ISO 11329:2001
(Main)Hydrometric determinations — Measurement of suspended sediment transport in tidal channels
Hydrometric determinations — Measurement of suspended sediment transport in tidal channels
This International Standard deals with the method and techniques for the sampling of suspended sediment and estimation of sediment transport rates in natural and man-made channels influenced by tidal action.
Déterminations hydrométriques — Mesurage du transport solide dans les canaux à marée
General Information
Relations
Buy Standard
Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 11329
Second edition
2001-05-01
Hydrometric determinations —
Measurement of suspended sediment
transport in tidal channels
Déterminations hydrométriques — Mesurage du transport solide dans les
canaux à marée
Reference number
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be
edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file,
parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
©
ii ISO 2001 – All rights reserved
Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Salient features of sediment transport in tidal channels . 2
5 Guidelines for measurement and estimation of suspended sediment transport . 2
6 Selection of sampling site in the tidal channel . 3
7 Principles of measurement . 4
8 Estimation of suspended sediment transport . 5
Bibliography. 6
©
ISO 2001 – All rights reserved iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 11329 was prepared by Technical Committee ISO/TC 113, Hydrometric determinations,
Subcommittee SC 6, Sediment transport.
This second edition cancels and replaces the first edition (ISO 11329:1998), which has been technically revised.
©
iv ISO 2001 – All rights reserved
Introduction
Estuaries and creeks have become regions of major developments pertaining to port and harbour facilities,
navigation, reclamation and effluent disposal. Human interference with water bodies, for example, providing
navigational channels, installing major or minor structures and reclaiming land, need thorough examination of their
impact on morphological changes, stability of banks and channels, the consequences of capital and maintenance
dredging, and the selection of disposal grounds. For these purposes, it is necessary to estimate the suspended
sediment transport rates in tidal channels, which can be based on data on morphological characteristics of the
channel, flowrates and the corresponding suspended sediment concentration.
In comparison to the situation in unidirectional flow, the flow as well as sediment concentration at different locations
along tidal channels are much more complex. The salt water flow from the sea at one end and the fresh water flow
from the river at the other end are responsible for spatial and temporal variations in water and sediment movement in
tidal channels. When measuring the flowrate and suspended sediment concentrations for estimating sediment
transport rates, these factors need to be considered.
©
ISO 2001 – All rights reserved v
INTERNATIONAL STANDARD ISO 11329:2001(E)
Hydrometric determinations — Measurement of suspended
sediment transport in tidal channels
1 Scope
This International Standard deals with the method and techniques for the sampling of suspended sediment and esti-
mation of sediment transport rates in natural and man-made channels influenced by tidal action.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publica-
tions do not apply. However, parties to agreements based on this International Standard are encouraged to investi-
gate the possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain reg-
isters of currently valid International Standards.
Hydrometric determinations — Vocabulary and symbols.
ISO 772,
ISO 2425, Measurement of liquid flow in open channels under tidal conditions.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 772 and the following apply.
3.1
mixed tides
tides which have two markedly unequal successive high waters, or two markedly unequal successive low waters, or
both, during most of each month
3.2
divergence
�
deviation of the angle between the flood and ebb axes from 180
NOTE In a straight reach, the flood and ebb flow directions are ideally expected to lie on the same axis but in the opposite
�
direction, i.e. the change in flow direction is 180 . However, in most situations the directions of flood and ebb flows are not along
the same axis, due to prevailing approach conditions from either side.
3.3
flood [ebb] predominance
net flow, in the flood [ebb] direction, resulting when the flood [ebb] velocity-time curve is such that the net flow
integrated over a tidal period, either at a point or over a vertical, is not zero
NOTE In a typical situation, one part of a tidal channel may have flood predominance whereas the other may have ebb
predominance.
3.4
creek
inlet or arm of a river or a small stream joining the coast
©
ISO 2001 – All rights reserved 1
4 Salient features of sediment transport in tidal channels
Measurement of discharge and estimation of corresponding suspended sediment concentration by analysis of water
samples are essential to estimating the rate of sediment transport through a channel section. The following aspects
shall be taken into account when planning the collection of data and estimation of sediment transport.
a) Flow is two-way in tidal channels as a result of tidal fluctuation in the sea. During the flood phase, the water level
rises and water flows from the sea upstream, whereas during the ebb phase, the water level falls and water flows
toward the sea.
b) The extent of tidal excursion, magnitude and direction of tidal current, and flood and ebb periods (at any cross-
section) differ from tide to tide depending on the tidal range and freshwater discharge.
c) The variation in water level from section to section in a tidal channel depends on the freshwater discharge, tidal
range in the sea, the channel bed slope and frictional resistance at the bed and banks of the channel.
d) All the above aspects result in temporal and spatial variation in the sediment transport at all points in a tidal
channel.
e) The quantity and type of sediment which enters a tidal channel depends on the freshwater discharge, the wave
climate and tides in the sea. As a result, there can be a large variation in the amount of suspended load in tidal
channels.
f) The variation in the strength of the current from spring to neap or from neap to spring results in significant
changes in the bed configuration along the channel. Variation in the freshwater discharge also causes such
changes.
�
g) The directions of flood and ebb currents in a cross-section of the tidal channel do not necessarily differ by 180
(i.e. complete reversal) as the flow is governed by the bed and bank configurations upstream of flow.
Furthermore, the flood flow may dominate one part of the cross-section whereas the ebb flow dominates the
other part.
h) The time of reversal and the direction of transport are commonly different across the cross-section of the tidal
channel and at different depths on a vertical.
i) In a wide channel near the mouth, the time of reversal from flood to ebb or from ebb to flood differs appreciably
from one part to another in the section, resulting in a large circulation.
j) The difference in densities of sea water and river water affects the mixing characteristics of tidal and freshwater
flows, depending on their relative magnitudes. The flow in the channel can be well-mixed, partially mixed or
stratified.
k) Water level is affected by atmospheric pressure fluctuations and wind drag.
l) Biological effects can determine the erosivity within an estuary, which can affect the suspended sediment
concentrations in time and space.
m) Variations in temperature change water viscosity and also affect the settling velocity of different sediments, thus
affecting the suspended sediment load throughout the year.
n) Human activities, such as dredging, disposal and trawling, will also influence the amount of suspended sediment
within the water column.
5 Guidelines for measurement and estimation of suspended sediment transport
Consideration should be given to the following points for the measurement and estimation of suspended sediment
transport in a tidal channel.
a) Long-term measurements of flow and simultaneous water sampling are required for estimating sediment
13 h
transport in tidal channels. For regular semidiurnal tides, data should be collected for a minimum of .
However, in the case of diurnal tides or where there is a strong diurnal component (mixed tides), an observation
period of 25 h is recommended. The time interval between the observations shall also be kept as small as
possible (no more than 0,5 h) due to the unsteady nature of tidal flow.
b) The period of data collection may need to cover various ranges of tide, from neap to spring, to account for the
variation in velocity and suspended sediment concentration if morphological changes are to be estimated.
©
2 ISO 2001 – All rights reserved
c) During the preliminary survey, the mixing characteristics of the tidal channel shall be identified by taking
simultaneous observations at the surface and at the bed. If the flow is stratified, it may be necessary to extend the
observation period to cover a period from neap to spring tides.
d) As the presence of freshwater discharge affects the flow field and sediment transport, collection of data is
necessary to cover both dry and freshet seasons.
e) Items a) through d) emphasize the need for long-term observations. Depending on the hydraulic conditions, a
decision should be taken on the required period and time of observations necessary to serve the purpose for
which the investigation is undertaken. It may also be possible to limit the field observations if suitable numerical
models are available to simulate the range of prevailing hydraulic conditions.
f) The scatter in data for suspended sediment concentration is more than for unidirectional flow in tidal channels,
due to the variable nature of the flow. Repeated observations for the same tidal conditions are therefore
necessary to arrive at a reliable estimation of sediment transport.
g) The sampling points on a vertical need to be changed with variation in flow depth in a tidal cycle. The sampling
points should be selected on the basis of depth of stratification for stratified flow.
h) The level of the sampling point with respect to the water surface is easily measured. However, the elevation of
water surface itself changes with time. This change shall be taken into account while analysing and interpreting
the data in absolute terms. The simultaneous measurement of water level with respect to a known datum is
necessary.
i) Simultaneous observations are desirable at several verticals in a section of the tidal channel, as well as at a
number of sections, depending on the reach to be covered. This requires more resources with respect to boats,
equipment and personnel so as to determine the effects of variations on flows.
j) Point sampling is better than depth-integrated sediment sampling in tidal channels.
k) During the collection of dat
...
INTERNATIONAL ISO
STANDARD 11329
Second edition
2001-05-01
Hydrometric determinations —
Measurement of suspended sediment
transport in tidal channels
Déterminations hydrométriques — Mesurage du transport solide dans les
canaux à marée
Reference number
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be
edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file,
parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
©
ii ISO 2001 – All rights reserved
Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Salient features of sediment transport in tidal channels . 2
5 Guidelines for measurement and estimation of suspended sediment transport . 2
6 Selection of sampling site in the tidal channel . 3
7 Principles of measurement . 4
8 Estimation of suspended sediment transport . 5
Bibliography. 6
©
ISO 2001 – All rights reserved iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 11329 was prepared by Technical Committee ISO/TC 113, Hydrometric determinations,
Subcommittee SC 6, Sediment transport.
This second edition cancels and replaces the first edition (ISO 11329:1998), which has been technically revised.
©
iv ISO 2001 – All rights reserved
Introduction
Estuaries and creeks have become regions of major developments pertaining to port and harbour facilities,
navigation, reclamation and effluent disposal. Human interference with water bodies, for example, providing
navigational channels, installing major or minor structures and reclaiming land, need thorough examination of their
impact on morphological changes, stability of banks and channels, the consequences of capital and maintenance
dredging, and the selection of disposal grounds. For these purposes, it is necessary to estimate the suspended
sediment transport rates in tidal channels, which can be based on data on morphological characteristics of the
channel, flowrates and the corresponding suspended sediment concentration.
In comparison to the situation in unidirectional flow, the flow as well as sediment concentration at different locations
along tidal channels are much more complex. The salt water flow from the sea at one end and the fresh water flow
from the river at the other end are responsible for spatial and temporal variations in water and sediment movement in
tidal channels. When measuring the flowrate and suspended sediment concentrations for estimating sediment
transport rates, these factors need to be considered.
©
ISO 2001 – All rights reserved v
INTERNATIONAL STANDARD ISO 11329:2001(E)
Hydrometric determinations — Measurement of suspended
sediment transport in tidal channels
1 Scope
This International Standard deals with the method and techniques for the sampling of suspended sediment and esti-
mation of sediment transport rates in natural and man-made channels influenced by tidal action.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publica-
tions do not apply. However, parties to agreements based on this International Standard are encouraged to investi-
gate the possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain reg-
isters of currently valid International Standards.
Hydrometric determinations — Vocabulary and symbols.
ISO 772,
ISO 2425, Measurement of liquid flow in open channels under tidal conditions.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 772 and the following apply.
3.1
mixed tides
tides which have two markedly unequal successive high waters, or two markedly unequal successive low waters, or
both, during most of each month
3.2
divergence
�
deviation of the angle between the flood and ebb axes from 180
NOTE In a straight reach, the flood and ebb flow directions are ideally expected to lie on the same axis but in the opposite
�
direction, i.e. the change in flow direction is 180 . However, in most situations the directions of flood and ebb flows are not along
the same axis, due to prevailing approach conditions from either side.
3.3
flood [ebb] predominance
net flow, in the flood [ebb] direction, resulting when the flood [ebb] velocity-time curve is such that the net flow
integrated over a tidal period, either at a point or over a vertical, is not zero
NOTE In a typical situation, one part of a tidal channel may have flood predominance whereas the other may have ebb
predominance.
3.4
creek
inlet or arm of a river or a small stream joining the coast
©
ISO 2001 – All rights reserved 1
4 Salient features of sediment transport in tidal channels
Measurement of discharge and estimation of corresponding suspended sediment concentration by analysis of water
samples are essential to estimating the rate of sediment transport through a channel section. The following aspects
shall be taken into account when planning the collection of data and estimation of sediment transport.
a) Flow is two-way in tidal channels as a result of tidal fluctuation in the sea. During the flood phase, the water level
rises and water flows from the sea upstream, whereas during the ebb phase, the water level falls and water flows
toward the sea.
b) The extent of tidal excursion, magnitude and direction of tidal current, and flood and ebb periods (at any cross-
section) differ from tide to tide depending on the tidal range and freshwater discharge.
c) The variation in water level from section to section in a tidal channel depends on the freshwater discharge, tidal
range in the sea, the channel bed slope and frictional resistance at the bed and banks of the channel.
d) All the above aspects result in temporal and spatial variation in the sediment transport at all points in a tidal
channel.
e) The quantity and type of sediment which enters a tidal channel depends on the freshwater discharge, the wave
climate and tides in the sea. As a result, there can be a large variation in the amount of suspended load in tidal
channels.
f) The variation in the strength of the current from spring to neap or from neap to spring results in significant
changes in the bed configuration along the channel. Variation in the freshwater discharge also causes such
changes.
�
g) The directions of flood and ebb currents in a cross-section of the tidal channel do not necessarily differ by 180
(i.e. complete reversal) as the flow is governed by the bed and bank configurations upstream of flow.
Furthermore, the flood flow may dominate one part of the cross-section whereas the ebb flow dominates the
other part.
h) The time of reversal and the direction of transport are commonly different across the cross-section of the tidal
channel and at different depths on a vertical.
i) In a wide channel near the mouth, the time of reversal from flood to ebb or from ebb to flood differs appreciably
from one part to another in the section, resulting in a large circulation.
j) The difference in densities of sea water and river water affects the mixing characteristics of tidal and freshwater
flows, depending on their relative magnitudes. The flow in the channel can be well-mixed, partially mixed or
stratified.
k) Water level is affected by atmospheric pressure fluctuations and wind drag.
l) Biological effects can determine the erosivity within an estuary, which can affect the suspended sediment
concentrations in time and space.
m) Variations in temperature change water viscosity and also affect the settling velocity of different sediments, thus
affecting the suspended sediment load throughout the year.
n) Human activities, such as dredging, disposal and trawling, will also influence the amount of suspended sediment
within the water column.
5 Guidelines for measurement and estimation of suspended sediment transport
Consideration should be given to the following points for the measurement and estimation of suspended sediment
transport in a tidal channel.
a) Long-term measurements of flow and simultaneous water sampling are required for estimating sediment
13 h
transport in tidal channels. For regular semidiurnal tides, data should be collected for a minimum of .
However, in the case of diurnal tides or where there is a strong diurnal component (mixed tides), an observation
period of 25 h is recommended. The time interval between the observations shall also be kept as small as
possible (no more than 0,5 h) due to the unsteady nature of tidal flow.
b) The period of data collection may need to cover various ranges of tide, from neap to spring, to account for the
variation in velocity and suspended sediment concentration if morphological changes are to be estimated.
©
2 ISO 2001 – All rights reserved
c) During the preliminary survey, the mixing characteristics of the tidal channel shall be identified by taking
simultaneous observations at the surface and at the bed. If the flow is stratified, it may be necessary to extend the
observation period to cover a period from neap to spring tides.
d) As the presence of freshwater discharge affects the flow field and sediment transport, collection of data is
necessary to cover both dry and freshet seasons.
e) Items a) through d) emphasize the need for long-term observations. Depending on the hydraulic conditions, a
decision should be taken on the required period and time of observations necessary to serve the purpose for
which the investigation is undertaken. It may also be possible to limit the field observations if suitable numerical
models are available to simulate the range of prevailing hydraulic conditions.
f) The scatter in data for suspended sediment concentration is more than for unidirectional flow in tidal channels,
due to the variable nature of the flow. Repeated observations for the same tidal conditions are therefore
necessary to arrive at a reliable estimation of sediment transport.
g) The sampling points on a vertical need to be changed with variation in flow depth in a tidal cycle. The sampling
points should be selected on the basis of depth of stratification for stratified flow.
h) The level of the sampling point with respect to the water surface is easily measured. However, the elevation of
water surface itself changes with time. This change shall be taken into account while analysing and interpreting
the data in absolute terms. The simultaneous measurement of water level with respect to a known datum is
necessary.
i) Simultaneous observations are desirable at several verticals in a section of the tidal channel, as well as at a
number of sections, depending on the reach to be covered. This requires more resources with respect to boats,
equipment and personnel so as to determine the effects of variations on flows.
j) Point sampling is better than depth-integrated sediment sampling in tidal channels.
k) During the collection of dat
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.