ASTM D5130-95(2008)

Standard Test Method for Open-Channel Flow Measurement of Water Indirectly by Slope-Area Method

SIGNIFICANCE AND USE
This test method is particularly useful for determining the discharge when it cannot be measured directly by some type of current meter to obtain velocities and with sounding weights to determine the cross section.
Even under optimum conditions, the personnel available cannot cover all points of interest during a major flood. Field personnel cannot always obtain reliable results by direct methods if the stage is rising or falling very rapidly, if flowing ice or debris interferes with depth or velocity measurements.
Under the worst conditions, access roads are blocked, cableways and bridges may be washed out, and knowledge of the flood frequently comes too late to obtain direct measurements of flow. Therefore, some type of indirect measurement is necessary. The slope-area method is a commonly used method.
SCOPE
1.1 This test method covers the computation of discharge (the volume rate of flow) of water in open channels or streams using representative cross-sectional characteristics, the water-surface slope, and coefficient of channel roughness as input to gradually-varied flow computations.  
1.2 This test method produces an indirect measurement of the maximum discharge for one flow event, usually a specific flood. The computed discharge may be used to help define the high-water segment of a stage-discharge relation.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 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: 30-Sep-2008
• ICS: 17.120.20 - Flow in open channels
• Technical Committee: D19 - Water
• Drafting Committee: D19.07 - Sediments, Geomorphology, and Open-Channel Flow

Relations

• Replaces: ASTM D5130-95(2003) - Standard Test Method for Open-Channel Flow Measurement of Water Indirectly by Slope-Area Method
• Effective Date: 01-Oct-2008
• Referred By: ASTM D5674-22 - Standard Guide for Operation of a Gaging Station
• Effective Date: 01-Oct-2008

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:D5130 −95(Reapproved 2008)
Standard Test Method for
Open-Channel Flow Measurement of Water Indirectly by
1
Slope-Area Method
This standard is issued under the fixed designation D5130; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
4
1. Scope 2.2 ISO Standards:
ISO 748 Liquid Flow Measurements in Open Channels—
1.1 This test method covers the computation of discharge
Velocity-Area Method
(the volume rate of flow) of water in open channels or streams
ISO 1070 Liquid Flow Measurements in Open Channels—
using representative cross-sectional characteristics, the water-
Slope-Area Method
surface slope, and coefficient of channel roughness as input to
2
gradually-varied flow computations.
3. Terminology
1.2 This test method produces an indirect measurement of
3.1 Definitions: For definitions of terms used in this test
the maximum discharge for one flow event, usually a specific
method, refer to Terminology D1129.
flood. The computed discharge may be used to help define the
3.2 Definitions of Terms Specific to This Standard:
high-water segment of a stage-discharge relation.
3.2.1 SeveralofthefollowingtermsareillustratedinFig.1:
1.3 Thevaluesstatedininch-poundunitsaretoberegarded
3.2.2 alpha (α)—a velocity-head coefficient that represents
as standard. The values given in parentheses are mathematical
the ratio of the true velocity head to the velocity head
conversions to SI units that are provided for information only
computedonthebasisofthemeanvelocity.Itisassumedequal
and are not considered standard.
to 1.0 if the cross section is not subdivided. For subdivided
sections, α is computed as follows:
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3
k
i
S D
responsibility of the user of this standard to establish appro- ( 2
A
i
priate safety and health practices and determine the applica-
α 5
3
bility of regulatory limitations prior to use. K
T
2
A
T
2. Referenced Documents
where:
3
2.1 ASTM Standards:
K and A = the conveyance and area of the subsection
D1129Terminology Relating to Water
indicated by the subscript i, and
D2777Practice for Determination of Precision and Bias of
K and A = the conveyance and area of the entire cross
T T
Applicable Test Methods of Committee D19 on Water
section.
D3858Test Method for Open-Channel Flow Measurement
3.2.3 conveyance(K)—ameasureofthecarryingcapacityof
of Water by Velocity-Area Method
achannelandhasdimensionsofcubicfeetpersecondorcubic
metres per second. Conveyance is computed as follows:
1
This test method is under the jurisdiction ofASTM Committee D19 on Water
1.486
and is the direct responsibility of Subcommittee D19.07 on Sediments,
2/3
K 5 AR
Geomorphology, and Open-Channel Flow.
n
Current edition approved Oct. 1, 2008. Published November 2008. Originally
approved in 1990. Last previous edition approved in 2003 as D5130–95 (2003).
where:
DOI: 10.1520/D5130-95R08.
n = the Manning roughness coefficient,
2
This test method is similar to methods developed by the U.S. Geological
2 2
A = the cross-section area, ft (m ), and
Survey and described in documents referenced in Footnotes 5, 6, and 7.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
4
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 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 States
1

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D5130−95 (2008)
h
f
S 5
f
L
that becomes:
∆h1∆h
v
S 5
f
L
when ∆h is negative (for a contracting reach),
v
or:
∆h
v
∆h1
2
S 5
f
L
when ∆ h is positive (for an expanding reach).
v
3.2.9 Froude number (F)—an index to the state of flow in
the channel. In a prismatic channel, the flow is tranquil or
subcritical if the Froude number is less than 1.0 and is rapid or
supercritical if it is greater than 1.0. The Froude number is
computed as follows:
FIG. 1 Definition Sketch of a Slope-Area Reach
V
F 5
=gd
m
R = the hydraulic radius, ft (m).
where:
NOTE 1—1.486 = 1.00 SI unit.
V = the mean velocity in ft/s (m/s),
3.2.4 cross sections (numbered consecutively in downstream
d = the average depth in the cross section in feet, and
m
order)—representativeofareachofchannelandarepositioned
g = the acceleration of gravity in ft/s/s (m/s/s).
as nearly as possible at right angles to the direction
...