1、Designation: D4410 10Terminology forFluvial Sediment1This standard is issued under the fixed designation D4410; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year o
2、f last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These terms are to be used by persons involved incollecting, reporting, and interpreting information pertaining tosedimentation and hydrologic processes as they apply in thedeve
3、lopment, use, control, and conservation of water and landresources.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Terminology2.1 Definitions:accelerated erosionerosion at a rate greater than geologic ornatural erosion.DI
4、SCUSSIONAccelerated erosion is usually associated with anthro-pogenic activities and usually reduces plant cover and increases runoff.accretiona process of sediment accumulation.aggradationthe geologic process by which stream beds,flood plains, and the bottoms of other water bodies are raisedin elev
5、ation by the deposition of material eroded andtransported by water from other areas.alluvial depositsediment deposited by the action of movingwater.alluviationthe process of accumulating sediment deposits atplaces where the flow is retarded.alluviuma general term for all fluvial deposits resultingdi
6、rectly or indirectly from the sediment transport of (mod-ern) streams, thus including the sediments laid down inriverbeds, flood plains, lakes, fans, and estuaries.armoringthe formation of a resistant layer of relatively largeparticles by erosion of the finer particles.avulsiona sudden, natural chan
7、ge of a stream channel, sothat the water flows elsewhere than in its previous course.bag samplera sampler that utilizes a collapsible bag as thesample collection container.base flowstream flow that is sustained by ground water andother delayed sources.bed-loadmaterial moving on or near the stream be
8、d byrolling, sliding, and skipping.bed-load dischargethe quantity of bed-load passing a crosssection of a stream in a unit of time.bed-load samplera device for sampling the bed-load.bed materialthe sediment mixture of which the stream bedis composed.bed-material dischargethat part of the total sedim
9、ent dis-charge composed of grain sizes occurring in appreciablequantities in the bed material.bed-material loadthat part of the total load which iscomposed of particle sizes present in appreciable quantitiesin the shifting portions of the stream bed.boulder size (fluvial sediment)larger than 256 mm
10、indiameter.braided rivera wide- and shallow-river where the flowpasses through a number of small interlaced channelsseparated by bars or shoals.channela natural or artificial waterway that periodically orcontinuously contains moving water.clay size (fluvial sediment)0.00024 to 0.004 mm in diam-eter.
11、cobble size (fluvial sediment)64 to 256 mm in diameter.cohesive sedimentsthat material whose resistance to initialmovement or erosion depends upon the strength of the bondbetween particles.colloids (fluvial sediment)smaller than 0.00024 mm indiameter.colluvial depositsthat material accumulated along
12、 valleymargins by mass movements from the adjacent posite samplea sample formed by combining two ormore individual samples or representative portions of thesamples.concentration (volume)the ratio of the volume of drysediment to the volume of the water-sediment mixture.concentration of sediment (by m
13、ass)the ratio of the massof dry sediment in a water-sediment mixture to the mass ofthe mixture.critical flowopen channel flow in which the energy, ex-pressed in terms of depth plus velocity head, is a minimumfor a given flow rate and channel. The Froude number is1This terminology is under the jurisd
14、iction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.07 on Sediments, Geomor-phology, and Open-Channel Flow.Current edition approved Feb. 1, 2010. Published March 2010. Originallyapproved in 1984. Last previous edition approved in 2003 as D4410 03. DOI:10.1520/D4
15、410-10.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.unity at critical flow. D5614debrisas applied to geologic debris flows, a mixture ofloose, poorly-sorted rock fragments or soil material, or both,potentially ranging from clay to
16、 boulder-size particles thatmay include fragmental organic matter and other exoticdetritus.degradationthe geologic process by which stream beds,flood plains, the bottoms of other water bodies, and otherland surfaces are lowered in elevation by the removal ofmaterial by fluids.delivery rateuse sedime
17、nt delivery ratio or sediment yield,whichever is meant.deltaa sediment deposit formed where moving water isslowed by a slower moving body of water.density currentthe movement of one fluid under, through,or over another fluid of differing density.depositionthe chemical, mechanical, or biological proc
18、essesthrough which sediments accumulate in a resting place.diameter, sedimentationthe diameter of a hypotheticalsphere of the same specific gravity and the same settlingvelocity as the given particle in the same fluid.direct-measuring bed-load samplera device which physi-cally collects and holds bed
19、 load.dispersed systemin laboratory analysis of grain sizes, aninitial condition whereby the particles begin to settle from astirred mixture; when stirring stops, each particle settlesindependently of other particles.dissolved loadthe part of the stream load that is carried asdissolved solids.dissol
20、ved solidsthe mass of constituents in a filtered watersample. For operational purposes, the filter pore is usually0.00045 mm.drainage basinSee watershed.ephemeral gullya channel that is formed by gully erosion oncropland and that is routinely but temporarily obscured bymechanical operations such as
21、tilling.fall velocitythe settling rate of a particle in a given medium.filtratethe fluid that has passed through a filter.filtrationthe process of passing a liquid through a porousmedium for the removal of suspended matter.fine-material loadthat part of the total sediment load that iscomposed of par
22、ticles of a finer size than the particlespresent in appreciable quantities in the bed material; nor-mally, the fine-material load consists of material finer than0.062 mm.flocculantan agent that produces flocs or aggregates fromsmall suspended particles.flocculating agenta coagulating substance such
23、as alum,ferrous sulfate, or lime which, when added to water, forms aprecipitate that expedites the settling of suspended matter.fluvial sedimentparticles derived from rocks, biologicalmaterials, or chemical precipitants, that are transported by,suspended in, or deposited by flowing water.gauge heigh
24、tthe height of a water surface above an estab-lished or arbitrary datum at a particular gauging station; alsotermed stage. D5674gauging stationa particular site on a stream, canal, lake, orreservoir at which systematic observations of hydrologicdata are obtained. D5674geologic erosionthe erosion pro
25、cess on a given land formthat is not associated with the activities of man.graded streama stream in which a steady state has beenreached such that over a period of time the discharge andsediment load entering the system are balanced by thedischarge and sediment load leaving the system.gradingthe deg
26、ree of mixing of size classes in sedimentarymaterial.gravel size (fluvial sediment)between 2.0 and 64 mm indiameter.gross erosionthe total of all sheet, gully, and channel erosionin a watershed.hydraulic jumpan abrupt transition from supercritical flowto subcritical or tranquil flow, accompanied by
27、considerableturbulence or gravity waves, or both. D5614isokinetic samplingto sample in such a way that thewater-sediment mixture moves with no change in velocity asit leaves the ambient flow and enters the sampler intake.lateral accretion depositsSee point bar.maximum transit ratethe maximum speed a
28、t which thesampler can be lowered and raised in the sampling verticaland still have the sample collected isokinetically.median diameterthe grain diameter such that half of thesediment by mass is composed of particles of larger size andhalf by mass is composed of particles of smaller size;commonly de
29、noted by the symbol “D50”.naturally dispersed samplea sample having sediment thatwill not settle in about 4 h due to the character of fineness ofparticles or due to the nature of the dissolved constituents, orboth.nephelometeran instrument that measures the amount oflight scattered in a suspension.o
30、verland flowrainfall runoff from a surface containingconcentrated flow no larger than rill flow.plane beda sedimentary stream bed without elevations ordepressions larger than the maximum size of the bedmaterial.point barone or a series of low ridges, usually of coarsesediment, deposited on the inner
31、 (convex) side of a riverbend.point-integrated samplea sample of water-sediment mix-ture collected at a relatively fixed point in accordance withthe technique of point integration. A point-integrated sampleis discharge weighted. However, because the sample isobtained from a single point, the concent
32、ration of anycomponent of the mixture that is transported exactly atstream velocity can be considered as either a spatial or adischarge-weighted concentration. Samples collected withinstruments that instantaneously capture a quantity of water-sediment mixture are not true point-integrated samples. (
33、Seepoint sample.)point integrationa method of sampling at a relatively fixedpoint whereby the water-sediment mixture is withdrawnisokinetically for a specified period of time.pollutionthe condition caused by the presence of substancesof such character and in such quantities that the quality of theen
34、vironment is impaired.D4410 102reservoira man-made impounded body of water or con-trolled lake where water is collected and stored.reynolds numbera dimensionless number expressing theratio of inertia forces to viscous forces in a moving fluid. Thenumber is given by VLr/m where “V”, is the fluids vel
35、ocity,“L” is a characteristic length or distance such as pipediameter, “r” is the fluids mass density, and “m” is thefluids dynamic viscosity.ripplesmall, triangular-shaped bed forms that are similar todunes but smaller.roundnessthe ratio of the average radius of curvature of theindividual edges of
36、a particle to the radius of the maximumcircle that can be inscribed within the particle.runoffthat part of precipitation appearing in surface streams.sampled zonethat part of a transect presumed to be whollyrepresented by sediment samples.sampling verticalan approximately vertical path from thewater
37、 surface to the bottom along which one or moresamples are collected to define various properties of the flow,such as sediment concentration.sand size (fluvial sediment)0.062 to 2 mm in diameter.scale of particle sizesbased on AGU (American Geophysi-cal Union) scale.scourthe enlargement of a flow sec
38、tion by the removal of theboundary material by the motion of a fluid.sedimentSee fluvial sediment.sediment deliverySee sediment yield.sediment delivery ratiothe ratio of sediment yield to grosserosion expressed in percent.sediment loada general term that refers to material insuspension or in transpo
39、rt, or both; it is not synonymous witheither discharge or concentration. (See bed-load andsuspended-sediment load.)sedimentologythe scientific study of sediment, sedimentaryrocks, and the processes by which they were formed.sediment particlefragment of mineral or organic material ineither a singular
40、 or aggregate state.sediment transport rateSee sediment discharge.settlingthe process of depositing, by gravity, matter sus-pended in water.silt size (fluvial sediment)0.004 to 0.062 mm in diameter.siltationSee deposition.sloughsa stagnant or sluggish channel of water in a floodplain.sortingthe proc
41、ess by which sedimentary particles are se-lectively separated from associated but dissimilar particlesby flowing water.specific gravityratio of the mass of any volume of asubstance to the mass of an equal volume of water at 4C.specific weight (of sediment deposits) the dry weight ofsediment solids p
42、er unit volume of deposit in place. Syn-onymous with volume-weight.splaydeposits of flood debris, usually of sand, scattered onthe flood plain.split samplea single sample separated into two or moreindividual parts in a manner that each part is representativeof the original sample.standard-fall diame
43、terthe diameter of a sphere with aspecific gravity of 2.65 and the same standard-fall velocityas the particle.standard-fall velocitythe rate of fall that a particle wouldfinally attain if falling alone in quiescent distilled water ofinfinite extent and a temperature of 24C.standard-sedimentation dia
44、meterthe diameter of a spherewith the same specific gravity and fall velocity as the givenparticle.stream dischargethe quantity of flow passing through across section in a unit of time.subcritical flowopen channel flow that is deeper and atlower velocity than critical flow for the same flow rate;som
45、etimes called tranquil flow. A Froude number less thanone exists. D5614supercritical flowopen channel flow that is shallower and athigher velocity than critical flow for the same flow rate. AFroude number greater than one exists. D5614supernate or supernatantthe liquid above the surface ofsettled se
46、diment.suspended sedimentsediment that is carried in suspensionby the turbulent components of the fluid or by Brownianmovement.suspended-sediment concentrationSee concentration ofsediment (by mass).suspended-sediment dischargethe quantity of suspended-sediment passing through a stream cross section
47、per unit oftime.suspended-sediment samplera device that collects a repre-sentative portion of the water with its suspended-sedimentload.terminal velocitythe limiting velocity reached by a particlefalling under the action of gravity in a still liquid at aspecified temperature.thalwegthe line connecti
48、ng the lowest or deepest point alonga stream bed, valley, or reservoir, whether underwater or not.topset beda layer of sediment deposited on the top surfaceof an advancing delta that is continuous with the landwardalluvial plain.total-sediment dischargethe total quantity of sedimentpassing a section
49、 per unit of time.total-sediment load (total load)all of the sediment intransport; that part moving as suspended load plus thatmoving as bedload.tractiontransport of debris by running water in which theparticles are swept along close to the bed of the stream byrolling, sliding, or saltation.tranquil flowsee subcritical flow.transit ratethe speed at which the suspended-sedimentsampler is lowered and raised in the sampling vertical.transit-rate ratiothe ra
