1、Designation: D5674 95 (Reapproved 2014)Standard Guide forOperation of a Gaging Station1This standard is issued under the fixed designation D5674; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 The guide covers procedures used commonly for thesystematic collection of streamflow information. Continuousstreamflow information is necessary
3、 for understanding theamount and variability of water for many uses, including watersupply, waste dilution, irrigation, hydropower, and reservoirdesign.1.2 The procedures described in this guide are used widelyby those responsible for the collection of streamflow data, forexample, the U.S. Geologica
4、l Survey, Bureau of Reclamation,U.S. Army Corps of Engineers, U.S. Department ofAgriculture, Water Survey Canada, and many state and pro-vincial agencies. The procedures are generally from internaldocuments of the preceding agencies, which have become thedefacto standards used in North America.1.3 I
5、t is the responsibility of the user of the guide todetermine the acceptability of a specific device or procedure tomeet operational requirements. Compatibility between sensors,recorders, retrieval equipment, and operational systems isnecessary, and data requirements and environmental operatingcondit
6、ions must be considered in equipment selection.1.4 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.5 This standard does not purport to
7、address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Term
8、inology Relating to WaterD1941 Test Method for Open Channel Flow Measurementof Water with the Parshall FlumeD3858 Test Method for Open-Channel Flow Measurementof Water by Velocity-Area MethodD5129 Test Method for Open Channel Flow Measurementof Water Indirectly by Using Width ContractionsD5130 Test
9、Method for Open-Channel Flow Measurementof Water Indirectly by Slope-Area MethodD5242 Test Method for Open-Channel Flow Measurementof Water with Thin-Plate WeirsD5243 Test Method for Open-Channel Flow Measurementof Water Indirectly at CulvertsD5388 Test Method for Indirect Measurements of Dischargeb
10、y Step-Backwater MethodD5389 Test Method for Open-Channel Flow Measurementby Acoustic Velocity Meter SystemsD5390 Test Method for Open-Channel Flow Measurementof Water with Palmer-Bowlus FlumesD5413 Test Methods for Measurement of Water Levels inOpen-Water BodiesD5541 Practice for Developing a Stage
11、-Discharge Relationfor Open Channel Flow2.2 ISO Standards:3ISO 1100 Liquid Flow Measurement in Open ChannelsPart I: Establishment and Operation of a Gauging StationISO 6416 Measurement of Discharge by Ultrasonic (Acous-tic) Method3. Terminology3.1 DefinitionsFor definitions of terms used in this gui
12、de,refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 controlthe physical properties of a channel, whichdetermine the relationship between the stage and discharge ofa location in the channel.3.2.2 datuma level plane that represents zero elevation.3.2.3 dischargethe v
13、olume of water flowing through across-section in a unit of time, including sediment or other1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.07 on Sediments, Geomorphology,and Open-Channel Flow.Current edition approved Jan. 1, 2
14、014. Published March 2014. Originallyapproved in 1995. Last previous edition approved in 2008 as D5674 95 (2008).DOI: 10.1520/D5674-95R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
15、information, refer to the standards Document Summary page onthe ASTM website.3Measurement of Liquid Flow in Open Channels, ISO Standards Handbook 16,1983.Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.Copyright ASTM International, 100 Barr Ha
16、rbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1solids that may be dissolved in or mixed with the water; usuallycubic feet per second (f3/s) or metres per second (m/s).3.2.4 elevationthe vertical distance from a datum to apoint; also termed stage or gage height.3.2.5 gagea g
17、eneric term that includes water level mea-suring devices.3.2.6 gage datuma datum whose surface is at the zeroelevation of all of the gages at a gaging station. This datum isoften at a known elevation referenced to the national geodeticvertical datum (NGVD) of 1929.3.2.7 gage heightthe height of a wa
18、ter surface above anestablished or arbitrary datum at a particular gaging station;also termed stage.3.2.8 gaging stationa particular site on a stream, canal,lake, or reservoir at which systematic observations of hydro-logic data are obtained.3.2.9 national geodetic vertical datum (NGVD) of 1929prior
19、 to 1973 known as mean sea level datum, a spheroidaldatum in the conterminous United States and Canada thatapproximates mean sea level but does not necessarily agreewith sea level at a specific location.3.2.10 stilling wella well connected to the stream withintake pipes in such a manner that it perm
20、its the measurementof stage in relatively still water.4. Summary of Guide4.1 A gaging station is usually installed where a continuousrecord of stage or discharge is required. A unique relationshipexists between water surface elevation and discharge (flowrate) in most freely flowing streams. Water-le
21、vel recordinginstruments continuously record the water surface elevation,usually termed stage or gage height. Discharge measurementsare taken of the stream discharge to develop a stage-dischargecurve. The discharge data are computed from recorded stagedata by a stage-discharge rating curve.5. Signif
22、icance and Use5.1 This guide is useful when a systematic record of watersurface elevation or discharge is required at a specific location.Some gaging stations may be operated for only a few months;however, many have been operated for a century.5.2 Gaging station records are used for many purposes:5.
23、2.1 Resource appraisal of long-term records to determinethe maximum, minimum, and variability of flows of a particu-lar stream. These data can be used for the planning and designof a variety of surface water-related projects such as watersupply, flood control, hydroelectric developments, irrigation,
24、recreation, and waste assimilation.5.2.2 Management, where flow data are required for theoperation of a surface-water structure or other managementdecision.6. Site Location6.1 The general location of the station will be dependent onthe purpose for which the station is established. Locationconstraint
25、s for a resource appraisal-type station may be quitebroad, for example, between major tributaries. Constraints fora management-type station may require a location just below adam, contaminant discharge point, or other point at whichdischarge information is required specifically.6.2 Site Requirements
26、Certain hydraulic characteristics ofthe stream channel are desirable for collecting high-accuracydata of minimal cost. Hydraulically difficult sites can still begaged; however, accuracy and cost are affected adversely.Desirable conditions include the following:6.2.1 The general course of the river s
27、hould be straight forapproximately 300 ft (100 m) above and below the gage.6.2.2 The flow is confined to one channel at all stages.6.2.3 The stream bed is stable, not subject to frequent scourand fill, and is free of aquatic growth.6.2.4 The banks are sufficiently high to contain flow at allstages.6
28、.2.5 A natural feature such as ledge rock outcrop or stablegravel riffle, known as a “control,” is present in the stream. Itis necessary and practical in some cases to install a low-headdam or artificial control to provide this feature. Additionalinformation on man-made structures is given in Test M
29、ethodsD1941, D5242, and D5390.6.2.6 A pool is present behind the control where water-levelinstruments or stilling well intakes can be installed at a locationbelow the lowest stream stage. The velocity of water passingsensors in a deep pool also eliminates or minimizes draw-downeffects on stage senso
30、rs during high flow conditions.6.2.7 The site is not affected by the hydraulic effects of abridge, tributary stream entering the gaged channel, down-stream impoundment, or tidal conditions.6.2.8 A suitable site for making discharge measurements atall stages is available near the gage site.6.2.9 Ther
31、e is accessibility for construction and operation ofthe gage.6.3 Site SelectionAn ideal site is rarely available, andjudgement must be exercised when choosing between possiblesites to determine that meeting the best combination offeatures.6.3.1 Offce ReconnaissanceThe search for a gaging sta-tion be
32、gins with defining the limits along the stream at whichthe gage must be located on topographic maps of the area. Thetopographic information will indicate approximate bankheights or overflow areas, general channel width, constrictions,slope, roads, land use, locations of buildings, and other usefulin
33、formation so that promising locations can be checked out inthe field.6.3.2 Field ReconnaissanceIf the range of possible gagelocations is large, flying over the stream at a low altitude in asmall aircraft is an efficient way of checking for promisingsites. The view from the air on a clear day is much
34、 more helpfulthan peering off of a few highway bridges. Traversing thechannel in a canoe or small boat is an alternative method. Fieldreconnaissance is best performed during low flow conditions;however, additional reconnaissance at high flow conditions andunder ice-covered conditions for northern st
35、reams adds datathat result in improved site selection.D5674 95 (2014)26.3.3 Logistical ReconnaissanceOnce a site has beenselected that meets hydraulic considerations, and before designor construction begins, the following should occur:6.3.3.1 Property ownership must be ascertained and legalpermissio
36、n secured to install and maintain the gage. This mayinclude multiple landowners, especially if a cableway isrequired from which to make discharge measurements.6.3.3.2 Necessary permits must be obtained from applicablegoverning agencies for, but not limited to, building andexcavation, stream bank per
37、mits, and FAA notification forcableways or other local requirements.6.3.3.3 Where electrical or phone service is required foroperation, the availability of this service should be verified.6.3.3.4 Most gaging stations are intended to record over therange of stream stages. It is therefore important to
38、 obtain anylocal information available on historical flood levels and tomake estimates of stage for a 100-year event using locally usedflood-frequency equations. A cross-section survey of the chan-nel should be obtained during field reconnaissance to aid inestimating high flow stage.6.4 More detaile
39、d information is available in Refs (1-3)4and ISO-1100.7. Types of Gaging Stations7.1 Non-recording stations can be as simple as a permanentstaff gage attached to a bridge, pier, or other structure, which isread and recorded manually in an appropriate notebook once ormore each day. For details on non
40、-recording gages, see TestMethods D5413, ISO 1100, and Refs (1-4).7.2 Recording gages are usually nonattended installationsthat require a sensor in direct contact with the water that isconnected mechanically or electrically to a recording device.7.2.1 Stilling well-type gages use a vertical well ins
41、talled inthe stream bank with small-diameter intake pipes connectingthe river to the well. In this type of installation, a float on thewater surface in the well drives a recorder housed in a shelterover the well by mechanical means (Fig. 1). Stilling well gagestend to provide more reliable data beca
42、use water-level sensingas well as recording components of the system are protectedfrom direct installation in the stream. Disadvantages arelocations with unstable stream channels that may move awayfrom the intakes and higher initial cost. For details on stillingwell gages, see Test Methods D5413, IS
43、O 1100, and Refs (1-3,5).7.2.2 Bubbler-type gages consist of a gas supply, usuallynitrogen, which is fed through a controller and tube to anorifice attached near the bed of a stream. The gas pressure isequal to the liquid head in the stream. A pressure transducer,mercury, or balance-beam manometer s
44、enses this pressure andpasses this information either mechanically or electronically toa compatible recorder (Fig. 2). The advantage to this system isless expensive construction costs, which is especially desirablefor short-term gages or in locations in which stilling wellinstallations are difficult
45、. Disadvantages are maintaining theorifice in a stable mounting on the river bed. Keeping the4The boldface numbers in parentheses refer to the list of references at the end ofthis standard.FIG. 1 Stilling Well GageD5674 95 (2014)3orifice from being buried in silty streams is also a problem. Fordetai
46、ls on bubble-gages, see Test Methods D5413, ISO 1100,and Refs (1-3, 5, 6).7.2.3 Acoustic Velocity Meter (AVM) stations directly senseand record the velocity observed between two transducers atfixed elevations in the channel cross section. The AVM gagesare used in locations in which stage-discharge r
47、elations areunreliable, usually in deep, slow-moving channels or wheretidal or bidirectional flow occurs. Additional information isgiven in Test Method D5389.8. Gaging Station Structures8.1 Stilling Well Functional RequirementsA stilling wellmust provide a water surface at the same elevation as that
48、 ofthe stream at any point in time, dampen out the effect of surfacewaves, and provide a sensor, usually a float and recordingsystem.8.1.1 The stilling well must be sufficiently long to cover theentire range of stages that might occur reasonably.8.1.2 The stilling well can be any shape in plan view;
49、however, most are either round or square. Permanent long-termgages should have a large enough area to allow personnel towork inside them for servicing; the most common size isapproximately 4 by 4 ft (1.2 by 1.2 m). Some semipermanentstilling wells may be as small as 1 ft (0.3 m).8.1.3 Stilling wells may be fabricated from poured concrete,concrete blocks, galvanized steel, concrete culvert pipe, orother suitable material. The well must have a sealed bottom topreclude the interchange of water from the stream and groundwater.8.1.4 Stilling wells are usually install
