1、Designation: D 4410 03Terminology forFluvial Sediment1This standard is issued under the fixed designation D 4410; 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
2、 of last reapproval. Asuperscript epsilon (e) 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 thed
3、evelopment, use, control, and conservation of water and landresources.2. Terminology2.1 Definitions:accelerated erosionerosion at a rate greater than geologic ornatural erosion.DISCUSSIONAccelerated erosion is usually associated with anthro-pogenic activities and usually reduces plant cover and incr
4、eases runoff.accretiona process of sediment accumulation.aggradationthe geologic process by which stream beds,flood plains, and the bottoms of other water bodies are raisedin elevation by the deposition of material eroded andtransported by water from other areas.alluvial depositsediment deposited by
5、 the action of movingwater.alluviationthe process of accumulating sediment deposits atplaces where the flow is retarded.alluviuma general term for all fluvial deposits resultingdirectly or indirectly from the sediment transport of (mod-ern) streams, thus including the sediments laid down inriverbeds
6、, flood plains, lakes, fans, and estuaries.armoringthe formation of a resistant layer of relatively largeparticles by erosion of the finer particles.avulsiona sudden, natural change of a stream channel, sothat the water flows elsewhere than in its previous course.bag samplera sampler that utilizes a
7、 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 bed byrolling, sliding, and skipping.bed-load dischargethe quantity of bed-load passing a crosssection of a stream in a uni
8、t 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 sediment dis-charge composed of grain sizes occurring in appreciablequantities in the bed material.bed-material loadthat part
9、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 indiameter.braided rivera wide- and shallow-river where the flowpasses through a number of small interlaced channelssepar
10、ated 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.cobble size (fluvial sediment)64 to 256 mm in diameter.cohesive sedimentsthat material whose resistance to initialmovemen
11、t or erosion depends upon the strength of the bondbetween particles.colloids (fluvial sediment)smaller than 0.00024 mm indiameter.colluvial depositsthat material accumulated along valleymargins by mass movements from the adjacent posite samplea sample formed by combining two ormore individual sample
12、s 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 mass)the ratio of the massof dry sediment in a water-sediment mixture to the mass ofthe mixture.critical flowopen channel
13、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 isunity at critical flow. D 56141This terminology is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.0
14、7 on Sediments, Geomor-phology, and Open-Channel Flow.Current edition approved Aug. 10, 2003. Published September 2003. Originallyapproved in 1984. Last previous edition approved in 1998 as D 4410 98.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
15、 United States.debrisas applied to geologic debris flows, a mixture ofloose, poorly-sorted rock fragments or soil material, or both,potentially ranging from clay to boulder-size particles thatmay include fragmental organic matter and other exoticdetritus.degradationthe geologic process by which stre
16、am beds,flood plains, the bottoms of other water bodies, and otherland surfaces are lowered in elevation by the removal ofmaterial by fluids.delivery rateuse sediment delivery ratio or sediment yield,whichever is meant.deltaa sediment deposit formed where moving water isslowed by a slower moving bod
17、y of water.density currentthe movement of one fluid under, through,or over another fluid of differing density.depositionthe chemical, mechanical, or biological processesthrough which sediments accumulate in a resting place.diameter, sedimentationthe diameter of a hypotheticalsphere of the same speci
18、fic 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 load.dispersed systemin laboratory analysis of grain sizes, aninitial condition whereby the particles begin to settle from astirred mix
19、ture; when stirring stops, each particle settlesindependently of other particles.dissolved loadthe part of the stream load that is carried asdissolved solids.dissolved solidsthe mass of constituents in a filtered watersample. For operational purposes, the filter pore is usually0.00045 mm.drainage ba
20、sinSee watershed.ephemeral gullya channel that is formed by gully erosion oncropland and that is routinely but temporarily obscured bymechanical operations such as tilling.fall velocitythe settling rate of a particle in a given medium.filtratethe fluid that has passed through a filter.filtrationthe
21、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 particles of a finer size than the particlespresent in appreciable quantities in the bed material; nor-mally, the fine-material load consis
22、ts of material finer than0.062 mm.flocculantan agent that produces flocs or aggregates fromsmall suspended particles.flocculating agenta coagulating substance such as alum,ferrous sulfate, or lime which, when added to water, forms aprecipitate that expedites the settling of suspended matter.fluvial
23、sedimentparticles derived from rocks, biologicalmaterials, or chemical precipitants, that are transported by,suspended in, or deposited by flowing water.gage heightthe height of a water surface above an estab-lished or arbitrary datum at a particular gaging station; alsotermed stage. D 5674gaging st
24、ationa particular site on a stream, canal, lake, orreservoir at which systematic observations of hydrologicdata are obtained. D 5674geologic erosionthe erosion process on a given land formthat is not associated with the activities of man.graded streama stream in which a steady state has beenreached
25、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 degree of mixing of size classes in sedimentarymaterial.gravel size (fluvial sediment)between 2.0 and 64 mm indiameter.gross erosionthe tota
26、l of all sheet, gully, and channel erosionin a watershed.hydraulic jumpan abrupt transition from supercritical flowto subcritical or tranquil flow, accompanied by considerableturbulence or gravity waves, or both. D 5614isokinetic samplingto sample in such a way that thewater-sediment mixture moves w
27、ith no change in velocity asit leaves the ambient flow and enters the sampler intake.lateral accretion depositsSee point bar.maximum transit ratethe maximum speed at which thesampler can be lowered and raised in the sampling verticaland still have the sample collected isokinetically.median diametert
28、he 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 denoted by the symbol “D50”.naturally dispersed samplea sample having sediment thatwill not settle in about 4 h due to the character of fi
29、neness ofparticles or due to the nature of the dissolved constituents, orboth.nephelometeran instrument that measures the amount oflight scattered in a suspension.overland flowrainfall runoff from a surface containingconcentrated flow no larger than rill flow.plane beda sedimentary stream bed withou
30、t 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 (convex) side of a riverbend.point-integrated samplea sample of water-sediment mix-ture collected at a relatively fixed point in accord
31、ance withthe technique of point integration. A point-integrated sampleis discharge weighted. However, because the sample isobtained from a single point, the concentration of anycomponent of the mixture that is transported exactly atstream velocity can be considered as either a spatial or adischarge-
32、weighted concentration. Samples collected withinstruments that instantaneously capture a quantity of water-sediment mixture are not true point-integrated samples. (Seepoint sample.)point integrationa method of sampling at a relatively fixedpoint whereby the water-sediment mixture is withdrawnisokine
33、tically for a specified period of time.pollutionthe condition caused by the presence of substancesof such character and in such quantities that the quality of theD 4410 032environment is impaired.reservoira man-made impounded body of water or con-trolled lake where water is collected and stored.reyn
34、olds 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 velocity,“L” is a characteristic length or distance such as pipediameter, “r” is the fluids mass density, and “m” is thefluids dynamic vis
35、cosity.ripplesmall, triangular-shaped bed forms that are similar todunes but smaller.roundnessthe ratio of the average radius of curvature of theindividual edges of a particle to the radius of the maximumcircle that can be inscribed within the particle.runoffthat part of precipitation appearing in s
36、urface streams.sampled zonethat part of a transect presumed to be whollyrepresented by sediment samples.sampling verticalan approximately vertical path from thewater surface to the bottom along which one or moresamples are collected to define various properties of the flow,such as sediment concentra
37、tion.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 section by the removal of theboundary material by the motion of a fluid.sedimentSee fluvial sediment.sediment deliverySee sediment yield.s
38、ediment delivery ratiothe ratio of sediment yield to grosserosion expressed in percent.sediment loada general term that refers to material insuspension or in transport, or both; it is not synonymous witheither discharge or concentration. (See bed-load andsuspended-sediment load.)sedimentologythe sci
39、entific study of sediment, sedimentaryrocks, and the processes by which they were formed.sediment particlefragment of mineral or organic material ineither a singular or aggregate state.sediment transport rateSee sediment discharge.settlingthe process of depositing, by gravity, matter sus-pended in w
40、ater.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 process by which sedimentary particles are se-lectively separated from associated but dissimilar particlesby flowing water.specific gravity
41、ratio 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 per unit volume of deposit in place. Syn-onymous with volume-weight.splaydeposits of flood debris, usually of sand, scattered onthe floo
42、d plain.split samplea single sample separated into two or moreindividual parts in a manner that each part is representativeof the original sample.standard-fall diameterthe diameter of a sphere with aspecific gravity of 2.65 and the same standard-fall velocityas the particle.standard-fall velocitythe
43、 rate of fall that a particle wouldfinally attain if falling alone in quiescent distilled water ofinfinite extent and a temperature of 24C.standard-sedimentation diameterthe diameter of a spherewith the same specific gravity and fall velocity as the givenparticle.stream dischargethe quantity of flow
44、 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;sometimes called tranquil flow. A Froude number less thanone exists. D 5614supercritical flowopen channel flow that is shallower and athig
45、her velocity than critical flow for the same flow rate. AFroude number greater than one exists. D 5614supernate or supernatantthe liquid above the surface ofsettled sediment.suspended sedimentsediment that is carried in suspensionby the turbulent components of the fluid or by Brownianmovement.suspen
46、ded-sediment concentrationSee concentration ofsediment (by mass).suspended-sediment dischargethe quantity of suspended-sediment passing through a stream cross section per unit oftime.suspended-sediment samplera device that collects a repre-sentative portion of the water with its suspended-sedimentlo
47、ad.terminal velocitythe limiting velocity reached by a particlefalling under the action of gravity in a still liquid at aspecified temperature.thalwegthe line connecting the lowest or deepest point alonga stream bed, valley, or reservoir, whether underwater or not.topset beda layer of sediment depos
48、ited on the top surfaceof an advancing delta that is continuous with the landwardalluvial plain.total-sediment dischargethe total quantity of sedimentpassing a section per unit of time.total-sediment load (total load)all of the sediment intransport; that part moving as suspended load plus thatmoving
49、 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 ratio computed by dividing the transitrate by the mean stream velocity in the vertical beingsampled.trap efficiencythe percent of the i
