BS PD ISO TR 9212-2015 Hydrometry Methods of measurement of bedload discharge《液体比重测定法 水流细沙测量方法》.pdf

1、BSI Standards Publication PD ISO/TR 9212:2015 Hydrometry Methods of measurement of bedload dischargePD ISO/TR 9212:2015 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 9212:2015. It supersedes PD ISO/TR 9212:2006 which is withdrawn. The UK participatio

2、n in its preparation was entrusted to Technical Committee CPI/113, Hydrometry. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its cor

3、rect application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 83022 8 ICS 17.120.20 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy a

4、nd Strategy Committee on 30 June 2015. Amendments issued since publication Date Text affectedPD ISO/TR 9212:2015 ISO 2015 Hydrometry Methods of measurement of bedload discharge Hydromtrie Mthodes de mesurage du dbit des matriaux charris sur le fond TECHNICAL REPORT ISO/TR 9212 Reference number ISO/T

5、R 9212:2015(E) Third edition 2015-06-01PD ISO/TR 9212:2015ISO/TR 9212:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any for

6、m or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonn

7、et 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgPD ISO/TR 9212:2015ISO/TR 9212:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Measurement of bedload . 1 4.1 General . 1 4.2

8、Direct measurement methods . 1 4.3 Indirect measurement methods . 2 5 Design and strategy of measurement of bedload discharge . 2 6 Site selection . 2 7 Bedload samplers and traps . 3 7.1 Bedload samplers . 3 7.1.1 Requirements of an ideal bedload sampler 3 7.1.2 Basket or box type sampler 3 7.1.3 F

9、rame and net sampler. 4 7.1.4 Pressure-difference sampler . 4 7.1.5 Advantages and disadvantages 5 7.1.6 Characteristics of bedload samplers . 9 7.2 Measurement using bedload trap 10 7.2.1 Vortex tube bedload trap .10 7.2.2 Pit and Trough trap .11 7.2.3 Advantages and disadvantages .12 8 Procedures

10、for measurement of bedload discharge using bedload samplers 12 8.1 General 12 8.2 Sample identification 13 8.3 Calculations .14 8.4 Errors .15 9 Indirect measurement of bedload .16 9.1 General 16 9.2 Differential measurement 16 9.3 Volumetric measurement .16 9.4 Dune-tracking .17 9.4.1 Moving boat .

11、17 9.4.2 In situ echo sounder . .17 9.4.3 Accuracy of the dune-tracking methods .18 9.5 Tracers.18 9.6 Remote sensing LiDAR 18 9.7 Acoustic instruments 19 9.8 Acoustic Doppler current profiler .19 Annex A (informative) Bedload-surrogate monitoring technologies 820 Bibliography .24 ISO 2015 All right

12、s reserved iii Contents PagePD ISO/TR 9212:2015ISO/TR 9212:2015(E) 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

13、 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

14、 the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed f

15、or the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent righ

16、ts. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in thi

17、s document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers t

18、o Trade (TBT) see the following URL: Foreword - Supplementary information. The committee responsible for this document is ISO/TC 113, Hydrometry, Subcommittee SC 6, Sediment transport. This third edition cancels and replaces the second edition (ISO/TR 9212:2006), which has been technically revised.i

19、v ISO 2015 All rights reservedPD ISO/TR 9212:2015ISO/TR 9212:2015(E) Introduction The knowledge of the rate of sediment transport in a stream is essential in the solution of practically all problems associated with the flow in alluvial channels. The problems include river management, such as design

20、and operation of flood control works, navigation channels and harbours, irrigation reservoirs and canals, and hydroelectric installations. The bedload and suspended load broadly constitute total sediment load. The bedload is the material transported on or near the bed by rolling or sliding (contact

21、load) and the material bouncing along the bed, or moving directly or indirectly by the impact of bouncing particles (saltation load). Knowledge of the bedload-transport rate is necessary in designing reservoir capacity because virtually 100 % of all bedload entering a reservoir accumulates there. Be

22、dload should not enter canals and distributaries and diversion structures should be designed to minimize the transfer of bedload from rivers to canals. The bedload-transport rate can be measured either as mass per unit time or volume per unit time. Volume measurements should be converted to a mass r

23、ate. Measurements of mass rate of movement are made during short time periods (seconds, minutes), whereas measurements of volume rates of movement are measured over longer periods of time (hours, days). Regardless of whether the mass or volume rate is measured, the average particle-size distribution

24、 of moving material should be determined. Knowledge of particle-size distribution is needed to estimate the volume that the bedload material will occupy after it has been deposited. Knowledge of particle-size distribution also assists in the estimation of bedload- transport rates in other rivers tra

25、nsporting sediment. The movement of bedload material is seldom uniform across the bed of a river. Depending upon the river, hydraulic, and sediment properties (size and gradation), the bedload may move in various forms, such as ripples, dunes, or narrow ribbons. Its downstream rate of movement is al

26、so extremely variable. It is difficult to actually sample the rate of movement in a river cross-section or to determine and verify theoretical methods of estimation. ISO 2015 All rights reserved vPD ISO/TR 9212:2015PD ISO/TR 9212:2015Hydrometry Methods of measurement of bedload discharge 1 Scope Thi

27、s Technical Report reviews the current status of direct and indirect bedload-measurement techniques. The methods are mainly based on grain size distribution of the bedload, channel width, depth, and velocity of flow. This Technical Report outlines and explains several methods for direct and indirect

28、 measurement of bedload in streams, including various types of sampling devices. The purposes of measuring bedload-transport rates are to a) increase the accuracy of estimating total sediment load in rivers and deposition in reservoirs, b) gain knowledge of bedload transport that cannot be completel

29、y measured by conventional suspended-sediment collection methods, c) provide data to calibrate or verify theoretical transport models, and d) provide information needed in the design of river diversion and entrainment structures. NOTE The units of measurement used in this Technical Report are SI uni

30、ts. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any a

31、mendments) applies. ISO 772, Hydrometry Vocabulary and symbols 3 T erms a nd definiti ons For the purposes of this document, the terms and definitions given in ISO 772 apply. 4 Measurement of bedload 4.1 General Bedload can be measured by direct measuring bedload samplers or by indirect methods. 4.2

32、 Direct measurement methods a) Bedload samplers In this method, a mechanical device or sampler is required for measuring the bedload-transport rate. The bedload sampler is designed so that it can be placed directly on the channel bed in the flow, to collect a sample of the bedload over a specific ti

33、me interval. A sample thus obtained represents a time-averaged mass per unit width per unit time. TECHNICAL REPORT ISO/TR 9212:2015(E) ISO 2015 All rights reserved 1PD ISO/TR 9212:2015ISO/TR 9212:2015(E) b) Bedload trap The best measurement of bedload would occur when all of the bedload moving throu

34、gh the river cross was measured. Slot or pit samplers or traps meet this goal with near 100 % efficiencies. 4.3 Indirect measurement methods All other methods of bedload measurement in which no mechanical device or bedload sampler is used, are indirect methods. These include differential measurement

35、s of total and suspended-sediment loads, periodic volumetric measurements of accumulated sediment depositions, dune tracking, tracers, remote sensing, and acoustic measurements of moving sediment. 5 Design and strategy of measurement of bedload discharge Measurement of bedload is difficult because i

36、t is highly variable in both space and time. Bedload generally varies greatly both longitudinally along the channel and transversely across a cross section. These variations are caused by several factors and are difficult to predict. The design of bedload sampling needs to account for the spatial an

37、d temporal variability inherent in the processes of bedload transport. Pit, vortex-tube, or other samplers that sample for long periods of time and encompass a significant portion of the width of a stream cross section integrate the fluctuations in bedload-transport rate in a cross section. In many

38、instances, time, monetary constraints, or logistics precludes the use of these types of samplers. The use of portable samplers that essentially only collect samples at a point for short periods of time is often the only practical way to collect samples of bedload. To effectively use portable sampler

39、s, the number and location of the samples collected shall be carefully designed. Sufficient information about the temporal and spatial variability is collected. To accomplish this task, information on the scales of spatial and temporal variability is needed. To design an adequate sampling strategy,

40、these time and length scales shall be known at least approximately before the sampling procedure is defined. Flow in many streams and rivers are not steady for periods of hours to days. For streams in which variable flow is the norm, portable samplers will not be practical unless many flow events ca

41、n be sampled. No single sampling design can be used at all stations. A sampling design should be derived for each site where bedload is to be sampled. Initial samples collected can provide information to serve as a basis for developing the sampling plan. 6 Site selection a) Depending upon the method

42、 of measurement, the site for conducting bedload measurements can be either a river reach or a cross-section. The site should be relatively close to the geographical location where bedload-transport rate information is needed. There should be no inflow or outflow from the river between the measuring

43、 site and the site where bedload transport estimates will be used. b) When using a method such as dune-tracking, a straight reach where the channel width and depth are fairly uniform throughout the reach is desirable. Flow through the reach should be uniform and steady during the bedload-measurement

44、 period (see 9.4). c) A single cross-section site should be selected if the method of measurement is by bedload sampler. The channel width and mean depth of the cross-section site should be representative of the average channel width and depth upstream and downstream. Ideally, a cross-section used f

45、or bedload measurement by bedload sampler should be at the centre of a straight reach selected for measurement of bedload by the dune-tracking method. d) If it is not possible to place the cross-section site in the centre of an ideal straight, uniform reach, then the cross-section should be located

46、at least 10 to 20 channel widths downstream from any 2 ISO 2015 All rights reservedPD ISO/TR 9212:2015ISO/TR 9212:2015(E) bend in the channel. It should not be located at an excessively narrow section, such as might be present at a bridge site, or at an excessively wide section. 7 Bedload samplers a

47、nd traps 7.1 Bedload samplers 7.1.1 Requirements of an ideal bedload sampler In order that the samples taken are truly representative of the bedload material of a river at the point of sampling, the ideal bedload sampler should fulfil the following technical requirements. a) It should be calibrated

48、for bedload-sampler efficiency of specific sediment particle sizes. b) It should be designed to minimize disturbances to normal bedload movement. In particular, local erosion near the sampler mouth should be avoided so as to not form scour holes. c) The lower edge of the sampler and nozzle should be

49、 in contact with the river bed. d) The velocity of inflow at the mouth of the sampler should be as close as possible to the ambient velocity of the stream at the sampling point, irrespective of what this velocity may be. This aspect is very important if large sampling errors are to be avoided. e) The mouth of the sampler should always face into the current and the sample should be taken parallel to flow direction at the sampling point, into a specially designed chamber. f) The mouth of the sampler should be outside the zone of the disturbances