Practical Channel Hydraulics is a technical guide for estimating flood water levels in rivers using the innovative software known as the Conveyance and Afflux Estimation System (CES-AES). The stand alone software is freely available at HR Wallingford’s website www.river-conveyance.net.
Features
Presents an expanded text (3 additional chapters) of a renowned handbook in the field
Covers other applications of SKM, CES and AES
Extensive worked examples on SKM, CES & AES illustrate the use of software
Allows postgraduate students to improve their theoretical knowledge
Provides pointers for further research in related engineering topics
Summary
Practical Channel Hydraulics is a technical guide for estimating flood water levels in rivers using the innovative software known as the Conveyance and Afflux Estimation System (CES-AES). The stand alone software is freely available at HR Wallingford’s website www.river-conveyance.net. The conveyance engine has also been embedded within industry standard river modelling software such as InfoWorks RS and Flood Modeller Pro. This 2nd Edition has been greatly expanded through the addition of Chapters 6-8, which now supply the background to the Shiono and Knight Method (SKM), upon which the CES-AES is largely based.
With the need to estimate river levels more accurately, computational methods are now frequently embedded in flood risk management procedures, as for example in ISO 18320 (‘Determination of the stage-discharge relationship’), in which both the SKM and CES feature. The CES-AES incorporates five main components: A Roughness Adviser, A Conveyance Generator, an Uncertainty Estimator, a Backwater Module and an Afflux Estimator. The SKM provides an alternative approach, solving the governing equation analytically or numerically using Excel, or with the short FORTRAN program provided.
Special attention is paid to calculating the distributions of boundary shear stress distributions in channels of different shape, and to appropriate formulations for resistance and drag forces, including those on trees in floodplains. Worked examples are given for flows in a wide range of channel types (size, shape, cover, sinuosity), ranging from small scale laboratory flumes (Q = 2.0 1s-1) to European rivers (~2,000 m3s-1), and large-scale world rivers (> 23,000 m3s-1), a ~ 107 range in discharge. Sites from rivers in the UK, France, China, New Zealand and Ecuador are considered.
Topics are introduced initially at a simplified level, and get progressively more complex in later chapters. This book is intended for post graduate level students and practising engineers or hydrologists engaged in flood risk management, as well as those who may simply just wish to learn more about modelling flows in rivers.
Table of Contents
1 Introduction
1.1 Context and motivation for book
1.2 Scope of book and introduction to the CES-AES
1.3 Limitations of the CES-AES
1.4 Outline of book
1.5 Origin of the CES-AES
2 Practical and theoretical issues in channel hydraulics
2.1 Getting started with some practical examples on calculating flows in watercourses
2.2 Common difficulties in modelling flow in rivers and watercourses
2.3 Flow in simple engineered channels
2.4 Inbank flow in natural rivers
2.5 Overbank flow in natural and engineered rivers
2.6 Flows through bridges and culverts
2.7 Data sources used in this book
3 Understanding roughness, conveyance and afflux
3.1 Flow structures in open channel flow
3.2 Governing equations
3.3 Dealing with uncertainty
3.4 Introduction to the CES-AES software
4 Practical issues – roughness, conveyance and afflux
4.1 An overview of the CES-AES use in practice
4.2 Estimating and using stage-discharge relationships and spatial velocities
4.3 Use of backwater module for estimating water levels along the River Main
4.4 Estimating afflux at bridges
4.5 Estimating afflux at culverts
4.6 Dealing with vegetation and maintenance of weedy rivers
5 Further issues on flows in rivers
5.1 Ecological issues
5.2 Sediment and geomorphological issues
5.3 Trash screen and blockage issues
5.4 Wider modelling issues
5.5 Software architecture and calculation engines
6 The Shiono & Knight Method (SKM) for analyzing open channel flows
6.1 Theoretical background to the governing equation used in the SKM
6.2 Physical background to the governing equation used in the SKM
6.3 Boundary conditions
6.4 Analytical solutions using the SKM
6.5 Boundary shear stress distributions in channel flow and shear forces on boundary elements
6.6 Resistance equations for surfaces, shape effects and trees
6.7 Flow dependent resistance issues
7 Worked examples using the Shiono & Knight Method (SKM)
7.1 Using Excel to solve the SKM equations together with analytical expressions for the Ai coefficients
7.2 Using Excel to solve the SKM equations numerically
8 Further examples – estimating flow, level and velocity in practice
8.1 Estimating and using stage-discharge relationships
8.2 Estimating and using spatial velocities
9 Concluding remarks
9.1 Concluding remarks
9.2 CES and SKM: Differences and Similarities
9.3 Future developments
Appendix 1 The finite element approximations for the CES equations
Appendix 2 Summary of hydraulic equations used in the AES
Appendix 3 Cross-section survey data
Appendix 4 Derivation of the governing depth-averaged equation used in the SKM
Appendix 5 Analytical solutions to the governing equation used in the SKM
Appendix 6 Fortran program for solving the governing depth-averaged equation used in the SKM