ASTM D4410-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact
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Designation: D 4410 – 98
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Terminology for
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Fluvial Sediment
This standard is issued under the fixed designation D 4410; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope bed-load sampler—a device for sampling the bed-load.
bed material—the sediment mixture of which the stream bed
1.1 These terms are to be used by persons involved in
is composed.
collecting, reporting, and interpreting information pertaining to
bed-material discharge—that part of the total sediment dis-
sedimentation and hydrologic processes as they apply in the
charge composed of grain sizes occurring in appreciable
development, use, control, and conservation of water and land
quantities in the bed material.
resources.
bed-material load—that part of the total load which is
2. Terminology composed of particle sizes present in appreciable quantities
in the shifting portions of the stream bed.
2.1 Definitions:
boulder size (fluvial sediment)—larger than 256 mm in
accelerated erosion—erosion at a rate greater than geologic or
diameter.
natural erosion.
braided river—a wide- and shallow-river where the flow
passes through a number of small interlaced channels
DISCUSSION—Accelerated erosion is usually associated with anthro-
separated by bars or shoals.
pogenic activities and usually reduces plant cover and increases runoff.
channel—a natural or artificial waterway that periodically or
accretion—a process of sediment accumulation.
continuously contains moving water.
aggradation—the geologic process by which stream beds,
clay size (fluvial sediment)—0.00024 to 0.004 mm in diam-
flood plains, and the bottoms of other water bodies are raised
eter.
in elevation by the deposition of material eroded and
cobble size (fluvial sediment)—64 to 256 mm in diameter.
transported by water from other areas.
cohesive sediments—that material whose resistance to initial
alluvial deposit—sediment deposited by the action of moving
movement or erosion depends upon the strength of the bond
water.
between particles.
alluviation—the process of accumulating sediment deposits at
colloids (fluvial sediment)—smaller than 0.00024 mm in
places where the flow is retarded.
diameter.
alluvium—a general term for all fluvial deposits resulting
colluvial deposits—that material accumulated along valley
directly or indirectly from the sediment transport of (mod-
margins by mass movements from the adjacent hillsides.
ern) streams, thus including the sediments laid down in
composite sample—a sample formed by combining two or
riverbeds, flood plains, lakes, fans, and estuaries.
more individual samples or representative portions of the
armoring—the formation of a resistant layer of relatively large
samples.
particles by erosion of the finer particles.
concentration (volume)—the ratio of the volume of dry
avulsion—a sudden, natural change of a stream channel, so
sediment to the volume of the water-sediment mixture.
that the water flows elsewhere than in its previous course.
concentration of sediment (by mass)—the ratio of the mass
bag sampler—a sampler that utilizes a collapsible bag as the
of dry sediment in a water-sediment mixture to the mass of
sample collection container.
the mixture.
base flow—stream flow that is sustained by ground water and
critical flow—open channel flow in which the energy, ex-
other delayed sources.
pressed in terms of depth plus velocity head, is a minimum
bed-load—material moving on or near the stream bed by
for a given flow rate and channel. The Froude number is
rolling, sliding, and skipping.
unity at critical flow. D 5614
bed-load discharge—the quantity of bed-load passing a cross
debris—as applied to geologic debris flows, a mixture of
section of a stream in a unit of time.
loose, poorly-sorted rock fragments or soil material, or both,
potentially ranging from clay to boulder-size particles that
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may include fragmental organic matter and other exotic
This terminology is under the jurisdiction of ASTM Committee D-19 on Water
and is the direct responsibility of Subcommittee D19.07 on Sediments, Geomor- detritus.
phology, and Open-Channel Flow.
degradation—the geologic process by which stream beds,
Current edition approved Dec. 10, 1998. Published March 1999. Originally
flood plains, the bottoms of other water bodies, and other
published as D 4410 – 84. Last previous edition D 4410 – 97.
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NOTICE:¬This¬standard¬has¬either¬been¬superceded¬and¬replaced
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