1、 Reference number ISO 4363:2002(E) ISO 2002INTERNATIONAL STANDARD ISO 4363 Third edition 2002-12-01 Measurement of liquid flow in open channels Methods for measurement of characteristics of suspended sediment Mesure de dbit des liquides dans les canaux dcouverts Mthodes de mesurage des caractristiqu
2、es des sdiments en suspension ISO 4363:2002(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes 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 per
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5、 Secretariat at the address given below. ISO 2002 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 t
6、he address below or ISOs 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 copyrightiso.ch Web www.iso.ch Printed in Switzerland ii ISO 2002 All rights reservedISO 4363:2002(E) ISO 2002 All rights r
7、eserved iiiContents Page Foreword iv Introduction. v 1 Scope 1 2 Normative references 1 3 Terms and definitions. 1 4 Units of measurement. 2 5 Selection of site. 3 6 Selection of samplers . 3 7 Measurement methods and frequencies 3 7.1 Principle for measurement of cross-sectional mean sediment mass
8、concentration 3 7.2 Principle for measurement and calculation of cross-sectional mean particle size distribution 4 7.3 Conventional method 4 7.4 Simplified method. 7 7.5 Distribution and requirements of measurements 8 7.6 Additional information 8 7.7 Source and control of errors 9 8 Calculation. 10
9、8.1 Sediment discharge and mass concentration 10 8.2 Calculation of particle size distribution 11 9 Estimation of random uncertainty and systematic error for measurement of suspended sediment. 12 9.1 General. 12 9.2 Sources of error 13 9.3 Estimation of component errors 13 9.4 Total random uncertain
10、ty for measurement of cross-sectional mean sediment mass concentration. 13 9.5 Total systematic error for one measurement of cross-sectional mean sediment mass concentration. 14 Annex A (informative) Data collection for determining the error in measurement of cross-sectional mean sediment mass conce
11、ntration and estimation of errors. 15 Annex B (informative) Procedures and examples of methods for combining samples collected in a cross-section . 22 ISO 4363:2002(E) iv ISO 2002 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of nation
12、al 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. Internatio
13、nal 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 rule
14、s given in the ISO/IEC Directives, Part 3. The main task of technical committees is to prepare International Standards. 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 l
15、east 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. ISO 4363 was prepared by Technical Commi
16、ttee ISO/TC 113, Hydrometric determinations, Subcommittee SC 6, Sediment transport. This third edition cancels and replaces the second edition (ISO 4363:1993), which has been technically revised. Annexes A and B of this International Standard are for information only. ISO 4363:2002(E) ISO 2002 All r
17、ights reserved vIntroduction Sediment has been defined generally as solid particles that are moved or might be moved, by stream flow in a channel. Sediment transportation creates numerous problems such as soil erosion, local scour, degradation and aggradation of streams, siltation in irrigation cana
18、ls and navigation channels, loss of capacity of reservoirs, meandering of streams, damages to hydraulic machinery, etc. For solving varied sediment related issues arising out of human endeavours for development and management of water resources, a comprehensive knowledge of the mechanism of sediment
19、 transport and methods of determination of sediment load is highly essential. Erosion is caused by water, wind, ice and human activities such as cultivation urbanization, mining, etc. Clods and aggregates of soil in the catchment area are broken down into small particles which are thrown into suspen
20、sion and carried away as sediment. Not all the eroded material enters the stream channel. The total amount of eroded material which travels from a source to a downstream measuring point is termed as sediment yield. The purpose for making measurements on suspended sediment is to determine the variati
21、on of the cross-sectional mean mass concentration and mean particle size distribution of suspended sediment in sediment transport processes using appropriate methods at a suitable frequency; then to determine the characteristic values of suspended sediment transport such as sediment load, mean parti
22、cle size distribution, and sediment load of various particle sizes in various periods by jointly using the data of water stage, discharge, and suspended sediment. INTERNATIONAL STANDARD ISO 4363:2002(E) ISO 2002 All rights reserved 1Measurement of liquid flow in open channels Methods for measurement
23、 of characteristics of suspended sediment 1 Scope This International Standard specifies conventional and simplified methods for the measurement of cross-sectional mean suspended sediment mass concentration and mean particle size distribution. The conventional method is used for routine measurements
24、in periods of stable or slowly varied flow. The simplified method is mainly used for sediment measurements for the purpose of observing the variation process of sediment transport and can be performed under difficult conditions. Empirical relationships are established between the cross-sectional mea
25、n suspended sediment mass concentrations and mean particle size distributions measured by conventional and simplified methods. The methods specified in this International Standard are applicable to suspended sediment measurements at hydrological stations. 2 Normative references The following normati
26、ve 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 publications do not apply. However, parties to agreements based on this International Standard ar
27、e encouraged to investigate 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 registers of currently valid International Standards.
28、 ISO 31 (all parts), Quantities and units ISO 748, Measurement of liquid flow in open channels Velocity-area methods ISO 772, Hydrometric determinations Vocabulary and symbols ISO 1000, SI units and recommendations for the use of their multiples and of certain other units ISO 3716, Liquid flow measu
29、rement in open channels Functional requirements and characteristics of suspended sediment load samplers ISO 4365, Liquid flow in open channels Sediment in streams and canals Determination of concentration, particle size distribution and relative density 3 Terms and definitions For the purposes of th
30、is International Standard, the terms and definitions given in ISO 772 and the following apply. 3.1 suspended sediment discharge mass of suspended sediment passing through a specific cross-section of streams or canals per unit time 3.2 suspended sediment load total mass of suspended sediment, general
31、ly expressed in mass or volume of dry sediment, passing through a specific cross-section of streams or canals in a given period of time ISO 4363:2002(E) 2 ISO 2002 All rights reserved3.3 vertical average sediment mass concentration ratio of the suspended sediment discharge per unit width (q s ) to t
32、he flow discharge per unit width (q) in a vertical 3.4 cross-sectional mean sediment mass concentration ratio of the cross-sectional suspended sediment discharge (Q A,s ) to the cross-sectional flow discharge (Q A ) 3.5 method for combining samples collected in a cross-section method for measurement
33、 of cross-sectional mean sediment mass concentration in accordance with the segmental discharge-weighted principle NOTE The method involves dividing a cross-section by verticals into several segments with equal water surface width, or equal flow area or equal discharge. Samples are taken by a specif
34、ic method in each vertical passing through each segment centre. (The flow velocity at a sediment sampling point should be measured simultaneously with the taking of the sediment sample or as soon as practicable after the collection of the sediment sample. In rivers subjected to rapidly changing stag
35、e, it is strongly recommended that the sediment sample be taken at the same time as the measurement of flow velocity.) Then the sediment mass concentration of the combined samples is determined as the cross-sectional mean sediment mass concentration. 3.6 particle size analysis entire technological o
36、peration for determining the ratio of sediment mass of each size group to the total sediment mass of a sample as specified in ISO 4365 3.7 particle size distribution distribution in ratios of sediment mass of each size group to the total sediment mass of a sample NOTE It is generally expressed in ra
37、tios of mass of sediment coarser or finer than a given diameter to the total sediment mass of the sample. 3.8 cross-sectional mean size distribution of suspended sediment conceptual characteristic value representing the ratios of sediment mass of each size group to the total suspended sediment mass
38、in the cross-section 4 Units of measurement 4.1 The International System of Units (SI Units) is used in this International Standard in accordance with ISO 31 (all parts) and ISO 1000. 4.2 The suspended sediment concentration is expressed in one of the following three ways. a) Mass concentration of t
39、he water-sediment mixture ws , generally expressed in milligrams per litre (mg/l), grams per litre (g/l) or kilograms per cubic metre (kg/m 3 ), is dry sediment per unit volume of the water- sediment mixture. This is the expression used in this International Standard. b) Volume fraction , expressed
40、as a percentage (%), is the ratio of the volume of sediment to the volume of the water-sediment mixture and is given by Equation (1): s ws V V = (1) where V sis the volume of sediment; V wsis the volume of the water-sediment mixture. ISO 4363:2002(E) ISO 2002 All rights reserved 3c) Mass fraction, w
41、 w , expressed as a percentage (%), is the ratio of the mass of dry sediment to the mass of water-sediment mixture and is given by Equation (2): ws w w ww s s 1 w = + (2) where wsis defined in a) and wand sare the mass concentrations of water and sediment, respectively, expressed in mg/l, g/l, or kg
42、/m 3 . If no measured data are available, smay be adopted as 2 650 kg/m 3 . 5 Selection of site The cross-section for measurement of suspended sediment shall preferably coincide with that for measurement of velocity and shall meet the requirements specified in ISO 748. 6 Selection of samplers Sample
43、rs shall conform to the requirements specified in ISO 3716. In measurement of suspended sediment, a time-integration type sampler and an in-situ velocity measurement device with good performance shall be used to eliminate or mitigate the influence of fluctuation of sediment concentration. 7 Measurem
44、ent methods and frequencies 7.1 Principle for measurement of cross-sectional mean sediment mass concentration As the distributions of velocity and sediment mass concentration in a cross-section of a stream vary spatially, the time-mean velocity v and sediment mass concentration shall be measured at
45、a number of points in the cross- section, with each point representing a small area of dA = dhdb. From 00 dd BH A Qv h b = and ,s 00 dd BH A Qv h b = . the cross-sectional flow discharge and sediment discharge can be calculated. From the definition given in 3.4, the cross-sectional mean sediment mas
46、s concentration A is given by: ,s 00 0 00 0 dd d dd d Q BH A A A BH Q A A vhb q Q Q vhb q = = (3) where db and dh are the width and depth of the small area represented by the point, respectively; B and H are the surface width and vertical depth of flow, respectively; dq A(= vdhdb) is the discharge p
47、assing through the small area. The cross-sectional mean sediment mass concentration is determined by weighting the mass concentration for the discharge of each section. This is the basic principle for measurement of cross-sectional mean sediment mass ISO 4363:2002(E) 4 ISO 2002 All rights reservedco
48、ncentration. In practice, it is normally simplified into the sediment discharge method and the method for combining samples collected in a cross-section. 7.2 Principle for measurement and calculation of cross-sectional mean particle size distribution The product of the cross-sectional mean particle
49、size distribution and the cross-sectional sediment discharge shall be equal to the sum of the products of segmental particle size distribution and the corresponding sediment discharges. The cross-sectional mean particle size distribution conforms to the principle of weighting sediment mass concentration based on water discharge. The particle size distribution determined by the method for combining samples collected in a cross-section specified in this International Standard als
