ASTM_D_5541_-_94_2014.pdf

Designation:D554194(Reapproved 2014)Standard Practice forDeveloping a Stage-Discharge Relation for Open ChannelFlow1This standard is issued under the fixed designation D5541;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 of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the development of a curve relatingstage(elevation)to discharge.Standard test methods have beendocumented for measuring discharge and for measuring stage(see Practice D3858,and Test Methods D5129,D5130,D5243,D5388,and D5413).This practice takes the discharge andstage determined by each respective test method and shows arelation between them using a curved line.This curved line iscalled a stage-discharge relation or rating curve.1.2 The procedures described in this practice are usedcommonly by those responsible for investigations ofstreamflow,for example,the U.S.Geological Survey,ArmyCorps of Engineers,Bureau of Reclamation,and U.S Agricul-ture Research Service.For the most part,these procedures areadapted from reports of the U.S.Geological Survey.2,31.3 The procedures described in this practice apply only tosimple freely flowing open-channel flow.Ratings for complexhydraulic conditions of extremely low slope channels usingmultiple-stage inputs,channels affected by man-inducedregulation,or tidal conditions are not described.These types ofratings are described in detail in the documents listed inFootnotes 2 and 3.2,31.4 This practice uses the results of current-meter dischargemeasurements or indirect discharge measurements and thecorresponding measured stage to define as much of thestage-discharge relation curve as possible.A theoretical curveis developed for the full range of stage and discharge to shapethe curve.1.5 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.1.6 This standard does not purport 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:4D1129 Terminology Relating to WaterD3858 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 Method for Open-Channel Flow Measurementof Water Indirectly by Slope-Area MethodD5243 Test Method for Open-Channel Flow Measurementof Water Indirectly at CulvertsD5388 Test Method for Indirect Measurements of Dischargeby Step-Backwater MethodD5413 Test Methods for Measurement of Water Levels inOpen-Water Bodies2.2 ISO Standard:5ISO 1100/2 Liquid Flow Measurement in Open ChannelsPart 2,Determination of Stage-Discharge Relation3.Terminology3.1 DefinitionsFor definitions of terms used in thispractice,refer to Terminology D1129.3.2 Symbols:3.2.1 GHgauge height or stage,ft(m).3.2.2 Qdischarge,ft3/s(m3/s).1This practice is under the jurisdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.07 on Sediments,Geomorphology,and Open-Channel Flow.Current edition approved Jan.1,2014.Published March 2014.Originallyapproved in 1994.Last previous edition approved in 2008 as D5541 94(2008).DOI:10.1520/D5541-94R14.2Kennedy,E.J.,“Discharge Ratings at Gaging Stations:U.S.GeologicalSurvey,”Techniques of Water-Resource Investigations,Book 3,Chapt.A10,1984,p.59.3Rantz,S.E.,et al.,Measurement and Computation of Streamflow:Vol 2,Computation of Discharge,U.S.Geological Survey,Water-Supply Paper No.2175,1982,p.631.4For 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.5Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Practice4.1 The stage-discharge relation is developed by plottingstage versus discharge from discharge measurements or otherdeterminations of flow,either manually or through the use ofcomputer programs and fitting a curve to these points.Thestage should be determined at a single gage datum for the entirerange in stage.Stages determined in stilling wells,at outsidegages,and at bridge abutments can be significantly differentand should not be interchanged.Discharge measurements maynot be available for the entire range in stage of the stage-discharge relation.A theoretical r