank
and simultaneous accretion of the opposite bank.
mud:
A soft, saturated mixture mainly of silt and clay.
natural levee:
A low ridge that slopes gently away from the channel banks
that is formed along streambanks during floods by deposition.
nominal diameter:
Equivalent spherical diameter of a hypothetical sphere of the
same volume as a given sediment particle.
nonalluvial channel:
A channel whose boundary is in bedrock or non-erodible
material.
normal stage:
The water stage prevailing during the greater part of the year.
overbank flow:
Water movement that overtops the bank either due to stream
stage or to overland surface water runoff.
oxbow:
The abandoned former meander loop that remains after a
stream cuts a new, shorter channel across the narrow neck of
a meander. Often bow-shaped or horseshoe-shaped.
pavement:
Streambank surface covering, usually impermeable, designed
to serve as protection against erosion. Common pavements
used on streambanks are concrete, compacted asphalt, and
soil-cement.
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