ASTM D5541-94(2003)

Standard Practice for Developing a Stage-Discharge Relation for Open Channel Flow

SIGNIFICANCE AND USE
This practice is particularly useful for determining the discharge at a gaging station or a location where discharge information is repeatedly needed.
This practice is applicable only for open-channel flow conditions where channel hydraulics permit a stable relation between stage and discharge.
SCOPE
1.1 This practice covers the development of a curve relating stage (elevation) to discharge. Standard test methods have been documented for measuring discharge and for measuring stage (see Practice D 3858, and Test Methods D 5129, D 5130, D 5243, D 5388, and D 5413). This practice takes the discharge and stage determined by each respective test method and shows a relation between them using a curved line. This curved line is called a stage-discharge relation or rating curve.
1.2 The procedures described in this practice are used commonly by those responsible for investigations of streamflow, for example, the U.S. Geological Survey, Army Corps of Engineers, Bureau of Reclamation, and U.S Agriculture Research Service. For the most part, these procedures are adapted from reports of the U.S. Geological Survey.²,³
1.3 The procedures described in this practice apply only to simple freely flowing open-channel flow. Ratings for complex hydraulic conditions of extremely low slope channels using multiple-stage inputs, channels affected by man-induced regulation, or tidal conditions are not described. These types of ratings are described in detail in the documents listed in Footnotes 2 and 3.
1.4 This practice uses the results of current-meter discharge measurements or indirect discharge measurements and the corresponding measured stage to define as much of the stage-discharge relation curve as possible. A theoretical curve is developed for the full range of stage and discharge to shape the curve.
1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Jun-2003
• Technical Committee: D19 - Water
• Drafting Committee: D19.07 - Sediments, Geomorphology, and Open-Channel Flow

Relations

• Replaces: ASTM D5541-94(1998) - Standard Practice for Developing a Stage-Discharge Relation for Open Channel Flow
• Effective Date: 10-Jun-2003
• Replaced By: ASTM D5541-94(2008) - Standard Practice for Developing a Stage-Discharge Relation for Open Channel Flow
• Effective Date: 01-Oct-2008
• Referred By: ASTM D5674-22 - Standard Guide for Operation of a Gaging Station
• Effective Date: 10-Jun-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D 5541–94 (Reapproved 2003)
Standard Practice for
Developing a Stage-Discharge Relation for Open Channel
Flow
This standard is issued under the fixed designation D 5541; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This practice covers the development of a curve relating
bility of regulatory limitations prior to use.
stage(elevation)todischarge.Standardtestmethodshavebeen
documented for measuring discharge and for measuring stage
2. Referenced Documents
(see Practice D 3858, and Test Methods D 5129, D 5130,
2.1 ASTM Standards:
D 5243, D 5388, and D 5413). This practice takes the dis-
D 1129 Terminology Relating to Water
charge and stage determined by each respective test method
D 3858 Practice for Open-Channel Flow Measurement of
and shows a relation between them using a curved line. This
Water by Velocity-Area Method
curved line is called a stage-discharge relation or rating curve.
D 5129 Test Method for Open Channel Flow Measurement
1.2 The procedures described in this practice are used
of Water Indirectly by Using Width Contractions
commonly by those responsible for investigations of stream-
D 5130 Test Method for Open-Channel Flow Measurement
flow, for example, the U.S. Geological Survey,Army Corps of
of Water Indirectly by Slope-Area Method
Engineers, Bureau of Reclamation, and U.S Agriculture Re-
D 5243 Test Method for Open-Channel Flow Measurement
search Service. For the most part, these procedures are adapted
,
2 3 of Water Indirectly at Culverts
from reports of the U.S. Geological Survey.
D 5388 Test Method for Measurement of Discharge by
1.3 The procedures described in this practice apply only to
Step-Backwater Method
simple freely flowing open-channel flow. Ratings for complex
D 5413 Test Methods for Measurement of Water Levels in
hydraulic conditions of extremely low slope channels using
Open Water Bodies
multiple-stage inputs, channels affected by man-induced regu-
2.2 ISO Standard:
lation, or tidal conditions are not described. These types of
ISO 1100/2 Liquid Flow Measurement in Open Channels—
ratings are described in detail in the documents listed in
Part 2, Determination of Stage-Discharge Relation
Footnotes 2 and 3.
1.4 This practice uses the results of current-meter discharge
3. Terminology
measurements or indirect discharge measurements and the
3.1 Definitions—For definitions of terms used in this prac-
corresponding measured stage to define as much of the
tice, refer to Terminology D 1129.
stage-discharge relation curve as possible. A theoretical curve
3.2 Symbols:Symbols:
is developed for the full range of stage and discharge to shape
GH = gage height or stage, ft (m).
the curve.
3 3
Q = discharge, ft /s (m /s).
1.5 The values stated in inch-pound units are to be regarded
as the standard. The values given in parentheses are for
4. Summary of Practice
information only.
4.1 The stage-discharge relation is developed by plotting
1.6 This standard does not purport to address all of the
stage versus discharge from discharge measurements or other
safety concerns, if any, associated with its use. It is the
determinations of flow, either manually or through the use of
computer programs and fitting a curve to these points. The
This practice is under the jurisdiction of ASTM Committee D19 on Water and
stageshouldbedeterminedatasinglegagedatumfortheentire
is the direct responsibility of Subcommittee D19.07 on Sediments, Geomorphology,
range in stage. Stages determined in stilling wells, at outside
and Open-Channel Flow.
gages, and at bridge abutments can be significantly different
Current edition approved June 10, 2003. Published August 2003. Originally
approved in 1994. Last previous edition approved in 1998 as D 5541 – 94(1998). and should not be interchanged. Discharge measurements may
Kennedy, E. J., “Discharge Ratings at Gaging Stations: U.S. Geological
Survey,” Techniques of Water-Resource Investigations, Book 3, Chapt. A10, 1984,
p. 59.
3 4
Rantz, S. E., et al., Measurement and Computation of Streamflow: Vol 2, Annual Book of ASTM Standards, Vol 11.01.
Computation of Discharge, U.S. Geological Survey, Water-Supply Paper No. 2175, Available from American National Standards Institute, 25 West 43rd St., 4th
1982, p. 631. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5541–94 (2003)
not be available for the entire range in stage of the stage- In other instances, a combination control may consist of two
discharge relation. A theoretical rating curve should be devel- section controls, where each has partial controlling effect.
oped for the entire range in stage using Test Method D 5388. Combination controls or transition zones, or both, occur for
This theoretical curve is used as a guide to shape the stage- very limited parts of a stage-discharge relation and can usually
discharge relation at places where discharge measurements are be defined by plotting procedures. In particular, transition
not available. zones represent changes in the slope or shape of a stage-
discharge relation.
5. Significance and Use
6.2 Low flows are usually controlled by a section control,
5.1 This practice is particularly useful for determining the
whereas high flows are usually controlled by a channel control.
discharge at a gaging station or a location where discharge
Medium flows may be controlled by either type of control. A
information is repeatedly needed.
combination of section and channel control may occur at some
5.2 This practice is applicable only for open-channel flow
stages. These are general rules, and exceptions can and do
conditions where channel hydraulics permit a stable relation
occur.
between stage and discharge.
7. Interferences
6. Channel Hydraulics
7.1 The stage-discharge relation may be affected by the
6.1 The stage-discharge relation for open-channel flow at a
deposition or removal of stream bed or bank material by
gaging station or other stage reference point is governed by
flowing water, usually at high flow conditions or manmade
channel conditions downstream from that point, referred to as
changes. Large changes may require a redefinition of the rating
a control. Knowledge of the channel features that control the
curve. Small, transitory changes may be facilitated by adjust-
stage-discharge relation is important. The development of
ments to the stage observations. An example of a temporary
stage-discharge curves where more than one control is effec-
shift would be a beaver dam on a section control or debris
tive, control features change, and the number of measurements
deposited on a dam or bridge piling that would be expected to
is limited usually requires judgment in interpolating between
be removed or eventually wash away.
measurements and in extrapolating beyond the highest or
7.2 Aquatic growth may develop in a stream during the
lowest measurements.
growing season. This growth would result in a temporary
6.1.1 Section Controls—Asection control is a specific cross
backwater situation. Adjustments to stage observations would
section of the stream channel that controls the relation between
normally be made during these periods.
stage and discharge at that point in the channel. A section
7.3 Ice cover changes river hydraulics and alters the stage-
control can be a natural feature such as a rock ledge, sand bar,
discharge relation.
or severe constriction in the channel. A section control can
7.4 Hysteresis may affect the high flow stage-discharge
likewise be a manmade f
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