Practical Channel Hydraulics
Practical Channel Hydraulics Roughness, Conveyance and Afflux
Donald W. Knight The University of Birmingham, Birmingham, UK
Caroline Mc Gahey HR Wallingford, Wallingford, Oxfordshire, UK
Rob Lamb JBA Consulting, Skipton, North Yorkshire, UK
Paul G. Samuels HR Wallingford, Wallingford, Oxfordshire, UK
CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business © 2010 Taylor & Francis Group, London, UK Typeset by Vikatan Publishing Solutions (P) Ltd, Chennai, India. Printed and bound in Great Britain by TJ International Ltd, Padstow, Cornwall All rights reserved. No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, by photocopying, recording or otherwise, without written prior permission from the publisher. Although all care is taken to ensure integrity and the quality of this publication and the information herein, no responsibility is assumed by the publishers nor the authors for any damage to the property or persons as a result of operation or use of this publication and/or the information contained herein. Published by: CRC Press/Balkema P.O. Box 447, 2300 AK Leiden, The Netherlands e-mail:
[email protected] www.crcpress.com – www.taylorandfrancis.co.uk – www.balkema.nl Library of Congress Cataloging-in-Publication Data Knight, Donald W. Practical channel hydraulics : roughness, conveyance, and afflux / Donald W. Knight . . . [et al.] p. cm. Includes bibliographical references and indexes. ISBN 978-0-415-54974-5 (hardcover : alk. paper) – ISBN 978-0-203-86418-0 (e-book) 1. Channels (Hydraulic engineering) I. Title. TC175.K55 2010 627’.042–dc22 2009026759 ISBN: 978-0-415-54974-5 (Hbk) ISBN: 978-0-203-86418-0 (eBook)
Contents
Foreword Acknowledgements Notation Acronyms Glossary of terms 1
2
xi xiii xv xxi xxiii
Introduction
1
1.1
Context and motivation for book
1
1.2
Scope of book and introduction to the CES-AES
6
1.3
Limitations of the CES-AES
7
1.4
Outline of book
8
1.5
Origin of the CES-AES
9
Practical and theoretical issues in channel hydraulics 2.1 2.2
15
Getting started with some practical examples on calculating flows in watercourses
15
Common difficulties in modelling flow in rivers and watercourses
24
2.2.1
Modelling flow in rivers and watercourses
25
2.2.2
Schematisation of channel geometry
26
2.2.3
Roughness and resistance
29
vi Contents
2.3
Energy and friction slopes
33
2.2.5
Velocity distributions and implications for 1-D modelling
37
2.2.6
Hydraulic structures and controls
42
2.2.7
Calibration data for river models
44
Flow in simple engineered channels
45
2.3.1
Flows in rectangular channels
50
2.3.2
Flows in trapezoidal channels
54
2.4
Inbank flow in natural rivers
57
2.5
Overbank flow in natural and engineered rivers
59
2.5.1
Overbank flow in an engineered river
60
2.5.2
Overbank flow in a natural river
64
2.6
2.7
3
2.2.4
Flows through bridges and culverts
69
2.6.1
Flows through bridges and contractions