Adrian Laycock Ltd. Company Logo Irrigation Systems - Book

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    Irrigation Systems Design, Planning and Construction

    Adrian Laycock

     
     
    Published: June 2007 320 pages Hardback

    ISBN: 978 1 84593 263 3

    Price: £65.00 / US$130.00 / €105.00

    Subject Classification: KNAC, TVDR Territorial

    Market Rights: World

    Publisher:

     
    Of all the confrontations man has engineered with nature, irrigation systems have had the most widespread and far-reaching impact on the natural environment. Over a quarter of a billion hectares of the planet are irrigated and entire countries depend on irrigation for their survival and existence. Considering the importance of irrigation schemes, it is unfortunate that until recently the technology and principles of design applied to their construction has hardly changed in 4,000 years. Modern thinking on irrigation engineering has benefited from a cross-fertilization of ideas from many other fields including social sciences, control theory, political economics and agriculture. However, these influences have been largely ignored by irrigation engineers.

    Drawing on almost 40 years of experience of irrigation in the developing world, Laycock introduces new ideas on the design of irrigation systems and combines important issues from the disciplines of social conflict, management, and political thinking.

    Audience:

    Designed to appeal to all those involved in planning, managing and operating irrigation systems, this book will interest engineers, technicians, agriculturalists, economists, students and policy makers.

    Contents:

    • Evolution and a Prelude to Change
    • Elements of Irrigation
    • Water Management
    • Canal Operation and Automation
    • Irrigation Water Demands
    • Canal Architecture
    • Canal Control Structures
    • Low-Pressure Pipelines
    • Canal Lining
    • Canal Hydraulic Design
    • Troubleshooting – Feedback from the Field
    • Costs and Economics

     
    Back to Top

    Table of Contents

    CHAPTER 1

       EVOLUTION AND A PRELUDE TO CHANGE

    1

    1.1

    A World of Canals

    1

    1.2

    The Importance of Small Canals

    2

    1.3

    All- purpose Canals

    3

    1.4

    Pipelines- why and when

    4

    1.5

    Evolution of Irrigation Systems

    5

    1.6

    Aid, Finance and Politics

    6

     

    Historical

    7

     

    Colonial

    7

     

    Post-colonial

    8

     

    Socialist economic decree

    9

     

    The European Union

    12

     

    Oil wealth

    12

     

    Developed countries

    13

     

    Private development and self-help

    14

     

    Commercial schemes

    14

     

    Virtual water and self-sufficiency

    15

    1.7

    We have an Attitude Problem

    15

    1.8

    Prelude to Change

    16

     

    References and further reading for chapter 1

    16

     

    PART 1 - PLANNING

    17


    CHAPTER 2

       ELEMENTS OF IRRIGATION

    18

    2.1

    What can irrigation do?

    18

    2.2

    Productive, Partial and Protective Irrigation

    18

     

    The Upper Swat Canal, evolution from protective to productive

    19

     

    Deficit irrigation – the strange case of Albania

    21

    2.3

    Equity and Equality

    23

    2.4

    Sustainability

    24

    2.5

    Guaranteed Flow

    25

    2.6

    The Downside – tragic environmental side effects

    25

     

    References and further reading for chapter 2

    26


    CHAPTER 3

       WATER MANAGEMENT

    27

    3.1

    Levels of Water Management

    27

     

    Level 0 - Bulk issues

    27

     

    Levels 1 and 2 - Main system

    28

     

    Level 3 - Distribution

    28

     

    Level 4 - Watercourses, blocks and farm groups

    28

    3.2

    Delivery Scheduling

    28

    3.3

    Uncontrolled continuous flow

    31

     

    Basin flooding of paddy rice

    32

     

    The Talli project - wild flooding

    32

     

    Controlled wild flooding on the Rufiji

    33

     

    The Gezira project flows continuously against the rules

    34

     

    Proportional flow

    35

    3.4

    Supply scheduling

    36

     

    Rotation

    36

     

    Pivot points

    37

     

    Warabandi

    39

     

    Shejpali

    39

     

    Indenting

    39

    3.5

    Flexibility

    41

    3.6

    Demand Scheduling

    42

     

    Water on demand

    42

     

    Arranged scheduling

    43

     

    Semi-demand, arranged scheduling

    44

     

    Limited rate, arranged scheduling

    44

    3.7

    Intermittent Flow

    44

     

    Response time

    44

     

    Filling time

    44

     

    Absorption

    45

     

    Health

    45

    3.8

    Institutional Management

    45

     

    Line management

    45

     

    Unit management

    46

     

    Authority and assistance - conflicting roles of water managers

    48

     

    Farmer participation in management

    48

     

    Privatisation

    49

    3.9

    Water Charges

    49

     

    By volume

    50

     

    By area

    51

     

    By crop

    52

     

    By time

    52

     

    By number of irrigations

    52

     

    By season

    52

     

    By manipulation of controlled prices

    52

     

    By forfeit of crop

    53

     

    Free water

    53

     

    Education

    53

     

    References and further reading for chapter 3

    54


    CHAPTER 4

       CANAL OPERATION & AUTOMATION

    55

    4.1

    How Water Flows

    55

    4.2

    Canal Sensitivity and Response Time

    56

    4.3

    Modes of Control

    58

     

    Upstream control

    58

     

    Downstream control

    59

     

    Mixed control

    60

     

    Constant volume control

    60

     

    Centralised control

    61

    4.4

    Intermediate Storage

    62

     

    Storage ponds

    62

     

    Night storage canals

    63

     

    Night storage vs. night irrigation

    64

     

    Level-top canals

    65

     

    Related level control

    65

     

    Operational spillage

    65

     

    Conjunctive use of groundwater

    66

     

    Low-pressure pipelines

    66

    4.5

    Gate Operation

    66

     

    Manual gate operation

    66

     

    Powered or motorised gate operation

    67

     

    Gate self-operation

    67

    4.6

    Gate Control

    67

     

    Manual control

    67

     

    Refusal gates

    68

     

    Remote control and configuration

    68

     

    SCADA

    69

    4.7

    Why Automation

    70

     

    Automation to save labour

    70

     

    Automation for easier operation

    71

     

    Automation and control

    71

     

    Partial Automation

    72

    4.8

    Passive Automation

    73

     

    Long-crested weirs

    73

     

    Self-regulating float-operated gates for constant water level

    74

     

    Hunting and transients

    76

     

    Counterweighted gates for upstream control

    76

     

    Proportional dividers

    76

     

    Flumed outlets for proportional discharge

    78

     

    Baffle distributors for constant discharge

    78

    4.9

    Active Automation

    79

     

    Control theory

    79

     

    Fuzzy logic

    80

     

    Active automation of a canal system

    81

     

    Instrumentation, communication and motorisation

    82

    4.1

    Evolution from Manual Protective to Automated Productive - a case study

    84

     

    References and further reading for chapter 4

    86


    CHAPTER 5

       IRRIGATION WATER DEMANDS

    87

    5.1

    Estimating Irrigation Requirements

    87

     

    Why plants need water

    87

     

    Evapotranspiration

    87

     

    Crop water demand

    89

     

    Estimating rainfall

    89

     

    Field irrigation requirements

    91

     

    The root zone

    91

     

    Available water

    92

     

    Cropping patterns and intensity

    92

     

    Calculating field application rate

    93

     

    Stream size

    94

    5.2

    Water losses

    94

     

    Seepage

    95

     

    Leakage

    97

     

    Management loss

    97

     

    Dead storage

    98

     

    Absorption loss

    99

     

    Evaporation

    99

     

    Deep percolation

    99

     

    Runoff

    99

    5.3

    Irrigation Efficiencies

    99

     

    Conveyance efficiency

    100

     

    Management efficiency

    101

     

    Application efficiency (in-field)

    101

     

    Distribution efficiency

    101

     

    Overall efficiency

    102

     

    Other efficiencies

    103

    5.4

    Canal and system duties

    103

     

    Canal duty

    104

     

    Water management affects canal duties

    104

     

    The demand envelope

    105

     

    Cropwise irrigation demand - the engineer’s approach

    106

     

    The unit stream - the farmer’s approach

    106

     

    Flexibility and congestion

    107

     

    References and further reading for chapter 5

    109

     

    PART 2 - DESIGN

    110


    CHAPTER 6

       CANAL ARCHITECTURE

    111

    6.1

    Canal Layout and Water Delivery

    111

     

    Command

    111

     

    Head

    111

     

    Canal hierarchy

    111

     

    The tail-end, and associated problems

    112

    6.2

    Planning a canal layout

    113

     

    Drainage lines

    113

     

    Ridge lines

    113

     

    Major and minor slopes

    113

     

    Blocking out

    113

    6.3

    Canal Architecture

    114

     

    Parabolic

    115

     

    Trapezoidal

    117

     

    Filleted trapezoidal

    118

     

    Triangular

    118

     

    Rectangular

    118

     

    Circular or half-round

    119

     

    Other shapes

    119

     

    Compound channels

    120

    6.4

    Canal lining philosophy

    121

     

    To line, or not to line?

    121

     

    Reasons for canal lining

    121

     

    Rapid response time

    121

     

    Pumping costs reduced

    122

     

    Land tenure problems reduced

    122

     

    More land available for cultivation

    122

     

    Integrity of cross-section maintained

    123

     

    Animal damage prevention

    123

     

    Crop encroachment prevention

    125

     

    Health

    125

     

    Ease of maintenance

    125

     

    Reduction of management losses

    125

     

    Prevention of seepage out

    125

     

    Prevention of seepage in

    126

     

    Reduction of siltation

    126

     

    Erosion prevention

    127

     

    Farmer damage reduced

    127

     

    Structures simplified

    127

     

    Discharge increased

    127

     

    Command level increased

    127

     

    Bank stability

    128

    6.5

    Reasons for Not Lining

    128

    6.6

    Strategies for Lining

    128

     

    Durability

    128

     

    Hydraulic performance

    128

     

    Water management systems

    129

     

    Construction requirements

    129

     

    Labour resources

    129

     

    Material resources

    129

     

    Maintenance

    129

     

    Levels of technology

    129

     

    Quality control and supervision

    129

     

    Reducing wastage

    130

     

    Reducing salinity

    130

    6.7

    Canal Geometry

    130

     

    Slope

    130

     

    Best hydraulic section

    130

     

    Freeboard

    131

     

    Wind waves

    131

     

    Waves generated from gate operation

    132

     

    Waves caused by channel slope change

    132

     

    Bends

    132

     

    Bank width and slope

    134

     

    References and further reading for chapter 6

    135


    CHAPTER 7

       CANAL CONTROL STRUCTURES

    136

    7.1

    Access and Safety

    136

     

    Canal inspection roads

    136

     

    Bridges

    136

     

    Access ramps

    136

     

    Escape steps

    137

     

    Limited side slopes

    137

     

    Trash racks

    137

    7.2

    Health

    137

    7.3

    Water Discharge Control

    138

     

    Head regulators - sluice gate type

    138

     

    Head regulators – moveable weir type

    139

     

    Turnouts - undershot gate type

    139

     

    Turnouts - overshot gate type

    140

     

    Turnouts - drop inlet type

    140

     

    Modular control gates

    141

     

    Constant discharge modules

    141

    7.4

    Flow division

    141

     

    Proportional dividers – bifurcators & trifurcators

    142

     

    Open flumes and proportional modules

    143

    7.5

    Water Level Control - Cross Regulators and Checks

    144

     

    Gated cross regulators for upstream control

    145

     

    Choice of gate

    146

     

    Self-regulating cross regulators for upstream control

    147

     

    Self-regulating cross regulators for downstream control

    147

     

    Fixed weirs as cross regulators

    148

     

    Notched falls

    149

     

    Check structures

    150

    7.6

    Velocity control

    150

     

    Drop structures

    150

     

    Baffled chute drops

    152

     

    Overfall and chute drops

    153

     

    Pipe drops

    153

     

    Rough channels

    153

     

    Flow arresters

    153

    7.7

    Turbulence Control

    153

     

    Stilling basins

    154

     

    Transitions and fluming

    154

    7.8

    Conveyance and Cross Drainage

    155

     

    Choice of structure

    155

     

    Culverts

    156

     

    Superpassages

    157

     

    Aqueducts

    158

     

    Conveyance flumes

    158

     

    Canalettes

    158

     

    Inverted siphons

    159

     

    Drainage inlets

    160

    7.9

    Overflow Control

    161

     

    Side escapes

    161

     

    Flushing sluices

    161

     

    Tail escapes

    161

     

    Siphon spillways

    161

     

    Automatic outlet plugs

    162

    7.1

    Field Outlets

    162

     

    Open cuts

    162

     

    Spiles

    162

     

    Precast nuccas

    163

     

    Undershot gates

    163

     

    Overflow slots

    163

     

    Plastic siphons

    163

    7.11

    Measurement Structures

    164

     

    Weirs

    165

     

    Crump weirs

    165

     

    Replogle weirs

    165

     

    Vee-notch weirs

    166

     

    Flumes

    166

     

    Cut-throat flumes

    168

     

    Parshall flumes

    168

     

    Meters

    168

     

    Ultrasonics

    168

     

    Stage-discharge measurement

    169

    7.12

    Sediment control

    169

     

    Sources of sediment

    169

     

    Modes of operation and design options

    170

     

    Watershed management

    171

     

    Reservoir trapping

    171

     

    Regime canals

    171

     

    Continuous flushing

    172

     

    Silt ejectors and vortex tubes

    172

     

    Settlement reaches and settlement basins

    173

     

    Dredging

    174

     

    Prevention of sand ingress

    174

     

    Wind breaks

    174

     

    Culverting

    175

     

    Removal of dunes

    175

     

    References and further reading for chapter 7

    176


    CHAPTER 8

       LOW-PRESSURE PIPELINES

    177

    8.1

    Principles of Pipeline Operation

    177

     

    The advantage of low pressure

    177

     

    Open and closed pipelines

    178

     

    Flexibility, and guarantees for success

    180

     

    In-built constraints

    180

    8.2

    Pipeline Layout

    181

     

    General layout

    181

     

    Field outlets

    181

     

    Involvement of farmers

    182

     

    Blocking out and farm groups

    182

    8.3

    Administrative Organisation

    183

     

    Farm groups and the group irrigator

    183

     

    Water Users Association

    183

     

    Ownership

    184

     

    Water charging

    184

    8.4

    Why and When to Use a Pipeline

    184

    8.5

    Designing the pipeline

    186

     

    Unit stream size

    186

     

    Congestion

    186

     

    Calculating the pipeline capacity

    187

     

    Sizing the pipeline

    187

     

    Pipe materials and laying

    188

    8.6

    Pressure and Flow Control

    189

     

    Harris valves

    189

     

    Pressure-reducing valves

    189

     

    Float-operated sleeve and disc valves

    189

     

    Outlets

    192

     

    Pipe inlets

    194

    8.7

    Design Procedures

    194

     

    Topographic mapping

    195

     

    Cadastral mapping

    195

     

    Pipe layout

    195

     

    Use of spreadsheets in designing a pipeline

    195

     

    Choice of Harris valve

    197

     

    References and further reading for chapter 8

    197


    CHAPTER 9

       CANAL LINING

    198

    9.1

    Physical Influences on Lining

    198

     

    Structural stress

    198

     

    Hydrostatic pressure

    198

     

    Point loads

    199

     

    Durability

    200

     

    Thermal and shrinkage stresses

    200

     

    Soil movement

    200

     

    Soil dispersion

    200

     

    Scour

    200

     

    Vegetation

    201

     

    Accidental damage

    201

     

    Animal damage

    201

     

    Deliberate damage

    202

    9.2

    Masonry Lining

    202

     

    Stone masonry

    202

     

    Stone packing

    202

     

    Laterite masonry

    202

     

    Clay bricks

    203

     

    Stone slabs

    204

     

    Precast concrete slabs

    204

     

    Precast concrete sides with in situ concrete bed

    204

    9.3

    In Situ Concrete

    205

     

    Thin mass concrete

    205

     

    Slip-forming

    207

     

    Joints

    207

     

    Reinforced concrete

    208

     

    Jointless lining

    209

     

    Plaster

    209

     

    Ferrocement

    209

     

    Fibre reinforced concrete

    209

     

    Sprayed concrete

    210

    9.4

    Precast Concrete Segments

    210

     

    Design

    210

     

    Shapes - parabolic is best

    211

     

    Size

    212

     

    Manufacture

    212

     

    Wet casting

    212

     

    Hydraulic pressing

    213

     

    Pipe spinning

    213

     

    Building-up

    214

     

    Jointing

    214

     

    Laying

    214

     

    Canalettes

    214

    9.5

    Flexible Impermeable Membranes

    215

     

    Polythene LLDPE

    216

     

    HDPE

    216

     

    Butyl rubber, EPDM

    216

     

    PVC

    216

     

    Buried membranes

    216

     

    Membranes with in situ concrete

    217

     

    Membranes with bricks or precast slabs

    217

     

    Bitumen and asphalt

    218

     

    Geosynthetic clay liners (GCL)

    218

    9.6

    Geotextiles, Geogrids and Geocells

    218

     

    Geotextiles

    218

     

    Geogrids

    219

     

    Geocells

    219

    9.7

    Other Prefabricated Materials

    219

     

    Steel

    219

     

    GRP

    220

     

    GRC

    220

     

    Asbestos cement

    220

     

    Timber

    220

     

    Recycled plastic

    220

    9.8

    Stabilised Earth Lining

    221

     

    Compacted earth

    221

     

    Soil cement, and cement-bound fill

    221

     

    Bentonite

    221

     

    Silty water

    222

     

    Oil, molasses

    222

    9.9

    Unlined canals

    222

     

    Tight soils

    223

     

    Earth cut

    223

     

    Rock

    223

     

    References and further reading for chapter 9

    223

     

     

     


    CHAPTER 10

       CANAL HYDRAULIC DESIGN

    225

    10.1

    Basic Tools

    225

     

    Stable channels and Manning’s formula

    225

     

    Alluvial channels and Lacey’s regime formula

    226

     

    The depth/top width ratio

    227

     

    Other sediment transport theories

    228

    10.2

    Canal Architecture

    228

     

    Channel roughness

    229

     

    Hydraulic geometry

    230

    10.3

    Water flow in canals

    231

     

    Permissible velocity

    231

     

    Velocity distribution

    232

     

    Steady and non-steady flow

    232

     

    Uniform and non-uniform flow

    232

     

    Energy and head

    233

     

    Momentum

    233

     

    Critical flow

    234

     

    Secondary flow

    235

     

    Turbulence

    235

    10.4

    The Process of Design

    236

    10.5

    Using Computer Spreadsheets for Canal Design

    236

    10.6

    Manning - a program for canal design charts

    245

     

    The usefulness of charts

    245

     

    Using the chart

    245

    10.7

    Formulae relating to chapter 10

    249

     

    References and further reading for chapter 10

    251

     

    PART 3 – EXPERIENCE

     


    CHAPTER 11

       TROUBLESHOOTING - FEEDBACK FROM THE FIELD

    253

    11.1

    Canals That Don’t Work

    253

    11.2

    Spotting the Trouble

    254

     

    Water doesn’t flow

    254

     

    Water overflows

    256

     

    Water disappears

    256

     

    The drains are running

    256

     

    Categories of problem

    257

    11.3

    Bad Construction

    257

     

    Construction tolerances

    257

     

    Supervision

    257

     

    Unqualified staff

    258

     

    Bad workmanship

    258

     

    Obsolete construction techniques

    258

     

    Difficult access

    258

     

    Poor soil compaction

    258

     

    Poor concrete compaction

    259

     

    Poor concrete curing

    260

     

    Poor concrete finishing

    260

     

    Poor control of concrete mixing

    260

     

    Inadequate thickness control

    261

     

    Bad formwork

    261

    11.4

    Bad Design

    261

     

    Obsolescence

    261

     

    Poor planning

    262

     

    Sedimentation

    262

     

    Oversizing

    262

     

    Unsuitable local materials

    262

     

    Not enough turnouts

    262

     

    Undershot turnouts

    263

     

    Regulators and division structures

    263

     

    Quaternaries

    263

     

    Design for short life

    263

     

    Over-design for high cost

    264

    11.5

    Bad Water Management

    264

     

    Lack of training

    264

     

    Political interference

    264

     

    Pressure from farmers

    264

     

    Improper gate operation

    265

    11.6

    Natural Causes

    265

     

    Swelling soils

    265

     

    External hydrostatic pressure

    266

     

    Animal damage

    267

     

    Root penetration

    268

     

    Landslips

    268

     

    Thermal Expansion

    268

    11.7

    Bad Maintenance

    268

     

    Siltation

    268

     

    Over excavation

    269

     

    Vegetation

    269

     

    Masonry repair

    269

     

    Closing of holes

    270

     

    Leaking structures

    270

    11.8

    Bad Farmers

    270

     

    Incomplete understanding of irrigation

    270

     

    Water charges encourage wastage

    270

     

    Social quarrels and wilful damage

    270

     

    Crops on canal banks

    270

     

    Theft

    271

    11.9

    Farmer Interference

    271

     

    Unofficial turnouts

    271

     

    Drainage

    272

     

    Redundant canals

    272

     

    Damaged structures

    273

    11.1

    Corruption

    273

     

    Honest John

    273

     

    Endemic micro-corruption

    274

     

    Macro-corruption

    275

     

    Corruption in water management

    276

    11.11

    The Answers

    276

     

    Proper supervision

    276

     

    Design with the times

    277

     

    Proper training

    277

     

    What engineering is

    277

     

    References and further reading for chapter 11

    278


    CHAPTER 12

       COSTS AND ECONOMICS

    279

    12.1

    Small Scale Irrigation Projects - the Hidden Costs

    279

     

    Cheap schemes - a myth exploded

    279

    12.2

    Counting the Cost of Failure - the cost of bad quality

    280

     

    Lost crop production

    280

     

    Maintenance effort

    281

     

    Social conflict

    281

     

    Lost Revenue

    282

     

    The cost of poor design

    282

     

    The cost of bad supervision

    282

     

    The real cost

    282

    12.3

    The Cost of Good Supervision

    283

     

    Supervision cost

    283

     

    Supervision cost in perspective

    283

    12.4

    Spending Money on Simplicity – The Cost of Automation

    284

    12.5

    Spending Money on Posterity – the Cost of Parabolics

    284

    12.6

    Spending Money on Flexibility – The Cost of Pipelines

    284

     

    References and further reading for Chapter 12

    285


     
    Back to Top

    List of Tables, Figures and Supplementary Figures

    LIST OF TABLES

    5.1

    Crop factors

    5.2

    Calculation of irrigation demands

    5.3

    Rooting depths

    5.4

    Indicative water movement rates in various soils, m/day

    5.5

    Canal duties, Upper Swat System, Pakistan

    5.6

    Calculation of congestion

    6.1

    Canal Nomenclature

    6.2

    Reasons for canal lining

    6.3

    Freeboard

    6.4

    Bends

    7.1

    Head loss (m) in plastic siphons

    7.2

    Settling rates of sediment

    8.1

    Pipeline nomenclature

    8.2

    Typical congestion figures

    8.3

    Typical pipe friction coefficients for diameters 300 - 900 mm

    8.4

    Head losses – alfalfa and orchard valves

    8.5

    Congestion calculation

    8.6

    Harris valve sizes and head loss coefficients

    9.1

    Profile coordinates for precast parabolic canals

    9.2

    Minimum thickness of membranes for use in canal lining

    9.3

    Durability of canal linings

    10.1

    Design guidelines for unlined canals in silty soil

    10.2

    Canal roughness

    10.3

    Permissible non-scouring mean velocities

    10.4

    Non-silting mean velocities

     

    LIST OF FIGURES

    1.1

    View Chapter 1 Figures
    Arch aqueduct on the Upper Swat Canal, Pakistan

    2

    1.2

    The parabolic Pehur High Level Canal, Pakistan

    3

    1.3

    A minor headsluice in the Gezira, Sudan

    7

    1.4

    An irrigation channel flows through the Fier oilfield, Albania

    11

    1.5

    Centre pivots in Nebraska. Each circle fills a half-mile square

    13

    1.6

    A linear-move sprinkler on a commercial farm in Sudan

    14

    1.7

    Abandoned land due to salinisation in the Aral Sea basin, Kazakstan

    16

     

     

     

    2.1

    View Chapter 2 Figures
    Machai Branch, Upper Swat system, Pakistan

    20

    2.2

    Irrigation demands and reservoir storage curve – Durres, Albania

    21

    2.3

    Tarinit Dam, Albania

    22

     

     

     

    3.1

    View Chapter 3 Figures
    Delivery scheduling

    30

    3.2

    Paddy fields in Java with a continuous throughflow, using bamboo spiles

    31

    3.3

    The Rufiji Delta, Tanzania

    33

    3.4

    Gezira cotton

    34

    3.5

    Katlang Distributary of the Upper Swat Canal

    35

    3.6

    Cross regulator on Machai Branch

    36

    3.7

    Pivot points on the Upper Swat Canal system

    38

    3.8

    Imperial Valley, California. Indenting on a massive scale

    40

    3.9

    Continuous flow, rotation and demand scheduling

    43

    3.1

    A traditional line management structure, and improved Unit Management

    47

    3.11

    ‘Acquacard’ unit controlling water to a hectare of artichokes, Foggia, Italy

    51

     

     

     

    4.1

    View Chapter 4 Figures
    Response curves

    57

    4.2

    Upstream control by a float-operated self-regulating gate, Thailand

    59

    4.3

    Downstream control gates on the Pehur High Level Canal, Pakistan

    60

    4.4

    A pump station on the California Aqueduct

    61

    4.5

    Modes of canal regulation

    62

    4.6

    Silt accumulating in a Gezira minor canal, Sudan

    63

    4.7

    A lever-operated check gate, Imperial Valley, California

    67

    4.8

    Refusal gates installed on a precast outlet, Pakistan

    68

    4.9

    SCADA-controlled outlet valves supply the Pehur High Level Canal

    72

    4.1

    Labyrinth weir used as an emergency overflow structure

    73

    4.11

    Parabolic self-regulating upstream control gates, Maskane Project, Syria

    75

    4.12

    Principle of operation of downstream control self-regulating gates

    75

    4.13

    Downstream control in adjacent canal reaches

    76

    4.14

    A proportional divider abstracts a fixed proportion of the flow

    77

    4.15

    Modular distributor

    78

    4.16

    Motorisation

    83

     

     

     

    5.1

    View Chapter 5 Figures
    A typical irrigated cropping pattern for north-eastern Nigeria

    93

    5.2

    Conveyance curves for the Yeleru Left Bank Canal

    96

    5.3

    Yeleru Left Bank Canal

    97

    5.4

    Wasted water from Arshingeri Tank, Karnataka

    98

    5.5

    Management losses from Zaida Minor flood the road in NWFP, Pakistan

    98

    5.6

    Conditions leading to heavy water use. The Multaga project in Sudan

    100

    5.7

    Poor distribution in furrow irrigation

    102

    5.8

    Plastic vanes retard the rate of advance in furrows

    102

    5.9

    Demand curves of commandable area versus field irrigation requirement

    105

     

     

     

    6.1

    View Chapter 6 Figures
    A typical scheme canal layout

    114

    6.2

    Yeleru Left Bank Canal, a natural parabolic

    115

    6.3

    Equivalent parabolic and trapezoidal profiles for the Pehur High Level Canal

    117

    6.4

    Rectangular brick canal, Pakistan, with a ‘pucca nucca’ outlet

    118

    6.5

    Half-round canalettes, Morocco

    119

    6.6

    Constructing a large circular canal, Spain

    120

    6.7

    irrigating the slopes of a volcano, Lawu, Eastern Java

    123

    6.8

    In Eastern Java cassava grown on canal banks soon destroys the lining

    124

    6.9

    Cattle can wreck small canals, especially in India where cows are sacred

    124

    6.1

    Brick side lining stabilises the outside of a bend on the Maira Branch Canal

    126

    6.11

    Standing wave at the end of a steep canal reach

    132

    6.12

    Merowe Left Bank Canal profiles, capacity 230 cumecs

    133

    6.13

    Alternative profiles for Pehur High Level Canal, capacity 30 cumecs

    134

    6.14

    Precast parabolic segments, and the traditional profiles they replaced

    135

     

     

     

    7.1

    View Chapter 7 Figures
    An access ramp for canal maintenance, Colorado

    136

    7.3

    Simple lift gates used for check and turnout, India

    140

    7.4

    A drop inlet turnout in Sudan – inlet gate and outlet pipe

    140

    7.5

    Modular control gates

    141

    7.6

    Design for a Crump weir bifurcator

    142

    7.7

    Double trifurcator. The flow to each outlet is divided twice

    143

    7.8

    Open flume, Pakistan

    144

    7.1

    A long-crested weir with convex duckbill configuration, Sri Lanka

    149

    7.11

    Parabolic check plate, with field outlet closed at left, open at right

    150

    7.12

    Baffled chute drop

    151

    7.13

    Notch falls, Upper Swat Canal, Pakistan

    151

    7.14

    Glacis fall

    152

    7.15

    Stepped Drop cascade in a parabolic watercourse

    152

    7.16

    Inlet transitions to siphon aqueducts on the Shamozai Distributary

    155

    7.17

    Reverse ellipse flumed transition, trapezoidal channel

    156

    7.18

    Drop inlet culvert under construction

    157

    7.19

    Small superpassage on the Pehur High Level Canal, Pakistan

    158

    7.2

    Siphonic aqueduct, Shamozai Distributary of Upper Swat Canal, Pakistan

    159

    7.21

    Kundal Khwar siphon under construction on the Pehur High Level Canal

    160

    7.22

    A siphon side escape structure on the Genil-Cabra Canal, Spain

    162

    7.23

    Plastic siphons with long-line furrows, Columbia Basin, USA

    164

    7.24

    A Replogle Weir at Patterson Irrigation Scheme, California

    166

    7.25

    Weir types and discharge formulae

    167

    7.26

    design for small cut-throat flumes

    168

    7.27

    A canal blocked by Barchan sand dunes in the Nubian Desert

    170

    7.28

    A vortex tube structure

    173

    7.29

    Silt accumulation in a Gezira main canal, Managil extension, Sudan

    175

    7.3

    Desilting basins, Dam Jati, east Java

    176

     

     

     

    8.1

    View Chapter 8 Figures
    A low-pressure pipeline offers near-constant outlet pressures

    177

    8.2

    Open, semi-closed and closed pipelines

    179

    8.3

    An extreme example of an open pipeline, Westlands, California

    179

    8.5

    Blocking out for a flexible delivery pipeline system

    182

    8.6

    Gated pipe system, USA

    185

    8.7

    Installing MDPE pipe, India

    186

    8.8

    Float valves for downstream control

    190

    8.9

    Harris valve stands in Topi, Pakistan

    191

    8.1

    Installing a Harris valve float

    191

    8.12

    Field outlet in a low-pressure pipeline system

    193

    8.13

    A Beaumont circular weir outlet from a buried pipeline, Sulawesi

    193

    8.14

    Pipe intake from a level-top canal

    194

    8.15

    Interactive pipeline design, longitudinal section and pressure distribution

    196

     

     

     

    9.1

    View Chapter 9 Figures
    Finite element analysis shows high stress in a trapezoidal section

    199

    9.2

    Canal profiles and forces on them

    201

    9.3

    Stone masonry, India

    203

    9.4

    Brick lining, Sri Lanka. Every joint is a potential source of leakage

    203

    9.5

    Precast slabs sliding under their own weight, India.

    204

    9.6

    Concrete placing on the Pehur High Level Canal

    206

    9.7

    Slip forming the Ghazi-Barotha power canal, Pakistan

    206

    9.8

    A paving train for a parabolic canal

    207

    9.9

    Laying ferrocement

    209

    9.1

    Shotcreting a small canal, Swaziland

    210

    9.11

    Parabolic lining is so smooth

    211

    9.12

    A field casting yard for parabolics, India

    213

    9.13

    Parabolic canalettes, Kazakstan

    215

    9.14

    How not to build a canal. Dozing up the banks without compaction, Sri Lanka

    222

     

     

     

    10.1

    View Chapter 10 Figures
    Depth/top-width ratio for unlined canals

    227

    10.2

    A rough canal. The Pitched Channel of the Upper Swat System, Pakistan

    229

    10.3

    Channel velocity profiles and distribution with depth

    232

    10.4

    Specific energy curve for different canals

    234

    10.5

    Toru Minor longitudinal section

    243

    10.6

    Toru Minor velocity profile

    243

    10.7

    Longitudinal section for Toru Minor

    244

    10.8

    Sample charts

    246

    10.9

    Sample charts

    247

    10.1

    Sample charts

    247

    10.11

    Sample charts

    248

    10.12

    Sample charts

    248

    10.13

    Sample charts

    249

     

     

     

     11. 1

    View Chapter 11 Figures
    The most likely time for a canal breach is during first filling

    253

     11. 2

    Bogribail Canal long section

    254

     11. 3

    Bogribail Canal through rock

    255

     11. 4

    Paddy in canal

    255

     11. 6

    Lining burst by external hydrostatic pressure

    266

     11. 7

    Lining undermined by piping of soil through concrete joints

    266

     11. 8

    Heavy weed growth in Yeleru Left Bank Canal, Andhra Pradesh

    269

     11. 9

    Crops on canal banks damage lining. Cassava, Java

    271

     11. 10

    Diverted watercourse in a boundary dispute

    272

     11. 11

    Redundant tertiary takes up useful land

    273

     

     

    LIST OF SUPPLEMENTARY FIGURES AVAILABLE ON THE WEBSITE AND CD

    (Supplementary figures are prefixed with the letter A and numbered with relevance to chapters).

     
    View Chapter 1 Figures
    A1.1        Nouria, Orontes River, Syria
    A1.1b      Nouria, Orontes River, Syria
    A1.2        Women planting rice, India
    A1.3        The Pitched Channel, Upper Swat Canal
    A1.4        Precast parabolic canal, India
    A1.5        Jalala distributary, Upper Swat canal
    A1.6        Drain confluence, Swabi SCARP
    A1.7        Coffee under surface irrigation, Zambia
    A1.8        Coffee under sprinkler irrigation, Zambia
    A1.9        Coffee under drip irrigation, Zambia
    A1.10      Kyzl Orda canal
    A1.10b    Kyzl Orda canal
    A1.11      Lake Koronia , Greece
    A1.11b    Lake Koronia, Greece
    A1.12      Genil Cabra Canal, Spain
    A1.13      Wind River Canal, Nebraska
    A1.14      Flour mill on the Upper Swat Canal
     
    View Chapter 2 Figures
    A2.1        Desilting Mahabrabhata Canal, India
    A2.2        Desilting a village canal, Burma
    A2.3        Irrigating in the rain, India
    A2.4        Irrigating coconuts, India
    A2.5        Irrigating groundnuts, India
    A2.6        Irrigating sugar, India
    A2.7        Washing in canal, India
    A2.8        Swimming in canal, Ethiopia
     
    View Chapter 3 Figures
    A3.1        Bhandara, India
    A3.2        Bhandara, India
    A3.3        Bhandara, India
    A3.4        Bhandara, India
    A3.5        Bhandara, India
    A3.6        Bhandara, India
    A3.7        Bhandara, India
     
    View Chapter 4 Figures
    A4.1        Precast parabolic segments
    A4.2        Precast parabolic check gates
    A4.4        Friant Kern Canal
    A4.6        Refusal gate
    A4.7        Manual irrigation of sugar cane, Jember, East Java
    A4.8        Side weir, Nakambala
    A4.9        Folded weir, Abazai Branch Canal
    A4.10      Avio gate, Brazil
    A4.11      Installing downstream control gates
    A4.11b    Installing downstream control gates
    A4.11c    Commissioning downstream control gates
    A4.11d    Commissioning downstream control gates
    A4.11e    Avio downstream control gates
    A4.11f     Commissioning Avio downstream control gates
    A4.12      Vlugter gate, sulawesi
     A4.14     Neyrtec distributor, Thailand
    A4.15      Tush Canal, Kirgystan
    A4.16      Radial gates, Morocco
    A4.17      Balancing pond spillway, Morocco
    A4.18      Silt in night storage pond, Metahara, Ethiopia
    A4.19      Silt dredger, Metahara
     
    View Chapter 5 Figures
    A5.1        Turnout leakage
     
    View Chapter 6 Figures
    A6.1        Flow arresters, abazai
    A6.2        Protection groynes, Machai Branch Canal
     
    View Chapter 7 Figures
    A7.1        Butcher gate moveable weir, Sudan
    A7.2        Romijn gate, Indonesia
    A7.3        Overfall gate, Ethiopia
    A7.4        Rack & pinion gates, Upper Swat Canal
    A7.4b      Rack & pinion gate, Maira Branch distributary head
    A7.5        Wheel gate, Benton Tunnel outlet, Upper Swat Canal
    A7.6        Stoney roller gates, Amandara Headworks, Swat River
    A7.6A      Stoney roller gates, amandara headworks
    A7.7        Farmers cross regulator, Kinda main canal, Burma
    A7.8        Combined cross regulator, el Ghab left bank, syria
    A7.9        Weir configurations
    A7.10      Notch fall, Pakistan
    A7.11      Notch fall, Machai Branch Canal
    A7.12      Notched check weir, Sri Lanka
    A7.13a    Stone Masonry rapid fall, Abazai Branch Canal
    A7.13b    Stone Masonry rapid fall, Abazai Branch Canal
     A7.14     Step drop, Karnataka
    A7.15      Flow arresters in a small pumped canal, Karnataka
    A7.16      Vertical drop, Upper Swat Distributary
    A7.17      Baffled chute under construction, Abazai Branch canal
    A7.18      Pipe drop, Sudan
    A7.19      Onion stilling basin, Burma
    A7.20      Parabolic-rectangular transition, Pehur High Level Canal
    A7.21      Reverse elliptical transitions
    A7.22a    Inverted siphon blocked with sediment
    A7.22b    Inverted siphon entrance blocked
    A7.23      Large superpassage, Ghazi-Barotha canal
    A7.24      Rectangular section aqueduct, Malaprabha scheme, India
    A7.25      Strutted rectangular section aqueduct
    A7.26a    Siphonic aqueduct, Bheram Dheri distributary, Upper Swat System
    A7.26b    Siphonic aqueduct, Bheram Dheri distributary, Upper Swat System
    A7.27      Conveyance flume, Lezhe, Albania
    A7.28      Conveyance flume, Elbasan, Albania
    A7.29      Siphon aqueduct, Machai Branch Canal
    A7.30      Kundal Khwar siphon inlet
    A7.31      Kundal Khwar siphon outlet surge tower
    A7.32      Placing concrete in Kundal Khwar Siphon
    A7.33      Gandaf cut & cover tunnel under construction
    A7.34      Badri siphon, Pehur High Level Canal
    A7.35      Badri siphon under construction
    A7.36      Formwork for concreting Badri siphon
    A7.37      MDPE sleeving in a leaking concrete pipeline
    A7.38      Drain inlet                               
    A7.39      Side escape in a small canal
    A7.40      Escape chute at an inverted siphon, Kalpani distributary, Lower Swat canal
    A7.41      Gated sluice escape with baffled chute, Maira Branch Canal
    A7.42      Flushing sluice and labyrinth weir, Machai Branch tail escape
    A7.43      Weir type side escape on Maira Branch canal
    A7.45a    Ardrishaig waster, Crinan Canal, Scotland
    A7.45b    Ardrishaig waster, Crinan Canal, Scotland
    A7.45c    Ardrishaig waster, Crinan Canal, Scotland
    A7.46      Slide gate turnouts, Karnataka
    A7.47      Veenotch weir at a Javanese tubewell
    A7.48      Cutthroat flume, India
    A7.49b    Propeller meter installed in a low pressure pipeline
    A7.49a    Propeller meter for a low pressure pipeline
    A7.50      Silt deposits in an oversized canal
    A7.51      Siltation in multaga main canal, Sudan
    A7.52      Skimmer weir intake, Sulawesi
    A7.53      Desilting the Rahad main canal, Sudan
    A7.54      Irrigating with plastic siphons, Zambia
    A7.55      Shamozai inverted siphon, Pakistan
    A7.56      Kalpani siphon inlet
    A7.57      Parabolic check plate turnout
    A7.58      Throttled fall, Upper Swat distributary
    A7.59      Glacis fall
    A7.60      Washing place on a tubewell scheme, java
    A7.61      A fall on the pitched channel, Pakistan
    A7.62      Desilting reach, Wonji main Canal, Ethiopia
     
    View Chapter 8 Figures
    A8.2        Low pressure pipe irrigating grapes , Brazil
    A8.1        Low pressure pipe irrigating grapes , Brazil
    A8.3        MDPE sleeve in a concrete pipeline
    A8.4        Installing a buried concrete pipe, India
    A8.5        Orange Cove pipeline intake pumps
    A8.6        Slotted outlets to a low-pressure pipeline, Orange Cove
    A8.7        Drainage reuse in a low-pressure pipeline, Coachella Valley, California
    A8.8        Harris valve stands, Coachella
    A8.9        Harris valve
    A8.10      Intermediate storage pond, california
    A8.11      Harris float
    A8.12      Harris floats
    A8.13      Drip irrigatiopn from a low-pressure pipeline, California
    A8.14      Flow meter in a Coachella pipeline
    A8.15      Propeller meter
    A8.16      Parabolic canalettes feeding a buried pipeline system, Syria
    A8.17      Pressure testing buried concrete pipes, Pakistan
    A8.18      Concrete pipe leaks
    A8.19      Pipe spinning, pakistan
    A8.20      Concrete pipe ready for backfilling
    A8.21      Concrete pipe ready for bacckfilling
    A8.22      Orifice plate outlet in a low pressure pipeline.
     
    View Chapter 9 Figures
    A9.1        Placing concrete lining with a vibrating plate compactor
    A9.2        Placing side lining using a plate compactor
    A9.3        Manual placement of concrete lining
    A9.4        Placing concrete side lining with a Bunyan Tube
    A9.5        Placing concrete bed lining with a Bunyan Tube
    A9.6        Excavating for a large parabolic canal
    A9.7        Parabolic formwork for screed bars
    A9.8        Excavating the Pehur High Level Canal
    A9.9        Templates and formwork for the Pehur High Level Canal
    A9.10      Chain template for trimming a parabolic profile
    A9.11      Positioning parabolic screedbar formwork
    A9.12      Striking screedbar formwork
    A9.13      Screedbar after stripping formwork
    A9.14      Screedbars in place, ready for concrete lining
    A9.15      Placing concrete lining by crane skip
    A9.16      Placing concrete lining by chute and Bunyan Tube
    A9.17      Placing concrete lining by chute and Bunyan Tube
    A9.18      Placing concrete lining by Bunyan Tube
    A9.19      Bunyan Tube in operation
    A9.20      Placing concrete parabolic lining
    A9.21      Placing concrete parabolic lining
    A9.22      Inlet to Kundal Khwar Siphon
    A9.23      Repairs to concrete lining using a Bunyan Tube
    A9.24      The Pehur High Level Canal
    A9.25      Slipforming the Sheik Zayed canal, Egypt
    A9.26      Slipforming the Ghazi Barota canal, Pakistan
    A9.27      Slipformer on Ghazi Barota canal
    A9.28      Excavation of the Ghazi Barotha canal by Holland loader
    A9.29a    Excavation of the Ghazi Barotha canal by elevating scraper and conveyor
    A9.29b    Excavation of the Ghazi Barotha canal by elevating scraper and conveyor
    A9.30      Parabolic full span trimmer, Genil-Cabra Canal, Spain
    A9.31      Concrete lining to a circular profile, Spain
    A9.32a    Cement/sand plaster lining a small canal
    A9.32b    Cement/sand plaster lining a small canal
    A9.33a    Placing ferrocement lining, India
    A9.33b    Placing ferrocement lining, India
    A9.34      Steam curing precast parabolic units
    A9.35      Vibrating table for precast parabolic segments
    A9.36      Curing pond for parabolic segments
    A9.37      Casting yard for parabolic segments
    A9.38      Casting parabolic segments on a vibrating table
    A9.39      Completed parabolic segments, Pakistan
    A9.40      A lifting device for parabolic segments
    A9.41      Parabolic watercourse, Pakistan
    A9.42      A parabolic following tight field boundary
    A9.43      Parabolic segments in place, India
    A9.44      Parabolic segment placing by gantry, Java
    A9.45      Parabolic placing manually, Java
    A9.46      Joint blow in parabolic segments due to external hydrostatic pressure
    A9.47      Laying parabolics in wet soils
    A9.48      Parabolic segment joint
    A9.49      Mastic jointing precast parabolics
    A9.50      Gasketed joint in precast parabolic segment, Syria
    A9.51      Parabolic segments, Syria
    A9.52      Transporting large precast parabolic segments, Syria
    A9.53      Precast half round pipes, India
    A9.56      Precast hexagonal slabs, Sri Lanka
    A9.57      Precast hexagonal slabs, Sri Lanka
    A9.58      Precast hexagonal slabs over polythene membrane, Sri Lanka
    A9.59      Brick lining, Sri Lanka
    A9.60      Buried polythene membrane, Sri Lanka
    A9.61      Polythene temporary lining
    A9.62      Precast wall segments in a rectangular canal, Kirgystan
    A9.63a    Preformed GRC lining, Egypt
    A9.63b    Laying GRC lining, Egypt
    A9.64      Half-round timber flume, Montana
    A9.65      Asbestos cement channel
    A9.66      The Unlined Abazai Branch canal, Pakistan
    A9.67      Dry stone packing, India
    A9.68      Stone slab lining, India
    A9.69      Buried bitumen membrane, Sri lanka
    A9.70      Rectangular brick watercourse, Pakistan
    A9.71      Rectangular watercourse and pucca nuccas, Pakistan
    A9.72      Half-round segments, India
    A9.73      Vibrating plate compactor, India
    A9.74      Parabolic segments along a rough boundary, India
    A9.75      Precast Parabolics, Pakistan
     
     
    View Chapter 11 Figures
    A11.1      Compaction failure beneath concrete lining
    A11.2      El Ghab canal, lining failure
    A11.3      Failure of thin lining, Java
    A11.4      Failure of thin lining, Java
    A11.5      Failure of thin lining, Java
    A11.6      Cracked masonry lining in swelling soils
    A11.7      Farmer turnout , Java
    A11.9      Farmer turnout, Java
    A11.10    Cracked masonry, java
    A11.11    Failure of concrete lining through external water pressure
    A11.12    Failure of concrete lining through external water pressure
    A11.13    Burst lining
    A11.14    Burst lining
    A11.15    Burst lining
    A11.16    Correct edge lining
    A11.17    Collapsed GRC lining
    A11.18    A land crab, destroyer of linings
    A11.19    Crab hole
    A11.20    Rat damage
    A11.21    Animal damage, Java
    A11.22    Rat damage in an earth canal
    A11.23    Avoiding animal damage at a tubewell, java
    A11.24    Salvinia choking an Indian reservoir
    A11.25    Salvinia choking an Indian reservoir
    A11.26    Weed growth in an oversized canal
    A11.27    Leaking masonry
    A11.28a Failure of a large pipe due to floatation
    A11.28b Pipe damage
    A11.29    Avio gates in a secure compound
    A11.30    Avis gates in an enclosed structure
    A11.31    Farmer damage to an offtake structure
    A11.32    Overflowing canal
    A11.33    Oversized divisor
    A11.34    Conjunctive use and leaking canals
    A11.35    Missing precast slabs
    A11.36    Scoured masonry
    A11.37    Thin lining damage
    A11.38    Thin lining damage
    A11.39    Crazed lining
    A11.40    Erosion in the mainline Upper Swat Canal, Pakistan
    A11.41    Erosion in the mainline Upper Swat Canal, Pakistan
    A11.42    Concrete pipe floating failure
    A11.43    Concrete pipe floating failure
    A11.44    Concrete pipe floating failure
    A11.45    Piping failure at a dam drawoff tower
    A11.46    Leaking lining, Java
     
     
     

     
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