1、Designation: D 5674 95 (Reapproved 2008)Standard Guide forOperation of a Gaging Station1This standard is issued under the fixed designation D 5674; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、 in 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 necessa
3、ry 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. Geologi
4、cal Survey, Bureau of Reclamation,U.S. Army Corps of Engineers, U.S. Department of Agricul-ture, Water Survey Canada, and many state and provincialagencies. The procedures are generally from internal docu-ments of the preceding agencies, which have become thedefacto standards used in North America.1
5、.3 It 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 operatingco
6、nditions 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
7、 to 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:2D 1129
8、 Terminology Relating to WaterD 1941 Test Method for Open Channel Flow Measurementof Water with the Parshall FlumeD 3858 Test Method for Open-Channel Flow Measurementof Water by Velocity-Area MethodD 5129 Test Method for Open Channel Flow Measurementof Water Indirectly by Using Width ContractionsD 5
9、130 Test Method for Open-Channel Flow Measurementof Water Indirectly by Slope-Area MethodD 5242 Test Method for Open-Channel Flow Measurementof Water with Thin-Plate WeirsD 5243 Test Method for Open-Channel Flow Measurementof Water Indirectly at CulvertsD 5388 Test Method for Indirect Measurements o
10、f Dis-charge by Step-Backwater MethodD 5389 Test Method for Open-Channel Flow Measurementby Acoustic Velocity Meter SystemsD 5390 Test Method for Open-Channel Flow Measurementof Water with Palmer-Bowlus FlumesD 5413 Test Methods for Measurement of Water Levels inOpen-Water BodiesD 5541 Practice for
11、Developing a Stage-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 Definitions: For definitions of te
12、rms used in this guide,refer to Terminology D 1129.3.2 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
13、.3.2.3 dischargethe volume of water flowing through across-section in a unit of time, including sediment or othersolids 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 t
14、ermed stage or gage height.1This 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 Oct. 1, 2008. Published November 2008. Originallyapproved in 1995. Last pr
15、evious edition approved in 2003 as D 5674 95 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Measurem
16、ent 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 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.5 gagea
17、generic 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 w
18、ater 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 1929prio
19、r 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 per
20、mits 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-l
21、evel 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. Signi
22、ficance 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. Locationconstrain
25、ts 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 Requirement
26、sCertain 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
27、should 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.
28、6.2.5 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
29、MethodsD 1941, D 5242, and D 5390.6.2.6 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 s
30、ensors 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
31、There 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-tio
32、n begins 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 usef
33、ulinformation 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
34、much 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 norther
35、n streams adds datathat result in improved site selection.6.3.3 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 legalpermission secured to
36、 install and maintain the gage. This mayinclude multiple landowners, especially if a cableway isrequired from which to make discharge measurements.D 5674 95 (2008)26.3.3.2 Necessary permits must be obtained from applicablegoverning agencies for, but not limited to, building andexcavation, stream ban
37、k permits, 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 importa
38、nt to 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 de
39、tailed 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 o
40、n non-recording gages, see TestMethods D 5413, 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 we
41、ll installed 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 dat
42、a because 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 D 5
43、413, ISO 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 mano
44、meter senses 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 di
45、fficult. Disadvantages are maintaining theorifice in a stable mounting on the river bed. Keeping theorifice from being buried in silty streams is also a problem. Fordetails on bubble-gages, see Test Methods D 5413, ISO 1100,and Refs (1-3, 5, 6).7.2.3 Acoustic Velocity Meter (AVM) stations directly s
46、enseand record the velocity observed between two transducers atfixed elevations in the channel cross section. The AVM gagesare used in locations in which stage-discharge relations areunreliable, usually in deep, slow-moving channels or wheretidal or bidirectional flow occurs. Additional information
47、isgiven in Test Method D 5389.4The boldface numbers in parentheses refer to the list of references at the end ofthis standard.FIG. 1 Stilling Well GageD 5674 95 (2008)38. Gaging Station Structures8.1 Stilling Well Functional RequirementsA stilling wellmust provide a water surface at the same elevati
48、on as that 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
49、plan view;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 usuall
