ISO INTERNATIONAL STANDARD 6421 First edition 2012-08-01 Hydrometry Methods for assessment of reservoir sedimentation Hydrometrie-Methodesd'évaluationdelasédimentationdansles réservoirs Reference number ISO 6421:2012(E) so @IS0012 ISO 6421:2012(E) COPYRIGHTPROTECTEDDOCUMENT ISO2012 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 [email protected] Web www.iso.org Published in Switzerland @ ISO 2012 - All riahts reserved ISO6421:2012(E) Contents Page Foreword .iv Introduction 1 Scope. 2 Normative references 3 Terms and definitions.. 4 General... 4.1 Originofthe sedimentdeposited inthereservoir 4.2 Overview of reservoir-sedimentation assessment methods 5 Sediment transport balance. 6 Topographic survey methods .. 6.1 General 6.2 Reservoirsedimentationsurveys. 3 6.3 Frequency.. 6.4 Survey equipment 6.5 Density measurements and sediment samplers 7 Topographic survey using the contour method. 8 7.1 General 8 7.2 Hydrographic survey. 9 7.3 Topographicsurveys. 9 7.4 Computation of reservoir capacity 10 8 Topographic survey using a cross-sectional (range line) method ..10 8.1 General. .10 8.2 Reference frames/graphs. .11 8.3 Calculation of reservoir capacity .15 9 Sub-bottom mapping 19 10 Remote-sensing methods 20 10.1 General..... 20 10.2 Advantages 20 10.3 Limitations. .20 11 Light detection and ranging .20 11.1 General... .20 11.2 Aerial applications of LiDAR 21 11.3 Ground-based applications of LiDAR 21 12 Aerial imagery methods. 22 12.1 General.. .22 12.2 Photogrammetry methods 22 12.3 Satellite imagery methods 23 13 Uncertainty analysis 23 13.1 General .23 13.2 Principles. 23 13.3 Estimation of uncertainty.. 24 AnnexA (informative)Optimization ofthe arrangement of ranges. .28 Annex B (informative) Introduction to measurement uncertainty 32 Bibliography. .40 @.iso.2n12...All.rightsreserved ili